Borealis-1: a randomized, first-line, placebo-controlled, phase II study evaluating apatorsen and chemotherapy for patients with advanced urothelial cancer.

BACKGROUND: Five-year survival of patients with inoperable, advanced urothelial carcinoma treated with the first-line chemotherapy is 5%-15%. We assessed whether the Hsp27 inhibitor apatorsen combined with gemcitabine plus cisplatin (GC) could improve overall survival (OS) in these patients. PATIENTS AND METHODS: This placebo-controlled, double-blind, phase II trial randomized 183 untreated urothelial carcinoma patients (North America and Europe) to receive GC plus either placebo (N = 62), 600 mg apatorsen (N = 60), or 1000 mg apatorsen (N = 61). In the experimental arm, treatment included loading doses of apatorsen followed by up to six cycles of apatorsen plus GC. Patients receiving at least four cycles could continue apatorsen monotherapy as maintenance until progression or unacceptable toxicity. The primary end point was OS. RESULTS: OS was not significantly improved in the single or combined 600- or 1000-mg apatorsen arms versus placebo [hazard ratio (HR), 0.86 and 0.90, respectively]. Exploratory study of specific statistical modeling showed a trend for improved survival in patients with baseline poor prognostic features treated with 600 mg apatorsen compared with placebo (HR = 0.72). Landmark analysis of serum Hsp27 (sHsp27) levels showed a trend toward survival benefit for poor-prognosis patients in 600- and 1000-mg apatorsen arms who achieved lower area under the curve sHsp27 levels, compared with the placebo arm (HR = 0.45 and 0.62, respectively). Higher baseline circulating tumor cells (≥5 cells/7.5 ml) was observed in patients with poor prognosis in correlation with poor survival. Treatment-emergent adverse events were manageable and more common in both apatorsen-treatment arms. CONCLUSIONS: Even though apatorsen combined with standard chemotherapy did not demonstrate a survival benefit in the overall study population, patients with poor prognostic features might benefit from this combination. Serum Hsp27 levels may act as a biomarker to predict treatment outcome. Further exploration of apatorsen in poor-risk patients is warranted.

Performance enhancement in swimming: the effect of mental training with biofeedback.

In this study, the relationship between mental training with biofeedback and swimmers' performance was investigated. The Wingate five-step approach was used as a mental preparation technique for enhancing the performance among 16-18 year-old pre-elite swimmers. Participants (n = 40) were randomly assigned to one of two conditions: (a) experimental--regular training plus the Wingate 5-step mental training program (adapted for swimming), and (b) control--regular training plus relaxing activities. After a baseline measurement, participants were tested on running and swimming five times during a 10-week period. Results indicated that the experimental group improved its performance over time on both running and swimming, with improvement being most substantial during transformation and realisation (steps 4 and 5). In contrast, the control group remained relatively stable on both dependent measures. Results are discussed in reference to previous work on the 5-step approach, including several methodological and theoretical aspects that are particularly relevant to the use of such interventions with other athletic tasks and populations.

The percentage of free prostate-specific antigen does not predict extracapsular disease in patients with clinically localized prostate cancer before radical prostatectomy.

OBJECTIVE: To determine whether the percentage of free/total prostate-specific antigen (f/tPSA) can predict the pathological features in patients with clinically localized prostate cancer before radical prostatectomy. PATIENTS AND METHODS: Univariate and multivariate logistic regression was used to analyse data from 171 untreated patients who underwent radical prostatectomy. Variables included the total PSA (tPSA), fPSA, f/tPSA, biopsy Gleason score, clinical stage and patient age. RESULTS: In 115 patients with pathologically organ-confined tumours ( pT2N0) the mean (SD) tPSA value was 6.9 (5.6) ng/mL; in 56 patients with extracapsular disease ( pT3pN0/N+) it was 10.2 (7.6) ng/mL; the respective f/tPSA values were 14.9 (8.1)% and 14.2 (12.9)%. In the univariate and multivariate analysis, tPSA and biopsy Gleason score were highly significant in predicting extracapsular disease (P < 0.001 and 0.002) but the f/tPSA was not (P = 0.18). There was no significant difference between the mean f/tPSA and final Gleason scores. CONCLUSION: The f/tPSA does not predict extracapsular disease in patients with clinically localized prostate cancer before radical prostatectomy. Knowing the f/tPSA provides no significant additional information in predicting extracapsular disease when the biopsy Gleason score and tPSA are known.

Nephrectomy followed by interferon alfa-2b compared with interferon alfa-2b alone for metastatic renal-cell cancer.

BACKGROUND: The value of nephrectomy in metastatic renal-cell cancer has long been debated. Several nonrandomized studies suggest a higher rate of response to systemic therapy and longer survival in patients who have undergone nephrectomy. METHODS: We randomly assigned patients with metastatic renal-cell cancer who were acceptable candidates for nephrectomy to undergo radical nephrectomy followed by therapy with interferon alfa-2b or to receive interferon alfa-2b therapy alone. The primary end point was survival, and the secondary end point was a response of the tumor to treatment. RESULTS: The median survival of 120 eligible patients assigned to surgery followed by interferon was 11.1 months, and among the 121 eligible patients assigned to interferon alone it was 8.1 months (P=0.05). The difference in median survival between the two groups was independent of performance status, metastatic site, and the presence or absence of a measurable metastatic lesion. CONCLUSIONS: Nephrectomy followed by interferon therapy results in longer survival among patients with metastatic renal-cell cancer than does interferon therapy alone.

The prognostic significance of S-phase analysis in stage Ta/T1 bladder cancer. A Southwest Oncology Group Study.

OBJECTIVES: An intergroup study (SWOG 8795) comparing two forms of adjunctive therapy (immuno and chemo), bacillus Calmette-Guerin (BCG) and mitomycin C (MMC), furnished preregistration index tumors for 244 patients with superficial, papillary stage Ta/T1 TCC. These were examined by flow cytometry to learn whether DNA ploidy or proliferation (low vs high S-phase fraction (SPF) helped to predict disease recurrence or progression. METHODS: Cell cycle analysis using commercially available (Multicycle) programs was performed on 249 Ta/T1 bladder cancers. Tumor grade, available for 223 cases, was assigned by a single study pathologist. The SWOG statistical office reviewed follow-up information and other data and performed statistical analysis. RESULTS: Disease recurrence occurred in half the cases studied. The most parsimonious model predictive of recurrence included only treatment arm and tumor grade, with the MMC arm and tumor grade greater than I indicating worse prognosis (p = 0. 014). Neither ploidy nor SPF predicted recurrence-free survival or contributed prognostic information that was additive to tumor grade. Within 5 years of follow-up, disease progression or death from bladder cancer occurred for 29/223 (13%) of patients. The most parsimonious model for progression-free survival included only grade greater than I (p<0.001) and high SPF (p = 0.029) (relative risk: tumor grade, 4.3, high SPF, 1.9). CONCLUSIONS: Knowledge of tumor proliferation (low versus high SPF) contributes prognostic information about tumor progression that is additive to tumor grade.

Maintenance bacillus Calmette-Guerin immunotherapy for recurrent TA, T1 and carcinoma in situ transitional cell carcinoma of the bladder: a randomized Southwest Oncology Group Study.

PURPOSE: Bacillus Calmette-Guerin (BCG) immunotherapy has been widely accepted as the optimal treatment for carcinoma in situ and high grade superficial transitional cell carcinoma. However, controversy remains regarding the role of maintenance therapy, and its long-term effect on recurrence and progression. MATERIALS AND METHODS: All patients in the study had transitional cell carcinoma of the bladder with carcinoma in situ or an increased risk of recurrence. The criteria for increased risk were 2 or more episodes of tumor within the most recent year, or 3 or more tumors within 6 months. At least 1 week following biopsy of carcinoma in situ and resection of any stage Ta or T1 transitional cell tumors 660 patients were started on a 6-week induction course of intravesical and percutaneous Connaught BCG. Three months following initiation of BCG induction therapy 550 consenting patients were stratified by purified protein derivative skin test and the presence of carcinoma in situ, and then randomized by central computer to receive BCG maintenance therapy (maintenance arm) or no BCG maintenance therapy (no maintenance arm). Maintenance therapy consisted of intravesical and percutaneous BCG each week for 3 weeks given 3, 6, 12, 18, 24, 30 and 36 months from initiation of induction therapy. The 384 eligible patients who were disease-free at randomization constitute the primary intent to treat analytic group because they could be followed for disease recurrence. All patients were followed for adverse effects of treatment, recurrence, disease worsening and survival. RESULTS: No toxicities above grade 3 were noted in the 243 maintenance arm patients. The policy of withholding maintenance BCG from patients with increased side effects may have diminished the opportunity to observe severe toxicity. Estimated median recurrence-free survival was 35.7 months (95% confidence interval 25.1 to 56.8) in the no maintenance and 76.8 months (64.3 to 93.2) in the maintenance arm (log rank p<0.0001). Estimated median time for worsening-free survival, defined as no evidence of progression including pathological stage T2 disease or greater, or the use of cystectomy, systemic chemotherapy or radiation therapy, was 111.5 months in the no maintenance and not estimable in the maintenance arm (log rank p = 0.04). Overall 5-year survival was 78% in the no maintenance compared to 83% in the maintenance arm. CONCLUSIONS: Compared to standard induction therapy maintenance BCG immunotherapy was beneficial in patients with carcinoma in situ and select patients with Ta, T1 bladder cancer. Median recurrence-free survival time was twice as long in the 3-week maintenance arm compared to the no maintenance arm, and patients had significantly longer worsening-free survival.

Cancer pain and common pain: a comparison of patient-reported intensities.

PURPOSE/OBJECTIVES: To compare patient reports of present and worst cancer-related pain intensity to the recalled intensity of several commonly experienced types of pain. DESIGN: A secondary analysis on baseline data from patients with cancer pain. SETTING: Tertiary-care facilities and patients' homes. Patients were enrolled between 1988 and 1995. SAMPLE: Patients who were diagnosed with either primary lung cancer or cancer metastatic to bone, able to read and write English, over 18 years of age, and able to provide written informed consent. The sample of 125 patients was 62% male with a mean age of 60 years (SD = 11). METHODS: Patients completed the McGill Pain Questionnaire as a baseline measure in a pain research study. Investigators conducted comparisons among pain intensity scores reported for present pain intensity and worst cancer pain with the worst toothache, headache, and stomachache ever experienced using the Stuart test of marginal homogeneity. MAIN RESEARCH VARIABLES: Present cancer pain intensity and worst toothache, headache, and stomachache pain intensity. FINDINGS: Only 14% of the subjects reported that their present pain intensity was distressing, horrible, or excruciating, but 83% of them reported that their worst cancer pain was at these levels. The subjects reported that they experienced (a) significantly more intense pain with their worst toothache than either their present pain intensity (p < 0.001) or their worst cancer pain (p < 0.001), (b) significantly more intense pain with their worst headache than their present pain intensity (p < 0.001), and (c) significantly more intense pain with their worst stomachache than their present pain intensity (p < 0.001). In contrast, subjects reported that their worst cancer pain was significantly more intense than their worst headache (p = 0.047) or stomachache (p = 0.001). CONCLUSIONS: The findings suggest that present cancer pain is not only experienced at lower intensity levels than common pains, but at lower levels than expected by patients, their families, and the public. Consistent with common beliefs though, the worst cancer pain is severe and not adequately controlled for 9 out of 10 patients. IMPLICATIONS FOR NURSING PRACTICE: Healthcare professionals could use study findings to inspire hope in patients with lung cancer or bone metastasis and their families that present pain in cancer can be controlled successfully. Clinicians should devote greater efforts to relieve the worst cancer pain to levels achieved for the present pain experienced by people with cancer.

Cisplatin, methotrexate and bleomycin for the treatment of carcinoma of the penis: a Southwest Oncology Group study.

PURPOSE: We ascertained whether combined cisplatin, methotrexate and bleomycin have efficacy for treating locally advanced or metastatic carcinoma of the penis, and evaluate the toxicity resulting from this regimen. MATERIALS AND METHODS: Patients had biopsy proved locally advanced or metastatic epidermoid carcinoma of the penis. Chemotherapy consisted of 75 mg./m.2 cisplatin infused intravenously on day 1, 25 mg./m.2 intravenous bolus of methotrexate on days 1 and 8, and 10 unit per m.2 intravenous bolus of bleomycin on days 1 and 8 with a cycle length of 21 days. Our study was performed as a standard phase II evaluation with 2 stages of accrual. RESULTS: Enrolled in this study were 45 patients, including 40 who were evaluable for a response. There were 5 complete and 8 partial responses for a 32.5% response rate. Five treatment related deaths occurred and 6 of the 36 remaining patients evaluable for toxicity had 1 or more life threatening toxic episodes. CONCLUSIONS: A regimen of cisplatin, methotrexate and bleomycin appears to have promising results. However, toxicity was prodigious, and an emphasis of future research should be to decrease toxicity.

The relationship between serial measurements of the level of a bladder tumor associated antigen and the potential for recurrence.

PURPOSE: We evaluate the relationship between a serially assessed quantitative diagnostic marker (QDM) and the hazard function for the diagnosis of recurrence of bladder cancer. The marker is based on a bladder tumor associated antigen (BTA TRAK) assay. We present a rigorous approach to the evaluation of diagnostic markers to be used for recurrence monitoring. MATERIALS AND METHODS: Archival voided urine samples serially collected from 187 patients with a prior diagnosis of transitional cell carcinoma of the bladder were measured for BTA TRAK, an assay performed in clinical laboratories. All patients had been treated for stage Ta or T1 transitional cell carcinoma and were undergoing periodic assessments for recurrence. The results from the QDM were not used in case management. Time to histologically confirmed recurrence of transitional cell carcinoma was modeled using proportional hazard regression with the serial measurements of QDM levels and other variables as covariates. QDM levels are in the model as a time dependent covariate on the base 10 logarithmic scale. RESULTS: The estimated hazard ratio for QDM level indicated a 60% increase in the hazard for the diagnosis of recurrence for each 10-fold increment in the marker level (p = 0.013). CONCLUSIONS: A statistically significant relationship between the serially assessed QDM levels and the hazard for the diagnosis of recurrence has been established but the definition of optimum strategies for use of this relationship in clinical practice will require further study. Meanwhile, a prudent action based on the statistical relationship would be to shorten surveillance intervals for patients with high QDM levels.

Bilateral orchiectomy with or without flutamide for metastatic prostate cancer.

BACKGROUND: Combined androgen blockade for the treatment of metastatic prostate cancer consists of an antiandrogen drug plus castration. In a previous trial, we found that adding the antiandrogen flutamide to leuprolide acetate (a synthetic gonadotropin-releasing hormone that results in medical ablation of testicular function) significantly improved survival as compared with that achieved with placebo plus leuprolide acetate. In the current trial, we compared flutamide plus bilateral orchiectomy with placebo plus orchiectomy. METHODS: We randomly assigned patients who had never received antiandrogen therapy and who had distant metastases from adenocarcinoma of the prostate to treatment with bilateral orchiectomy and either flutamide or placebo. Patients were stratified according to the extent of disease and according to performance status. RESULTS: Of the 1387 patients who were enrolled in the trial, 700 were randomly assigned to the flutamide group and 687 to the placebo group. Overall, the incidence of toxic effects was minimal; the only notable differences between the groups were the greater rates of diarrhea and anemia with flutamide. There was no significant difference between the two groups in overall survival (P=0.14). The estimated risk of death (hazard ratio) for flutamide as compared with placebo was 0.91 (90 percent confidence interval, 0.81 to 1.01). Flutamide was not associated with enhanced benefit in patients with minimal disease. CONCLUSIONS: The addition of flutamide to bilateral orchiectomy does not result in a clinically meaningful improvement in survival among patients with metastatic prostate cancer.

Quality of life in advanced prostate cancer: results of a randomized therapeutic trial.

BACKGROUND: For patients with metastatic prostate cancer, treatment is primarily palliative, relying mainly on the suppression of systemic androgen hormone levels. To help document the achievement of palliation and to characterize positive and negative effects of treatment, we evaluated quality-of-life (QOL) parameters in patients with metastatic prostate cancer who were randomly assigned to two methods of androgen deprivation. METHODS: Patients (n = 739) with stage M1 (bone or soft tissue metastasis) prostate cancer were enrolled in a QOL protocol that was a companion to Southwest Oncology Group INT-0105, a randomized double-blind trial comparing treatment with bilateral orchiectomy (surgical castration) plus either flutamide or placebo. Patients completed a comprehensive battery of QOL questionnaires at random assignment to treatment and at 1, 3, and 6 months later. Data were collected on three treatment-specific symptoms (diarrhea, gas pain, and body image), on physical functioning, and on emotional functioning. All P values are two-sided. RESULTS: Questionnaire return rates for this study never dropped below 80%; only 2% of the patients did not submit baseline QOL assessments. Cross-sectional analyses (corrected for multiple testing) identified statistically significant differences that favored orchiectomy plus placebo for two of the five primary QOL parameters as follows: patients receiving flutamide reported more diarrhea at 3 months (P = .001) and worse emotional functioning at 3 and 6 months (both P<.003). Longitudinal analyses replicated these findings. Other analyzed QOL parameters favored the group receiving placebo but were not statistically significant after adjustment for multiple testing. CONCLUSIONS: We found a consistent pattern of better QOL outcomes at each follow-up assessment during the first 6 months of treatment for orchiectomized patients with metastatic prostate cancer who received placebo versus flutamide. Improvement over time was evident in both treatment groups but more so for patients receiving placebo.

Serum percent free prostate-specific antigen in metastatic prostate cancer.

OBJECTIVES: To define the serum prostate-specific antigen (PSA) isoform profile in patients who have prostate cancer but do not have a prostate gland, that is, men who have had a previous radical prostatectomy (RP) and subsequently persistent disease as evidenced by elevated PSA. PSA can be reliably measured in the serum in two major isoforms: PSA complexed to alpha1-antichymotrypsin and uncomplexed free PSA (fPSA). Multiple investigations have illustrated the usefulness of the free/total PSA proportion (percent fPSA) in differentiating prostate cancer from benign prostate disease in patients who still have their prostate gland in situ. METHODS: Sera were evaluated from 52 men who underwent RP and postoperatively had increased PSA. fPSA and total PSA (tPSA) concentrations were determined using the Abbott AxSYM PSA assays. Percent fPSA was calculated for all patients. RESULTS: Median tPSA was 5.45 ng/mL (range 0.93 to 214.99). Median fPSA was 0.69 ng/mL (range 0.11 to 54.93); the median percent fPSA was 13.3% (range 3.9% to 62.9%). There were 27 (52%) patients with percent fPSA less than 15%, 25 (48%) patients with greater than 15%, and 7 (13%) with greater than 30%. No significant relationship was found between percent fPSA and grade, stage, and severity of disease. Percent fPSA was significantly increased in patients who received hormonal, radiation, or combination treatment versus those who received no treatment (P = 0.02 to 0.0007). CONCLUSIONS: Serum percent fPSA in men after RP with persistent prostate cancer encompasses a wide range of values with no clear stratifying factor or factors. These observations and further serial studies in patients with progressive metastatic disease may be important in determining the mechanism(s) for lower percent fPSA in men with newly diagnosed prostate cancer.

Temporal trends in rates of prostate cancer: declining incidence of advanced stage disease, 1974 to 1994.

PURPOSE: We examined the temporal trends in prostate cancer incidence and mortality rates in the Seattle-Puget Sound region. MATERIALS AND METHODS: Prostate cancer incidence and treatment data collected by the Cancer Surveillance System, part of the Surveillance, Epidemiology, and End Results program, were analyzed for temporal trends in disease and treatment. Analyses were restricted to white and African-American men 35 years or older residing in the 13-county area of northwestern Washington state and diagnosed between 1974 and 1994. Data for the treatment analyses were limited to the time period 1983 through 1992. RESULTS: Incidence of prostate cancer increased slowly from 1974 (169/100,000) to 1984 (230/100,000) and then rapidly to a peak in 1991 (486/100,000) before declining (293/100,000 in 1994). Mortality increased from 49/100,000 in 1974 to 67/100,000 in 1994. All stages of prostate cancer followed the same incidence trend peaking in 1991, except distant stage disease, which peaked in 1986 and subsequently declined by over 60% (p <0.001). Proportions of men undergoing radical prostatectomy increased from 1983 to 1992 with the biggest increase in men under 65 years old. CONCLUSIONS: The incidence rate of prostate cancer in the Seattle-Puget Sound region is higher than the rate in some other regions of the country. This is likely due to widespread, more intense prostate specific antigen screening of the population in this region compared to other areas of the country. The incidence rate of prostate cancer in the Seattle-Puget Sound region has peaked and is now declining.

Improved detection of recurrent bladder cancer using the Bard BTA stat Test.

OBJECTIVES: To evaluate the BTA stat Test in the detection of recurrent bladder cancer. METHODS: Sensitivity and specificity were determined using frozen voided urine samples from patients with recurrent bladder cancer, volunteers, patients with nonurologic conditions, and patients with a history of bladder cancer but free of disease. Results of cytology and the original BTA Test were compared with the sensitivity of the BTA stat Test in a large subgroup of the patients with cancer. RESULTS: The BTA stat Test detected 147 (67%) of 220 recurrent cancers. For those urine samples with previous cytologic and BTA Test results available, cytology had a sensitivity of 23%, the BTA Test 44%, and the BTA stat Test 58% for detection of recurrent cancer (P < 0.001, stat versus cytology). The specificity of the BTA stat Test was 72% for benign genitourinary disease and 95% in healthy volunteers. CONCLUSIONS: The BTA stat Test has high sensitivity and is significantly superior to voided urine cytologic analysis in the detection of recurrent bladder cancer.

Comparison of the Bard BTA test with voided urine and bladder wash cytology in the diagnosis and management of cancer of the bladder.

OBJECTIVES: To compare the Bard BTA test, a simple latex-agglutination test for cancer of the bladder (BC) that can be performed in less than 3 minutes in the urologist's office, with voided urine or bladder wash cytology in the diagnosis of subjects suspected of having BC on the basis of symptoms or recent abnormal cystoscopy or intravenous urography. METHODS: The study was performed at three medical centers in 414 subjects (147 female and 267 male; mean age 60 years), 345 of whom (83%) had no prior history of BC. The cytologic examinations were performed by pathologists unaware of the results of the BTA test. RESULTS: Cystoscopy or cystoscopy and biopsy revealed BC in 71 subjects (17%). The overall sensitivities of the BTA test and cytology were 70% and 25%, respectively. The specificities of the BTA test and cytology in the 337 subjects without BC were 90% and 100%, respectively. The sensitivities of the BTA test by tumor grade were 17%, 64%, and 92% for grades 1, 2, and 3, respectively; those of cytology were 17%, 14%, and 44%. Regression analysis suggests that tumor grade but no other study variable explains the sensitivity of the BTA test. CONCLUSIONS: The BTA test is considerably more sensitive than cytology in the detection of BC. For urologists who use cytology in the diagnosis and follow-up of patients with BC, the BTA test may replace cytology.

Phase II studies on prostate cancer.

OBJECTIVES: To evaluate different study designs and the general utility of phase II trials on prostate cancer. METHODS: Extensive literature studies and correspondance within the working group during 1 year were summarized in a preliminary manuscript. The manuscript was finalized at a 1 day meeting and is presented here as a consensus document. RESULTS: The main objectives of phase II studies are to assess whether a treatment is sufficiently active to justify comparative phase III studies, and to obtain further information on adverse reactions. Bidimensionally measurable lesions are traditionally studied, allowing objective criteria for response and progression to be applied. However, as skeletal metastases do not fulfill the criteria for such lesions, the majority of patients with metastatic prostate cancer are not eligible for traditionally-designed phase II trials. Therefore, ancillary response parameters, especially serum prostate-specific antigen (PSA), have been proposed for use. For the evaluation of adverse reactions, the criteria of the World Health Organization were proposed for use. A review of various statistical designs was presented, with a focus on their advantages and disadvantages in phase II trials. CONCLUSIONS: The role of PSA in phase II trials has not yet been firmly established. Further study of its correlation with other endpoints is needed. In future phase II trials, a shift to softer endpoints than traditionally used may enhance the process of evaluation of new antitumor drugs. Phase II studies may even be replaced by early phase III studies, especially in situations where new drugs do not have very heavy adverse effects.

Polymorphic repeats in the androgen receptor gene: molecular markers of prostate cancer risk.

We analyzed the polymorphic (CAG)n and (GGN)n regions within the androgen receptor gene from participants in a population-based case-control study of prostate cancer in middle-aged (40-64 years) Caucasian men. The associations between repeat lengths and risk of prostate cancer and the effects of confounding and modifying factors, such as age, family history of prostate cancer, and body mass index, were evaluated. DNA was available for 301 cases and 277 controls. The overall age-adjusted relative odds of prostate cancer associated with the number of (CAG) repeats as a continuous variable was 0.97 [95% confidence interval (CI), 0.92-1.03], suggesting a 3% decrease in risk of prostate cancer for each additional (CAG) repeat. Further analyses identified several subgroups at increased risk. These were men with less than the median number of CAG repeats (< 22) that were younger [< 60 years; relative odds (RO), 1.47; 95% CI, 0.96-2.25], had an affected first-degree relative (RO, 1.59; 95% CI, 0.62-4.14), or were relatively thin (Quetelet index < 24.4; RO, 2.21; 95% CI, 1.07-4.69). Although only the latter result was statistically significant, these results are provocative and support the hypothesis that (CAG)n array length is a predictor of risk for prostate cancer. Similar analyses of (GGN)n showed that with the exception of men with a family history of prostate cancer and those in the highest quartile of body mass index, men with < or = 16 repeats had higher risk estimates than did men with > 16 repeats. Overall, those men who had < or = 16 repeats had a significant elevation in risk (RO, 1.60; 95% CI, 1.07-2.41). When both repeat lengths were considered jointly, the subgroup with two short repeats (CAG, < 22; GGN, < or = 16) had a 2-fold elevation in odds (RO, 2.05; 95% CI, 1.09-3.84) relative to those with two long repeats (CAG, > or = 22; GGN, > 16). These data suggest that determination of both androgen receptor repeats within germ-line DNA may be useful in assessing an individual's risk of developing prostate cancer.