Sentinel node dissection to select clinically node-negative prostate cancer patients for pelvic radiotherapy : impact on biochemical recurrence and systemic progression
Menée sur 224 patients atteints d'un cancer de la prostate ne présentant pas de signes cliniques d'envahissement ganglionnaire, cette étude évalue l'intérêt d'une exérèse laparoscopique radioguidée du ganglion sentinelle pour diagnostiquer des métastases ganglionnaires et identifier les patients nécessitant une radiothérapie externe et un traitement anti-androgénique de longue durée
Purpose : To assess the efficacy of (robotic-assisted) laparoscopic sentinel node (SN) dissection (sLND) to select those prostate cancer (PCa) patients who would benefit from additional pelvic external beam radiotherapy (EBRT) and long term androgen deprivation therapy (ADT).
Methods and Materials : Radio-guided sLND was performed in 224 clinically node negative patients planned for treatment with EBRT. Patients with histologically positive SNs (pN1) were additionally offered radiation on the pelvic nodes combined with three years of ADT. Biochemical recurrence (BCR), overall survival (OS) and metastases (including pelvic and non-regional lymph nodes) free survival (MFS) rates were retrospectively calculated. The Briganti and Kattan nomogram predictions were compared with the observed pN status and BCR, accordingly.
Results : The median value of prostate-specific antigen (PSA) was 15.4 ng/ml (interquartile range (IQR): 8–29). A total number of 834 SNs (median: 3 per patient; IQR: 2–5) were removed. Nodal metastases were diagnosed in 42% of the patients, with 150 affected SNs (median: 1; IQR: 1–2). Five-year BCR-free and MFS rates for pN0 patients were 67.9% and 87.8%, respectively. Corresponding values for pN1 patients were 43% and 66.6%, respectively. PSA and number of removed SNs were independent predictors of BCR and MFS, while pN status was additionally independent predictor of BCR. Five year OS rate was 97.6% and was only correlated with pN status. The predictive accuracy of the Briganti nomogram was 0.665. Patients in higher quartiles of Kattan nomogram prediction of BCR, had better than expected outcome. The complication rate from sLND was 8.9%.
Conclusions : For radio-guided sLND high staging accuracy is accompanied by low morbidity. The better than expected outcomes observed in the lower quartiles of BCR prediction suggest a role for SN biopsy as a potential selection tool for the addition of pelvic radiotherapy and ADT intensification in pN1 patients.
International Journal of Radiation Oncology • Biology • Physics , résumé, 2015