[Indications for pelvic lymphadenectomy in clinically localized prostate cancer].

INTRODUCTION: Pelvic lymphadenectomy for localized prostate cancer (stage T1-T2) provides prognostic information. It can be performed by laparoscopy or by open surgery. Systematic lymphadenectomy is controversial and should be performed according to the stage of the tumour and the type of management. Frozen section examination of lymph nodes during total prostatectomy is also controversial due to its low sensitivity (66%). The objective of this article is to define the indications for lymphadenectomy and frozen section examination.

METHODS: Systematic review of the literature.

RESULTS: Recommendations concerning the indications for bilateral pelvic lymphadenectomy and frozen section examination for stage T1-T2 prostate cancer as a function of the risk of lymph node metastases. A low risk (<5%) of lymph node metastases is defined by an initial PSA < 10 ng/ml, a Gleason score of biopsies < 7 (3 + 4 or < 50% of grade 4) and possibly non-suspicious lymph node imaging. In this case, prior pelvic lymphadenectomy either some time before or immediately before local treatment is optional (Level of Evidence III-2). Due to the morbidity related to lymphadenectomy, the benefit of the procedure is not justified. However, the following situations are distinguished for open or laparoscopic total prostatectomy: --if open total prostatectomy is considered, exploration of the lymph nodes by palpation at the beginning of the operation is recommended. If exploration does not suggest any lymph node invasion, lymphadenectomy is then optional (without frozen section examination). If exploration shows induration or a mass deforming the shape of the lymph nodes, lymphadenectomy is recommended. Frozen section examination is requested only when the surgeon decides not to perform prostatectomy in the case of lymph node invasion. Lymphadenectomy without frozen section examination is optional in the case of laparoscopic total prostatectomy. Macroscopic examination of any lymph node invasion is less accurate via laparoscopy. A high risk (> 5%) of lymph node metastases is defined by a PSA > 10 ng/ml and/or a Gleason score > 7 (4 + 3 or > 50% of grade 4), and/or suspicious lymph node imaging. Pelvic lymphadenectomy is then recommended (Level of Evidence III-2). The following situations can be distinguished according to the type of treatment envisaged (total prostatectomy or external radiotherapy): when the surgeon decides not to perform total prostatectomy in the case of microscopic or macroscopic lymph node invasion (pN1), lymphadenectomy (open or laparoscopic) may be performed either before or at the same time as prostatectomy with frozen section examination. In the case of external radiotherapy, laparoscopic (or open) lymphadenectomy is recommended (without frozen section examination) when it is decided to extend the irradiation field to pelvic lymph nodes in the case of stage pN1 (1st option) or withhold radiotherapy (2nd option). Lymphadenectomy is optional in other cases, as lymphadenectomy induces considerable morbidity and the benefit of systematic pelvic lymph node irradiation has not been demonstrated. It should be stressed that all indications for lymphadenectomy for localized prostate cancer proposed in the literature are based on the results of standard or limited pelvic lymphadenectomy. These indications could be revised if it is confirmed that lymphadenectomy extended to the internal iliac nodes, for patients at high risk of lymph node invasion, is truly informative and contributive to the treatment decision.