p53 status and prognosis of locally advanced prostatic adenocarcinoma: a study based on RTOG 8610.

BACKGROUND: The p53 tumor suppressor gene (also known as TP53) is one of the most frequently mutated genes in human cancer. Several studies have shown that p53 mutations are infrequent in prostate cancer and are associated with advanced disease. PURPOSE: We assessed the prognostic value of identifying abnormal p53 protein expression in the tumors of patients with locally advanced prostate cancer who were treated with either external-beam radiation therapy alone or total androgen blockade before and during the radiation therapy. METHODS: The study population consisted of a subset of patients entered in Radiation Therapy Oncology Group protocol 8610 ("a phase III trial of Zoladex and flutamide used as cytoreductive agents in locally advanced carcinoma of the prostate treated with definitive radiotherapy"). Immunohistochemical detection of abnormal p53 protein in pretreatment specimens (i.e., needle biopsies or transurethral resections) was achieved by use of the monoclonal anti-p53 antibody DO7; specimens in which 20% or more of the tumor cell nuclei showed positive immunoreactivity were considered to have abnormal p53 protein expression. Associations between p53 protein expression status and the time to local progression, the incidence of distant metastases, progression-free survival, and overall survival were evaluated in univariate (logrank test) and multivariate (Cox proportional hazards model) analyses. Reported P values are two-sided. RESULTS: One hundred twenty-nine (27%) of the 471 patients entered in the trial had sufficient tumor material for analysis. Abnormal p53 protein expression was detected in the tumors of 23 (18%) of these 129 patients. Statistically significant associations were found between the presence of abnormal p53 protein expression and increased incidence of distant metastases (P = .04), decreased progression-free survival (P = .03), and decreased overall survival (P = .02); no association was found between abnormal p53 protein expression and the time to local progression (P = .58). These results were independent of the Gleason score and clinical stage. A significant treatment interaction was detected with respect to the development of distant metastases: Among patients receiving both radiation therapy and hormone therapy, those with tumors exhibiting abnormal p53 protein expression experienced a reduced time to the development of distant metastases (P = .001); for patients treated with radiation therapy alone, the time to distant metastases was unrelated to p53 protein expression status (P = .91). CONCLUSIONS: Determination of p53 protein expression status yield significant, independent prognostic information concerning the development of distant metastases, progression-free survival, and overall survival for patients with locally advanced prostate cancer who are treated primarily with radiation therapy. IMPLICATIONS: The interaction of radiation therapy plus hormone therapy and abnormal p53 protein expression may provide a clinical link to experimental evidence that radiation therapy and/or hormone therapy act, at least in part, by the induction of apoptosis (a cell death program) and suggests that this mechanism may be blocked in patients whose tumors have p53 mutations.

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.

Postoperative radiotherapy in the treatment of extremity soft tissue sarcomas.

From 1966 to 1983, 50 patients with extremity soft tissue sarcomas were treated with wide local excision and postoperative radiotherapy at the Mallinckrodt Institute of Radiology. The median follow-up was 70 months (range 28 to 168). Grade was the most significant factor affecting survival: all 11 patients with well differentiated tumor survived versus 6/8 patients with moderate and 17/31 patients with poorly differentiated tumors (p less than 0.01). In addition, lymph node involvement at diagnosis conferred a worse prognosis with only 2/5 patients alive after treatment (p less than 0.05). Eleven of 50 (22%) failed locally. Factors affecting local control included gross residual tumor after operation and limited treatment volume. Among the 35 patients who did not have gross residual tumor or limited treatment volume, two patients who received less than 5000 cGy failed locally versus 1/18 patients who received between 5000-6000 cGy and 2/15 patients who received more than 6000 cGy. Microscopically positive margins and a volume encompassing less than the total muscular compartment was not associated with an increase in the incidence of local failure. Eight patients developed local complication: five due to retreatment for local recurrence. Overall, 24/26 patients who are alive have had their limbs preserved with normal function.

Tumor control in definitive irradiation of localized carcinoma of the prostate.

At the Mallinckrodt Institute of Radiology, Washington University, 343 patients with carcinoma of the prostate were treated with definitive radiotherapy. All patients are available for minimal 3 year follow-up; the median period of observation is 5.2 years. The incidence of pelvic recurrence with or without distant metastases was 0% in 10 patients with Stage A2, 11% in 113 patients with Stage B, 34% in 204 patients with Stage C, and 40% in 16 patients with Stage D1. There was no significant difference in pelvic tumor control when correlated with the degree of differentiation of the tumors in each stage. In Stage B, patients who exhibited complete regression 3 months after completion of therapy had a pelvic failure rate of 5%, those with 50-75% regression-8% and less than 50% regression-18%. In Stage C, patients with more than 50% tumor regression had a pelvic failure rate of 25%, in contrast to 37% when less than 50% regression was noted at 3 months after completion of irradiation. However, there was no correlation between tumor regression and NED survival. In patients with Stage B, there was no significant correlation between doses of irradiation ranging from 6000 to 7000 cGy and pelvic tumor control. In Stage C, patients receiving doses higher than 6500 cGy had a probability of failure rate in the pelvis of 25% (40/173), in comparison with 44% with doses between 6000-6500 cGy (15/32). The 10 year NED survival for Stage A2 was 100%, Stage B-70%, and Stage C-40%. In Stage B, there was no correlation between local tumor control and 5 year overall survival. However, at 10 years 88 patients without evidence of local failure or distant metastases had a survival rate of 70% in contrast to only 25% if they recurred. In Stage C, 110 patients without local recurrence or distant metastases had a 40% 10 year survival in contrast to 20% in 55 patients who had pelvic recurrence (with or without distant metastases) and 39 patients with distant metastases only. In 105 patients with Stage B tumor controlled in the pelvis, the incidence of distant metastases was 16%, in contrast to 50% in eight patients with pelvic failure. In Stage C, only 26% of 149 patients with pelvic tumor controlled developed distant disease, versus 60% in 55 patients failing in the pelvis. Ninety-five percent of the pelvic failures and 80% of the distant metastases appeared within 5 years after therapy. The administration of hormones did not significantly influence either the probability of pelvic tumor control or the appearance of distant metastases.

Postoperative irradiation in carcinoma of the prostate.

Twenty-eight patients received postoperative radiotherapy with curative intent following either radical prostatectomy (18 patients) or enucleative prostatectomy (10 patients). In patients undergoing radical prostatectomy, the indications for postoperative radiotherapy included positive margins in 13, "close" margins in 2, and seminal vesicle involvement in 3 patients. The majority of patients (82%) received total dose to the prostatic bed in excess of 6500 rad. In over 80% of the patients, the pelvic lymphatics are also treated (to a total dose of 4000-5000 rad). Minimum follow-up is one year, maximum is 10 years, average 54 months, median 41 months. Local recurrence was observed in only 1 patient, who was treated post-enucleation. All of the patients irradiated after radical prostatectomy clinically remained disease-free locally. Approximately one-half of the patients in both the enucleation and radial prostatectomy groups developed evidence of distant metastases. The complications of treatment have been comparable to those in patients treated with radiotherapy only. The continence status has not been affected significantly. All patients (5 in the radical prostatectomy group and 2 in the enucleation group) with incontinence following completion of radiotherapy had documented impairment of continence prior to radiotherapy. Postoperative radiotherapy administered following either radical or enucleative prostatectomy was tolerated well and resulted in excellent local control.

Computed tomography in definitive radiotherapy of prostatic carcinoma, part 2: definition of target volume.

Pretreatment computed tomography (CT) scanning of the pelvis was performed in 100 consecutive patients with carcinoma of the prostate treated with external irradiation (82 patients) or interstitial I125 (18 patients). Treatment plan modifications prompted by CT scan findings were most frequent in patients with (clinical) involvement of the seminal vesicles in whom the conventional treatment planning often resulted in an underestimate of tumor volume. Seventeen of 32 (53%) such patients required an enlargement of treatment fields to adequately encompass the target volume. Using skeletal landmarks as reference, the dimensions of the prostate, seminal vesicles and the detectable tumor and their topographic relationships were systematically tabulated. These measurements provide a basis for the definition of the target volume in patients with carcinoma of the prostate in whom CT scans might not be available.

Carcinoma of the nasal cavity--results of primary and adjuvant radiotherapy.

Carcinomas of the nasal cavity are uncommon and the reported experience with radiotherapy is scarce. From 1969-1984, 62 patients with carcinoma of the nasal cavity received radiotherapy as all or part of initial treatment at the Mallinckrodt Institute of Radiology, Washington University Medical Center. Epidermoid carcinoma was the most common histologic subtype, occurring in 46 cases (73%), undifferentiated carcinoma in 10 cases (16%), and adenoid cystic carcinoma in 6 cases (10%). Minimum follow-up was 2.1 years, maximum 16.9 years, and the median was 6.9 years. Relapse-free survival and overall actuarial survival at 5 years were 47% and 52%, respectively; at 10 years, they were 42% and 32%, respectively. Of 35 recorded deaths, 16 were due to the nasal cavity carcinoma, 17 to intercurrent disease, 2 to postoperative complications. Survival was not significantly affected by histology (epidermoid vs undifferentiated), site, nodal status or treatment (radiotherapy alone vs radiotherapy + surgery). Local control was correlated significantly with tumor extent (p less than 0.04) and marginally with treatment (p = 0.15). Elective neck irradiation was not given. Nodal failure occurred in 10/52 patients (19%) with initially N0 necks. Of four patients presenting with N1 disease, one failed in the untreated contralateral neck.

Extended field (periaortic) irradiation in carcinoma of the prostate--analysis of RTOG 75-06.

From 1976 to 1983 the Radiation Therapy Oncology Group conducted a study of extended field (periaortic) irradiation in carcinoma of the prostate. Eligible patients were those with clinical Stage C tumor with or without evidence of pelvic lymph node involvement and also those with Stage A-2 and B with evidence of pelvic lymph node involvement. The stratification criteria included histological grade, clinical stage, absence or presence of hormonal manipulation, and method of lymph node evaluation (lymphangiogram vs. laparotomy vs. no nodal evaluation). The patients were randomized to either receive pelvic irradiation followed by a boost to the prostate or pelvic and periaortic irradiation followed by a boost to the prostate. The prescribed daily dose was 180-200 rad to a total midplane dose to the regional lymphatics to 4000-4500 rad. The prostatic boost target volume was to receive additional 2000-2500 rad bringing the total dose to that area to a minimum of 6500 rad. A total of 523 analyzable patients have been accessioned to the protocol. Four hundred forty-eight of these are known to have received treatment per protocol. Median follow-up is 4 years and 3 months. The analyzable patients were evaluated for the incidence of distant metastases, NED survival and survival as a function of treatment arm. No statistically significant differences between the treatment arms could be documented. Similarly, no significant difference between treatment arms could be documented within a number of subpopulations such as those characterized by a particular grade, hormonal status, stage, age, acid phosphatase level, etc. The results of the study revealed no apparent benefit of elective periaortic irradiation in patients with detectable disease confined to the pelvis.

Interaction of bleomycin and hyperthermia--results of a clinical pilot study.

In vitro and animal studies indicate that concomitant administration of Bleomycin and hyperthermia result in a dramatic potentiation of cytotoxic (anti-tumor) activity. This effect takes place at temperatures above 42 degrees C. A Phase I/II pilot study has been conducted to assess the clinical feasibility of concomitant Bleomycin-hyperthermia application. Eligible patients were those with measurable tumors persistent or recurrent following treatment with conventional modalities including full dose radiotherapy. The protocol required placement of at least two interstitial catheters for continuous monitoring of temperature. Skin probes were also used and thermal mapping of all catheters was required. The therapeutic aim was minimal tumor temperature of 43 degrees C +/- .5 degrees C, the maximal normal tissue temperature was not to exceed 45 degrees C. Pretreatment evaluation included pulmonary function studies and arterial blood gases. Bleomycin was administered within 1 hour prior to initiation of hyperthermia at the dose of 15 units/m2. Twelve patients received therapy according to this protocol. Eight presented with carcinomas of the head and neck area, 4 with adenocarcinoma of the breast. Complete response was recorded in 4, partial in 6 patients. Rapid tumor lysis occurred in 2 patients. Reaction of the normal skin and subcutaneous tissues were mild in all cases and ranged from erythema to mild fibrosis. Three patients experienced pulmonary toxicity, only one of which was severe enough to cause cessation of therapy. Early clinical experience with thermochemotherapy using Bleomycin in heavily pretreated patients indicates a promising response rate and acceptable tolerance. Further studies of Bleomycin-hyperthermia alone and in combination with other modalities including radiotherapy appear warranted.

Definitive radiotherapy in resectable (stage A2 and B) carcinoma of the prostate--results of a nationwide overview.

To evaluate the efficacy of definitive radiotherapy in a population of patients with carcinoma of the prostate who satisfy the customary selection criteria for radical prostatectomy, a nation-wide search was conducted. The assessed population consists of patients with clinical Stage A2 and B carcinoma of the prostate, negative staging lymphadenectomy, negative bone scan, and normal serum acid phosphatase. The search included patients from Stanford University, Washington University in St. Louis, those participating in the Radiation Therapy Oncology Group and a broad range of radiotherapy practices surveyed by the PCS (Patterns of Care Study). A total of 209 patients satisfying the selection criteria received definitive radiotherapy during the surveyed period. The end-point of analysis was the time to progression (distant metastases). The results of the analysis indicate a very low (less than 10%) probability of progression within the first 5 years after completion of treatment. Contrary to the recent report from the VA Uro-Oncology Group the study demonstrates a comparable outcome in radiotherapeutically and surgically treated patients.

Correlation of radiotherapeutic parameters and treatment related morbidity--analysis of RTOG Study 77-06.

The current report is an updated and detailed analysis of treatment related morbidity in RTOG 77-06, a Phase III randomized study comparing prostatic irradiation versus pelvic irradiation followed by a prostatic boost, in patients with Stage A2 and B carcinoma of the prostate without evidence of nodal involvement. A total of 453 analyzable cases were accrued from 1978 to 1983, when the study was closed. All cases of treatment related morbidity were classified as to severity (using a clinical severity grading system). The data were then correlated with a number of radiotherapeutic parameters including treatment volumes (fields), doses, and techniques. Overall, pelvic irradiation, compared to prostate irradiation only, was not associated with a significantly increased incidence of treatment related morbidity. Within the range of pelvic doses used in this study a significant dose effect could not be detected. Total doses to the prostate of more than 7000 cGy were associated with an increased risk of rectal bleeding. Certain treatment techniques, (AP/PA irradiation of the pelvic lymphatics) were associated with an increased incidence of bowel complications.

Regional hyperthermia--assessment of tolerance to treatment.

To assess the patient's tolerance and the complications of treatment associated with delivery of regional hyperthermia using APAS BSD equipment, the data on 30 patients who received regional hyperthermia at the Radiation Oncology Center, Washington University School of Medicine, St. Louis, Missouri, has been reviewed. Most patients presented with advanced or recurrent tumors not amenable to conventional treatment modalities. Hyperthermia was administered in combination with either radiotherapy or chemotherapy. Cardiovascular evaluation was a standard part of pre-treatment work-up. Temperatures were obtained through interstitial probes, catheters inserted into the body cavities and (to record core temperature) esophagus. Local discomfort, anxiety, systemic temperature elevation, and tachycardia were the predominant factors limiting the number of sessions, the duration of sessions and the deposition of power, in 18, 6, 3, and 2 patients, respectively. The complications of treatment were rare. Significant injuries of the superficial tissues were recorded in two patients in whom this could be attributed to contact of urine and stool with the skin surface. Neuropathy was observed in two patients, both of whom had pelvic masses adjacent to or invading into the affected nerves. Both patients had received pelvic irradiation. Neuropathy developed within several days after the first hyperthermia session and proved reversible within several months. No injuries of the visceral organs that could be clearly attributed to hyperthermia have been recorded.

Treatment-related morbidity in phase III RTOG studies of extended-field irradiation for carcinoma of the prostate.

The incidence, severity, time of onset, and clinical course of complications of treatment have been reviewed in the RTOG studies of extended field irradiation in carcinoma of the prostate. A total of 526 patients, entered between 1976 and 1980 and followed for a minimum of 18 months, comprised the study population. In most instances of treatment-related morbidity, the symptoms were recorded during the first several months to 1 year following completion of treatment. Late occurrences, however, were not uncommon in certain types of radiation-produced injuries, such as proctitis, hematuria, and urethral strictures. Resolution of symptoms has been observed in a large proportion of patients including those with late occurrences of treatment-related morbidity, although the probability and the pattern of resolution differed considerably from one type of morbidity to another. Symptoms of cystitis are more likely to abate than those of proctitis. In patients who develop symptoms of proctitis the probability of persistence of symptoms beyond the second year following occurrence has been estimated at 20%-30%. Hematuria and symptoms secondary to urethral strictures seem to be even more likely to recur or persist, while genital and leg edema remain chronic in the majority of patients.

Correlation of survival with quantitative tissue staining of prostate specific acid phosphatase in patients with prostate carcinoma by using microscopic image analysis: a preliminary report of correlative studies on RTOG protocols 75-06, 77-06, and 83-07.

PURPOSE: We have previously shown that the intensity (graded semiquantitatively as 1-4+) of tissue prostate-specific acid phosphatase (PSAP) staining determined immunocytochemically in a cohort of prostate carcinoma patients from Radiation Therapy Oncology Group Protocols (RTOG) protocols 75-06 and 77-06 correlated with survival. The extent of this staining was heterogeneous and was estimated. The extent of staining was not found to be significantly associated with survival. We undertook the present quantitative study to see if the improved precision and reliability of measurement of the intensity and extent of prostate specific acid phosphatase staining would confirm and extend our previous observations. METHODS AND MATERIALS: Patient cohorts representative of the entire group were obtained from RTOG 75-06 plus 77-06 and 83-07. The RTOG 77-06 plus 75-06 patients (No-Hormone population) did not receive preradiation hormonal therapy. RTOG 83-07 patients (Prehormone population) received one of two types of preradiation chemical androgen ablation. In this study, histologic slides of tumors were immunocytochemically stained for PSAP by the peroxidase-antiperoxidase (PAP) technique using diaminobenezidene (DAB) as a substrate and hematoxylin as a nuclear counterstain. The intensity and extent of immunocytochemical PSAP staining (IPSAP stain) was quantified using our dual wavelength and batch mode image process technique. RESULTS: Our study of 151 cases confirmed that overall survival of patients in both populations was positively correlated with the intensity and extent of IPSAP stain. Results of the two studies were similar. The statistical significance of the relationship of both extent and intensity was greater in the cohort from protocol 83-07, which was the patient group receiving pretreatment with hormones. In a Cox multiple regression analysis including clinical stage, Gleason and M. D. Anderson grades, and the cohort of patients (Prehormone or No-Hormone group) as covariables, both the intensity and extent of the IPSAP stain significantly correlated with survival along with M. D. Anderson grade of the tumor. CONCLUSION: Quantitative image analysis of the IPSAP stain predicts survival in patients treated with external beam radiotherapy with and without prior hormonal therapy.

Patterns of Care and RTOG studies in prostate cancer: long-term survival, hazard rate observations, and possibilities of cure.

PURPOSE: This study was undertaken to show the long-term survival and probability of cure of prostate cancer patients treated with external beam radiation in USA national surveys and in the prospective clinical trials of the RTOG. METHODS AND MATERIALS: Two national patterns of care surveys of patients treated in 1973 and 1978 are reported along with two RTOG prospective trials (7506 and 7706). Hazard rates represent the risk of death and are compared to the rate expected for a normal population. RESULTS: For patients with Stage A cancers, the survival is not different from the expected survival for any of the reported surveys. The hazard rate for death does not significantly exceed the expected hazard rate out to 15 years. For patients with Stage B cancer, there is a decrease in survival below expected and hazard rates show a continuing excess mortality as long as 15 years after treatment. For patients with Stage C cancers, there is a more rapid decrease in survival that then becomes parallel to the expected survival. Hazard rates indicate there has been a return to expected mortality at 15 years. CONCLUSION: These data make a strong argument for the long-term cure of prostate cancer by external beam radiation, and support the continued use and study of radiation therapy as a curative modality in prostate cancer. No similar national data is available for any other method of management.

Three-dimensional treatment planning for postoperative treatment of rectal carcinoma.

The role of three-dimensional (3-D) treatment planning for postoperative radiation therapy was evaluated for rectal carcinoma as part of an NCI contract awarded to four institutions. It was found that the most important contribution of 3-D planning for this site was the ability to plan and localize target and normal tissues at all levels of the treatment volume, rather than using the traditional method of planning with only a single central transverse slice and simulation films. There was also a slight additional improvement when there were no constraints on the types of plans (i.e., when noncoplanar beams were used). Inhomogeneity considerations were not important at this site under the conditions of planning, i.e., with energies greater than 4 MV and multiple fields. Higher beam energies (15-25 MV) were preferred by a small margin over lower energies (down to 4 MV). The beam's eye view and dose-volume histograms were found quite useful as planning tools, but it was clear that work should continue on better 3-D displays and improved means of translating such plans to the treatment area.

Three-dimensional treatment planning considerations for prostate cancer.

Over 300 treatment plans for a total of eight disease sites based on 3-D treatment planning considerations utilizing serial CT delineated target volumes were generated by four institutions as part of an NCI supported contract to both assess the current state-of-the-art capabilities and point directions for future efforts. Two patients with stage C prostate cancer were evaluated with protocol plans which required treatment of the prostate to 70 Gy and the pelvic lymph nodes to 46 Gy. When full 3-D target definition and multiple beam arrangements were employed, all institutions were able to submit plans which scored higher on tumor coverage and had lower normal tissue complication scores compared to traditional plans. The 3-D plans using standard beam arrangements, however, were often rated as highly as the 3-D unconstrained plans due to the multiple beam arrangements already selected to optimize standard plans at most institutions. For this site, heterogeneity corrections, beam energy changes and changes in CT number did not substantially change plan scores.

Outcome for lymph node dissection negative T-1b, T-2 (A-2,B) prostate cancer treated with external beam radiation therapy in RTOG 77-06.

One hundred four patients with stage T-1b, T-2 N-O M-O prostate cancer were treated with external beam irradiation as part of RTOG 77-06. Lymph nodes were negative by lymph node dissection in 16 patients with T-1b and 88 patients with T-2 cancers. Survival exceeds age matched expected survival for the 10 years of observation (63% vs 59% at 10 years). Patterns of failure at 10 years show 87% of patients were free of isolated local recurrence, 79% free of metastatic failure, 67% free of any failure, and cause specific survival shows 86% free of cancer death at 10 years. The outcome of this group is equal or superior to reports of radical prostatectomy in similar stage patients.

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.

Predicting long-term survival, and the need for hormonal therapy: a meta-analysis of RTOG prostate cancer trials.

PURPOSE: To assess the impact of short-term and long-term androgen suppression on the disease-specific and overall survival of 2200 men treated with radiotherapy on one of 5 prospective randomized trials when stratified by prognostic risk groups. METHODS AND MATERIALS: Between 1975 and 1992, 2742 men were treated for clinically localized prostate cancer on one of 5 consecutive prospective Phase III randomized trials. Patients were selected for this analysis if they were deemed evaluable and eligible for the trial, and if follow-up information was available. For this analysis patients were stratified into four previously described prognostic risk groups: Group 1 patients had a Gleason score (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 median pretreatment prostate-specific antigen (PSA) was 25 ng/ml for the 434 evaluable patients for whom this information was available. The median follow-up times for patients treated on early studies exceeded 11 years, and for more recent studies 6 years. RESULTS: Risk group 2 patients with "bulky" or T3 disease appeared to have a disease-specific survival benefit at 8 years with the addition of 4 months of goserelin and flutamide. Group 3 and 4 patients were noted to have an approximately 20% higher survival at 8 years with the addition of long-term hormonal therapy (p < or =0.0004). CONCLUSIONS: Based on this meta-analysis of RTOG trials, subsets of patients can be identified who either do not appear to benefit from the use of hormonal therapy, benefit from short-term hormonal therapy, or who benefit only from long-term hormonal therapy. These observations should be confirmed by prospective randomized trials before they can be considered conclusive. In the meantime, however, these observations provide rational guidelines for deciding who should receive hormonal therapy and for how long.