Cross-sectional and longitudinal comparisons of health-related quality of life between patients with prostate carcinoma and matched controls§

Authors

  • Richard M. Hoffman M.D., M.P.H.,

    Corresponding author
    1. Medicine Service, New Mexico Veterans Affairs Health Care System, Albuquerque, New Mexico
    2. Epidemiology and Cancer Prevention Program, Cancer Research and Treatment Center, University of New Mexico, Albuquerque, New Mexico
    • Medicine Service, New Mexico Veterans Affairs Health Care System 111GIM, 1501 San Pedro SE, Albuquerque, NM 87108
    Search for more papers by this author
    • Fax: (505) 256-2888

  • Frank D. Gilliland M.D., Ph.D.,

    1. Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles, California
    Search for more papers by this author
  • David F. Penson M.D., M.P.H.,

    1. Department of Surgery, University of Southern California School of Medicine, Los Angeles, California
    Search for more papers by this author
  • S. Noell Stone M.P.H.,

    1. Epidemiology and Cancer Prevention Program, Cancer Research and Treatment Center, University of New Mexico, Albuquerque, New Mexico
    Search for more papers by this author
  • William C. Hunt M.S.,

    1. Epidemiology and Cancer Prevention Program, Cancer Research and Treatment Center, University of New Mexico, Albuquerque, New Mexico
    Search for more papers by this author
  • Arnold L. Potosky Ph.D.

    1. Division of Cancer Control and Prevention, National Cancer Institute, Bethesda, Maryland
    Search for more papers by this author

  • This article is a U.S. Government work and, as such, is in the public domain in the United States of America.

  • The opinions expressed herein do not necessarily reflect the views of the National Cancer Institute or the U.S. Government.

  • §

    Presented in part at the 26th Annual Meeting of the Society of General Internal Medicine, Vancouver, British Columbia, Canada, April 30–May 3, 2003.

Abstract

BACKGROUND

Prostate carcinoma and treatments affect health-related quality of life (HRQOL). The authors prospectively compared prostate and general HRQOL between prostate carcinoma cases and an age-matched and ethnicity-matched control group.

METHODS

The case cohort consisted of 293 men with localized prostate carcinoma who were selected randomly from the population-based New Mexico Tumor Registry, and the control cohort consisted of 618 men who were selected randomly from administrative databases and matched for age and ethnicity. Subjects completed a baseline survey of demographics, socioeconomic status, comorbidity, and prostate and general HRQOL. Also, 210 cases (71.7%) and 421 controls (67.8%) completed a follow-up survey 5 years later. Multinomial logistic regression models compared baseline characteristics as well as 5-year general HRQOL outcomes measured by selected domains of the Medical Outcomes Study SF-36. The authors used a mixed-model repeated-measures analysis of variance and multinomial regression analyses to compare longitudinal changes in urinary, bowel, and sexual function between groups.

RESULTS

At baseline, patients with prostate carcinoma had better urinary control and sexual function than controls. Over 5 years, sexual function declined significantly among controls, although urinary function remained stable. However, patients with cancer subsequently reported significant declines in both domains and were left with much worse function and more bother than controls. Bowel function and general HRQOL were similar for both groups at follow-up.

CONCLUSIONS

Prostate carcinoma treatment led to significant 5-year declines in urinary and sexual function that far exceeded age-related changes in controls. Patients with cancer had significantly worse function and more bother than controls for these disease-specific domains of HRQOL. Bowel function and general HRQOL were not affected by cancer status. Cancer 2004. Published 2004 American Cancer Society.

The number of prostate carcinoma cases has increased substantially since the advent of prostate-specific antigen (PSA) testing.1 Cancers detected by screening are predominantly clinically localized and often are treated aggressively with radical prostatectomy or radiotherapy. Although the primary goal of treating early-stage cancer is to reduce disease-specific morbidity and mortality, only one randomized study of radical prostatectomy has shown that treatment reduces prostate carcinoma mortality compared with watchful waiting.2 No randomized trials have evaluated radiotherapy for early-stage cancer. In the absence of mortality data, general and disease-specific quality of life (QOL) become important outcomes. Because men with screening-detected cancers usually have a long life expectancy, they may live for many years with treatment complications. Aggressive therapies are well documented to adversely—although variably—affect QOL, particularly the disease-specific domains of urinary, sexual, and bowel function.3 Treatment decisions often are based on their expected impact on QOL. However, the effects of these treatments on QOL should be balanced against the normal decline in these functions associated with aging.

Many investigators have reported on the prevalence and incidence of functional impairment in men with clinically localized prostate carcinoma.4, 5 However, results from these studies are often difficult to interpret because investigators frequently used cross-sectional designs or failed to include a control group. Findings from such studies are unable to distinguish whether the effects were related to baseline dysfunction or treatment effects. Longitudinal prospective better assess the effects of prostate carcinoma diagnosis and treatment on QOL because they can account for baseline functional status. We are unaware of any studies that have compared longitudinal data for men with prostate carcinoma against an age-matched control group.

We obtained longitudinal data on urinary, sexual, and bowel function and bother as well as cross-sectional data on general health-related quality of life (HRQOL) from subjects in the population-based Prostate Cancer Outcomes Study (PCOS). Although PCOS data have been used previously to compare outcomes for different treatments,6, 7 this report represents the first comparison of PCOS cases with a randomly and concurrently selected population-based, age-matched, and ethnicity-matched control group. We studied New Mexican men with localized prostate carcinoma and age-and ethnicity-matched New Mexican controls to compare the effects of cancer diagnosis and treatment with the effects of aging on prostate and general HRQOL over a period of 5 years.

MATERIALS AND METHODS

Case Selection

PCOS cases were selected from the National Cancer Institute's Surveillance, Epidemiology, and End Results program, a population-based tumor registry system that provides information on cancer incidence and survival for selected geographic regions within the United States. Details of the PCOS have been published elsewhere.3 Briefly, PCOS subjects were identified using a rapid case ascertainment system to identify men diagnosed with microscopically confirmed invasive carcinoma of the prostate between October 1, 1994 and October 31, 1995. Diagnosed patients resided in the states of Connecticut, Utah, and New Mexico and in the metropolitan areas of Atlanta, GA, Los Angeles, CA, and King County, WA (which includes Seattle). Eligible patients were sampled within strata of age, self-described race/ethnicity, and tumor registry to ensure adequate demographic representation. Patients with a race/ethnicity other than non-Hispanic white, African-American, or Hispanic were excluded, because the numbers in these groups were small and race/ethnicity could not be identified readily at the time of sampling. Eligible cases for this analysis were New Mexican men of age 20–89 at the time of diagnosis with a clinically localized prostate carcinoma. The institutional review board for the University of New Mexico approved the study.

The New Mexico Tumor Registry identified 753 non-Hispanic white cases and we randomly selected 294 (39.0%) to participate. We also randomly selected 246 (38.4%) of the 640 Hispanic cancer cases. The total number of potential eligible cases identified for the study was 540. Of these, 50 (9.3%) were later found to be ineligible due to an inappropriate diagnosis date or a diagnosis of a primary cancer other than prostate carcinoma. Physicians refused to give us permission to contact four potential case subjects, and the physicians for eight subjects determined that their patients did not have prostate carcinoma. Eleven (2.0%) cases died before we could contact them, and 27 (5.0%) answered on the questionnaire that they had not been diagnosed with prostate carcinoma. Thus, 425 of the originally selected subjects were presumed eligible to be cases, of which 351 (82.6%) participated by responding to the first survey. We restricted our analysis to the 293 men with clinically localized prostate carcinoma.

Control Selection

We randomly selected controls that were frequency matched on 5-year age groups and ethnicity to the prostate carcinoma cases. We identified controls < 65 years using the New Mexico Motor Vehicles Department (MVD) data files and centers for Medicare and Medicaid Services (CMS) claims files to identify controls ≥ 65 years. We used the GUESS program, a validated algorithm developed at the University of New Mexico Cancer Center, to classify race and ethnicity.8 We selected 1400 controls to participate, including 795 non-Hispanic white men and 605 Hispanic men. We were unable to contact 265 (18.9%) because the address was incorrect, 41 (2.9%) died before being contacted, and 14 (1.0%) were found to be ineligible for various reasons, including assignment of incorrect gender in the MVD or CMS files or controls were not New Mexico residents. Overall, we contacted 1080 of the eligible controls, and 618 (57.2%) participated in the study.

Data Collection

We collected data from all cases on general and disease-specific measures of HRQOL, symptoms, and specific treatments received for prostate carcinoma using a mailed self-administered HRQOL questionnaire. Disease-specific HRQOL was measured using a newly adapted prostate carcinoma-specific instrument, based on items from three existing instruments.9–11 Most participants returned the self-administered questionnaire (91%). Those who did not return the questionnaire were contacted by telephone and completed the survey by telephone or in person. Demographic and socioeconomic questions from this survey were used to determine race/ethnicity, employment status, educational level, household income, insurance status, and marital status. Subjects were surveyed on their prostate-related HRQOL and symptoms, including the domains of urinary, bowel, and sexual function, 6 months after initial diagnosis. They were also asked to recall their prostate-related HRQOL and symptoms just before their prostate carcinoma was diagnosed. General HRQOL was measured with six selected domains of the Medical Outcomes Study SF-36: general health, role limitations caused by physical problems (role-physical), role limitations caused by emotional problems (role-emotional), bodily pain (pain), vitality, and mental health.12

Comorbidity was ascertained from a questionnaire item that asked subjects about the presence or absence of 12 medical conditions that were believed likely to affect prostate carcinoma treatment decisions and long-term QOL. The conditions were derived from the Charlson index,13 as well as from the expert opinions of the PCOS investigators.

Men with prostate carcinoma were asked to sign a release form allowing investigators to review medical records from all physicians and facilities diagnosing or providing care for prostate carcinoma. Trained tumor registry abstractors used standard protocols to review these medical records and collect information on PSA levels, tumor characteristics, clinical staging procedures and results, and treatment details. A random sample of 5% of the medical records was reabstracted to assess and correct systematic coding errors.

Initial treatment, determined from medical record abstractions, was classified using a hierarchy based on the most aggressive treatment received within the 6 months after diagnosis. Men undergoing radical prostatectomy were classified as receiving surgical treatment even if they also received radiotherapy or androgen deprivation. Radiation treatment could also include androgen deprivation, and conservative management could include androgen deprivation or watchful waiting.

Clinical cancer stage determinations were based on an algorithm using clinical information obtained from digital rectal examinations (DRE) and imaging test results abstracted from the medical records. The algorithm was necessary because the community-based medical records were not detailed enough to classify cases with TNM staging.14 The clinically localized cancers included T1 and T2 tumors. T1 tumors were defined as tumors confined to the prostate—men had a normal DRE and no positive scans (magnetic resonance imaging, computed tomography, and bone scans) or evidence of metastasis. T2 tumors were defined as tumors confined to the prostate—men had abnormal or suspicious DRE, but no positive scans or evidence of metastasis. Advanced cancers included T3 tumors, defined as extending beyond the prostate—men did not have positive scans or evidence of metastasis. Finally, men with T4 tumors were defined as having at least one positive scan, positive lymph node, or distant metastasis.

Controls were mailed a similar survey to the one received by cases except that there were no questions about cancer diagnosis or treatment. The survey instrument was then mailed to all surviving cases and controls 5-years after completion of the initial survey. Study subjects were again questioned about general QOL with the SF-36 items, as well as about urinary, bowel, and sexual function and bother.

Statistical Analysis

The dependent variables were urinary (level of urinary control, frequency of incontinence, frequency of urination, and extent of any problem with incontinence), sexual (interest in sex, frequency of sex, firmness of erections, difficulty maintaining erections, and extent of problem with sexual function), and bowel (multiple bowel movements, pain with bowel movements, urgent bowel movements, painful hemorrhoids, and extent of problem with bowel function) function measured at baseline and 5 years later. The function (as opposed to bother) items in each category were combined to create a composite score ranging from 0 to 100 points. The SF-36 domain item responses were also transformed to create a composite score ranging from 0 to 100 points. Higher composite scores represented better function for all scales.

We used multinomial logistic regression, adjusting for the matching factors of age and ethnicity, to compute the predicted marginals for the distribution of baseline characteristics for cases and controls.15 We also used this analysis to compare SF-36 domain scores at follow-up. We compared changes in continuous variables (mean function scores) from baseline to 5 years between cases and controls using a mixed-model, repeated-measures analysis of variance with covariates for age and ethnicity. We compared changes in categorical variables (individual function items, bother) using a multinomial logistic regression with the generalized estimating equation method to adjust for within-subject correlation arising from repeated measures. Statistical analyses were performed with SAS.16P < 0.05 was significant.

RESULTS

Approximately 70% of cases and controls were > 60 years. In the current study, 53.9% of cases and 60.0% of controls were non-Hispanic whites. The age and ethnicity-adjusted distributions of baseline demographic and socioeconomic variables for cases and controls are shown in Table 1. The groups were fairly well matched, although cases were more likely to be retired. Baseline urinary, bowel, and sexual functions—which were assessed retrospectively within 6 months of diagnosis—are compared in Table 2. Cases had better urinary control and more obstructive urinary symptoms than controls. Cases were also less likely to report being bothered by incontinence. Cases were more likely to have frequent bowel movements, but overall bowel function was high for both groups and neither group perceived much problem with bowel function. Sexual function and interest in sexual activity were significantly higher for cases. However, approximately one-third of patients in both groups were unable to have erections firm enough for intercourse.

Table 1. Baseline Demographic, Socioeconomic, and Clinical Characteristics of Case and Control Patientsa
Variable% of patientsP value
Cases (n = 297)Controls (n = 618)
  • COPD: chronic obstructive pulmonary disease; CHF: congestive heart failure; CVA: cerebrovascular accident; HTN: hypertension; MI: myocardial infarction.

  • a

    Predicted marginals were adjusted for ethnicity and age.

Education level  0.98
 Not a high school graduate24.823.6 
 High school graduate+43.046.2 
 College graduate+32.231.2 
Income  0.50
 ≤ $20,00037.132.1 
 $20,000–$40,00026.931.6 
 > $40,00036.036.3 
Marital status  0.32
 Married81.178.2 
 Unmarried18.921.8 
Employment  0.004
 Full-time24.127.7 
 Part-time5.610.5 
 Retired67.858.0 
Comorbidities   
 Diabetes12.114.30.35
 COPD12.213.30.63
 CHF7.810.00.29
 CVA4.73.60.45
 HTN36.834.60.50
 MI9.212.10.19
Table 2. Baseline Prostate Health-Related Quality of Life for Case and Control Patientsa
Variable% of patientsP value
Cases (n = 297)Controls (n = 618)
  • a

    Predicted marginals and means were adjusted for ethnicity and age.

Urinary control  0.002
 Total control77.269.5 
 Occasional incontinence16.526.5 
 Frequent incontinence/no control6.44.1 
Frequency of incontinence  <0.0001
 Not at all or ≤ once per week83.689.8 
 Once per week2.74.8 
 ≥ once per day13.75.1 
Frequent need to urinate   
 No/rarely51.250.70.91
 ≤ half of the time37.639.5 
 > half of the time11.19.8 
Push/strain to urinate  0.002
 No/rarely75.884.5 
 ≤ half of the time17.112.6 
 > half of the time7.02.9 
Urinary problems  0.03
 No problem77.469.9 
 Small problem16.425.0 
 Moderate-to-large problem6.25.1 
3+ bowel movements daily  0.005
 No/rarely75.780.7 
 Some days16.516.4 
 Almost every day7.93.0 
Painful bowel movements  0.76
 No/rarely90.088.4 
 Some days9.010.5 
 Almost every day1.01.1 
Urgent bowel movements  0.17
 No/rarely83.479.6 
 Some days/almost every day16.620.4 
Painful/bleeding hemorrhoids  0.11
 No/rarely83.688.6 
 Some days14.09.8 
 Almost every day2.41.6 
Bowel problems  0.21
 None71.872.9 
 Very small17.219.4 
 Small/moderate-to-large11.07.7 
Level of interest in sexual activity  0.005
 None14.317.6 
 Some49.957.4 
 A lot35.825.0 
Frequency of sexual activity  0.68
 None17.014.5 
 ≤ once a week40.939.6 
 > once a week42.145.9 
Erections firm enough for intercourse  0.16
 No32.136.4 
 Yes67.963.6 
Difficulty keeping an erection  0.25
 None41.636.9 
 Some/a lot41.941.7 
 No erections16.521.5 
Sexual problems  0.21
 No problem49.146.4 
 Small problem24.427.6 
 Moderate-to-large problem26.626.0 

The 5-year survey was completed by 210 (71.7%) cases and 421 (67.8%) controls. Among the cases, 135 underwent radical prostatectomy, 34 received radiotherapy, and 41 were managed conservatively (21 with androgen deprivation, 20 with watchful waiting). Although response rates varied considerably by baseline characteristics, the response rates between cases and controls were generally similar. However, we found substantial response differences for baseline urinary control and problems with urinary dripping. Among men reporting frequent urinary leakage, cases were less likely than controls to complete the follow-up survey: 42.1% versus 56.0% (P = 0.027). Similarly, among men reporting that urinary dripping was a moderate-to-large problem, cases were less likely than controls to complete the follow-up survey: 36.8% versus 58.1% (P = 0.057).

Table 3 shows the grouped changes in prostate HRQOL for the subjects responding to both surveys. Urinary function declined significantly in men with prostate carcinoma by 5 years after diagnosis. Only 41.0% of cases reported total urinary control compared with 84.0% at baseline. The proportion of controls reporting total urinary control decreased from 71.6% to 69.1%. At follow-up, 10.8% of cases reported a moderate-to-large problem with urinary incontinence compared with only 3.0% at baseline. Meanwhile, the proportion of controls reporting moderate-to-large urinary problems decreased slightly, from 4.2% to 2.8%. Sexual function declined in both groups, with a much greater deterioration in cancer cases. The proportion of men with prostate carcinoma reporting no erectile difficulties decreased from 45.0% to 8.8%, whereas controls decreased from 40.0% to 32.0%. The proportion of cases reporting moderate-to-large problems with sexual function increased from 24.9% to 43.6%. The proportion also increased in controls, but only from 24.5% to 29.3%. Bowel function remained high for both groups over time.

Table 3. Baseline and 5-Year Measures of Prostate Health–Related Qualify of Life Outcomesa
Variable% of patientsP valueb
Baseline5 yr
Cases (n = 210)Controls (n = 421)Cases (n = 210)Controls (n = 421)
  • a

    Predicted marginals and means adjusted for age and ethnicity.

  • b

    P values for between-group changes over time.

Urinary control     
 Total control84.071.641.069.1< 0.0001
 Occasional incontinence12.424.947.526.7 
 Frequent incontinence/no control3.611.611.64.2 
Frequency of incontinence    < 0.0001
 Not at all or ≤ once per week89.085.357.479.7 
 Once per week2.56.614.98.7 
 ≥ once per day8.58.227.711.6 
Frequent need to urinate    0.07
 No/rarely53.652.451.959.1 
 ≤ half of the time36.738.435.934.7 
 > half of the time9.79.212.26.2 
Push/strain to urinate    <0.02
 No/rarely77.386.993.090.3 
 ≤ half of the time16.710.35.28.7 
 > half of the time6.02.71.81.0 
Urinary problems    < 0.0001
 None83.171.751.475.5 
 Small13.925.137.821.7 
 Moderate-to-large3.04.210.82.8 
3+ bowel movements daily    0.07
 No/rarely78.980.377.773.6 
 Some days14.316.716.119.5 
 Almost every day6.82.96.37.0 
Painful bowel movements    0.78
 No/rarely92.590.690.390.3 
 Some days7.08.77.57.7 
 Almost every day0.50.72.31.9 
Urgent bowel movements    < 0.02
 No/rarely86.379.579.281.7 
 Some days/almost every day13.720.520.818.3 
Painful/bleeding hemorrhoids    0.26
 No/rarely82.987.587.986.4 
 Some days14.710.911.112.6 
 Almost every day2.41.71.01.0 
Bowel problems    0.28
 None73.873.569.076.9 
 Small22.422.424.819.1 
 Moderate-to-large3.84.16.34.0 
Level of interest in sexual activity    < 0.0001
 A lot37.427.920.821.4 
 Some55.057.651.160.8 
 None7.614.428.317.8 
Frequency of sexual activity    < 0.0001
 At least once weekly41.639.623.433.1 
 1–3 times monthly36.335.021.635.4 
 Never22.125.455.031.5 
Erections firm enough for intercourse    < 0.0001
 Yes73.270.528.063.7 
 No26.829.572.036.3 
Difficulty keeping an erection    < 0.0001
 None45.040.08.832.0 
 Some/a lot43.042.531.545.4 
 No erections12.017.559.722.6 
Sexual problems    0.02
 None51.546.229.640.4 
 Small23.629.326.730.3 
 Moderate-to-large24.924.543.629.3 

We also studied the adjusted mean composite urinary, sexual, and bowel function scores. Figures 1–3 show baseline and 5-year scores for controls and cases (overall and stratified by treatment). Overall, the adjusted mean composite urinary function score decreased significantly in cases, whereas it remained essentially unchanged in controls (P < 0.0001 for a group × time interaction). However, stratified analyses showed significant declines in the adjusted mean composite urinary function score only for cases undergoing radical prostatectomy (P < 0.0001) or conservative management (P < 0.03). Adjusted mean composite sexual function scores declined significantly in both cases and controls, but the decline was considerably greater in cases (P < 0.0001 for a group × time interaction). The sexual function scores declined significantly in each treatment group. Bowel function remained stable for both cases and controls (P = 0.70 for a group × time interaction), and there were no differences between controls and cases when stratified by treatment group.

Figure 1.

Comparisons of baseline and 5-year follow-up adjusted mean composite urinary function scores between controls and cases (combined and stratified by treatment). RP: radical prostatectomy; XRT: radiotherapy; Cons: conservative management. Dark bars: baseline; gray bars: 5 years.

Figure 2.

Comparisons of baseline and 5-year follow-up adjusted mean composite sexual function scores between controls and cases (combined and stratified by treatment). RP: radical prostatectomy; XRT: radiotherapy; Cons: conservative management. Dark bars: baseline; gray bars: 5 years.

Figure 3.

Comparisons of baseline and 5-year follow-up adjusted mean composite bowel function scores between controls and cases (combined and stratified by treatment). RP: radical prostatectomy; XRT: radiotherapy; Cons: conservative management. Dark bars: baseline; gray bars: 5 years.

We found no significant differences between cases and controls for SF-36 domain scores measured at the 5-year follow-up (data not shown). We also stratified cases by treatment received. Cases that underwent either radiotherapy or conservative management had similar SF-36 domain scores 45 controls at follow-up. The mean pain score was significantly higher for men who underwent radical prostatectomy than for controls, 74.4 versus 69.1 (P = 0.031).

DISCUSSION

We reported the first comparisons of PCOS subjects with a randomly and concurrently selected population-based, age and ethnicity-matched control group. We selected cases with clinically localized prostate carcinoma because these men were most likely to be detected by screening. Any effects from these early-stage cancers on disease-specific QOL, therefore, would largely result from cancer treatments. We found important differences in prostate carcinoma-specific HRQOL between New Mexican PCOS subjects with clinically localized prostate carcinoma and matched controls. Men with cancer had better sexual and urinary function at the time of diagnosis than the control group. Cases had an adjusted mean composite sexual function score of 63.5 compared with 58.7 for controls. Also, 35.8% of cases reported having a lot of interest in sexual activity compared with just 25.0% of controls. Although the adjusted mean composite urinary function scores were similar between cases and controls, 77.2% of cases reported complete urinary control compared with only 69.5% of controls.

During a 5-year follow-up period, sexual function significantly declined in both groups. However, the change was markedly greater among the patients with cancer, most of whom underwent radical prostatectomy or received radiotherapy. The adjusted mean composite sexual function score decreased in cases by 31.6 points (47%) compared with only 5.6 points (9%) in controls. At follow-up, only 28.0% of cases reported having erections firm enough for intercourse whereas 63.7% of controls reported normal erectile function. Urinary function scores also declined markedly in cases (14.7 points, 17%), but remained virtually unchanged in controls. At follow-up, only 41.0% of cases reported total urinary control compared with 69.1% of controls. Radical prostatectomy caused the most substantial decrements for urinary and sexual function compared with control subjects. Radiotherapy adversely affected sexual function but not urinary function. Similar findings were reported for the entire PCOS cohort.17 However, it should be noted that our urinary function scale was designed to assess incontinence. Other investigators have shown that radiotherapy is more likely to cause urinary irritation than incontinence.18 Cases and controls maintained good bowel function during follow-up. Despite the substantial changes in disease-specific HRQOL, we found that the general HRQOL measured at follow-up did not significantly differ between groups.

Functional declines in disease-specific HRQOL after treatments for localized prostate carcinoma have been well documented. Cross-sectional and longitudinal studies have consistently shown poorer sexual and urinary function after radical prostatectomy and worse bowel function after external-beam radiation.6, 19–30 The proportions of subjects in these studies with prostate-specific dysfunction were comparable to our findings.

Sexual, urinary, and bowel functions also decline with age. Bacon et al.31 reported data from 19,263 subjects in the Health Professionals Study, excluding men with prostate carcinoma. Among men 60–69 years old, 22% reported that sexual function was a moderate-to-big problem and 26% reported poor erectile function. In the Bacon et al. study, the proportion reporting that sexual function was a moderate to big problem increased to 29% in men 70–79, and 50% reported poor erectile function. In the early 1990s, Litwin32 conducted a comprehensive population-based survey of 268 older men (mean age 72.5 years) without prostate carcinoma. Among the respondents, 31% reported that sexual desire was poor-to-very poor and sexual function was a moderate to big problem for 45%. Greater than 30% reported occasional or frequent dribbling, although urinary incontinence was a moderate-to-big problem for only 8%. Rectal urgency more than once weekly was reported by 31%, although only 6% had moderate-to-big problems with bowel function. Our control group responses at baseline were similar to those reported in the literature, with 26.0% reporting moderate-to-big problems with sexual function and 33.7% reporting very poor erectile function. Occasional or frequent incontinence was reported by 30.6% of controls, and only 5.1% reported moderate to big problems with incontinence. Overall, 92.3% of controls reported having no or only very small problems with bowel function.

We found that men treated for localized prostate carcinoma had considerably greater loss of urinary and sexual function and poorer residual function than age-matched controls. Other investigators have also reported poorer urinary, sexual, and bowel function for men with prostate carcinoma after treatment with either radical prostatectomy, radiotherapy, or brachytherapy, compared with age-matched control groups.21, 24, 33, 34 However, results from these analyses are difficult to interpret because study designs were cross-sectional. Differences in functional status could result from either treatment effects or high rates of baseline dysfunction among cases. In addition, the cross-sectional studies surveyed cases at variable intervals after treatment. The PCOS results are more generalizable because we assembled an inception cohort of newly diagnosed cases and concurrently collected prospective data from cases and controls.

We found that general HRQOL was less affected than disease-specific HRQOL by prostate carcinoma diagnosis and treatment. Overall, we found no significant differences between all cases and controls in the mean scores for 6 selected SF-36 domains 5 years after cases were diagnosed. Subjects undergoing radical prostatectomy had higher mean pain scores than controls. The implications of this five-point difference are uncertain because the cases were comparable to the published norms for their age range.35 We found no other general HRQOL differences between cases and controls when stratified by treatment type. Penson et al.7 had reported previously that general HRQOL evaluated 2 years after diagnosis in the entire PCOS cohort was similar across all primary treatment groups. Most cross-sectional and longitudinal studies have also shown that localized prostate carcinoma and treatment had a minimal effect on general HRQOL.6, 21, 22, 26, 27, 29, 34, 36 Steineck et al.37 found no differences in self-reported psychological symptoms, well-being, and QOL in 326 Swedish subjects approximately 4 years after being assigned randomly to receive radical prostatectomy or watchful waiting.

Our study had some potential limitations, particularly from attrition bias. Although the proportions of cases (70.7%) and controls (68.1%) completing the 5-year survey were essentially identical, there were some significant differential losses related to baseline characteristics. Cases with either poorer urinary control or more bother from urinary incontinence at baseline were less likely than controls with similar problems to complete the 5-year survey. However, despite this differential attrition, we still found that urinary function was substantially worse for cases than controls at the 5-year follow-up. This suggests that we may have actually underestimated the differences between cases and controls. We also did not obtain detailed information on comorbidities or medications that could have affected urinary and sexual function. However, the prevalence of major comorbidities was similar between cases and controls. Another limitation arose because we asked subjects to recall their baseline symptoms 6 months after diagnosis. Recall errors could lead us to misclassify baseline disease-specific HRQOL. However, Legler et al.38 prospectively studied a subset of PCOS subjects and found high concordance for symptom recall at 6 months after diagnosis compared with reports at the time of diagnosis. Even if baseline HRQOL was misclassified in cases, they had significantly poorer urinary and sexual function than controls at the 5-year follow-up.

In summary, we found that men without prostate carcinoma often reported poor sexual and urinary function. During a 5-year period, sexual function also declined significantly. However, declines in urinary and sexual function domains after diagnosis and treatment of localized cancer far exceeded any effects from aging, particularly for men undergoing radical prostatectomy. Patients with cancer had much poorer urinary and sexual function than controls at the 5-year follow-up, although bowel function and general HRQOL were relatively high for both groups.

Acknowledgements

The authors thank the men who participated in the Prostate Cancer Outcomes Study as well as their physicians. The authors also thank the study teams at all participating research centers for their contributions to the current investigation.

Ancillary