• American Indian;
  • care delivery;
  • clinical trial enrollment;
  • patient navigation;
  • treatment interruptions


  1. Top of page
  2. Abstract


A study was undertaken to assess patient navigation utilization and its impact on treatment interruptions and clinical trial enrollment among American Indian cancer patients.


Between February 2004 and September 2009, 332 American Indian cancer patients received patient navigation services throughout cancer treatment. The patient navigation program provided culturally competent navigators to assist patients with navigating cancer therapy, obtaining medications, insurance issues, communicating with medical providers, and travel and lodging logistics. Data on utilization and trial enrollment were prospectively collected. Data for a historical control group of 70 American Indian patients who did not receive patient navigation services were used to compare treatment interruptions among those undergoing patient navigation during curative radiation therapy (subgroup of 123 patients).


The median number of contacts with a navigator was 12 (range, 1-119). The median time spent with the navigator at first contact was 40 minutes (range, 10-250 minutes), and it was 15 minutes for subsequent contacts. Patients treated with radiation therapy with curative intent who underwent patient navigation had fewer days of treatment interruption (mean, 1.7 days; 95% confidence interval [CI], 1.1-2.2 days) than historical controls who did not receive patient navigation services (mean, 4.9 days; 95% CI, 2.9-6.9 days). Of the 332 patients, 72 (22%; 95% CI, 17%-26%) were enrolled on a clinical treatment trial or cancer control protocol.


Patient navigation was associated with fewer treatment interruptions and relatively high rates of clinical trial enrollment among American Indian cancer patients compared with national reports. Cancer 2011. © 2010 American Cancer Society.

It is well established that cancer-related health disparities exist with respect to race/ethnicity and socioeconomic status,1-5 and American Indians in the Northern Plains region of the United States exhibit some of the highest cancer mortality rates in the nation.6, 7 Investigators have demonstrated that reasons underpinning health disparities among vulnerable populations are multifactorial.2, 8, 9 Studies have shown lower rates of screening utilization among American Indians,6, 10-12 as well as higher rates of presenting to medical care with advanced stages of cancer at diagnosis for American Indians in this region.13 In addition, American Indian cancer patients in the Northern Plains, where some of the largest reservation-base American Indian communities are located, demonstrate lack of trust of healthcare providers and hospitals14 and negative attitudes about cancer treatment.15 American Indians in the Northern Plains reside in some of the poorest census tracts in the United States, with almost half of individuals living below the federal poverty level and the unemployment rate at approximately 80% on some reservations.16 Furthermore, the Indian Health Service (IHS), which provides health services to enrolled tribal members, has been chronically underfunded, thus hobbling a primary source of healthcare delivery for this vulnerable population.17-19

As the field of health disparities research evolves from one of defining the extent and causes of disparate health outcomes to solutions to health inequities, patient navigation has emerged as a potential strategy to mitigate access barriers in targeted populations. The early model for cancer patient navigation, established by Freeman and colleagues in Harlem, New York in the early 1990s,20, 21 showed improved 5-year survival (from 39% to 70%) for breast cancer patients in a low-income inner city population. Since that time, multiple investigators have shown improvement in cancer-related health outcomes after implementation of patient navigation services among various populations.22-28 Most cancer patient navigation studies have focused on increasing screening rates among minority populations or decreasing the time intervals between the various critical points in early cancer management, such as that between detection of a screening test abnormality through diagnosis and initiation of cancer treatment.24, 27, 29 Relatively few studies provide data on patient navigation during cancer treatment itself.30 Data are needed on the intensity and nature of patient navigation utilization during cancer treatment, and the impact of navigation on treatment-related outcomes. For example, treatment adherence may be improved by patient navigation. This possibility is especially relevant for patients undergoing curative irradiation, a situation where treatment interruptions have been shown to impact survival and recurrence outcomes.31-33 Another potential benefit of patient navigation may be the ability to boost clinical trial enrollment among minority populations, through the presence of a culturally competent navigator to help establish trust and assist in identifying eligible patients who have typically been under-represented in clinical trial participation.34, 35

In 2003, a review of the Rapid City Regional Hospital's (Rapid City, SD) tumor registry (from 1990 to 2003) revealed that American Indian cancer patients presented with disproportionately high rates of advanced-stage malignancy.13, 36 Subsequent to these findings, a culturally tailored patient navigation program was implemented to assist American Indian cancer patients through the cancer care continuum from diagnosis through follow-up after cancer treatment completion. The purpose of this study is to report upon patient navigation utilization during cancer treatment and to evaluate potential impacts on clinical care.


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  2. Abstract

Study Population

Between January 2004 and September 2009, 375 American Indian cancer patients presented to the Rapid City Regional Hospital Cancer Care Institute in Rapid City, South Dakota and were approached and offered the services of a culturally competent patient navigator. Of those, 43 (11%) patients refused patient navigation for the following reasons: 39 felt that patient navigation was not necessary; 2 patients did not trust a patient navigator to be involved in their care; and 2 patients did not specify a reason. The remaining 332 American Indian cancer patients were enrolled on a patient navigation protocol for patient navigation throughout cancer treatment. Patients were identified and enrolled on the protocol at first visit to the Cancer Care Institute if at all possible or as soon as possible if eligibility capture was not established at first visit. Race was self-identified by the patient.

All American Indian patients presenting to Rapid City Regional Hospital with a diagnosis of malignancy were eligible to participate. Rapid City Regional Hospital serves as the major secondary and tertiary cancer care provider for >70,000 adult American Indians in the region, which includes the Oglala Sioux Tribe (Pine Ridge), Cheyenne River Sioux Tribe, Rosebud Sioux Tribe, and the Rapid City American Indian population. All American Indian patients in this study reside in one of these communities, but eligibility for participation was not restricted to specific tribal affiliation. The Rapid City Regional Hospital's institutional review board granted approval to conduct the patient navigation intervention and study. In addition, the protocol was also approved by the following entities before initiation: the institutional review board of the Aberdeen Area IHS; Aberdeen Area IHS Tribal Chairman's health board; tribal councils, research review boards; and health departments (Cheyenne River Sioux Tribe, Oglala Sioux Tribe, Rosebud Sioux Tribe); and IHS Hospital Chief Executive Officers (Cheyenne River IHS Hospital, Pine Ridge [Oglala] IHS Hospital, Rapid City Sioux San IHS Hospital, and Rosebud IHS Hospital).

Patient Navigation Program

In 2003, Rapid City Regional Hospital was awarded a Cancer Disparities Research Partnership grant to study cancer-related disparities previously documented in this vulnerable population6, 7, 13 and to increase clinical trial availability and enrollment in this medically underserved region.37 Since that time, a multifaceted, community-based participatory research and intervention effort, called the Walking Forward Program,13, 36, 38, 39 has been developed to explore root causes of disparities, increase cancer screening and education, enroll patients on and educate them about clinical trials, and provide comprehensive, culturally tailored patient navigation throughout cancer treatment. Through this effort, American Indian cancer patients were offered patient navigation services, whereby patients were assisted in navigating the medical system by trained, culturally competent staff to serve as advocates through the cancer care continuum after cancer diagnosis. The patient navigators assist with coordinating appointments, insurance issues, following up on tests, obtaining medications and specialty services or devices, and facilitating transportation and lodging, and offer psychosocial support during treatment. In addition to the hospital-based navigators, the navigation program also includes community research representatives, who work closely with the hospital staff and are embedded in the surrounding American Indian communities, providing cancer education, networking with local heath resources, and serving as liaisons between the cancer center, hospital-based patient navigators, and patients or tribal governments. Patient education materials were translated into the Lakota language. The cancer center staff members involved in this effort were either closely connected with or are members of the American Indian communities served by this program. More details regarding the development of this patient navigation program have been described elsewhere in the literature.39, 40

Utilization Data Collection and Statistical Analysis

We prospectively collected data regarding needs addressed and services rendered for each contact with the patient navigator. The navigator completed a contact sheet at each interaction with a patient whether it was by telephone or in person. The barriers that were addressed and time spent with the patient were recorded for each contact. Data were tracked as patients moved through the cancer care continuum from diagnosis (if it occurred at the Cancer Care Institute) and evaluation through follow-up/surveillance after treatment completion. Contact with the navigator occurred either in person or on the telephone (except for the initial contact, which was always in person), or in some cases the navigator went to homes or hotel rooms of patients to offer assistance when patients were too sick to come to the Cancer Care Institute for scheduled treatments. In addition, patient demographics and cancer site, stage, and treatment information were abstracted from the medical record or obtained at enrollment interviews. Data were deidentified, and all analyses were performed using SPSS version 17.0 statistical software (Apache Software Foundation, Forest Hill, Md). Analysis of variance was performed to test for difference between means. Confidence intervals (CIs) were calculated for proportions and means where appropriate and used along with proportions and means to describe general characteristics.

Analysis of Treatment Interruptions

We performed an analysis of radiation therapy (RT) delays for patients treated with RT with curative intent. Those treated with curative intent were the focus of this analysis because data exist that show RT treatment delays can result in compromise of cancer control and survival outcomes for some cancers that are curable at presentation.31-33 Details of cancer treatment were compiled by a review of the RT records and hospital chart. Complete data regarding chemotherapy details and interruptions were not available to our staff members, who are housed in the Department of Radiation Oncology; therefore, analyses regarding chemotherapy interruptions were not performed as part of this study. For the purposes of comparison, 72 consecutive American Indian patients treated with RT with curative intent at the Cancer Care Institute between April 1991 and April 2004 and who did not undergo patient navigation during treatment were identified to serve as a control group for comparison of days of RT treatment interruptions. Two patients did not complete RT, and their data were not analyzed. For the remaining 70 patients (68 treated before the availability of patient navigation services and 2 who refused patient navigation services early in the program's existence), RT charts were retrospectively reviewed to ascertain how many days of treatment delay occurred as well as whether the treatment delay was because of machine maintenance or repair versus other reasons (eg, weather or patient canceled for other reasons). Delay because of RT machine maintenance or repair was not considered a day of treatment delay.

Clinical Trial Availability

The Rapid City Cancer Care Institute has primary membership and access to clinical trials through the North Central Cancer Treatment Group. The center also has clinical trial access as an affiliate of the Radiation Therapy Oncology Group, Eastern Cooperative Oncology Group, National Surgical Adjuvant Breast and Bowel Project, Gynecologic Oncology Group, and Cancer Therapy Evaluation Program. In addition, cancer treatment trials were written for prostate and breast cancer under the auspices of the Cancer Disparities Research Partnership grant program. During the time of the study, approximately 75 cancer-related clinical trials were open. Clinical trial enrollment data were prospectively tracked for all navigated patients.


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  2. Abstract

Patient and Cancer-Specific Characteristics for the Study Population

Table 1 shows patient characteristics among navigated patients. The largest percentage of patients reside on the Pine Ridge (Oglala Sioux) reservation, which is located approximately 100 miles from Rapid City (over 2 hours by car if no inclement weather). The median distance lived from the Cancer Care Institute (1 way) for all patients was 121 miles (range, 10-444 miles), and it should be noted that road conditions on the reservations are such that travel is slower than that possible on average US highways, even in the absence of inclement weather. The primary payer source for medical bills was Medicare for a third of patients, and the next most common primary payer was the IHS (25% of patients). Very few patients did not speak English (2%), but 36% of patients did speak the Lakota language.

Table 1. Sociodemographic Characteristics of Navigated Patients: 332 Patients Undergoing Patient Navigation Between February 2004 and September 2009
  1. VA indicates Veterans Administration.

Total patients navigated332 
Age, median y (range)60 (16-89) 
Reservation/tribal community geographical affiliation [not tribal enrollment affiliation]
 Pine Ridge/Oglala Sioux16049
 Rosebud Sioux6119
 Cheyenne River5416
 Standing Rock Sioux31
 Rapid City (Sioux San)3310
 Other tribal affiliation186
Distance lived from cancer center [1 way], median miles (range)121 (10-444) 
Primary payor of medical bills
 Indian Health Service8225
 Private insurer5216
Patients who do not speak English52
Speak Lakota language
 Missing data7924

The majority of patients, 205 (62%), underwent cancer treatment with curative intent, and 112 (34%) underwent palliative treatment, corresponding to the similar percentage of patients who presented with stage IV disease (37%). The remaining 15 (5%) did not have their treatment intent established before discontinuing care at the Cancer Care Institute (eg, underwent only consultation or 1 visit at the Cancer Care Institute but sought patient navigation services at the time of that consultation). At the time of this analysis, 113 (34%) patients had died, 76 (67%) of whom were stage III or IV at diagnosis.

Patient Navigation Utilization

Patients were most commonly referred or recruited to the patient navigation program by a community research representative or patient navigation program staff member within the hospital (119 patients, 36%), or by their treating physician or oncology nurse (89 patients, 27%). The remaining 124 (37%) patients sought patient navigation through self-referral or referral by someone other than hospital or grant program staff. All 332 patients had at least 1 visit with a patient navigator, and the median time spent with the navigator at initial contact was 40 minutes (range, 10-250 minutes; mean, 45 minutes; mode, 60 minutes). The median number of contacts with a navigator per patient was 12 (range, 1-119 contacts). The mode number of contacts was 1 contact, with 39 (12%) patients having only 1 contact with a patient navigation. The median time spent with the navigator for subsequent contacts with a navigator after the initial visit was 15 minutes.

For the initial patient navigation contact, the majority of patients were referred to patient navigation for financial assistance (54%) or logistical support, for example, travel and lodging help (35%). Other reasons included (>1 reason possible): psychosocial support (35%), care coordination (22%), advocacy (20%), or education (20%). Figure 1 illustrates the reasons for accessing patient navigation services for subsequent visits through the first 5 contacts with a patient navigation. Generally, a decreasing proportion of patients accessed a patient navigation for help with case management or care coordination after the first visit, but requests for help with financial assistance increased after the first visit. Requests for psychosocial support also increased over the first 5 contacts with the patient navigation. A higher proportion of patients requested help with advocacy or cancer care education during the first contact with the patient navigation than at subsequent visits through the first 5 contacts.

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Figure 1. Trends in reason for accessing the patient navigator services are shown. The chart shows the percentage of patients seeking various types of assistance from patient navigator through the first 5 contacts with the navigator.

Download figure to PowerPoint

Table 2 shows cancer and treatment-related characteristics of the study population. Patients undergoing RT had more contacts with a navigator than those not receiving RT (mean, 25 vs 13 contacts, respectively; P = .0001), as did those receiving chemotherapy versus those who did not (mean, 24 vs 15 contacts, respectively; P = .001). Patients who received both chemotherapy and RT also had more encounters with a navigator than those not receiving both modalities (mean, 30 vs 16 contacts, respectively; P = .0001). Patients undergoing curative treatment had an average of 21 contacts with a navigator compared with 17 contacts for patients receiving palliative treatment (P = .02).

Table 2. Cancer Patient and Treatment-Related Characteristics of the 332 Navigated Patients
  1. GU indicates genitourinary; PN, patient navigation; RT, radiotherapy; CCI, Cancer Care Institute; Chemo, chemotherapy.

Type of cancer
 Head and neck216
 Nonprostate GU (renal, penile, testicular)185
 Unknown primary site72
Stage at enrollment into PN program
 In situ disease72
 Stage I4012
 Stage II8124
 Stage III6620
 Stage IV9237
RT received/planned20060
 At CCI18856
 At another facility124
Treatment intent for those receiving RT at CCI
Chemo received/planned16149
 Chemo received outside CCI278
 Chemo received at CCI13441
Patient underwent surgery for their cancer

Treatment Interruptions

For the historical control group of 70 American Indian patients treated curatively but who did not receive patient navigation during their treatment, the average number of treatment days missed was 4.9 days (95% CI, 2.9-6.9; range, 0-43 days). Of the 332 navigated patients, 188 received RT at the Cancer Care Institute. Of these, 129 were treated with curative intent, and 59 were treated with palliative intent. Of the 129 patients undergoing RT with curative intent, 6 did not complete their radiation treatment course. For the remaining 123 patients treated with curative RT, mean number of days of treatment delay = 1.7 (95% CI, 1.1-2.2; range, 0-20). The difference in mean number of days missed for the 2 groups was statistically significant (P = .0001) (Table 3). There was no significant difference in the proportion of patients who did not complete treatment (P > .05). The proportion of days missed in each group because of weather was not significantly different (4% for the control group and 5% for the navigated group, P > .05).

Table 3. Days of Treatment Interruption for American Indian Patients Undergoing Curative Radiation Therapy
SubjectsNo.Average days of treatment interruption (95% CI)
  1. CI indicates confidence interval.

Historical controls [no patient navigation]704.9 (2.9-6.9)
Patients with patient navigation during treatment1231.7 (1.1-2.2)

Clinical Trial and Protocol Enrollment

Among the 332 patients enrolled on the patient navigator protocol, 72 (22%; 95% CI, 17%-26%) were enrolled on a clinical treatment trial or cancer control protocol. Specifically, 50 patients participated in a molecular genetic study for presence of ataxia-telangiectasia mutation (ATM); 17 were enrolled on a clinical treatment trial (10 of these were enrolled on a cooperative group trial); and 5 patients were enrolled on both the ATM study and a clinical treatment trial. Patients were also enrolled on cancer control protocols.


  1. Top of page
  2. Abstract

In this study, we demonstrate that American Indian cancer patients receiving patient navigation services while undergoing curative RT as part of their cancer treatment have significantly fewer RT interruptions than their historical counterparts who did not undergo patient navigation. Furthermore, our data reveal a high rate of clinical trial enrollment among American Indian cancer patients receiving patient navigation services when compared with previous studies, which have shown low rates (<1%) of clinical trial participation for American Indians.34, 35, 41 We also describe patient navigation utilization patterns for American Indian patients receiving cancer treatment to provide insight into the resources necessary to provide cancer treatment navigation services to this or a similar population. Specifically, our study contributes unique information about the number of navigator-patient interactions, the time resources typical of these interactions, and the types of services requested in these interactions during cancer treatment for a population with significant health access barriers. Patients who underwent more intensive treatment regiments tended to more heavily use patient navigation services.

Much of the patient navigation literature addressing care of cancer patients focuses on increasing screening incidence and/or decreasing intervals between screening and diagnostic management of initiation of treatment for various cancers,28-30, 42, 43 and most studies do show improvement in the corresponding outcomes when patient navigation is available. American Indians specifically have been shown to benefit from patient navigation in the setting of facilitating screening and timely diagnostic follow-up.29, 44 However, few studies report upon the role of patient navigation after a patient is diagnosed and undergoing the rigors of cancer treatment,30, 45 arguably a time when patients may experience more barriers caused by logistical complexities and financial burden of receiving many weeks or months of treatment, for example, RT or chemotherapy. Some of the reports that have been published on patient navigation during cancer treatment show improvement in patient satisfaction or decrease in barriers to care.46, 47 Ell and colleagues24 showed that treatment adherence was improved compared with previous studies among patients who were randomized to either enhanced usual care (written resource navigation information) or active patient navigation, although there was no statistical difference between the 2 navigation approaches. Only 1 other study offers utilization data regarding the types of barriers addressed and the amount of time navigators spend with cancer patients.48

Our finding of fewer treatment interruptions for patients undergoing curative RT is one that has important implications for this population, which has been shown to have disparately high cancer mortality. It has been demonstrated that prolonged RT interruption is a predictor for locoregional relapse among patients treated for head and neck cancers.32, 33 Similarly, it has been established that prolongation of the RT course during treatment for cervical cancer—a disease that disproportionately affects poor and minority women, and for which American Indian women in the Northern plains have the highest incidence and mortality6, 49–is associated with increased risk for local recurrence and poorer survival outcomes.31 Patient navigation, in this study, seems to offer an effective strategy to mitigate barriers that may prolong definitive cancer treatment.

Multiple studies have indicated that clinical trial participation among American Indian cancer patients is low, with trial accrual rates of <1%.34, 35, 41 Reasons underpinning low minority participation in clinical trials are multifactorial and may differ across regions as well as between racial/ethnic groups.50, 51 In this region, it has previously been shown that American Indian cancer patients exhibit relatively high rates of medical mistrust and dissatisfaction with prior healthcare received.14 Our patient navigation program specifically targets health access barriers in this population and seeks to address them in a culturally sensitive manner while partnering with tribal communities. This effort toward establishing rapport with American Indian patients and communities to meet their needs may account for our relatively higher proportion of American Indian patients willing to enroll on clinical trials.

Our study supports the role of patient navigation in addressing health access barriers to cancer treatment, but it does so with certain limitations. First, our study is not a randomized trial, and our analyses did not include a temporally parallel control group against which to compare outcomes. To ensure community-based participation and engagement, it simply was not feasible for the purposes of comparison to deny half of American Indian patients the types of logistical support, financial assistance, and 1-on-1 advocacy offered by our navigators. In other words, community engagement necessary for the implementation of our effort might have been hindered if we had attempted to provide these services to fewer than all of the patients who desired patient navigation services given the high level of need in the community being served.

More investigation is needed into the impact of patient navigation,30, 45 and a coordinated, national effort is underway to provide critical insight into the role of patient navigation in cancer care delivery as well as its cost-effectiveness.52, 53 Until such data are available, data on working models that deliver care effectively via patient navigation provide guidance that can be developed and tailored to various populations.

In conclusion, we have shown that patient navigation is associated with fewer treatment interruptions among American Indian patients receiving curative RT for their cancer. We have also observed a high rate of clinical trial participation among American Indians, who have historically been under-represented in clinical trial research. Furthermore, we characterize utilization specifics for our program to provide insight into resources entailed in administering a patient navigation program in a regional healthcare center that provides healthcare to an underserved population. Further research is needed, not only into the cost-effectiveness of patient navigation, but into other metrics of quality of care that may be improved with patient navigation during cancer treatment.


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  2. Abstract

This research was supported in part by National Institutes of Health/National Cancer Institute grant 5U56CA99010 (to D.G.P.). The opinions expressed in this paper are those of the authors and do not necessarily reflect the views of the National Cancer Institute or the National Institutes of Health.


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  • 1
    Haynes M, Smedley B, The Unequal Burden of Cancer: An Assessment of NIH Research and Programs for Ethnic Minorities and the Medically Underserved. Washington, DC: National Academy Press; 1999.
  • 2
    Geiger H. Racial and ethnic disparities in diagnosis and treatment: a review of the evidence and consideration of causes. In: Smedley B, Smith A, Nelson A, eds. Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care. Washington, DC: Institute of Medicine: National Academies Press; 2003: 415-454.
  • 3
    Smedley B, Stith A, Nelson A. Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care. Washington, DC: National Academy Press; 2003.
  • 4
    Freeman HP. Cancer in the socioeconomically disadvantaged. CA Cancer J Clin. 1989; 39: 266-288.
  • 5
    Wilson RT, Adams-Cameron M, Burhansstipanov L, et al. Disparities in breast cancer treatment among American Indian, Hispanic and non-Hispanic white women enrolled in Medicare. J Health Care Poor Underserved. 2007; 18: 648-664.
  • 6
    Espey DK, Wu XC, Swan J, et al. Annual report to the nation on the status of cancer, 1975-2004, featuring cancer in American Indians and Alaska Natives. Cancer. 2007; 110: 2119-2152.
  • 7
    Espey D, Paisano R, Cobb N. Cancer Mortality Among American Indians and Alaska Natives: Regional Differences, 1994-1998. Rockville, MD: Indian Health Service; 2003.
  • 8
    Lannin DR, Mathews HF, Mitchell J, Swanson MS, Swanson FH, Edwards MS. Influence of socioeconomic and cultural factors on racial differences in late-stage presentation of breast cancer. JAMA. 1998; 279: 1801-1807.
  • 9
    Blackman DJ, Masi CM. Racial and ethnic disparities in breast cancer mortality: are we doing enough to address the root causes? J Clin Oncol. 2006; 24: 2170-2178.
  • 10
    Ward E, Jemal A, Cokkinides V, et al. Cancer disparities by race/ethnicity and socioeconomic status. CA Cancer J Clin. 2004; 54: 78-93.
  • 11
    Coughlin SS, Uhler RJ, Blackman DK. Breast and cervical cancer screening practices among American Indian and Alaska Native women in the United States, 1992-1997 Prev Med. 1999; 29: 287-295.
  • 12
    Swan J, Breen N, Coates RJ, Rimer BK, Lee NC. Progress in cancer screening practices in the United States: results from the 2000 National Health Interview Survey. Cancer. 2003; 97: 1528-1540.
  • 13
    Petereit DG, Rogers D, Govern F, et al. Increasing access to clinical cancer trials and emerging technologies for minority populations: the Native American Project. J Clin Oncol. 2004; 22: 4452-4455.
  • 14
    Guadagnolo BA, Cina K, Helbig P, et al. Medical mistrust and less satisfaction with health care among Native Americans presenting for cancer treatment. J Health Care Poor Underserved. 2009; 20: 210-226.
  • 15
    Guadagnolo BA, Cina K, Helbig P, et al. Assessing cancer stage and screening disparities among Native American cancer patients. Public Health Rep. 2009; 124: 79-89.
  • 16
    Pine Ridge CDP, South Dakota-DP-3. Profile of Selected Economic Characteristics. Washington, DC: US Census Bureau; 2000.
  • 17
    Lillie-Blanton M, Roubideaux Y. Understanding and addressing the health care needs of American Indians and Alaska Natives. Am J Public Health. 2005; 95: 759-761.
  • 18
    Roubideaux Y. Perspectives on American Indian health. Am J Public Health. 2002; 92: 1401-1403.
  • 19
    Zuckerman S, Haley J, Roubideaux Y, Lillie-Blanton M. Health service access, use, and insurance coverage among American Indians/Alaska Natives and whites: what role does the Indian Health Service play? Am J Public Health. 2004; 94: 53-59.
  • 20
    Freeman HP, Muth BJ, Kerner JF. Expanding access to cancer screening and clinical follow-up among the medically underserved. Cancer Pract. 1995; 3: 19-30.
  • 21
    Oluwole SF, Ali AO, Adu A, et al. Impact of a cancer screening program on breast cancer stage at diagnosis in a medically underserved urban community. J Am Coll Surg. 2003; 196: 180-188.
  • 22
    Battaglia TA, Roloff K, Posner MA, Freund KM. Improving follow-up to abnormal breast cancer screening in an urban population. A patient navigation intervention. Cancer. 2007; 109( 2 suppl): 359-367.
  • 23
    Ell K, Vourlekis B, Lee PJ, Xie B. Patient navigation and case management following an abnormal mammogram: a randomized clinical trial. Prev Med. 2007; 44: 26-33.
  • 24
    Ell K, Vourlekis B, Xie B, et al. Cancer treatment adherence among low-income women with breast or gynecologic cancer: a randomized controlled trial of patient navigation. Cancer. 2009; 115: 4606-4615.
  • 25
    Gabram SG, Lund MJ, Gardner J, et al. Effects of an outreach and internal navigation program on breast cancer diagnosis in an urban cancer center with a large African-American population. Cancer. 2008; 113: 602-607.
  • 26
    Frelix GD, Rosenblatt R, Solomon M, Vikram B. Breast cancer screening in underserved women in the Bronx. J Natl Med Assoc. 1999; 91: 195-200.
  • 27
    Ferrante JM, Chen PH, Kim S. The effect of patient navigation on time to diagnosis, anxiety, and satisfaction in urban minority women with abnormal mammograms: a randomized controlled trial. J Urban Health. 2008; 85: 114-124.
  • 28
    Christie J, Itzkowitz S, Lihau-Nkanza I, Castillo A, Redd W, Jandorf L. A randomized controlled trial using patient navigation to increase colonoscopy screening among low-income minorities. J Natl Med Assoc. 2008; 100: 278-284.
  • 29
    Dignan MB, Burhansstipanov L, Hariton J, et al. A comparison of 2 Native American navigator formats: face-to-face and telephone. Cancer Control. 2005; 12( suppl 2): 28-33.
  • 30
    Wells KJ, Battaglia TA, Dudley DJ, et al. Patient navigation: state of the art or is it science? Cancer. 2008; 113: 1999-2010.
  • 31
    Petereit DG, Sarkaria JN, Chappell R, et al. The adverse effect of treatment prolongation in cervical carcinoma. Int J Radiat Oncol Biol Phys. 1995; 32: 1301-1307.
  • 32
    McCloskey SA, Jaggernauth W, Rigual NR, et al. Radiation treatment interruptions greater than 1 week and low hemoglobin levels (12 g/dL) are predictors of local regional failure after definitive concurrent chemotherapy and intensity-modulated radiation therapy for squamous cell carcinoma of the head and neck. Am J Clin Oncol. 2009; 32: 587-591.
  • 33
    Rades D, Stoehr M, Kazic N, et al. Locally advanced stage IV squamous cell carcinoma of the head and neck: impact of pre-radiotherapy hemoglobin level and interruptions during radiotherapy. Int J Radiat Oncol Biol Phys. 2008; 70: 1108-1114.
  • 34
    Sateren WB, Trimble EL, Abrams J, et al. How sociodemographics, presence of oncology specialists, and hospital cancer programs affect accrual to cancer treatment trials. J Clin Oncol. 2002; 20: 2109-2117.
  • 35
    Murthy VH, Krumholz HM, Gross CP. Participation in cancer clinical trials: race-, sex-, and age-based disparities. JAMA. 2004; 291: 2720-2726.
  • 36
    Rogers D, Petereit DG. Cancer disparities research partnership in Lakota Country: clinical trials, patient services, and community education for the Oglala, Rosebud, and Cheyenne River Sioux tribes. Am J Public Health. 2005; 95: 2129-2132.
  • 37
    Guidelines for Medically Underserved Area and Population Designation. Washington, DC: US Department of Health and Human Services; 2008.
  • 38
    Petereit DG, Rogers D, Burhansstipanov L, et al. Walking forward: the South Dakota Native American project. J Cancer Educ. 2005; 20( 1 suppl): 65-70.
  • 39
    Molloy K, Reiner M, Ratteree K, et al. Patient navigation and cultural competence in cancer care. Assoc Commun Cancer Centers Oncol Issues. 2007; 22: 38-41.
  • 40
    Petereit D, Molloy K, Reiner M, et al. Establishing a patient navigator program to reduce cancer disparities in the American Indian communities of western South Dakota: initial observations and results. Cancer Control J Moffitt Cancer Center. 2008; 15: 254-259.
  • 41
    Stewart JH, Bertoni AG, Staten JL, Levine EA, Gross CP. Participation in surgical oncology clinical trials: gender-, race/ethnicity-, and age-based disparities. Ann Surg Oncol. 2007; 14: 3328-3334.
  • 42
    Nash D, Azeez S, Vlahov D, Schori M. Evaluation of an intervention to increase screening colonoscopy in an urban public hospital setting. J Urban Health. 2006; 83: 231-243.
  • 43
    Weinrich SP, Boyd MD, Weinrich M, Greene F, Reynolds WA Jr, Metlin C. Increasing prostate cancer screening in African American men with peer-educator and client-navigator interventions. J Cancer Educ. 1998; 13: 213-219.
  • 44
    Burhansstipanov L, Dignan MB, Wound DB, Tenney M, Vigil G. Native American recruitment into breast cancer screening: the NAWWA project. J Cancer Educ. 2000; 15: 28-32.
  • 45
    Dohan D, Schrag D. Using navigators to improve care of underserved patients: current practices and approaches. Cancer. 2005; 104: 848-855.
  • 46
    Carroll JK, Humiston SG, Meldrum SC, et al. Patients' experiences with navigation for cancer care. Patient Educ Couns. 2010; 80: 241-247.
  • 47
    Campbell C, Craig J, Eggert J, Bailey-Dorton C. Implementing and measuring the impact of patient navigation at a comprehensive community cancer center. Oncol Nurs Forum. 2010; 37: 61-68.
  • 48
    Lin CJ, Schwaderer KA, Morgenlander KH, et al. Factors associated with patient navigators' time spent on reducing barriers to cancer treatment. J Natl Med Assoc. 2008; 100: 1290-1297.
  • 49
    Haverkamp D, Espey D, Paisano R, Cobb N. Cancer Mortality Among American Indians and Alaska Natives: Regional Differences, 1999-2003. Rockville, MD: Indian Health Service; 2008.
  • 50
    Bruner DW, Jones M, Buchanan D, Russo J. Reducing cancer disparities for minorities: a multidisciplinary research agenda to improve patient access to health systems, clinical trials, and effective cancer therapy. J Clin Oncol. 2006; 24: 2209-2215.
  • 51
    Ford JG, Howerton MW, Lai GY, et al. Barriers to recruiting underrepresented populations to cancer clinical trials: a systematic review. Cancer. 2008; 112: 228-242.
  • 52
    Freund KM, Battaglia TA, Calhoun E, et al. National Cancer Institute Patient Navigation Research Program: methods, protocol, and measures. Cancer. 2008; 113: 3391-3399.
  • 53
    Ramsey S, Whitley E, Mears VW, et al. Evaluating the cost-effectiveness of cancer patient navigation programs: conceptual and practical issues. Cancer. 2009; 115: 5394-5403.