Miljenko V. Pilepich

Phase III radiation therapy oncology group (RTOG) trial 86-10 of androgen deprivation adjuvant to definitive radiotherapy in locally advanced carcinoma of the prostate

PURPOSE To test the hypothesis that androgen ablation before and during radiotherapy for locally advanced carcinoma of the prostate may, by reducing tumor bulk and enhancing tumor cell kill, improve locoregional control and ultimately survival. METHODS AND MATERIALS The study was conducted from 1987 to 1991. Eligible patients were those with bulky tumors (T2--T4) with or without pelvic lymph node involvement and without evidence of distant metastases. They were randomized to receive goserelin, 3.6 mg every 4 weeks; and flutamide, 250 mg t.i.d. for 2 months before radiation therapy and during radiation therapy (Arm I), or radiation therapy alone (Arm II). Of 471 randomized patients, 456 were evaluable: 226 on Arm I and 230 on Arm II. RESULTS As of November 1999, the median follow-up has reached 6.7 years for all patients and 8.6 years for alive patients. At 8 years, androgen ablation has been associated with an improvement in local control (42% vs. 30%, p = 0.016), reduction in the incidence of distant metastases (34% vs. 45%, p = 0.04), disease-free survival (33% vs. 21%, p = 0.004), biochemical disease-free survival = PSA <1.5 (24% vs. 10%, p < 0.0001), and cause-specific mortality (23% vs. 31%, p = 0.05). However, subset analysis indicates that the beneficial effect of short-term androgen ablation appears preferentially in patients with Gleason score 2--6. In that population, there is a highly significant improvement in all endpoints, including survival (70% vs. 52%, p = 0.015). In patients with Gleason 7--10 tumors, the regimen has not resulted in a significant enhancement in either locoregional control or survival. CONCLUSION In patients with Gleason score 2--6 carcinoma of the prostate, a short course of androgen ablation administered before and during radiotherapy has been associated with a highly significant improvement in local control, reduction in disease progression, and overall survival.

Phase III trial of androgen suppression using goserelin in unfavorable-prognosis carcinoma of the prostate treated with definitive radiotherapy: report of Radiation Therapy Oncology Group Protocol 85-31.

PURPOSE Although androgen suppression results in a tumor response/remission in the majority of patients with carcinoma of the prostate, its potential value as an adjuvant has not been substantiated. MATERIALS AND METHODS In 1987, the Radiation Therapy Oncology Group (RTOG) initiated a randomized phase III trial of adjuvant goserelin in definitively irradiated patients with carcinoma of the prostate. A total of 977 patients had been accessioned to the study. Of these, 945 remained analyzable: 477 on the adjuvant arm and 468 on the observation arm. RESULTS Actuarial projections show that at 5 years, 84% of patients on the adjuvant goserelin arm and 71% on the observation arm remain without evidence of local recurrence (P < .0001). The corresponding figures for freedom from distant metastases and disease-free survival are 83% versus 70% (P < .001) and 60% and 44% (P < .0001). If prostate-specific antigen (PSA) level greater than 1.5 ng is included as a failure (after > or = 1 year), the 5-year disease-free survival rate on the adjuvant goserelin arm is 53% versus 20% on the observation arm (P < .0001). The 5-year survival rate (for the entire population) is 75% on the adjuvant arm versus 71% on the observation arm (P = .52). However, in patients with centrally reviewed tumors with a Gleason score of 8 to 10, the difference in actuarial 5-year survival (66% on the adjuvant goserelin arm v 55% on the observation arm) reaches statistical significance (P = .03). CONCLUSION Application of androgen suppression as an adjuvant to definitive radiotherapy has been associated with a highly significant improvement in local control and freedom from disease progression. At this point, with a median follow-up time of 4.5 years, a significant improvement in survival has been observed only in patients with centrally reviewed tumors with a Gleason score of 8 to 10.

Androgen deprivation with radiation therapy compared with radiation therapy alone for locally advanced prostatic carcinoma: a randomized comparative trial of the radiation therapy oncology group

OBJECTIVES Androgen deprivation therapy before and during radiation therapy could, by reducing tumor volume, increase local tumor control, disease-free survival, and overall survival in patients with locally advanced adenocarcinomas of the prostate. METHODS In a randomized controlled clinical trial, patients with large T2, T3, and T4 prostate tumors, but no evidence of osseous metastasis, were randomized to receive goserelin 3.6 mg subcutaneously every 4 weeks and flutamide 250 mg orally three times daily 2 months before and during the radiation therapy course (Arm I) compared with radiation therapy alone (Arm II). Pelvic irradiation was administered with 1.8 to 2.0 Gy per day to a total dose of 45 +/- 1 Gy followed by a boost to the prostate target volume to a total dose of 65 to 70 Gy. RESULTS Of 471 randomized patients, 456 were evaluable, 226 on Arm I and 230 on Arm II. With a median potential follow-up of 4.5 years, the cumulative incidence of local progression at 5 years was 46% in Arm I and 71% in Arm II (P < 0.001). The 5-year incidence of distant metastasis on Arms I and II was 34% and 41%, respectively (P = 0.09). Progression-free survival rates including normal prostate-specific antigen (PSA) levels for 396 patients with at least one PSA recorded were 36% in Arm I and 15% in Arm II at 5 years (P < 0.001). At this time, no significant difference in overall survival could be detected (P = 0.7). CONCLUSIONS Short-term androgen deprivation with radiation therapy results in a marked increase in local control and disease-free survival compared with pelvic irradiation alone in patients with locally advanced carcinoma of the prostate. Long-term surveillance is required to assess effects on overall survival.

Short-Term Neoadjuvant Androgen Deprivation Therapy and External-Beam Radiotherapy for Locally Advanced Prostate Cancer: Long-Term Results of RTOG 8610

PURPOSE Radiation Therapy Oncology Group (RTOG) 8610 was the first phase III randomized trial to evaluate neoadjuvant androgen deprivation therapy (ADT) in combination with external-beam radiotherapy (EBRT) in men with locally advanced prostate cancer. This report summarizes long-term follow-up results. MATERIALS AND METHODS Between 1987 and 1991, 456 assessable patients (median age, 70 years) were enrolled. Eligible patients had bulky (5 x 5 cm) tumors (T2-4) with or without pelvic lymph node involvement according to the 1988 American Joint Committee on Cancer TNM staging system. Patients received combined ADT that consisted of goserelin 3.6 mg every 4 weeks and flutamide 250 mg tid for 2 months before and concurrent with EBRT, or they received EBRT alone. Study end points included overall survival (OS), disease-specific mortality (DSM), distant metastasis (DM), disease-free survival (DFS), and biochemical failure (BF). RESULTS Ten-year OS estimates (43% v 34%) and median survival times (8.7 v 7.3 years) favored ADT and EBRT, respectively; however, these differences did not reach statistical significance (P = .12). There was a statistically significant improvement in 10-year DSM (23% v 36%; P = .01), DM (35% v 47%; P = .006), DFS (11% v 3%; P < .0001), and BF (65% v 80%; P < .0001) with the addition of ADT, but no differences were observed in the risk of fatal cardiac events. CONCLUSION The addition of 4 months of ADT to EBRT appears to have a dramatic impact on clinically meaningful end points in men with locally advanced disease with no statistically significant impact on the risk of fatal cardiac events.

Long-term treatment sequelae following external beam irradiation for adenocarcinoma of the prostate: analysis of RTOG studies 7506 and 7706☆

Significant late intestinal and urinary morbidity from external beam irradiation for adenocarcinoma of the prostate has been a constant concern of both the urologist and the radiation oncologist. We analyzed two large Radiation Therapy Oncology Group trials (7506 and 7706) using primary irradiation in the treatment of local or locoregional adenocarcinoma of the prostate to assess morbidity via the Radiation Therapy Oncology Group scoring scheme (grade 1-5). One thousand twenty patients were treated in total with a minimum follow-up of 7 years in the surviving patients. There was a 3.3% incidence of intestinal complications defined as grade 3 toxicity or more with .6% of patients experiencing bowel obstruction or perforation. Urinary complications defined as grade 3 toxicity or more were found in 7.7% of patients with only 0.5% experiencing morbidity that would require a major surgical intervention such as laparotomy, cystectomy, or prolonged hospitalization. Intestinal and urinary complications were evaluated in reference to several parameters that might have an impact on their incidence (i.e., previous laparotomy, stage of disease, hypertension, positive lymph nodes, previous transurethral resection, total dose, and energy of accelerator used). Only total dose (greater than 70 Gray) was found to have a significant impact on the incidence of the urinary complications. None of these factors had a significant impact on the incidence of intestinal complications. These data from two large multi-institutional trials represent a fair estimate of the actual incidence of major intestinal and urinary complications from external beam irradiation in the management of local and locoregional adenocarcinoma of the prostate. Since the incidence of these major complications remains very low, we believe that external beam irradiation remains an excellent alternative to radical prostatectomy in the management of these patients.

Updated results of the phase III Radiation Therapy Oncology Group (RTOG) trial 85-31 evaluating the potential benefit of androgen suppression following standard radiation therapy for unfavorable prognosis carcinoma of the prostate

PURPOSE To determine the potential advantage of androgen ablation following standard external-beam radiation therapy in patients with locally advanced (clinical or pathologic T3; clinical or pathologic node positive) carcinoma of the prostate. METHODS AND MATERIALS In 1987 the RTOG initiated a Phase III trial of long-term adjuvant goserelin in definitively irradiated patients with carcinoma of the prostate. A total of 977 patients were accrued to the study of which 945 remain analyzable: 477 on the adjuvant hormone arm (Arm I); and 468 on the radiation only arm (Arm II) with hormones initiated at relapse. The initial results were reported in the Journal of Clinical Oncology in 1997. RESULTS With a median follow up of 5.6 years for all patients and 6.0 years for living patients local failure at 8 years was 23% for Arm I and 37% for Arm II (p < 0.0001). Distant metastasis was likewise favorably impacted with the immediate use of hormonal manipulation with a distant metastasis rate in Arm I of 27% and 37% in Arm II (p < 0.0001). Disease-free survival (NED survival) and NED survival with PSA of 1.5 ng/mL (bNED) or less were both statistically significant in favor of the immediate hormone arm (both p < 0.0001). Cause-specific failure was not statistically different with a cause-specific failure of 16% for Arm I and 21% in Arm II (p = 0.23). Overall survival was likewise not statistically different between two arms, with a 49% overall survival at 8 years in Arm I and 47% in Arm II (p = 0.36). Subset analysis of centrally reviewed Gleason 8-10 patients who did not undergo prostatectomy showed that for patients receiving radiation therapy plus adjuvant hormones there was a statistically significant improvement in both absolute (p = 0.036) and cause-specific survival (p = 0.019). CONCLUSIONS Use of long-term adjuvant androgen deprivation in addition to definitive radiation therapy results in a highly significant improvement in regards to local control, freedom from distant metastasis, and biochemical free survival in unfavorable prognosis patients with carcinoma of the prostate.

Cardiovascular Mortality After Androgen Deprivation Therapy for Locally Advanced Prostate Cancer: RTOG 85-31

PURPOSE Gonadotropin-releasing hormone (GnRH) agonists are associated with greater risk of coronary heart disease and myocardial infarction in men with prostate cancer, but little is known about potential impact on cardiovascular mortality. We assessed the relationship between GnRH agonists and cardiovascular mortality in a large randomized phase III trial of men treated with or without adjuvant goserelin after radiation therapy (RT) for locally advanced prostate cancer. PATIENTS AND METHODS Between 1987 and 1992, 945 men with locally advanced prostate cancer were randomly assigned to RT and adjuvant goserelin or RT alone. Fine and Grays regression was used to evaluate treatment effect on cardiovascular mortality. Covariates included age, prevalent cardiovascular disease (CVD), hypertension, diabetes mellitus (DM), body mass index, race, Gleason score, stage, acid phosphatase level, prostatectomy history, and nodal involvement. RESULTS After a median follow-up of 8.1 years, there were 117 cardiovascular-related deaths but no treatment-related increase in cardiovascular mortality. At 9 years, cardiovascular mortality for men receiving adjuvant goserelin was 8.4% v 11.4% for men treated without adjuvant goserelin (Grays P = .17). In multiple regression analyses, treatment arm was not significantly associated with increased risk of cardiovascular mortality (adjusted hazard ratio [HR] = 0.73; 95% CI, 0.47 to 1.15; P = .16; when censoring at time of salvage goserelin therapy, HR = 0.99; 95% CI, 0.58 to 1.69; P = .97). Traditional cardiac risk factors, including prevalent CVD and DM, were significantly associated with greater cardiovascular mortality. CONCLUSION GnRH agonists do not seem to increase cardiovascular mortality in men with locally advanced prostate cancer. Further studies are warranted to evaluate adverse effects of GnRH agonists in men with lower cancer-specific mortality.

Elective pelvic irradiation in stage A2, B carcinoma of the prostate: analysis of RTOG 77-06☆

From 1978 to 1983 the Radiation Therapy Oncology Group conducted a study to evaluate the role of elective pelvic lymph node irradiation in carcinoma of the prostate. Eligible patients were those with clinical Stage A2 (occult disease with more than 3 positive chips and poorly differentiated tumor) and Stage B without clinical (lymphangiogram) or biopsy evidence of lymph node involvement. The patients were randomized to receive 6.5 weeks of either prostatic bed irradiation only 6500 cGy at 180-200 cGy per treatment or pelvic node irradiation to 4500 cGy with a boost of 2000 cGy to the prostatic bed bringing the total dose to 6500 cGy. As of February, 1988, the median follow up has been 7 years and there were 445 analyzable cases who were evaluated for local control, incidence of distant metastases, ned (no evidence of disease) survival and survival. The results of the study revealed no statistically significant benefit of elective pelvic irradiation.

Cardiovascular Mortality and Duration of Androgen Deprivation for Locally Advanced Prostate Cancer: Analysis of RTOG 92-02

OBJECTIVES Gonadotropin-releasing hormone agonists (GnRHa) are associated with greater risk of coronary heart disease and myocardial infarction in men with prostate cancer, but little is known about their potential effects on cardiovascular mortality. We assessed the relationship between duration of GnRHa therapy and cardiovascular mortality in a large randomized trial of men treated with short-term versus longer-term adjuvant goserelin and radiation therapy (RT) for locally advanced prostate cancer. METHODS From 1992 to 1995, 1554 men with locally advanced prostate cancer (T2c-4, prostate-specific antigen [PSA] <150 ng/ml) received RT and 4 mo of goserelin and then were randomized to no additional therapy (arm 1) or 24 mo adjuvant goserelin (arm 2) in a phase 3 trial (Radiation Therapy Oncology Group [RTOG] 92-02). Cox regression analyses were performed to evaluate the relationship between treatment arm and cardiovascular mortality. Covariates included age, prevalent cardiovascular disease (CVD), hypertension, diabetes (DM), race, PSA, Gleason score, and stage. RESULTS After median follow-up of 8.1 yr, 185 cardiovascular-related deaths had occurred. No increase in cardiovascular mortality occurred for men receiving a longer duration of goserelin. At 5 yr, cardiovascular mortality for men receiving longer-term adjuvant goserelin was 5.9% versus 4.8% with short-term goserelin (Grays p=0.16). In multivariate analyses, treatment arm was not significantly associated with increased risk of cardiovascular mortality (adjusted hazard ratio [HR]=1.09; 95% confidence interval [CI], 0.81-1.47; p=0.58; when censoring at time of salvage goserelin, HR=1.02, 95%CI, 0.73-1.43; p=0.9). Traditional cardiac risk factors, including age, prevalent CVD, and DM, were significantly associated with greater cardiovascular mortality. CONCLUSIONS Longer duration of adjuvant GnRHa therapy does not appear to increase cardiovascular mortality in men with locally advanced prostate cancer.

Four prognostic groups predict long-term survival from prostate cancer following radiotherapy alone on Radiation Therapy Oncology Group clinical trials.

PURPOSE Gleason score (GS), T stage, and pathologic lymph node status have been described as major independent predictors of death due to prostate cancer in men treated with external beam radiotherapy (XRT). In this analysis we combine these three factors to define prognostic subgroups that correlate with disease-specific survival (DSS) death from prostate cancer. METHODS AND MATERIALS Men entered on one of four Radiation Therapy Oncology Group (RTOG) Phase III randomized trials between 1975 and 1992, for clinically localized prostate cancer (CAP) (n = 1557), were selected for this analysis. Patients were included if: 1) they were evaluable, and eligible for the trial; 2) they received no hormonal therapy with their initial treatment; and 3) follow-up was available. For this study a DSS event was declared if: 1) death was certified as due to CAP; 2) death was due to complications of treatment; or 3) death was from unknown causes with active malignancy. The median follow-up for patients treated on early and late RTOG studies exceeded 11 and 6 years respectively. Subgroups were identified based on their pretreatment GS, T-stage, and lymph node such that patients with similar risk of dying from prostate cancer were combined. RESULTS By combining patients with similar DSS, four subgroups were identified. Risk Group 1 patients had a GS = 2-6, and T1-2Nx; Group 2: GS = 2-6, T3Nx; or GS = 2-6, N+, or GS = 7, T1-2Nx; Group 3: T3Nx, GS = 7; or N+, GS = 7, or T1-2Nx, GS = 8-10; and Group 4 patients were T3Nx, GS = 8-10, or N+, GS = 8-10. The 5-, 10-, and 15-year DSS was 96%, 86%, and 72%; 94%, 75%, and 61%; 83%, 62%, and 39%; and 64%, 34%, and 27% for Groups 1 through 4, respectively. CONCLUSIONS Recognition of these four risk groups provides a basis for estimating the long-term DSS for men treated with XRT alone and should facilitate the design of future prospective randomized trials.