The challenge of treating node-positive prostate cancer. An approach to resolving the questions

Lymph node-positive prostate cancer: current issues, emerging technology and impact on clinical outcome

Lymph node metastasis in patients with prostate cancer indicates a poorer prognosis compared with patients without lymph node metastasis; however, some patients with node-positive disease have long-term survival. Many studies have attempted to discern what characteristics of lymph node metastasis are prognostically significant. These characteristics include nodal tumor volume, number of positive lymph nodes, lymph node density, extranodal extension, lymphovascular invasion and tumor dedifferentiation. Favorable characteristics of regional lymph node involvement included a smaller tumor size and smaller tumor volume. However, the current staging system for prostate cancer does not provide different subclassifications for patients with node-positive prostate cancer. In recent years numerous advanced technologies for the detection of lymph node metastasis have been developed, including molecular imaging techniques and the CellSearch Circulating Tumor Cell System. With the increased detection of patients with prostate cancer, emergence of new technology to identify lymph node metastasis and the number of radical prostatectomies being performed on the rise, subclassifying patients with lymph node-positive disease is imperative. Subclassification would provide a better picture of patient prognosis and allow for a better understanding of targeted therapies to treat patients with lymph node metastasis.

Current status of lymph node-positive prostate cancer: Incidence and predictors of outcome

In early surgical series, the incidence of positive lymph nodes in patients with prostate cancer was approximately 40%. In the modern era of screening and improved patient selection, the incidence is now <10%, although most series excluded patients with higher risk disease. The risk of having positive lymph nodes is influenced by disease stage, prostate-specific antigen level, and tumor grade and by the aggressiveness of lymph node dissection. Many of the same factors predict the outcome of these patients. Although the percentage of patients with positive lymph nodes has declined, there remain significant numbers of patients with lymph node-positive prostate cancer, and it remains a therapeutic dilemma.

Treatment options in lymph node-positive prostate cancer

With improved awareness and screening, the incidence of lymph node-positive prostate cancer has declined dramatically over the last 50 years. Stage of cancer, prostate-specific antigen, and grade are risk factors for positive lymph nodes; and those factors, along with the number of involved lymph nodes, are prognostic factors for outcome. Although the numbers have declined, the number of men with lymph node-positive prostate cancer remains significant, and the current challenge is how best to treat these patients. Commonly used treatments include any combination of androgen ablation, surgery, and radiation. There have been a few studies with chemotherapy, and no treatment has been proven superior to the others. Consequently, there remain several reasonable alternatives to treatment, and long-term survival is not unusual.

Risk of prostate carcinoma death in patients with lymph node metastasis

BACKGROUND

The presence of lymph node metastasis is a poor prognostic sign for patients with prostate carcinoma. Results of published reports on survival among patients with lymph node metastasis are difficult to assess because of treatment selections. The extent to which lymph node status will have an impact on a patient's survival is uncertain.

METHODS

The authors analyzed 3463 consecutive Mayo Clinic patients who underwent radical prostatectomy and bilateral pelvic lymphadenectomy for prostate carcinoma between 1987 and 1993. Of these patients, 322 had lymph node metastasis at the time of surgery, and 297 lymph node positive patients also received adjuvant hormonal therapy within 90 days of surgery. The progression free rate and the cancer specific survival rate were used as outcome endpoints in univariate and multivariate Cox proportional hazards models. The median follow-up was 6.3 years. Progression was defined by elevation of serum prostate specific antigen (PSA) > or = 0.4 ng/mL after surgery, development of local recurrence, or distant metastasis documented by biopsy or radiographic examination.

RESULTS

The 5-year and 10-year progression free survival rates (+/- standard error [SE]) for patients with lymph node metastasis were 74% +/- 2% and 64% +/- 3%, respectively, compared with 77% +/- 1% and 59% +/- 2%, respectively, for patients without lymph node metastasis. The 5-year and 10-year cancer specific survival rates were 94% +/- 1% and 83% +/- 4%, respectively, compared with 99% +/- 0.1% and 97% +/- 0.5%, respectively, for patients without lymph node metastasis. Among patients with a single lymph node metastasis, the 5-year and 10-year cancer specific survival rates were 99% +/- 1% and 94% +/- 3%, respectively. After adjustment for extraprostatic extension, seminal vesicle invasion, Gleason grade, surgical margins, DNA ploidy, preoperative serum PSA concentration, and adjuvant therapy, the hazard ratio for death from prostate carcinoma among patients with a single lymph node metastasis compared with patients who were without lymph node metastasis was 1.5 (95% confidence interval, 0.5-5.0; P = 0.478), whereas the hazard ratio for death from prostate carcinoma was 6.1 (95% confidence interval, 1.9-19.6; P = 0.002) for those with two positive lymph nodes and 4.3 (95% confidence interval, 1.4-13.0; P = 0.009) for those with three or more positive lymph nodes. There was no significant difference in the progression free survival rate among patients with or without lymph node metastasis in multivariate analysis after controlling for all relevant variables, including treatments (hazard ratio,1.0; 95% CI, 0.7-1.3; P = 0.90).

CONCLUSIONS

Patients with prostate carcinoma who have multiple regional lymph node metastases had increased risk of death from disease, whereas patients with single lymph node involvement appeared to have a more favorable prognosis after radical prostatectomy and immediate adjuvant hormonal therapy. Excellent local disease control was achieved by using combined surgery and adjuvant hormonal therapy in patients with positive lymph nodes.

Extranodal extension in lymph node-positive prostate cancer

Evaluation of extranodal tumor extension may provide prognostic information for patients with epithelial malignancies. However, its importance for the patient who has prostate cancer with regional lymph node metastasis requires further investigation and clarification. This study was performed to evaluate the prognostic significance of extranodal extension (ENE) in a large series of node-positive patients. The study group included 212 node-positive patients who were treated by bilateral pelvic lymphadenectomy, radical retropubic prostatectomy, and androgen deprivation between 1987 and 1992 at the Mayo Clinic. ENE was defined as cancer perforating through the lymph node capsule into perinodal tissue. Nodal cancer volume was measured by the grid method. Univariate and multivariate risk ratios (RR) for distant metastasis-free and cancer-specific survival were estimated using the Cox proportional model. The mean follow-up was 6.3 years (median, 6.1 years). Distant metastasis-free and cancer-specific survival at 5 years for all patients was 91% and 95%, respectively. ENE was found in 126 of 212 patients (59%). The presence of ENE was not significantly associated with distant metastasis-free (RR = 1.6; 95% confidence interval [CI], 0.7 to 3.9) or cancer-specific survival (RR = 2.2; 95% CI, 0.7 to 6.8). Among 98 patients with a single positive node, there was no significant difference in distant metastasis or cancer-specific survival according to the presence of ENE (P = .88 and P = .36, respectively). After adjusting for Gleason score, DNA ploidy, and ENE, only nodal cancer volume was significantly associated with adverse distant metastasis-free (RR = 1.9; 95% CI, 1.5 to 2.8) and cancer-specific survival (RR = 1.4; 95% CI, 1.1 to 1.9). Our data indicate that the presence of ENE is not associated with unfavorable survival in patients with node-positive prostate cancer treated by radical retropubic prostatectomy, bilateral pelvic lymphadenectomy, and androgen deprivation therapy. In contrast, nodal cancer volume was predictive of distant metastasis-free survival and cancer-specific survival.

Cancer volume of lymph node metastasis predicts progression in prostate cancer

Clinical outcome is variable in prostate cancer patients with regional lymph node metastasis. We studied 269 patients who had regional lymph node metastasis at the time of radical retropubic prostatectomy and bilateral pelvic lymphadenectomy at the Mayo Clinic between January 1987 and December 1992. Two hundred fifty-three (94%) patients received androgen deprivation therapy within 90 days of radical prostatectomy. Patients ranged in age from 47 to 79 years (median, 67 years). Median follow-up was 6.1 years (range, 0.3-10.5 years). Nodal cancer volume (size) was measured by the grid-counting method. Cox proportional hazards models were used to determine the impact of numerous clinical and pathologic findings on systemic progression-free survival. Systemic progression was defined as the presence of distant metastasis documented by biopsies or radiographic examinations (abdominal computerized tomography, plain radiographs, or bone scan). Five-year progression-free survival was 90%. In predicting systemic progression using Cox multivariate analysis, only nodal cancer volume added significantly to the model containing the primary cancer variables (Gleason score, cancer volume, and DNA ploidy). The relative hazard rate for a doubling in nodal cancer volume was 1.6 (95% confidence interval, 1.3 to 2.0; p < 0.0001). Spearman rank analysis showed a correlation between nodal cancer volume and Gleason score of the primary cancer, the number of positive nodes, the aggregate length of metastases, and the largest nodal cancer diameter (correlation efficient = 0.37, 0.63, 0.96, and 0.95, respectively). Our data indicate that nodal cancer volume was the most significant nodal determinant of progression to distant metastasis in lymph node-positive prostate cancer patients. We recommend that the diameter of the largest metastasis be evaluated in patients with metastases, because this is a more powerful predictor of patient outcome than current methods, which recommend mere counting of the number of positive nodes.

[Locally advanced prostate carcinoma (T2b-T4 N0) without and with clinical evidence of local progression (Tx N+) with lymphatic metastasis. Is radiotherapy for pelvic lymphatic metastasis indicated or not?]

BACKGROUND

There is a greater controversy regarding the indication of radiotherapy of the pelvic lymphatics in patients with suspected lymph node metastases in locally advanced prostate cancer (T2b-4 N0) on the one hand and in patients with pathologically proven lymph node metastases in locoregional advanced prostate cancer (Tx pN+) on the other hand following definitive radiotherapy and radical prostatectomy. This paper investigates the possible indications for radiotherapy of the pelvic lymphatics in the light of data from the literature.

PATIENTS AND METHODS

Because data from several retrospective studies concerning radiotherapy of the pelvic lymphatics indicated a better outcome, the RTOG conducted 2 prospective randomised studies (RTOG 75-06, 77-06) to address these questions. However, the results of these studies showed no better survival or cause specific survival for patients treated for the paraaortal or pelvic lymphatics and therefore, radiotherapy of the pelvic lymphatics was no more advocated. A reanalysis showed several problems of the study design and it was concluded that the studies couldn't prove the question of elective radiotherapy of the pelvic lymphatics. In RTOG 77-06 patients with T1b/T2 tumors were investigated. Therefore, there is no prospective study investigating the elective radiotherapy in patients with T3-tumors, who are at high risk of pelvic lymph node metastases.

RESULTS

Today there is no indication for treating the paraaortal lymphatics in patients with locoregional advanced prostate cancer. Many radiotherapists perform the elective radiotherapy of pelvic lymphatics when the risk of metastases is above 15 to 20% because retrospective data indicate a better outcome. On the other hand, many others don't treat them because RTOG 75-06 and 77-06 didn't demonstrate a better outcome. Laparoscopic lymphadenectomy with low morbidity seems to be helpful as in pN0 patients radiotherapy is not necessary. Where performing laparoscopic pelvine lymphadenectomy is impossible the probability of the frequency of lymph node metastases can be estimated using the clinical tumor stage, the Gleason-score and the pretherapeutic PSA. In case of proven metastases (pN+) some retrospective data indicate that patients with micrometastasis could profit from aggressive treatment. In case of proven metastases and extirpation by lymphadenectomy it seems that patients with hormonal therapy and radiotherapy have a longer tumor-free interval. However, there are no data from randomized trials.

CONCLUSIONS

Every radiotherapist has to make his own decision for radiotherapy of the pelvic lymphatics as there is no standard treatment. Two randomised studies are open and recruiting patients. These are one study of the ARO, investigating patients with histologically proven lymph node metastases and one study of the RTOG (RTOG 9413), investigating patients with an estimated risk of lymph node metastases > 15%. In case of radiotherapy of the pelvic lymphatics a dose of 45 Gy for suspected metastases and 50.4 Gy for proven metastases is recommended.

Ten-year outcomes for pathologic node-positive patients treated in RTOG 75-06

PURPOSE

This study was conducted to see what fraction of prostate cancer patients with biopsy-proven nodes are free of cancer 10 years after radiation treatment.

METHODS AND MATERIALS

RTOG protocol #75-06 included 90 patients with biopsy-proven pelvic nodal involvement treated with radiation. They have been continuously follow-up since treatment. When feasible, current prostate-specific antigen (PSA) levels have been solicited from patients clinically cancer-free (no evidence of disease, NED) at 10 years, to confirm cure.

RESULTS

The 10-year survival was 29%, the 10-year clinical NED survival 7%. PSA levels were obtained in 2 of 5 10-year clinical NED patients, they were both less than 0.8 ng/ml. The 2 proven cures were both clinical stage T-3, Gleason Score 6 and 8, and had 2 and 1 positive nodes, respectively. Multivariate analysis showed Gleason sum was significantly associated with clinical survival without disease.

CONCLUSION

A small fraction of node-positive patients are cured at 10-year follow-up by radiation therapy (2 of 90 with PSA +3 of 90 by clinical endpoints). Innovative treatment programs should be directed at node-positive patients in an effort to improve the fraction cured.

Long-term outcome in patients with pTxN+ adenocarcinoma of prostate treated with radical prostatectomy and early androgen ablation

PURPOSE

We assessed retrospectively the outcome after bilateral pelvic lymphadenectomy and radical prostatectomy for pathological pTxN+ adenocarcinoma of the prostate when treated with or without adjuvant androgen ablation therapy.

MATERIALS AND METHODS

A total of 790 men treated with radical prostatectomy for prostatic adenocarcinoma were found to have pTxN+ disease and treated further with or without androgen ablation therapy. Mean patient age was 64 years (range 40 to 79). Mean followup was 6.5 years, (range up to 25). Clinical stages were T2 or less in 60% of the cases, T3 in 38% and N+ in 2%. Gleason scores were 6 or less in 31% and 7 or greater in 69%. Deoxyribonucleic acid ploidy was diploid in 43%, tetraploid in 39% and aneuploid in 18%. Of the patients 96 (12%) received no androgen ablation therapy, with the remainder getting androgen ablation therapy within 90 days of radical prostatectomy.

RESULTS

Of the patients 186 (24%) died, with 109 (14%) dying of prostatic anedocarcinoma. Overall (and cause specific) survival probabilities at 5, 10 and 15 years were 87 (91), 69 (79) and 39% (60%), respectively. Patients with diploid tumors had better cause specific survival than those with nondiploid tumors (p = 0.009). Patients with diploid tumors were less likely to have progression biochemically, locally or systemically than those with nondiploid tumors (p = 0.038). Androgen ablation therapy had no effect on cause specific survival in nondiploid patients. Diploid patients treated with androgen ablation therapy for up to 10 years had no improvement in disease specific survival compared to those with no androgen ablation therapy. However, cancer death was significantly reduced after 10 years (p <0.002). The local control rate of pTxN+ cases that receive radical prostatectomy and androgen ablation therapy at 15 years is virtually identical to that of stage pT2c cases at our institution (79 +/- 3.0 versus 80% +/- 3.5%, respectively). There were no deaths secondary to radical prostatectomy, and complications were within the experience of that seen in patients with localized disease.

CONCLUSIONS

Radical prostatectomy with androgen ablation therapy is a viable option for patients with pTxN+ disease, particularly in view of excellent local control rates and low morbidity. Patients with diploid tumors have a more favorable outcome than those with nondiploid tumors when treated with androgen ablation therapy.

The use of combined radiation therapy and hormonal therapy in the management of lymph node-positive prostate cancer

PURPOSE

To determine the rate of tumor response and patterns of relapse following combined hormonal-radiation therapy of adenocarcinoma of the prostate and to measure the survival in a group of men with tumor metastatic to pelvic lymph nodes.

METHODS AND MATERIALS

66 patients with adenocarcinoma of the prostate with pathologically confirmed pelvic lymph node involvement were treated with combined radiation therapy and hormonal therapy. An additional five patients declined hormonal therapy. The patients treated with combined therapy represented a group with locally advanced disease including 44 patients (67%) with T3 or T4 tumors and 51 patients (80%) had N2 or N3 lymph node metastases. The pelvic lymph nodes were treated to a dose of 45 Gy and the prostate was boosted to a dose of 65 to 71 Gy. Hormonal therapy began up to 2 months before radiation and continued indefinitely. Patients were allowed to select their hormonal therapy and could choose DES (2 patients), orchiectomy (21 patients), LHRH agonist (7 patients) or combined androgen blockade (34 patients).

RESULTS

Median follow-up is 49 months (range 12 to 131 months) and 21 patients have been followed for longer than 5 years. There have been 15 recurrences the entire group including three local recurrences in the prostate, seven patients with distant metastases, four patients with biochemical recurrences without clinical evidence of disease, and one patient where the location was unknown. Two of the PSA recurrences occurred in patients who elected to discontinue hormones after less than 3 years of therapy. The overall survival at 5 and 8 years is 94 and 84%, the clinical disease free survival is 85 and 67%, and the biochemical disease-free survival is 78 and 47%. There was no increased toxicity of the combined modality regimen compared to the expected effects of radiation and hormonal therapy.

CONCLUSION

Combined hormonal and radiation therapy represents an effective treatment option for patients with adenocarcinoma of the prostate metastatic to pelvic lymph nodes. Combined modality therapy appears to extend the disease-free survival and allow patients to maintain their independent function.

[Radiotherapy after radical prostatectomy: indications, results and side effects]

BACKGROUND

Radiation therapy following radical prostatectomy in locally progressed prostate carcinoma has become increasingly important in the last few years as both adjuvant therapy in patients with pT3-tumors with or without positive margins and treatment for a PSA increase in local recurrence of disease. The background for this is the knowledge gained by using PSA that up to 60% of the patients with histopathologically confirmed pT3/4 tumors or involvement of the lymph nodes are systemically and/or locally progressive after 3 to 5 years if only surgical or radiation therapy was performed.

RESULTS

A number of studies, albeit exclusively retrospective, substantiated a significantly high local tumor control by radiotherapy after radical prostatectomy. This holds true for adjuvant therapy with a PSA in the "zero range" as well as with a PSA increase from the "zero range", whereby it must be taken into consideration that a certain percentage of treated patients with a PSA in the "zero-range" with or without positive margins actually do not need further therapy. Two retrospective studies demonstrated a significant better lengthening of "freedom from treatment failure" that is local and systemic progression of disease. Lengthening the survival time has, however, not yet been proven. With an increase in the PSA from the "zero range" after radical prostatectomy, there are indications that systemic metastatic spread already occurs with values higher than 2.5 to 4 ng/ml and the radiotherapy no longer has any curative intention.

CONCLUSIONS

Adjuvant RT following radical prostatectomy gives better local control rates and probably better rates of "freedom from treatment failure" in patients with locally advanced prostate cancer with positive margins and probably in patients with negative margins. However, in retrospective studies no advantage in overall survival was shown.

Prostate cancer. Who is best benefited by external beam radiation therapy?

The major indications for radical radiation therapy of prostate cancer for both early-stage and locally advanced disease are discussed. Important issues in the interpretation of long-term treatment series are reviewed. The outcomes of therapy are analyzed for both early-stage and locally advanced disease, including alternative therapeutic strategies. On the basis of this review of the literature, current treatment recommendations delineate patients most likely to benefit from radiation therapy as opposed to alternative therapeutic modalities.

Pharmacokinetics and dosimetry of [111In] F(ab')2 fragments against prostatic acid phosphatase after intraprostatic injection for immunoscintigraphy in prostate cancer

The purpose of this study was to investigate the pharmacokinetics and dosimetry of using [111In]-labelled F(ab')2 fragments against prostate acid phosphatase (FC-3001, Orion Corporation Farmos, Finland) for the detection of metastatic prostate cancer. Five patients in all were subjected to intraprostatic injection of 1 mg FC-3001 labelled with 85-100 MBq [111In]. In four of the patients the biodistribution was studied by sequential whole-body counting, gamma-camera scintigraphy of the abdomen in antero-posterior and postero-anterior projections. Blood and urine samples were collected sequentially up to 72 h after injection. Initially, significant amounts of antibody fragments were released from the site of injection. After the first 4 h, 22.0% of injected antibody (2.2-41.3% ID) remained in the prostate and was slowly released with a final half-life of 80.4 h (49.9-141.8 h). Labelled antibody appeared in the blood shortly after injection and was cleared from the blood with a final half-life of 27.7-300.9 h. The liver, the bone marrow and, in two patients, the kidneys accumulated antibody fragments in significant amounts during the period of investigation. An apparent relationship between the initial whole-body clearance and renal uptake is described. The effective dose averaged 0.37 mSv/MBq (range 0.24-0.52 mSv/MBq). The highest equivalent doses were received by the kidneys (0.46-2.81 mGy/MBq) the liver (0.44-1.59 mGy/MBq) and the bone marrow (0.37-0.57 mGy/MBq). Only in two of the patients with known metastases were pathological foci seen. The disappointing imaging results were probably caused by the biphasic release of antibody from the prostate, and indicates that intraprostatic injection of this antibody has no advantage for imaging, as well as being unpleasant for the patient. The biodistribution of the antibody following release from the prostate is similar to but more variable than the biodistribution seen in patients after intravenous injection of labelled antibodies.

Combined hormonal and radiation therapy for lymph node-positive prostate cancer

OBJECTIVES

To evaluate the efficacy of combined radiation and hormonal therapy in patients with prostate cancer metastatic to the pelvic lymph nodes.

METHODS

Fifty consecutive patients with node-positive prostate cancer were evaluated by the Departments of Urology and Radiation Oncology at the University of Pennsylvania and offered combined hormonal and radiation therapy. All patients received pelvic radiation to 45 Gy, with a boost dose to the prostate to 65 to 71 gy. Forty-five of the patients were treated with concurrent hormonal therapy consisting of diethylstilbestrol (2 patients), orchiectomy (18 patients), leuprolide (5 patients), or combined androgen blockade (20 patients); the other 5 patients declined hormonal therapy. Patients represented a group with locally advanced disease with a high incidence of T3 tumors (66%), high grade (74%; Gleason score more than 7), high prostate-specific antigen (PSA) (40%; more than 30.0 ng/mL), and a high incidence of gross (36%) or bilateral (30%) adenopathy and a high incidence of multiply involved lymph nodes (62%).

RESULTS

Median follow-up of patients is 42 months (range, 10 to 102). All 5 patients declining hormonal therapy relapsed within 18 months and only 1 patient survived longer than 3 years. Among patients treated with combined hormonal and radiation therapy, the 6-year survival rate is 82%, the clinical disease-free survival at 6 years is 71%, and the probability of survival free of recurrence, with a PSA less than 0.2 ng/mL, is 62%. Only two PSA recurrences occurred, both in patients who elected to discontinue hormone therapy. There was no synergistic toxicity observed as a result of combined therapy.

CONCLUSIONS

Combined hormonal and radiation therapy offers the potential for extended disease-free survival and may represent an effective treatment option for patients with locally advanced prostate cancer.

Adjuvant radiotherapy following radical prostatectomy--results of 56 patients

Patients with adenocarcinoma of the prostate with positive surgical margins and/or seminal vesicle invasion after radical prostatectomy (RP) have a high risk of local recurrence or distant spread of disease. Several investigators reported increased local control rates following adjuvant radiotherapy (RT). However, it is unclear whether this procedure, with or without hormonal therapy (HT), improves the outcome. From 1975 to 1987, 56 patients with adenocarcinoma of the prostate underwent adjuvant RT following RP (pathological stage C1, n = 19; stage C2, n = 17; stage D1, n = 20). In 27 of 56 patients an additional immediate orchiectomy was performed. 48 patients received 4000-5000 cGy to the pelvic lymphatics, including the prostatic fossa, followed by a boost to the prostatic fossa to complete 6400-7000 cGy, whereas 8 patients were treated to the prostatic fossa only. With a median follow-up of 89 months, the overall survival rate of patients with stages C1, C2 and D1 did not differ significantly (10-year overall survival rate 84, 74 and 71, respectively). The local control rate for 5- and 10-years was 96 and 90%, respectively. A significant advantage in overall survival (5- and 10-year rate: 92 versus 93% and 92 versus 63%; P < 0.05, respectively) and clinical disease-free survival (5- and 10-year rate: 92 versus 72% and 92 versus 49%; P < 0.05, respectively) was seen in 27 patients with orchiectomy compared with 29 patients without HT. A total of 15 patients (26%) developed at least one form of late toxicity, in most cases a mild proctitis, cystitis, or penile or leg oedema. However, 6 patients (11%) had severe grade 3 or 4 side-effects that necessitated a cystectomy in 2 cases as well as a colostomy in 2 cases. In all patients with grade 3 or 4 side-effects, 70 Gy as a tumour-encompassing isodose were applied. Adjuvant RT, following RP in stage C and D1 prostate cancer with positive surgical margins and/or seminal vesicle invasion increases local control. Whether immediate HT influences the outcome, as seen in this study, should be proven in prospective clinical trials.

Influence of radiotherapy on node-positive prostate cancer treated with androgen ablation

PURPOSE

Patients with node-positive prostate cancer that is regionally localized (T1-4, N1-3, M0) have a relatively poor prognosis when a single-treatment modality such as radical surgery, definitive radiotherapy, or androgen ablation is used. While promising results using radical surgery and androgen ablation have been reported, there are no data to support an analogous approach using local radiotherapy and androgen ablation. In this retrospective review, the outcome after local radiotherapy and early androgen ablation (XRT/HORM) was compared to early androgen ablation alone (HORM).

METHODS AND MATERIALS

Between 1984 and 1992 there were 181 patients treated with HORM and 27 patients treated with XRT/HORM at the University of Texas M. D. Anderson Cancer Center. The nodal status of all patients was established pathologically by lymph node dissection, which was terminated after frozen section confirmation of involvement. In the majority of cases androgen ablation was by orchiectomy. The median dose to the prostate in XRT/HORM group was 66 Gy. The median follow-up was 45 months; 49 months for the HORM group and 25 months for the XRT/HORM group.

RESULTS

The distribution of prognostic factors between the HORM and XRT/HORM groups was similar, with the exception of tumor grade. There was a significantly larger proportion of high grade tumors in the HORM group. In terms of actuarial disease outcome, at 4 years the results of patients in the HORM group were significantly worse, including a rising prostate specific antigen (PSA) of 53%, any disease progression of 32%, a rising PSA or disease progression of 55%, and local progression of 22%. None of the patients in the XRT/HORM group failed biochemically or clinically. To determine the impact of grade on these findings, the analyses were repeated, using only those with grade 2 tumors. A similar pattern was evidenced with significantly worse actuarial outcome at 4 years for the HORM group using the endpoints of a rising PSA (46%), any disease progression (24%), and a rising PSA or disease progression (47%).

CONCLUSION

Node-positive prostate cancer patients with regionally localized disease fared significantly better when combined local radiotherapy and early androgen ablation were used, as compared to early androgen ablation alone. Although the number of patients in the XRT/HORM group was small and follow-up was short, the combined treatment had a dramatic effect on disease outcome and, therefore, a larger prospective randomized trial is warranted.

Radical prostatectomy and radical radiation therapy for clinical stages T1 to 2 adenocarcinoma of the prostate: new insights into outcome from repeat biopsy and prostate specific antigen followup

Assessment of outcome following radical treatment for stages T1 to T2 prostate cancer has become more sensitive and rapid with the use of serum prostate specific antigen (PSA) in routine followup. PSA has identified substantially more failure following all radical therapies than was previously detected in series using clinical end points. Furthermore, it has also allowed a better assessment of the biological potential of histologically evident residual disease, that is a positive surgical margin after prostatectomy or positive repeat biopsy 2 years after radiation. Both situations are associated with subsequent biochemical failure in the majority of patients. The stages T1 to T2 cancer group is extremely heterogenous. In the few series with PSA followup that have evaluated long-term (greater than a decade) outcome for this group some report cure rates well below 40% for surgery and radiation. When comparing the results of any radical treatment series (surgery versus surgery and radiation versus radiation, as well as radiation versus surgery) selection may have a crucial role in predicting outcome. Surgical series tend to contain more patients with stages T1 to T2a tumors of low grade who have low initial PSA values and are known to have negative nodes. These patients, when treated with radical radiation, also have a favorable prognosis. It is hoped that the introduction of screening programs will improve outcome through earlier disease detection.

Adjuvant irradiation after radical prostatectomy for adenocarcinoma of prostate: analysis of freedom from PSA failure

A total of 84 consecutive men with extracapsular disease after radical prostatectomy who received postoperative irradiation and no adjuvant endocrine therapy were analyzed. Failure was defined as the development of clinical disease recurrence either locally or at a distant site, the development of detectable prostate-specific antigen (PSA) when postoperatively it had been undetectable, or any rise in PSA when postoperatively it still had been detectable. Sixteen of the 84 men had nodal disease. Overall, five-year actuarial freedom from relapse was 60 percent. For node-negative men, it was 64 percent and for node-positive men 43 percent. For the 68 men with pathologic Stage T3N0 disease, five-year freedom from relapse was 73 percent when seminal vesicles were negative and 43 percent when involved. Tumor grade also predicted the likelihood of recurrence. In a multivariate analysis the time interval from surgery to radiation and the level of postoperative PSA (detectable versus undetectable) did not influence the likelihood of relapse nor the median time to relapse. Fourteen separate patients treated with radiation alone for palpable tumor recurrence were also analyzed. Fewer than 40 percent were disease-free only two years after irradiation. We conclude that when treatment failure is defined in biochemical as well as clinical terms postoperative irradiation reduces the rate of relapse at five years relative to recently reported series in which adjuvant irradiation was not given. The additional morbidity is low. Whether or not this will translate into an overall cause-specific survival gain is currently unclear.