Stage D1 prostate cancer--is radiotherapy and early hormonal therapy equivalent to radical prostatectomy, radiotherapy, and early hormonal therapy? regarding Sands et al., IJROBP 31:13-19; 1995

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.

[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.

[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.