The efficacy of PSA density for the early detection of prostate cancer

OBJECTIVE: We studied on the efficacy of prostate specific antigen density (PSAD) for the detection of prostate cancer among patients with intermediate serum PSA levels. MATERIALS AND METHODS: Transrectal ultrasonography (TRUS) and transrectal prostate biopsy were performed in 103 patients whose PSA levels were 10 ng/ml or less despite positive digital rectal examination(DRE) or whose PSA levels were intermediate (4 to 10 ng/ml). Prostate volume was determined by TRUS and PSAD was calculated (serum PSA divided by volume of entire prostate volume). The rate of positive biopsy was compared with PSAD (more than 0.15 versus less than 0.15), DRE (positive versus negative) and patient's age (more than 61 versus 60 or less). RESULTS: The overall cancer detection rate was 43.7% in this study. There was no apparent correlation between patient's age and cancer detection rate when the patient's age was more than 61. DRE itself was not effective for the detection of prostate cancer in the patients whose PSA level was 10 ng/ml or less. Independent of DRE findings, the rate of positive biopsy was double in the patients whose PSAD was more than 0.15, compared with the patients whose PSAD was less than 0.15. CONCLUSIONS: For the early detection of prostate cancer, PSA density may be useful in the selection of patients for transrectal prostate biopsy.     

Bone metabolism and phosphorus metabolism in patients with prostate cancer: paracrine and endocrine effects produced by prostate neoplasm

We examined whether paracrine factors produced by prostate cancer cells can modulate bone metabolism in proportion to the volume of cancer cells in bone metastasis. Endocrine factors produced by prostate cancer cells affect both phosphate and 1,25-dihydroxyvitamin D metabolisms. Levels of urine pyridinoline (U-Pyr) excretion and serum carboxy-terminal propeptide of type 1 procollagen (P1CP) in patients with bone metastasis were significantly higher than those in patients without bone metastasis (P < 0.05). In patients with bone metastasis (n = 17), serum prostate-specific antigen (PSA) levels were significantly correlated with the levels of U-Pyr and urine deoxypyridinoline (U-dPyr) excretion, serum cross-linked carboxyterminal telopeptide of type 1 collagen (1CTP), and P1CP levels (p < 0.05). However, serum PSA levels were not correlated with U-Pyr, U-dPyr excretions, serum 1CTP and P1CP levels in patients without bone metastasis. Therefore, prostate cancer cells appear to have some paracrine effects on bone cells. In controls (n = 15), serum 1,25-dihydroxyvitamin D levels (1,25-(OH)2D) were inversely correlated with serum phosphorus levels (P < 0.01). In prostate cancer patients with bone metastasis, the ability to regulate the serum 1,25-(OH)2D levels in response to serum phosphorus levels is lost. These results suggest that endocrine factors produced by prostate cancer cells disturb the regulation of serum 1,25-(OH)2D in response to serum phosphorus levels.     

Argininosuccinate lyase: a new autoantigen in liver disease

OBJECTIVES: To (1) determine if patient age and total prostate-specific antigen (PSA) levels could enhance the ability of percent free PSA to distinguish prostate cancer from benign prostate disease within the 4.0 to 20 ng/mL total PSA range; (2) define the probability of prostate cancer based on patient age, total PSA, and percent free PSA; and (3) define a probability cutoff that distinguishes benign from malignant prostate disease. METHODS: The 3773 urologically referred patients with serum PSA values between 4.0 and 20 ng/mL had a sextant biopsy diagnosed as either prostatic carcinoma (1234) or benign prostatic disease (2539) within 60 days of serum specimen collection. We created a logistic regression model, using patient age, total PSA, and percent free PSA, to assign a probability of prostate cancer, and tested the model on an additional data set (525 patients) to calculate sensitivity and specificity. RESULTS: An 18% probability cutoff detected 95% of malignant biopsies and identified 34% of negative biopsies in the validation set. This approach yielded an 11% percentage point increase in specificity over percent free PSA alone. A 20% probability cutoff detected 90% of malignant cases and identified 42% of negative biopsies. CONCLUSIONS: A prostate cancer probability based on age, total PSA, and percent free PSA is more effective than percent free PSA alone in differentiating benign prostate disease from prostate cancer. This model may assist physicians and patients regarding the need for biopsy.     

Free-to-total prostate specific antigen ratio as a single test for detection of significant stage T1c prostate cancer

PURPOSE: We investigated whether impalpable, invisible (stage T1c) but significant prostate cancer can be detected better by determining the free-to-total prostate specific antigen (PSA) ratio of equivocal PSA serum levels. MATERIALS AND METHODS: The specificity of free-to-total PSA ratio using research monoclonal enzyme immunoassays was compared to that of PSA greater than 4.0 ng./ml. in 117 consecutive patients with PSA 3 to 15 ng./ml. (Hybritech Tandem-R assay) due to untreated benign prostatic hypertrophy or prostate cancer. Of the patients 77% underwent adenectomy or radical prostatectomy with thorough pathological evaluation of surgical specimens. RESULTS: Benign prostatic hypertrophy had a greater median free-to-total PSA ratio than stages T1c and T2 or greater prostate cancer (0.16 versus 0.09 and 0.11 ng./ml., p = 0.0001 and p = 0.0268, respectively). In stage T1c prostate cancer, areas under receiver operating characteristic curves were 0.58 and 0.84 for PSA and free-to-toal PSA ratio, and free-to-total PSA ratio correlated with prostate volume (r = 0.49, p = 0.005) and Gleason score (r = -0.37, p = 0.036). Pathologically, 84% of stage T1c cancers were significant and comparable to stage T2 or greater cancers. CONCLUSIONS: Free-to-total PSA ratio enhances the efficacy of PSA measurement by improving specificity for detecting impalpable, invisible but significant stage T1c prostate cancer.     

The effect of prostate volume, age, total prostate specific antigen level and acute inflammation on the percentage of free serum prostate specific antigen levels in men without clinically detectable prostate cancer

PURPOSE: We determine the influence of age, prostate volume, total serum prostate specific antigen (PSA) level and histological evidence of acute inflammation in biopsy specimens on the percent free serum PSA level in men without clinically detectable prostate cancer. MATERIALS AND METHODS: We studied 70 men with total PSA levels of 2.6 to 9.9 ng./ml. who had undergone at least 3 sets of prostate biopsies that were negative for cancer as part of our PSA based prostate cancer screening program. Total and free PSA levels were measured using Hybritech immunoassays. Prostate volume and the presence of acute inflammation were determined from the most recent transrectal ultrasonography and prostate needle biopsy. RESULTS: Percent free PSA levels correlated significantly with age (r = 0.48, p = 0.0001) and prostate volume (r = 0.44, p = 0.0002) but not with total PSA (r = 0.04, p = 0.7). The mean percent free PSA did not differ for those with or without acute inflammation. Multivariate regression models demonstrated that age and prostate volume were significant predictors of percent free PSA. CONCLUSIONS: Among men without detectable prostate cancer and a total PSA level between 2.6 and 9.9 ng./ml. percent free serum PSA was higher in older men and in men with a larger prostate gland but was not influenced by total PSA level or the presence of acute inflammation in the prostatic biopsy specimen.     

Prostate cancer volume adds significantly to prostate-specific antigen in the prediction of early biochemical failure after external beam radiation therapy

PURPOSE: A new clinical pretreatment quantity that closely approximates the true prostate cancer volume is defined. METHODS AND MATERIALS: The cancer-specific prostate-specific antigen (PSA), PSA density, prostate cancer volume (VCa), and the volume fraction of the gland involved with carcinoma (VCafx) were calculated for 227 prostate cancer patients managed definitively with external beam radiation therapy. 1. PSA density = PSA/ultrasound prostate gland volume. 2. Cancer-specific PSA = PSA - [PSA from benign epithelial tissue] 3. VCa = Cancer-specific PSA/[PSA in serum per cm3 of cancer] 4. VCafx = VCa/ultrasound prostate gland volume A Cox multiple regression analysis was used to test whether any of these clinical pretreatment parameters added significantly to PSA in predicting early postradiation PSA failure. RESULTS: The prostate cancer volume (p = 0.039) and the volume fraction of the gland involved by carcinoma (p = 0.035) significantly added to the PSA in predicting postradiation PSA failure. Conversely, the PSA density and the cancer-specific PSA did not add significantly (p > 0.05) to PSA in predicting postradiation PSA failure. The 20-month actuarial PSA failure-free rates for patients with calculated tumor volumes of < or = 0.5 cm3, 0.5-4.0 cm3, and > 4.0 cm3 were 92, 80, and 47%, respectively (p = 0.00004). CONCLUSION: The volume of prostate cancer (VCa) and the resulting volume fraction of cancer both added significantly to PSA in their ability to predict for early postradiation PSA failure. These new parameters may be used to select patients in prospective randomized trials that examine the efficacy of combining radiation and androgen ablative therapy in patients with clinically localized disease, who are at high risk for early postradiation PSA failure.     

National trends in the epidemiology of prostate cancer, 1973 to 1994: evidence for the effectiveness of prostate-specific antigen screening

OBJECTIVES: The use of prostate-specific antigen (PSA) to screen for prostate cancer remains controversial. Although it is still too early to measure directly the effects of PSA screening on mortality, we examined changes in the epidemiology of prostate cancer to determine if there is other evidence of the effectiveness of PSA as a screening tool. METHODS: We examined trends in age at diagnosis, and age-adjusted trends in stage and grade at diagnosis, for 140,936 white and 15,662 African American men diagnosed with prostate cancer from 1973 to 1994 in the National Cancer Institute's Surveillance Epidemiology and End Results data base. RESULTS: We found a significant downward trend in age at diagnosis, concomitant with a downward shift in stage of disease at diagnosis, starting with the advent of the PSA era in the late 1980s. We noted most cancers detected since the PSA era to be moderately well differentiated (International Classification of Diseases of the World Health Organization grade 2; Gleason score 5, 6, 7) and organ confined. Although findings were similar for both whites and African Americans, African Americans experienced a greater increase in poorly differentiated disease than did whites. CONCLUSIONS: Changes in the epidemiology of prostate cancer since the advent of the PSA era are consistent with the introduction of an effective screening test. This is evidenced by an increase in detection of significant prostate cancer in individuals who will likely benefit from treatment.     

The predictive value of race as a clinical prognostic factor among patients with clinically localized prostate cancer: a multivariate analysis of positive surgical margins

OBJECTIVES: Several investigators have reported that African-American men with clinically localized prostate cancer have poorer survival than do white men. In addition, prostate cancer in African-American men is commonly diagnosed at a more advanced stage of disease. Is race or ethnicity predictive of outcome of clinically localized prostate cancer? It has been reported that the presence of positive surgical margins significantly influences time to progression independently of other prognostic factors. Therefore, we have elected to conduct a multivariate analysis of clinical factors including race as potential predictors of positive surgical margin outcome. METHODS: We studied 369 consecutive men (120 African-American and 249 white) who had radical prostatectomies at a single institution. Comparisons by race of Gleason score, stage, presence of positive surgical margins, and mean preoperative prostate-specific antigen (PSA) level were carried out. RESULTS: Our data demonstrate that African-American men have more pathologically locally advanced prostate cancer than do white American men: 69% among blacks compared with 57% among whites. However, the difference in rate of positive surgical margins between blacks and whites is statistically significant: 58% among blacks versus 40% among whites (P = 0.002). Four factors were predictive of positive surgical margins: preoperative PSA level, race, clinical stage, and Gleason score. CONCLUSIONS: We have demonstrated that race is an independent predictor of positive surgical margins among patients with clinically localized prostate cancer and should be included in treatment decisions. In addition, the risk of positive surgical margins increases noticeably when PSA is greater than 10 ng/mL.     

Surgical control of clinically localized prostate carcinoma is equivalent in African-American and white males

BACKGROUND: Few studies have compared the outcome of radical prostatectomy between African-American males (AAM) and white males, and the results of the few studies that have are conflicting. Therefore, the authors examined the impact of radical surgery on localized prostate carcinoma in both patient populations, and assessed whether stratification by pathologic extent of local disease would yield an equivalent outcome. METHODS: Prostate specific antigen (PSA) failure and carcinoma-associated death rates were assessed in 1319 patients (115 AAM and 1204 white males), 872 of whom had a pretreatment serum PSA level taken. The percent of prostate involved by tumor, tumor wet weight, and DNA ploidy status were available in 755, 522, and 638 patients, respectively. RESULTS: AAM were diagnosed at an earlier age than white males (62.8 years vs. 65.4 years; P = 0.0001). The distribution of pathologic extent of local disease was similar in both races, and AAM had a statistically higher rate of tumors with a Gleason sum of 7-10 at surgery than white males (64% vs. 46%). Race did not play a role in the outcome of patients with organ-confined or specimen-confined tumors. However, in patients with positive surgical margins, the median time to PSA failure and the median carcinoma-associated survival were less in AAM compared with white males. Tumor volume was significantly larger in AAM compared with white males. After multivariate adjustment for the pathologic extent of local disease, tumor grade at surgery, preoperative PSA, tumor volume, and age, African-American race was not a significant prognostic indicator for carcinoma-associated death and PSA failure (P = 0.17 and 0.14, respectively). CONCLUSIONS: The outcome of radical prostatectomy was similar in both racial groups, although AAM with positive surgical margins tended to fail earlier than white males, suggesting greater biologic aggressiveness of residual disease. Because local extent of disease impacts on PSA failure and survival, and because the disease appears to present earlier in AAM, the AAM population may benefit from early detection programs.     

Tumor volume and prostate specific antigen: implications for early detection and defining a window of curability

PURPOSE: We attempted to determine the relationship between tumor volume and extent of localized prostate cancer, as well as the interrelationships of tumor volume with prostate specific antigen (PSA) level, grade and stage. MATERIALS AND METHODS: Serial whole mount sections from 128 patients who underwent radical prostatectomy were analyzed using a computer assisted volumetric program. Statistical evaluations were performed using logistic and simple regression analyses. RESULTS: The median tumor volume for patients with organ confined disease was significantly lower than for those with extraprostatic extension (1.25 versus 2.94 cc, p < 0.001). A significant incidence (32%) of small volume cancers (0.51 to 1.5 cc) exhibited extraprostatic extension while that of extraprostatic disease increased to 66% for patients with tumor volumes greater than 1.5 cc (p < 0.001). Of men with clinically significant (greater than 0.5 cc, or Gleason score 7 or more) pathological stage B disease 31% had a serum PSA value of 4 ng./ml. or less. Multivariate regression analysis of tumor volume as a function of PSA, grade and stage demonstrated that log PSA had the strongest association with tumor volume. Goodness-of-fit analysis (coefficient of determination) revealed that only 40 to 50% of the PSA levels are explained by tumor volume. CONCLUSIONS: These data suggest that the window of curability for prostate cancer decreases significantly once the tumor grows to a volume greater than 1.5 cc, and that grade and tumor volume are more significantly related to stage than PSA.     

Correlation between bone metabolic markers and bone scan in prostatic cancer

PURPOSE: We examined the correlation between bone metabolic markers and bone scintigraphy in prostatic cancer. MATERIALS AND METHODS: Osteoblastic and osteoclastic markers, prostate specific antigen (PSA) and bone scans were investigated in 83 specimens from 70 patients with prostatic cancer, including 32 with and 38 without bone metastasis. RESULTS: All markers except for osteocalcin were significantly greater in patients with than without bone metastasis. Pyridinoline cross-linked carboxyterminal telopeptide, an osteoclastic marker, reflected the extent of bone metastasis more accurately than PSA and other bone markers. CONCLUSIONS: Pyridinoline cross-linked carboxyterminal telopeptide might assist PSA and bone scintigraphy in monitoring metastatic bone activity of prostatic cancer.     

Exposure of hepatic sinusoidal mononuclear cells to UW solution in situ but not ex vivo induces apoptosis

OBJECTIVES: To determine the influence of race or ethnicity on serum prostate-specific antigen (PSA) levels and PSA density (PSAD) in a population of healthy men without clinically evident prostate cancer. METHODS: This retrospective study was conducted between January 1988 and January 1993. The serum PSA levels were measured in 859 men (586 African Americans, 142 whites, and 131 Hispanics) who were participants in a prostate cancer screening program or had urinary symptoms suggestive of prostate gland pathology. All men underwent a detailed clinical examination, including digital rectal examination, serum PSA determination, and transrectal ultrasound (TRUS). None of the subjects included had clinical or TRUS evidence of prostate cancer (furthermore, 283 men were pathologically proved to be cancer-free by prostate biopsies). Serum PSA levels and PSA densities as a function of each individual's ethnic background were determined. RESULTS: The mean serum PSA level in African Americans was 2.1 ng/mL, which was significantly higher than that of whites (mean PSA of 1.53 ng/mL) and Hispanics (mean PSA of 1.83 ng/mL) (P = 0.003). Similar differences among the three groups were observed in PSA density (the mean PSAD was 0.078, 0.057, and 0.065 for African Americans, whites, and Hispanics, respectively). A separate analysis for the biopsy-negative men was performed, and the findings were consistent with the observations for the entire study group. After adjustment for age and prostate volume, the differences remained statistically significant. CONCLUSIONS: Among men without evidence of prostate cancer, African Americans have higher serum PSA levels and PSA densities than do whites or Hispanics. Race or ethnicity was an independent factor that affected serum PSA levels even after adjustment for age and prostate volume.     

Evaluation of 6 weeks treatment of terbinafine in tinea unguium in a double-blind trial comparing 6 and 12 weeks therapy. The Lagos V Study Group

OBJECTIVES: This study sought to characterize the postoperative prostate-specific antigen (PSA) doubling time and time to biochemical recurrence in patients who have failed radical prostatectomy. METHODS: Of 539 consecutive patients who underwent radical prostatectomy between 1984 and 1992, postoperative PSA levels in 80 initially became undetectable (less than 0.07 ng/mL) before eventually increasing, as evidenced by rising PSA levels above the residual cancer detection limit of the Tosoh AIA-600 immunoassay run in the ultrasensitive mode (i.e., 0.07 ng/mL or higher). The PSA doubling time and time to biochemical recurrence were calculated for each of the 80 patients and were correlated with the histopathologic variables from the operative specimen. RESULTS: Postoperative PSA doubling times were predicted by the extent of capsular penetration, percent Gleason grade 4 or 5, lymph node involvement, and tumor volume on univariate analysis and by capsular penetration, percent Gleason grade 4 or 5, lymph node involvement, and patient age on multivariate analysis. Times to recurrence were predicted by the presence of positive margins and percent Gleason grade 4 or 5 in both univariate and multivariate regression models. The PSA doubling time did not correlate with recurrence time. The median PSA doubling time for all patients was 284 days, and the median time to recurrence was 648 days. CONCLUSIONS: These results demonstrate that PSA doubling time and recurrence time are indicative of different biologic characteristics of recurrent prostate cancer: Doubling time appears to represent the aggressiveness of the original prostate cancer, whereas time to recurrence reflects the extent of residual postoperative disease. This information should aid in the selection of men who need greater vigilance during postoperative surveillance.     

Prostate specific antigen: its proper diagnostic use

A TISSUE MARKER: Prostate specific antigen (PSA) is a tissue marker and not a tumor marker. When ordered for the right situation, i.e. when the clinical presentation is compatible with prostatic cancer, PSA assay can be a remarkable tool for early diagnosis and beneficial therapeutic care. IN PATIENTS OVER 70: A PSA assay is not necessarily indicated for men over 70 years of age unless digital exploration of the prostate or other signs suggest prostatic disease. IN PATIENTS UNDER 70: In patients whose life expectancy is greater than 10 to 15 years, serum PSA above the laboratory's upper limit for normal is an indication for ultrasonographic exploration of the prostate with systematic biopsy.     

Free-to-total prostate-specific antigen (PSA) ratio improves the specificity for detecting prostate cancer in patients with prostatism and intermediate PSA levels

OBJECTIVE: To investigate the clinical significance of the free-to-total prostate-specific antigen (PSA) ratio in improving the specificity of PSA measurement for detecting prostate cancer within the diagnostic intermediate range (4-10 ng/mL total PSA) in patients referred for the treatment of urinary symptoms. PATIENTS AND METHODS: Serum samples were obtained from 333 consecutive patients with obstructive and irritative urinary symptoms. Of these men, 114 had total PSA levels of 4-10 ng/mL; 22 had prostate cancer (group 1) and 71 had benign prostatic hyperplasia (BPH, group 2). Group 3 consisted of 21 patients with BPH and a chronic indwelling catheter. The concentrations of free and total PSA (ProStatus, Wallac Oy, Turku, Finland) and PSA complexed to alpha-1-antichymotrypsin were measured and the free-to-total PSA ratio calculated. All patients under 70 years of age or with suspicious findings on digital rectal examination or transrectal ultrasonography underwent ultrasound-guided sextant prostate biopsies. Of the 114 patients, 105 (92%) underwent transurethral resection of the prostate and six (5%) radical retropubic prostatectomy. RESULTS: Patients in group 1 had significantly lower median free PSA concentrations (0.78 ng/mL vs 1.13 ng/mL, P < 0.001) and a lower free-to-total PSA ratio (12.1% vs 19.9%, P < 0.001) than those in group 2. The differences were similar between group 1 and group 3 (median free PSA in group 3, 1.06 ng/mL, P = 0.03, and free-to-total PSA ratio 18.7%, P = 0.007). There were no significant differences between patients in groups 2 and 3. The free-to-total PSA ratio had a higher specificity than total PSA at all sensitivity levels, e.g. a threshold free-to-total PSA ratio of 0.20 detected 91% of cancers and spared 48% (group 2) or 46% (group 3) from unnecessary biopsies. The area under the receiver operating characteristic curve for group 1 vs group 2 was 0.56 (total PSA) and 0.78 (free-to-total PSA ratio) and for group 1 vs group 3 was 0.56 (total PSA) and 0.81 (free-to-total PSA ratio). CONCLUSION: In those patients with extensive symptoms from BPH and requiring surgical treatment, the free-to-total PSA ratio improves the specificity for detecting prostate cancer in the diagnostic 'grey zone' of 4-10 ng/mL total PSA. This improvement occurred in patients with or without a chronic indwelling catheter for urinary retention.     

Prostate-specific antigen, a serine protease, facilitates human prostate cancer cell invasion

Human prostatic epithelial cells constitutively secrete prostate-specific antigen (PSA), a kallikrein-like serine protease, which is a normal component of the seminal plasma. PSA is currently used as a specific diagnostic marker for the early detection of prostate cancer. We demonstrate that PSA degrades extracellular matrix glycoproteins fibronectin and laminin and, thus, may facilitate invasion by prostate cancer cells. Blocking PSA proteolytic activity with PSA-specific mAb results in a dose-dependent decrease in vitro in the invasion of the reconstituted basement membrane Matrigel by LNCaP human prostate carcinoma cells which secrete high levels of PSA. A novel PSA-SDS-PAGE zymography method for the detection of matrix degrading ability of PSA is also described. We propose that: (a) because of the dysplastic cellular disorganization in early neoplastic lesions called prostatic intraepithelial neoplasia (PIN), PSA may be secreted not only at the luminal end but also, abnormally, at the cell-basement membrane interface, causing matrix degradation and facilitating invasion; and (b) PSA, along with urokinase, another serine protease secreted by prostatic epithelium, may be involved in the proteolytic cascade during prostate cancer invasion and metastasis. The discovery of the extracellular matrix degrading ability of PSA not only makes it a marker for early detection but also a target for prevention and intervention in prostate cancer.     

Perioperative coagulopathy in patients undergoing primary cytoreduction

BACKGROUND: This study was performed to determine the frequency of a perioperative coagulopathy in patients undergoing primary cytoreduction for ovarian cancer or carcinoma of the peritoneum and to identify variables that might predict this phenomenon. METHODS: A retrospective review of 90 patients undergoing primary cytoreduction for ovarian cancer or carcinoma of the peritoneum was performed at Cedars Sinai Medical Center. Univariate analysis was performed to test the relationship between 15 variables and coagulopathy status. RESULTS: Six patients (6.7%) developed a perioperative coagulopathy that was unrelated to preoperative subcutaneous heparin or dilution. Coagulation disturbances developed intraoperatively before packed erythrocyte replacement equivalent to one blood volume. Four patients (4.4%) required a repeat laparotomy due to continued postoperative bleeding unresponsive to blood component replacement. Vascular pedicles were not the cause of bleeding in any patient. Univariate analysis demonstrated a significant association between perioperative coagulopathy and the following variables: ascites volume (P = 0.009), estimated blood loss (P = 0.002), preoperative serum albumin less than 3.5 g/dl (P < 0.0001), and metastasis greater than 10 cm (P = 0.033). CONCLUSIONS: Patients undergoing primary cytoreduction who have ascites, preoperative serum albumin less than 3.5 g/dl, or metastases greater than 10 cm may be at increased risk for development of a perioperative coagulopathy.     

Bicalutamide for advanced prostate cancer: the natural versus treated history of disease

PURPOSE: To determine the therapeutic effects of bicalutamide 200 mg in patients with prostate cancers of different hormone sensitivities. METHODS: Patients with progressive prostate cancer were treated with bicalutamide 200 mg daily. Before treatment, patients' tumors were classified on the basis of prior hormone exposure and by serum testosterone levels into androgen-dependent and androgen-independent groups. Prior exposure to flutamide and response to flutamide withdrawal was also considered. Outcomes were reported independently on the basis of posttherapy changes in prostate-specific antigen (PSA), measurable disease, and radionuclide bone scans. RESULTS: Outcomes varied by prior hormone exposure as a higher proportion of patients with progression of androgen-dependent tumors showed posttherapy PSA decreases of more than 50% or more than 80%, measurable disease regression, and improvement on radionuclide bone scans than did patients with androgen-independent progression. Within the category of androgen-independent progression, clinical benefit was observed in patients who had previously progressed on flutamide, independent of the response to flutamide withdrawal. Patients who had progressed on a gonadotropin-releasing hormone (GnRH) analog alone had a low response proportion, whereas those who progressed after two or more hormone therapies did not respond. Overall, the drug was well tolerated. After progression on bicalutamide monotherapy, one third of patients with androgen-dependent progression responded to medical castration with a GnRH analog. CONCLUSION: Classifying patient tumors on the basis of prior hormone exposure permits a more precise estimate of the potential benefit of a specific hormone therapy for the individual patient. The precision is further increased by reporting the effects of a drug on each parameter of disease independently. The difference in outcomes for patients with androgen-independent progression suggests that the specific hormone therapy administered and the response to that therapy can influence the biology of the relapsing tumor and the sensitivity to subsequent therapies. The sensitivity to bicalutamide after progression on flutamide deserves further study.