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Chemotherapy use and patient treatment preferences in advanced colorectal cancer†
A prospective cohort study
Version of Record online: 12 SEP 2012
Copyright © 2012 American Cancer Society
Volume 119, Issue 4, pages 854–862, 15 February 2013
How to Cite
Zafar, S. Y., Malin, J. L., Grambow, S. C., Abbott, D. H., Kolimaga, J. T., Zullig, L. L., Weeks, J. C., Ayanian, J. Z., Kahn, K. L., Ganz, P. A., Catalano, P. J., West, D. W., Provenzale, D. and for the Cancer Care Outcomes Research & Surveillance (CanCORS) Consortium (2013), Chemotherapy use and patient treatment preferences in advanced colorectal cancer. Cancer, 119: 854–862. doi: 10.1002/cncr.27815
The study sponsors played no role in study design, data collection, analysis, interpretation, writing, or the decision to submit for publication.
- Issue online: 4 FEB 2013
- Version of Record online: 12 SEP 2012
- Manuscript Revised: 27 JUL 2012
- Manuscript Accepted: 27 JUL 2012
- Manuscript Received: 11 JUL 2012
- colorectal cancer;
- decision making;
- patient preference;
- cohort studies;
- quality of health care
The objective of this study was to determine how patient preferences guide the course of palliative chemotherapy for advanced colorectal cancer.
Eligible patients with metastatic colorectal cancer (mCRC) were enrolled nationwide in a prospective, population-based cohort study. Data were obtained through medical record abstraction and patient surveys. Logistic regression analysis was used to evaluate patient characteristics associated with visiting medical oncology and receiving chemotherapy and patient characteristics, beliefs, and preferences associated with receiving >1 line of chemotherapy and receiving combination chemotherapy.
Among 702 patients with mCRC, 91% consulted a medical oncologist; and among those, 82% received chemotherapy. Patients ages 65 to 75 years and aged ≥75 years were less likely to visit an oncologist, as were patients who were too sick to complete their own survey. In adjusted analyses, patients aged ≥75 years who had moderate or severe comorbidity were less likely to receive chemotherapy, as were patients who were too sick to complete their own survey. Patients received chemotherapy even if they believed that chemotherapy would not extend their life (90%) or that chemotherapy would not likely help with cancer-related problems (89%), or patients preferred treatment focusing on comfort even if it meant not living as long (90%). Older patients were less likely to receive combination first-line therapy. Patient preferences and beliefs were not associated with receipt of >1 line of chemotherapy or combination chemotherapy.
The majority of patients received chemotherapy even if they expressed negative or marginal preferences or beliefs regarding chemotherapy. Patient preferences and beliefs were not associated with the intensity or number of chemotherapy regimens. Cancer 2013. © 2012 American Cancer Society.
A growing body of evidence has demonstrated the value of patient-centered care. Patients who are involved in decision making are more knowledgeable about their care and are more satisfied with their care.1, 2 Patient dissatisfaction with treatment-related decision making may have a negative impact on the quality of cancer care.3 Patient preferences should be emphasized particularly in the setting of advanced cancer, in which the treatment is palliative. For example, although chemotherapy for patients with advanced colorectal cancer can modestly extend survival, such treatment is associated with the risk of significant toxicity.4 This balance between possible benefit versus probable risk necessitates a patient-centered approach to treatment decision making. However, studies suggest that the improper use of chemotherapy near the end of life may reflect inadequate shared decision making between patient and physician.5 Physicians may believe it is easier to offer chemotherapy to the patient with advanced cancer rather than engaging in challenging end-of-life discussions.6 For their part, patients may prefer to take a passive decision-making role when considering therapy for advanced cancer.7, 8 What remains unclear is how patient preferences guide the course of palliative chemotherapy for advanced cancer.
To evaluate the quality of patient-centered care for patients with advanced cancer, an important question must be answered: Do patient preferences play a role in treatment-related decision making for palliative chemotherapy? We conducted a multiregional cohort study of patients with advanced colorectal cancer to assess factors associated with visiting a medical oncologist and receipt of chemotherapy, specifically addressing the effect of the patient's role in decision making, quality of communication with their physician, overall quality of care, preferences for treatment, and their beliefs and concerns regarding treatment. We hypothesized that patient preferences would play a role in treatment-related decision making.
MATERIALS AND METHODS
Study participants were enrolled by the Cancer Care Outcomes Research and Surveillance (CanCORS) Consortium. CanCORS is a prospective, observational, population-based and health care systems-based cohort study to determine how characteristics and beliefs of cancer patients, providers, and health care organizations influence treatments and outcomes.9 Patients aged ≥21 years with colorectal cancer were enrolled within 3 months of diagnosis between September 2003 and January 2006 from 1 of the following: 5 geographic regions, 5 integrated health care systems in the National Cancer Institute-funded Cancer Research Network, or 15 Veterans Affairs hospitals. Patients were followed for 15 months past enrollment. Only patients with stage IV colorectal cancer (n = 702) were included in this analysis.
Primary data were collected from medical records, patient surveys, and surrogate surveys.9-11 Trained abstractors at each of the data-collection sites abstracted medical records data, including cancer diagnosis, initial tumor location, and stage. Medical records data also wee used to verify medical oncology visits, to determine the first line of chemotherapy received (defined as the first chemotherapy regimen used to treat the patient's metastatic colorectal cancer), and to determine whether the first line of therapy was single-agent or combination therapy (more than 1 chemotherapeutic agent). Comorbidity was abstracted from the medical record and was scored using the Adult Comorbidity Evaluation 27, a 27-item index that was developed to provide prognostic information for cancer patients.12
Patient surveys were completed in English, Chinese, and Spanish using computer-assisted telephone interviews. A surrogate (relative or household member) who was familiar with the patient's cancer care was interviewed for patients who had died or were too ill to be interviewed. The surveys (available at www.cancors.org/public; [accessed August 26, 2012]) used previously validated items and scales whenever possible and assessed patients' sociodemographic characteristics (age, race/ethnicity, annual income), insurance coverage, comorbid conditions, and beliefs about cancer care; survey development has been previously described.11 Surveys also assessed quality of communication with their physician (5 items),11 overall quality of care (2 items), preferences for treatment (2 items), and beliefs and concerns regarding treatment (9 items).11 For patients who were too ill (n = 60) or had died (n = 140), a survey was administered to a surrogate when available. Most patients completed the survey after treatment was started. A human subject committee approved the study protocol at each participating site.
We calculated descriptive statistics summarizing sociodemographic characteristics, comorbidity, treatment, and survey-based patient preferences and beliefs. We used logistic regression to assess factors associated with visiting a medical oncologist and receipt of chemotherapy. Four analytic models were developed to assess factors associated with: 1) visiting a medical oncologist any time before survey completion, 2) receipt of chemotherapy, 3) receipt of combination versus single-agent first-line therapy, and 4) receipt of only 1 line versus more than 1 line of therapy. In Models 3 and 4, we considered the variables that addressed role in chemotherapy decision making, quality of communication with their physician, overall quality of care, preferences for treatment, and beliefs and concerns regarding treatment. These variables were not included in Model 1 because not all of those patients completed a survey. They also were not included in Model 2 because they were available only for patients who visited an oncologist and completed a full survey (n = 409). Among the patients who completed a full survey, only 23 patients did not receive chemotherapy; and an effective sample of 23 was too small to produce reliable results in logistic regression.
A consistent model-building approach was used for all outcomes. Four variables were included unconditionally in all models: age, comorbidity, sex, and race. Survey respondent (patient vs surrogate) was included as a variable in Models 1 and 2. Step-wise model refinement was applied with P = .20 criterion for entering variables into the models and P = .10 criterion for removing them from the models. If necessary to prevent over fitting, the least significant variables were removed to attain model degrees of freedom to an effective sample size ratio of ≥7.13 Multiple imputation was used to address item nonresponse for survey-based variables and was performed centrally by the CanCORS Statistical Coordinating Center.14 The results from multivariable models incorporated formal imputation adjustments.15
Data analysis was conducted at the Durham Veterans Affairs Medical Center, which is the coordinating site for Veterans Affairs hospitals participating in CanCORS. For the current analysis, we used CanCORS core data (version 1.9), medical record data (version 1.9), and patient survey data (version 1.8). Statistical analyses were performed using SAS for Windows (version 9.2; SAS Institute, Cary, NC).
|Characteristic||No. of Patients (%)a|
|ACE-27 comorbidity index score|
|0: None||221 (32)|
|1: Mild||265 (38)|
|2: Moderate||126 (18)|
|3: Severe||90 (13)|
|Medicare and supplemental||209 (30)|
|Veterans Administration||117 (17)|
|Integrated health system||282 (40)|
|Survey completed by patient||441 (63)|
|Survey completed by patient surrogate||200 (29)|
|Survey not completed||61 (9)|
|Primary tumor site|
|Primary tumor site|
Medical Oncology Visits
Ninety-one percent of 702 patients had at least 1 visit with a medical oncologist (n = 640) (Fig. 1). In multivariable analysis (Fig. 2), age was associated with visiting an oncologist: Patients ages 65 to 74 years and those aged ≥75 years were less likely than those aged <55 years to visit an oncologist. Survey type (self-completion vs completion by a surrogate) was associated significantly with visiting a medical oncologist, which reflected the greater severity of illness and functional decline among patients who were unable to fully participate in the survey. Patients who had their surveys completed by a surrogate or patients without any survey data were less likely to visit a medical oncologist than patients who completed their own surveys. Variables addressing role in chemotherapy decision making, quality of communication with their physician, overall quality of care, preferences for treatment, and beliefs and concerns regarding treatment were not included in this model because they were available only for patients who visited an oncologist and completed a full survey (n = 409).
Of those who consulted an oncologist (n = 640), 527 patients (82%) received chemotherapy. Figure 3 illustrates the most common first-line, second-line, and third-line chemotherapy regimens. For their first-line chemotherapy regimen, 32% of patients received only single-agent therapy (eg, fluorouracil or capecitabine). Among 477 patients who had available chemotherapy regimen data, 63% received more than 1 line of chemotherapy. The regimens received as first-line therapy generally were in concordance with those listed in the National Comprehensive Cancer Network's colorectal cancer guidelines between 2003 and 2006, a period inclusive of patient enrollment for the current study.
Receipt of Chemotherapy
Unadjusted analyses are presented (Table 2). Among those who visited an oncologist, patients who reported a preference for extending their life were more likely to receive chemotherapy than those who were focused on comfort (99% vs 90%; P < .001). Patients who believed chemotherapy would extend their life were more likely to receive chemotherapy than those who thought it unlikely that chemotherapy would extend their life (99% vs 90%; P = .008). Patients who believed that chemotherapy may help with cancer-related problems were more likely to receive chemotherapy than those who thought chemotherapy would be unlikely to help (100% vs 89%; P < .001).
|No. of Patients (%)|
|Survey Question||Total No.||No Chemotherapy||Received Chemotherapy||Pb|
|If you had to make a choice now, would you prefer treatment that extends life as much as possible, even if it means having more pain and discomfort, or would you want treatment that focuses on relieving pain and discomfort as much as possible, even if it means not living as long?||< .001|
|Relieve pain or discomfort as much as possible||164||17 (10)||147 (90)|
|Extend life as much as possible||204||2 (1)||202 (99)|
|Declined to answer/don't know||39||1 (3)||38 (97)|
|Missing response||2||2 (100)||0 (0)|
|If you had to make a choice now, would you prefer treatment that extends life as much as possible, even if it means using up all of your financial resources, or would you want treatment that costs you less, even if means not living as long?||.103|
|Prefer treatment that costs less||110||8 (7)||102 (93)|
|Prefer treatment to extend life at the risk of using all financial resources||245||8 (3)||237 (97)|
|Declined to answer/don't know||52||4 (8)||48 (92)|
|Missing response||2||2 (100)||0 (0)|
|After talking with your doctors about chemotherapy, how likely did you think it was that chemotherapy would help you live longer||.008|
|Not likely/a little likely||29||3 (10)||26 (90)|
|Somewhat likely/very likely||337||3 (1)||334 (99)|
|Not applicable/don't know||20||1 (5)||19 (95)|
|Missing response||23||15 (65)||8 (35)|
|After talking with your doctors about chemotherapy, how likely did you think it was that chemotherapy would help you with problems you were having because of your (cancer)?||< .001|
|Not likely/ a little likely||38||4 (11)||34 (89)|
|Somewhat likely/very likely||261||0 (0)||261 (100)|
|Not applicable/don't know||87||3 (3)||84 (97)|
|Missing response||23||15 (65)||8 (35)|
In multivariable analysis (Fig. 4) age, comorbidity, and survey respondent were associated significantly with receipt of chemotherapy. The oldest patients (aged ≥75 years) were least likely to receive chemotherapy compared with those aged <55 years. Patients with moderate or severe comorbidity were less likely to receive chemotherapy than those with no comorbidity. Patients who had their surveys completed by a surrogate were less likely than patients who completed their own surveys to receive chemotherapy. Patients without any survey data had a similarly lower likelihood of receiving chemotherapy. Variables addressing role in chemotherapy decision making, quality of communication with their physician, overall quality of care, preferences for treatment, and beliefs and concerns regarding treatment were not included in this model because they were available only for patients who visited an oncologist and completed a full survey (n = 409). Among this group, only 23 patients did not receive chemotherapy; the effective sample of n = 23 would have been too small to produce reliable results in logistic regression models.
Intensity of First-Line Chemotherapy
Multivariable analysis examined the association between characteristics, preferences, beliefs, and intensity of first-line chemotherapy, as defined by receipt of combination therapy (more than 1 drug) versus single-agent therapy (Fig. 5). The oldest patients were less likely to receive combination therapy as a part of their first-line regimen. Role in decision making, quality of communication with their physician, overall quality of care, preferences for treatment, beliefs, and concerns regarding treatment were assessed but were not associated significantly with the receipt of combination first-line therapy.
Number of Chemotherapy Regimens
Multivariable analysis examined the association between characteristics, preferences, beliefs, and the number of chemotherapy regimens received. Patient characteristics, role in decision making, quality of communication with their physician, overall quality of care, preferences for treatment, beliefs, and concerns regarding treatment were assessed, but none were associated significantly with the receipt of combination first-line therapy (data not shown).
Given the substantial toxicity and personal costs associated with modest survival gains from metastatic colorectal cancer treatment, we hypothesized that patient preferences would play an important role in the receipt of palliative chemotherapy. We observed that patients who had beliefs and preferences favoring chemotherapy were statistically more likely to receive treatment. Nonetheless, the vast majority of patients who expressed a preference for comfort-oriented care believed that chemotherapy would be unlikely to extend their life, or they did not believe that chemotherapy would help with cancer-related problems, although they still received chemotherapy. Patient preferences, beliefs, concerns about treatment, actual and preferred role in decision making, and the quality of communication with their physician were not associated with the intensity or number of chemotherapy regimens received.
Patient Preference in Palliative Chemotherapy Decision-Making
Why did the majority of patients receive chemotherapy despite reporting beliefs and preferences that would seem incongruent with this treatment choice? Patients who offered negative or marginal views about chemotherapy in our survey still may have elected to receive treatment in the hopes that they would fall into the group of patients who experience a meaningful benefit with minimal harm. This sense of optimism may have played a role in our findings, because patients who were a “little likely” to expect a benefit may have considered the risks of treatment reasonable. Patients with advanced cancer often are more willing than their providers to accept a greater risk of harm for a smaller benefit.16 In addition, patients may disregard their own negative views of treatment if they are in conflict with their physician's view.3, 17, 18
In the metastatic setting, in which the benefit of treatment is limited, patients may be more likely to defer treatment decision making to their physician.7 Hence, clinical factors rather than patient preference appear to have a disproportionate role in the treatment decision-making process. Our study indeed suggests that clinical factors, in particular age and comorbidity, influence the receipt of chemotherapy. These findings are consistent with a substantial body of literature indicating that older, sicker patients are less likely to receive chemotherapy,16, 19-22 including the analysis by Kahn et al, who focused on patients with stage III colorectal cancer who were enrolled on the same study described here.10 Furthermore, completion of the survey by a surrogate rather than by the patient likely serves as a proxy for poor performance status.10 We observed that that completion of a surrogate survey was negatively associated with visiting a medical oncologist, receiving any chemotherapy, and receiving more than 1 line of chemotherapy. Older patients who were diagnosed with metastatic colorectal cancer had lower odds of being referred to a medical oncologist. Although older patients are at greater risk of being diagnosed with colorectal cancer, our cohort included patients who already had been diagnosed. Furthermore, our model adjusted for comorbidity, race, and sex. Hence, age remains an independent predictor of referral to medical oncology.
Appropriateness of Palliative Chemotherapy Use
Multiple studies have suggested that there is under use of adjuvant chemotherapy for stage III colorectal cancer.10, 20, 22-26 The same degree of evidence is not available for the palliative setting in the United States, although several studies have described low rates of palliative chemotherapy use for advanced colorectal cancer outside the United States.27-31 However, appropriate use of palliative chemotherapy for advanced cancer is difficult to discern without detailed clinical information. Because guidelines do not recommend the treatment of patients with a poor performance status, some patients are not candidates for chemotherapy from the time of diagnosis. Our analysis does not suggest an under use of chemotherapy for advanced colorectal cancer in the United States. We observed that, among the patients who reported a preference for chemotherapy or who favored quantity over quality of life, virtually all received chemotherapy. In addition, the first-line chemotherapy regimens prescribed were largely those included in the clinical guidelines that were available at the time of data collection. Taken together, these data suggest that concerns regarding the potential under use of chemotherapy in patients with metastatic colorectal cancer largely may be put to rest.
Our findings are subject to limitations. We were unable to model the association between preferences, beliefs, and receipt of chemotherapy because of small effective sample sizes. However, unadjusted results are presented and are informative. In addition, we assessed associations between those variables, the intensity of chemotherapy, and the number of lines of chemotherapy. We did not collect data detailing the conversation between patient and provider, so we cannot determine how that conversation may have colored patient preferences or beliefs about chemotherapy. Most patients completed the survey after their treatment decisions had been made. Their preferences or beliefs may have been different if measured before treatment decision making. However, over the course of cancer care, patient preferences tend to shift in favor of treatment,32 and the majority of patients who expressed negative opinions toward chemotherapy still received treatment. Furthermore, we were unable to assess the impact of online, print, nursing, or navigation resources in patient decision making. We did not focus on the use of chemotherapy at the very end of life and cannot comment on overuse in that setting, as reported extensively in the literature.5 Our data were collected between 2003 and 2006, and the focus on shared decision making has evolved over time. Finally, some survey items pertaining to preferences and beliefs were created specifically for CanCORS. Their validity has not been tested, but the survey tool was thoroughly piloted.11
This study has several strengths. Our analyses are supported by both medical records and patient self-reported data. Patients were enrolled from multiple geographic regions and health care settings, and few exclusion criteria were applied. It has been demonstrated that the patients enrolled in CanCORS are demographically representative of the geographic regions in which they were enrolled.33
In summary, treatment decisions in the palliative setting were not always congruent with stated preferences and beliefs regarding chemotherapy. The vast majority of patients who expressed negative or marginal preferences or beliefs regarding chemotherapy still received chemotherapy. Patient preferences and beliefs were not associated with the intensity or number of chemotherapy regimens received. In addition, under use of palliative chemotherapy was not evident. These findings shed new light on the patient experience and decision making in the use of palliative chemotherapy and can shift the focus of health services research in advanced cancer from investigating under use of treatment to the inclusion of patient preferences in decision making. Research should focus on tailoring delivery of care based on patient preferences and beliefs.
Dr. Zafar is supported by an American Cancer Society Mentored Research Scholar Grant and the Duke Cancer Institute Cancer Control Pilot Award. Dr. Zullig is supported by the National Cancer Institute (5R25CA116339). This work and the CanCORS Consortium are supported by grants from the National Cancer Institute to the Statistical Coordinating Center (U01 CA093344) and the National Cancer Institute-supported Primary Data Collection and Research Centers (Dana-Farber Cancer Institute/Cancer Research Network [U01 CA093332]; Harvard Medical School/Northern California Cancer Center [U01 CA093324]; RAND/UCLA [U01 CA093348]; University of Alabama at Birmingham [U01 CA093329]; the University of Iowa [U01 CA093339]; and the University of North Carolina [U01 CA093326]); the Agency for Healthcare Research Quality (03-438MO-03); and by a Department of Veterans Affairs grant to the Durham Veterans Affairs Medical Center (HSRD CRS 02-164).
CONFLICT OF INTEREST DISCLOSURES
Dr. Zafar has received honoraria from Genetech. Dr. Grambow serves as a consultant to Gilead Sciences and Watermark Research Partners.
- 14Imputation in a Multiformat and Multiwave Survey of Cancer Care. Proceedings in Health Policy Statistics. Alexandria, VA: American Statistical Association; 2007., , , , .
- 15Statistical Analysis with Missing Data. 2nd ed. Hoboken, NJ: Wiley-Interscience; 2002., .
- 23Patterns of care for adjuvant therapy in a random population-based sample of patients diagnosed with colorectal cancer. Am J Gastroenterol. 2006; 101: 2308-2318., , , , , .Direct Link:
- 33Representativeness of participants in the Cancer Care Outcomes Research and Surveillance Consortium relative to the Surveillance, Epidemiology, and End Results Program [published online a head of print March 7, 2012]. Med Care. 2012., , , et al.