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

Magnetic Resonance Imaging-Guided Cryoablation of Prostate Cancer Lymph Node Metastasis

PURPOSE

To evaluate the safety and effectiveness of magnetic resonance (MR) imaging-guided cryoablation of prostate cancer metastatic lymph nodes (LNs).

MATERIALS AND METHODS

Fifty-two patients with prostate cancer who underwent MR imaging-guided LN ablation from September 2013 to June 2022 were retrospectively reviewed. Of these, 6 patients were excluded because adequate ablation margins (3-5 mm) could not be achieved secondary to adjacent structures. The remaining 46 patients (mean age, 70 years [SD ± 7]) underwent 55 MR imaging-guided cryoablation procedures of metastatic LNs (25 in the pelvic sidewall, 20 within the pelvic region, and 10 in the abdomen) with procedural intent of complete ablation. Locoregional tumor control (ie, technical success in the target LN) was evaluated on initial follow-up positron emission tomography (PET) scans at a mean of 4 months (SD ± 2). Preablation and postablation prostate-specific antigen (PSA) levels were recorded. Imaging follow-up continued until a median of 27.5 months (range: 3-108 months).

RESULTS

Ninety-five percent (52/55) of treated LNs demonstrated no considerable activity on PET scans at initial follow-up at 4 months (SD ± 2). PSA decreased to an undetectable level of <0.1 ng/mL after cryoablation in 14 of 46 (30.4%) patients with corresponding lack of activity in 13 of 46 (28.2%) patients on continued PET imaging follow-up. Only 6 of 55 (10.9%) patients had transient adverse events, which all resolved with no long-term sequelae.

CONCLUSIONS

MR imaging-guided percutaneous cryoablation of metastatic LNs is a safe and technically effective technique for treating metastatic prostate cancer in LNs.

Long-term Outcomes Following Radiation Therapy For Prostate Cancer Patients With Lymph Node Metastases at Diagnosis Treated With and Without Surgery

OBJECTIVES

To evaluate the long-term outcomes for prostate cancer (PCa) patients with lymph node involvement (LNI) treated with radiotherapy at the University of California San Francisco.

MATERIALS AND METHODS

All newly diagnosed PCa patients with LNI treated with radiotherapy as primary therapy or after surgery, each with and without hormonal therapy (HT) between 1988 and 2009 were included.Thirty-five patients (38%) were managed with external beam radiotherapy alone (eRT), 18 patients (20%) with radical prostatectomy (RP)+adjuvant radiotherapy, and 38 patients (42%) with RP+salvage radiotherapy. Overall 82% of the study sample received HT with similar proportions among radiation therapy (RT) subsets (P=0.83).

RESULTS

The median follow-up (FU) was 65, 42, and 86 months for patients treated with eRT, adjuvant radiotherapy, and salvage radiotherapy, respectively.The 10-year estimates from start of primary therapy for patients with LNI for overall survival (OS) was 78% (95% confidence interval [CI], 62%-88%) and for cause-specific survival was 89% (95% CI, 78%-95%). The 5-year estimates from the start of RT for biochemically no evidence of disease was 68% (95% CI, 56%-78%) and for disease-free survival was 67% (95% CI, 54%-77%). There was no difference in any of these outcomes among the 3 RT groups.Patients treated with HT were more likely to have a better 10-year OS (82% vs. 66%; log rank: P=0.001).Multivariate analysis indicated that only age and Gleason score were significant predictors for biochemically no evidence of disease and OS.

CONCLUSIONS

Patients diagnosed with PCa with LNI who were treated with RT with or without a prior surgery had relatively favorable long-term outcomes.

The expression of vascular endothelial growth factor-C correlates with lymphatic microvessel density and lymph node metastasis in prostate carcinoma: An immunohistochemical study

Aim:

To evaluate the expression of two different lymphatic vascular density (LVD) markers (D2-40 and LYVE-1) and a lymphangiogenic cytokine (Vascular Endothelial Growth Factor-C, [VEGF-C]) in prostate carcinoma and to investigate their relationship with the lymph node status.

Settings and Design:

Archival material study of 92 non-consecutive radical prostatectomy specimens.

Materials and Methods:

The mean LVD was assessed immunohistochemically in 24 prostate carcinoma specimens from patients with clinically localized disease, who were found to have nodal metastasis (pN1), and was compared with 68 pN0 cases. Furthermore, the mean LVD, VEGF-C expression, and lymphatic invasion were examined in relation to lymph node involvement.

Results:

Peritumoral (but not intratumoral) mean LVD assessed by D2-40 was higher in pN1 tumors (P = 0.015). LYVE-1 expression was limited and not associated with lymph node status. The VEGF-C expression was higher in the N1 cases and also correlated with the increased mean LVD in both the peri- and intratumoral compartments. Lymphatic invasion was strongly associated with nodal metastasis and higher VEGF-C expression.

Conclusions:

Our results indicate that increased peritumoral (but not intratumoral) LVD in the tumor specimen is associated with lymph node metastasis. Increased expression of VEGF-C is associated with higher LVD (in both intratumoral and peritumoral compartments) and with positive lymph node status, indicating a possible dual role in both lymphangiogenesis and lymphatic vessel invasion.

Management of prostate cancer patients with lymph node involvement: a rapidly evolving paradigm

Although widespread PSA screening has inevitably led to increased diagnosis of lower risk prostate cancer, the number of patients with nodal involvement at baseline remains high (nearly 40% of high risk patients initially staged cN0). These rates probably do not reflect the true incidence of prostate cancer with lymph node involvement among patients selected for external beam radiotherapy (EBRT), as patients selected for surgery often have more favorable prognostic features. At many institutions, radical treatment directed only at the prostate is considered standard and patients known to have regional disease are often managed palliatively with androgen deprivation therapy (ADT) for presumed systemic disease. New imaging tools such as MR lymphangiography, choline-based PET imaging or combined SPECT/CT now allow surgeons and radiation oncologists to identify and target nodal metastasis and/or lymph nodes with a high risk of occult involvement. Recent advances in the field of surgery including the advent of extended nodal dissection and sentinel node procedures have suggested that cancer-specific survival might be improved for lymph-node positive patients with a low burden of nodal involvement when managed with aggressive interventions. These new imaging tools can provide radiation oncologists with maps to guide delivery of high dose conformal radiation to a target volume while minimizing radiation toxicity to non-target normal tissue. This review highlights advances in imaging and reports how they may help to define a new paradigm to manage node-positive prostate cancer patients with a curative-intent.

Magnetic resonance lymphography findings in patients with biochemical recurrence after prostatectomy and the relation with the Stephenson nomogram

PURPOSE

To estimate the occurrence of positive lymph nodes on magnetic resonance lymphography (MRL) in patients with a prostate-specific antigen (PSA) recurrence after prostatectomy and to investigate the relation between score on the Stephenson nomogram and lymph node involvement on MRL.

METHODS AND MATERIALS

Sixty-five candidates for salvage radiation therapy were referred for an MRL to determine their lymph node status. Clinical and histopathologic features were recorded. For 49 patients, data were complete to calculate the Stephenson nomogram score. Receiver operating characteristic (ROC) analysis was performed to determine how well this nomogram related to the MRL result. Analysis was done for the whole group and separately for patients with a PSA <1.0 ng/mL to determine the situation in candidates for early salvage radiation therapy, and for patients without pathologic lymph nodes at initial lymph node dissection.

RESULTS

MRL detected positive lymph nodes in 47 patients. ROC analysis for the Stephenson nomogram yielded an area under the curve (AUC) of 0.78 (95% confidence interval, 0.61-0.93). Of 29 patients with a PSA <1.0 ng/mL, 18 had a positive MRL. Of 37 patients without lymph node involvement at initial lymph node dissection, 25 had a positive MRL. ROC analysis for the Stephenson nomogram showed AUCs of 0.84 and 0.74, respectively, for these latter groups.

CONCLUSION

MRL detected positive lymph nodes in 72% of candidates for salvage radiation therapy, in 62% of candidates for early salvage radiation therapy, and in 68% of initially node-negative patients. The Stephenson nomogram showed a good correlation with the MRL result and may thus be useful for identifying patients with a PSA recurrence who are at high risk for lymph node involvement.

Role of radiation therapy for the treatment of lymph nodes in urologic malignancies

Radiation therapy (RT) represents an important therapeutic component in the management of genitourinary (GU) malignancies. RT is used to treat patients with proven involvement of the regional lymph nodes or delivered electively to patients at risk for occult regional lymph node metastases. Advances in treatment planning and delivery of various types of RT provide the technology to precisely plan, target, and deliver RT with the goal of optimizing the radiation dose to the target while sparing normal tissue. This article provides an overview of the modalities, indications, and techniques of RT for treatment of the lymphatic basins in GU malignancies.

Helical Tomotherapy with Simultaneous Integrated Boost for High-Risk and Lymph Node-Positive Prostate Cancer: Early Report on Acute and Late Toxicity

The use of whole pelvic radiotherapy (WPRT) for high-risk and lymph node-positive prostate cancer (PC) remains controversial. The purpose of this study was to evaluate the acute toxicity associated with helical tomotherapy in the treatment of high-risk and lymph node-positive prostate cancer. To do so, twenty-eight patients were treated to a dose of 54 Gy in daily fractions of 1.8 Gy to the pelvic lymph node area, while the prostate and the seminal vesicles received a simultaneous integrated boost (SIB) to a dose of 70.5 Gy. A SIB to a dose of 60 Gy was delivered to the involved lymph node region(s) in 8 patients with pelvic lymph node metastases. All patients received concurrent hormonal treatment. The incidence of grade 2 and 3 acute gastrointestinal (GI) toxicity was 7% and 0% respectively. Grade 2 and 3 acute genito-urinary (GU) side effects were observed in 14% and 4% of the patients respectively. No grade 4 side effects occurred. No increased toxicity was observed in the 8 lymph node-positive patients receiving a simultaneous pelvic nodal dose escalation. In conclusion, WPRT with a SIB to the prostate and seminal vesicles by helical tomotherapy resulted in a favourable toxicity profile. Pelvic nodal dose escalation in node-positive patients is feasible without increasing toxicity.

Evidence-based radiation oncology: Definitive, adjuvant and salvage radiotherapy for non-metastatic prostate cancer

The standard treatment options based on the risk category (stage, Gleason score, PSA) for localized prostate cancer include surgery, radiotherapy and watchful waiting. The literature does not provide clear-cut evidence for the superiority of surgery over radiotherapy, whereas both approaches differ in their side effects. The definitive external beam irradiation is frequently employed in stage T1b-T1c, T2 and T3 tumors. There is a pretty strong evidence that intermediate- and high-risk patients benefit from dose escalation. The latter requires reduction of the irradiated normal tissue (using 3-dimensional conformal approach, intensity modulated radiotherapy, image-guided radiotherapy, etc.). Recent data suggest that prostate cancer may benefit from hypofractionation due to relatively low alpha/beta ratio; these findings warrant confirmation though. The role of whole pelvis irradiation is still controversial. Numerous randomized trials demonstrated a clinical benefit in terms of biochemical control, local and distant control, and overall survival from the addition of androgen suppression to external beam radiotherapy in intermediate- and high-risk patients. These studies typically included locally advanced (T3-T4) and poor-prognosis (Gleason score >7 and/or PSA >20 ng/mL) tumors and employed neoadjuvant/concomitant/adjuvant androgen suppression rather than only adjuvant setting. The ongoing trials will hopefully further define the role of endocrine treatment in more favorable risk patients and in the setting of the dose escalated radiotherapy. Brachytherapy (BRT) with permanent implants may be offered to low-risk patients (cT1-T2a, Gleason score <7, or 3+4, PSA <or=10 ng/mL), with prostate volume of <or=50 ml, no previous transurethral prostate resection and a good urinary function. Some recent data suggest a benefit from combining external beam irradiation and BRT for intermediate-risk patients. EBRT after radical prostatectomy improves disease-free survival and biochemical and local control rates in patients with positive surgical margins or pT3 tumors. Salvage radiotherapy may be considered at the time of biochemical failure in previously non-irradiated patients.

External beam radiotherapy as curative treatment of prostate cancer

External beam radiotherapy (RT) has been used as a curative treatment of prostate cancer for more than 5 decades, with the "modern" era emerging more than 3 decades ago. Its history is marked by gradual improvements punctuated by several quantum leaps that are increasingly driven by advancements in the computer and imaging sciences and by its integration with complementary forms of treatment. Consequently, the contemporary use of external beam RT barely resembles its earliest form, and this must be appreciated in the context of current patient care. The influence of predictive factors on the use and outcomes of external beam RT is presented, as is a selected review of the methods and outcomes of external beam RT as a single therapeutic intervention, in association with androgen suppression, or as a postoperative adjunct. Thus, the "state of the (radiotherapeutic) art" is presented to enhance the understanding of this treatment approach with the hope that this information will serve as a useful resource to physicians as they care for patients with prostate cancer.

Comparison of external radiation therapy vs radical prostatectomy in lymph node positive prostate cancer patients

INTRODUCTION

Treatment options for lymph node positive prostate cancer are limited. We retrospectively compared patients who underwent external radiotherapy (ERT) to patients treated by radical prostatectomy (RPX).

MATERIALS AND METHODS

A total of 102 lymph node positive patients from the RPX series at Ulm University were evaluated. In all, 76 patients received adjuvant androgen withdrawal as part of their primary treatment. In the ERT group, 44 patients were treated at the University of Michigan using a fractionated regimen. Of these, 21 patients received early adjuvant hormonal therapy. Patients with neoadjuvant therapy before RPX or ERT were excluded.

RESULTS

In the RPX group, PSA nadir (nadir < or = 0.2 vs > 0.2 ng/ml) showed a strong association with outcome. In the ERT group, pretreatment PSA was an independent predictor of outcome (P = 0.04) and patients with adjuvant hormonal therapy had a significant longer recurrence-free interval compared to patients without adjuvant therapy (P = 0.004). Comparing only patients with adjuvant hormonal treatment after cancer-specific therapy, the ERT-treated patients had a borderline longer PSA recurrence-free survival time compared to the RPX-treated patients (P = 0.05).

CONCLUSIONS

In case of positive lymph nodes, RPX and ERT might be considered and need to be explained to the patient. For future treatment decisions, the presented findings and a potential survival benefit need to be evaluated in a larger prospective setting.

[Prostate cancer. Treatment]

The discovery and the utilisation of the prostate specific antigen (PSA) that allows early diagnosis of prostate cancer, have considerably improved the management of this disease. Before the PSA era, prostate cancer was just a disease of the old man, generally detected at an advanced stage and incurable, with a fatal outcome delayed by the androgenic deprivation. Since early 1990's, prostate cancer has become primarily a disease of the man of 60 years, detectable earlier, and curable provided no extraprostatic dissemination has occurred. Early treatment of prostate cancer has benefited from important advances in surgical and radio-therapeutic techniques (conformational irradiation, brachytherapy), with, as principal goal, the combination of a better survival and the reduction of the potential adverse effects that alter quality of life. A better definition of the characteristics of the tumours in terms of progression regarding various parameters (clinical stage, PSA, tumoral differentiation) have resulted, despite the heterogeneity of the disease, in the determination of subgroups of tumours with different prognosis, which leads to an improved therapeutic strategy. The assessment of men's life expectancy (< or > 10 years) is the second primary parameter on which is based the indication for curative or non curative therapy in case of localized tumour. Roughly, before the age of 75, a curative therapy is indicated whereas after this age a surveillance is reasonable as first-line treatment, followed by hormone therapy in case of onset of symptoms indicating some progression of the disease (urinary symptoms, bone lesion). At a Later stage, in case of a metastatic or locally advanced cancer, hormone therapy by androgenic deprivation is highly indicated. The hormone sensitivity characterizes prostate cancer; it has been discovered more than 50 years ago by Charles Huggins (Nobel prize-winner). This hormone therapy is a palliative treatment since its efficacy is transient (ineluctable occurrence of hormone resistance in a variable time delay), but it constitutes an essential therapeutic means with a well-established efficacy. Hormone therapy has progressively improved, with the renunciation of oestrogen therapy and surgical castration which has been replaced by luteinizing hormone-releasing hormone (LH-RH) analogues, and/ or anti-androgens. Numerous works have resulted in a better rationalization of the prescription (date of treatment initiation, interest of combined androgenic deprivation, ...) but uncertainties remain, such as the therapeutic interest of intermittent treatment, or of earlier hormone therapy combined with the treatment of the primitive tumour (adjuvant hormone therapy). Finally, at the time of the hormonal escape of which the molecular mechanisms remain unclear, no therapy has proven any efficacy in survival lengthening, and the treatment remains palliative and symptomatic. Although improved knowledge of prostate cancer aetiology is expected for a real disease prevention, early diagnosis at a curable stage of the disease (by PSA assessment) remains the only means for mortality reduction.

Prognostic factors and survival in node-positive (N1) prostate cancer-a prospective study based on data from a Swedish population-based cohort

OBJECTIVE

At presentation of prostate cancer, patients with proven lymph node metastasis (N1) are comparatively rare. It is difficult to give prognostic information based on the present literature. The aim of this study was to evaluate the impact of known risk factors in patients with pelvic node involvement and without distant metastasis.

METHODS

From the population-based, prospective prostate cancer tumour registry of the South-East Region in Sweden, we collected data on all 181 patients with N1, M0 prostate cancer diagnosed from January 1987 to October 2000 with a follow-up to December 2001. Mean follow-up was 62 months. Pre-operative risk factors as age, T-category, serum PSA, tumour grade and also primary treatment given was correlated to the outcome.

RESULTS

Median age at diagnosis was 65 years. Cancer-specific survival was highly variable with 5-year survival of 72%, a median of 8 years and the projected 13-year figure was 31%. T-category, age, PSA or treatment did not affect the outcome while poorly differentiated tumours had a tendency towards lower cancer-specific survival (p=0.0523) when compared to well and moderately differentiated tumours.

CONCLUSIONS

This population-based cohort of prostate cancer patients with pelvic node involvement treated principally with non-curative intent had a median cancer-specific survival of 8 years. Preoperatively known risk factors seem to have but a modest impact on the prognosis for patients in this stage of the disease.

Addition of radiation therapy to androgen ablation improves outcome for subclinically node-positive prostate cancer

OBJECTIVES

To determine the outcome for node-positive prostate cancer treated by early androgen ablation with or without prostatic radiation.

METHODS

Two hundred fifty-five men with lymphadenectomy-proven pelvic nodal metastases treated with early androgen ablation alone (n = 183) or with combined ablation and radiation (n = 72) between 1984 and 1998 were retrospectively reviewed for disease outcome and survival. Post-treatment disease status was based on the prostate-specific antigen levels or on the clinical and radiographic status for patients treated before 1987. Univariate and multivariate statistics were used to determine the prognostic factors and assess the influence of radiation treatment.

RESULTS

With a median follow-up of 9.4 years, the 5, 10, and 13-year overall survival rate for those treated with early ablation alone was 83%, 46%, and 21%, respectively. The freedom from relapse or rising prostate-specific antigen rate for these patients was 41%, 25%, and 19% at 5, 10, and 13 years, respectively. Distant metastasis and local recurrence occurred with a 10-year actuarial incidence of 44% and 51%, respectively. With a median follow-up of 6.2 years, the 5 and 10-year overall survival rate for those treated with radiation and ablation was 92% and 67%, respectively. The freedom from relapse or rising prostate-specific antigen rate in these men was 91% and 80% at 5 and 10 years, respectively. The superior outcome for combined ablation and radiation was substantial and statistically significant in the univariate and multivariate analyses.

CONCLUSIONS

Early androgen ablation alone has little curative potential for node-positive prostate cancer. The addition of prostatic radiation to ablation resulted in substantial and significant improvement in disease control and patient survival.

Lymph node-positive prostate cancer: evaluation of the results of the combination of androgen deprivation therapy and radiation therapy

OBJECTIVE

To evaluate the outcome of patients with pathologic stage IV prostate cancer treated with androgen ablation plus external-beam radiation therapy.

PATIENTS AND METHODS

Sixty consecutive patients treated between August 1986 and February 1995 with androgen ablation plus radiation therapy for stage IV (T1-4 N1 M0) adenocarcinoma of the prostate were selected for outcome analysis in this retrospective study. Bilateral pelvic lymphadenectomy was performed in 56 patients (93%). The 4 remaining patients had pelvic adenopathy on computed tomography, which was confirmed histologically in all patients. The median pretreatment prostate-specific antigen (PSA) level was 28.8 ng/mL (mean, 55 ng/ mL; range, 0.1-428 ng/mL). All patients received radiation therapy to the prostate, and 29 (48%) had pelvic node radiation. Biochemical failure was defined according to the American Society for Therapeutic Radiology and Oncology criteria of 3 successive increases in the PSA level.

RESULTS

The median follow-up duration for surviving patients was 101.1 months (range, 20-134 months). Biochemical failure with (in 2 patients) or without (in 10 patients) clinically evident disease relapse was noted in 12 patients (20%). Four additional patients (7%) had clinical relapse without biochemical failure. Local recurrences were observed in 6 patients (10%), and this clinical impression was confirmed by biopsy in 4 patients. Thirteen patients (22%) died of causes related to prostate cancer. The biochemical relapse-free, clinical disease-free, overall, and cause-specific survival rates at 5 years were 82%, 84%, 76%, and 80%, respectively.

CONCLUSIONS

This observational case series of patients treated with the combination of external-beam radiation therapy and permanent androgen ablation for pathologic stage IV prostate cancer suggests that the addition of androgen deprivation therapy to radiation therapy may improve disease outcome. In the absence of randomized trial results, these observations may be beneficial in clinical decision making.

[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.

Androgen ablation in addition to radiation therapy for prostate cancer: is there true benefit?

Prostate cancer patients may now be identified as having a high risk of failing single-modality treatment based on pretreatment prostate specific antigen (PSA), Gleason score, and palpable stage. In particular, a PSA greater than 20 ng/mL portends a biochemical failure rate of 50% to 80% when radiation therapy, surgery, or androgen ablation is administered individually. A number of randomized trials as well as retrospective data show that failure rates are significantly reduced by combining androgen ablation and radiation. The improved results, however, are complicated by the ability to salvage radiation alone-treated patients with androgen ablation and the possibility of less effective salvage (or no effective salvage in the case of permanent androgen ablation) for patients treated with androgen ablation plus radiation. Thus, survival, which is obscured by high rates of intercurrent deaths in this elderly population, is the most important end point in such studies. Two randomized trials, one from the Radiation Therapy Oncology Group (RTOG) and one from the European Organization for Research on Treatment for Cancer (EORTC), of radiation therapy plus adjuvant (as opposed to neoadjuvant) androgen ablation have reported survival gains over radiation therapy alone. In contrast, one neoadjuvant trial from the RTOG failed to show a survival benefit when androgen ablation was added to radiation therapy. In this study, however, androgen ablation was administered for only 4 to 5 months, which may be insufficient. The weight of the evidence to date indicates a true benefit with androgen ablation plus radiation therapy over radiation therapy alone. There are clearly many unanswered questions concerning the optimal timing of androgen ablation and radiation therapy (neoadjuvant versus adjuvant), length of time that androgen ablation should be administered (6 months versus 3 years versus permanent), type of androgen ablation (total androgen ablation or not), and appropriate patient population (definition of high risk). The planned future clinical trials will address many of these issues; however, the full potential of this approach requires an understanding of the fundamental mechanisms involved.

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.

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.

Supraadditive apoptotic response of R3327-G rat prostate tumors to androgen ablation and radiation

PURPOSE

Androgen ablation is often combined with radiation in the treatment of patients with prostate cancer, yet, the optimal sequencing and the mechanisms governing the interaction are not understood. The objectives were to determine if cell killing via apoptosis is enhanced when the combined treatment is administered and to define the relationship of changes in this form of cell killing to tumor volume growth delay.

MATERIALS AND METHODS

Dunning R3327-G rat prostate tumors, grown in the flanks of Copenhagen rats, were used at a volume of approximately 1 cc. Androgen ablation was initiated by castration, and androgen restoration was achieved with 0.5 cm silastic tube implants containing testosterone. 60Co was used for irradiation. The terminal deoxynucleotidyl transferase (TUNEL) histochemical assay was used to quantify apoptosis.

RESULTS

Tumors from intact and castrate unirradiated control rats had average apoptotic indices (percent of apoptotic cells) of 0.4 and 1.0%, respectively. The apoptotic index varied only slightly over time (3 h to 28 days) after castration (range 0.75-1.43%). Irradiation of intact rats to 7 Gy resulted in a peak apoptotic response at 6 h of 2.3%. A supraadditive apoptotic response was seen when castration was initiated 3 days prior to 7 Gy radiation, with peak levels of about 10.1%. When the radiation was administered at increasing times beyond 3 days after castration, the apoptotic response gradually diminished and was back to levels seen in intact rats by 28 days after castration. Tumor volume growth delay studies were consistent with, but not conclusive proof of, a supraadditive effect when the combination was used.

DISCUSSION

A supraadditive apoptotic response was seen when androgen ablation and radiation were used to treat androgen sensitive R3327-G rat prostate tumors. This supraadditive effect was dependent on the timing of the two treatments. Further studies are required to more fully define the optimal timing and administration of androgen ablation and radiation.

The significance of DNA-ploidy and S-phase fraction in node-positive (stage D1) prostate cancer treated with androgen ablation

BACKGROUND

The prognostic significance of primary tumor DNA-ploidy and S-phase fraction (SPF) was evaluated in patients treated with androgen ablation for regionally localized node-positive prostate cancer.

METHODS

All patients were diagnosed with lymph node involvement by pelvic lymphadenectomy between 1984 and 1992 and were treated only with androgen ablation. Median follow-up was 45 months. Adequate material for DNA/nuclear protein flow cytometric analysis was available in 33 patients.

RESULTS

The tumors were classified as diploid in 11, near-diploid in 4, tetraploid in 10, and aneuploid in 8 cases. Grouping the patients by nonaneuploidy (diploid and near-diploid and tetraploid) and aneuploidy revealed actuarial 4-year disease progression rates of 14 and 48% (log-rank, P = 0.04), and overall survival rates of 100 and 61% (P = 0.008); however, biochemical progression (rising prostate-specific antigen profile) rates were similar at around 70%. In contrast, SPF was not significantly related to any of the endpoints tested. Several other potential prognostic factors were examined and none correlated significantly with disease progression or survival.

CONCLUSIONS

The biochemical progression rates for patients with nonaneuploid and aneuploid tumors were comparable and high, while the disease progression rates were higher and survival rates lower for those with aneuploid tumors. These data indicate that the lead time from biochemical to disease progression and death was shorter with aneuploidy. That these relationships were observed in such a small patient population attest to the strength of DNA-ploidy as a prognostic factor in this cohort.

[The conformal radiotherapy of localized prostatic carcinoma: acute tolerance and early efficacy]

AIM

In a prospective trial early effectiveness and acute toxicity of conformal 3D-planned radiotherapy for localized prostate cancer was quantified using dose-volume-histogramms and evaluated with respect of treatment technique.

PATIENTS AND METHOD

Thirty-two men (44 to 80 years old) with locally advanced carcinoma of the prostate (stage B2 or C) have been treated by 3D-planned conformal radiotherapy using high energy photons. In 28/32 men treatment technique was a monoaxial bisegmental rotation with irregular fields. With single doses of 2.0 Gy a mean total dose of 63.9 +/- 4.9 Gy according to ICRU was applied within 46 +/- 4 days. Maximum dose was in the mean 105.1% +/- 3.8%. 3D treatment volume was 274.1 +/- 113.4 cm3. Median follow-up is 1.8 years (15 to 34 months). Toxicity was evaluated according to RTOG-EORTC by patient interview and physical examination on a weekly basis during radiotherapy and by regular follow-up.

RESULTS

Eleven patients had none, 15 mild (RTOG grade 1) and 6 moderate symptoms (RTOG grade 2, mainly diarrhoea, dysuria and polyuria). Acute complications leading to treatment interruption did not occur. In 16 patients symptoms disappeared within 6 weeks after radiotherapy. Only 2 men had symptoms which lasted longer than 3 months and were endoscopically examined. Up to now no late complications were detected. Incidence and severity of toxicity was significantly (p < 0.05) related to the size of treatment volume. Acute toxicity was found to depend statistically significant (p < 0.05) on the proportional volume of bladder and rectum, irradiated with more than 35 Gy. In 81% of the patients with pretherapeutic elevated PSA levels normalisation of PSA was observed. Overall mean PSA levels of 15.7 +/- 22.6 micrograms/l at the beginning of radiotherapy fell to 2.1 +/- 3.7 micrograms/l 6 weeks after irradiation. Only 1 Patient relapsed locally 22 months after radiation therapy.

CONCLUSION

We conclude that due to modern 3D-planned conformal techniques with optimization of treatment dose and improved protection of critical organs such as urinary bladder and rectum, radiotherapy allows an effective and well tolerated therapy of localized prostatic carcinoma.

Radiotherapy for regionally localized hormone refractory prostate cancer

PURPOSE

Patients with regionally localized hormone refractory adenocarcinoma of the prostate are often referred for radiotherapy to relieve local symptoms, prevent further local progression, or prevent impending urinary tract obstruction. However, the merits of radiotherapy for this patient population have not been documented. In this retrospective series, the results of 29 such patients treated at our institution between 1987-1992 are reviewed.

METHODS AND MATERIALS

Prior to androgen ablation, the majority of these patients (79%) had Stage D0 or D1 disease. After androgen ablation, radiotherapy was given to 16 (55%) for progressive symptoms (mostly urinary obstructive), 11 (38%) for palpable local progression in the absence of symptoms, and 2 for a rising prostate specific antigen (PSA) profile without palpable disease. None of the patients had distant metastasis at the time of radiotherapy. The median dose to the prostate was 66 Gy and the median follow-up after radiotherapy was 43 months.

RESULTS

Following local-regional radiotherapy, the actuarial rate of local failure at 4 years was only 39%. However, 80% had disease progression or a rising PSA in this time period. The actuarial survival at 4 years following radiotherapy was 39%. Univariate analyses of potential prognostic factors revealed that preandrogen ablation Gleason score, preradiotherapy PSA, and preradiotherapy prostatic acid phosphatase (PAP) were predictive of patient outcome. Most importantly, doses above 60 Gy to the prostate at standard fractionation were associated with symptom-free local control in 90% of patients at 3 years. The majority of the patients were treated using limited fields (n = 20).

CONCLUSIONS

The regionally localized hormone refractory prostate cancer patients described benefited from high dose, continuous course, local radiotherapy in that excellent local control rates were obtained for an extended period. Because the majority of these patients fail with distant metastasis within 4 years, this treatment represents an aggressive approach to palliation that is justified by the maintenance of freedom from local symptoms.

Radiotherapy and androgen ablation for clinically localized high-risk prostate cancer

PURPOSE

The response of patients with clinical stages T1-4 prostate cancer to radiotherapy is variable. A particularly poor prognostic group has been found to be comprised of those with pretreatment prostate specific antigen (PSA) levels above 30 ng/ml with any tumor grade, or PSA levels > 10 and < or = 30 with tumors grade 3 or 4. These patients have over an 80% actuarial risk of biochemical failure 3 years after definitive external beam radiotherapy. Thus, patients with these high-risk features require more aggressive therapy. During the last 3-4 years, the policy to treat such patients with radiotherapy and androgen ablation (XRT/HORM) was instituted. A retrospective comparison was made between high-risk patients treated with radiotherapy alone (XRT) vs. XRT/HORM.

METHODS AND MATERIALS

Between 1987 and 1991, there were 81 high-risk patients treated with XRT. There were 38 high-risk patients treated with XRT/HORM between 1990 and 1992. The median follow-up was 37 months for the XRT group and 22 months for the XRT/HORM group. No patient had clinical, radiographic, or pathologic evidence of lymph node involvement. The median dose to the prostate was 66 Gy for the XRT group and 68 Gy for the XRT/HORM group.

RESULTS

The distributions of several potential prognostic factors were analyzed. Significant differences between the groups were observed for tumor grade, pretreatment prostatic acid phosphatase, and age. The XRT/HORM group was composed of patients with worse features, including a greater proportion of patients with grade 4 tumors, more with abnormal acid phosphatase levels, and more under 60 years of age. The actuarial incidence of a rising PSA at 3 years for the XRT group was 81% vs. 15% for the XRT/HORM group (p < 0.0001). In addition, local relapse at 3 years was 34% for the XRT group and 15% for the XRT/HORM group (p < 0.02). There was no difference between the groups in terms of survival. Cox proportional hazards analyses were performed using several disease end points, including a rising PSA, a rising PSA or disease relapse, any disease relapse, and local relapse, and the only prognostic factor of independent predictive value was treatment group, i.e., XRT vs. XRT/HORM.

CONCLUSIONS

Based on biochemical and disease relapse end points, definitive radiotherapy is insufficient treatment for high-risk prostate cancer patients. The addition of androgen ablation significantly reduces the recurrence rates, although longer follow-up is needed to determine if the combined treatment impacts significantly on survival.