PURPOSE: The Groningen International Study on Sentinel nodes in Vulvar cancer (GROINSS-V)-II investigated whether inguinofemoral radiotherapy is a safe alternative to inguinofemoral lymphadenectomy (IFL) in vulvar cancer patients with a metastatic sentinel node (SN). METHODS: GROINSS-V-II was a prospective multicenter phase-II single-arm treatment trial, including patients with early-stage vulvar cancer (diameter < 4 cm) without signs of lymph node involvement at imaging, who had primary surgical treatment (local excision with SN biopsy). Where the SN was involved (metastasis of any size), inguinofemoral radiotherapy was given (50 Gy). The primary end point was isolated groin recurrence rate at 24 months. Stopping rules were defined for the occurrence of groin recurrences. RESULTS: From December 2005 until October 2016, 1,535 eligible patients were registered. The SN showed metastasis in 322 (21.0%) patients. In June 2010, with 91 SN-positive patients included, the stopping rule was activated because the isolated groin recurrence rate in this group went above our predefined threshold. Among 10 patients with an isolated groin recurrence, nine had SN metastases > 2 mm and/or extracapsular spread. The protocol was amended so that those with SN macrometastases (> 2 mm) underwent standard of care (IFL), whereas patients with SN micrometastases (≤ 2 mm) continued to receive inguinofemoral radiotherapy. Among 160 patients with SN micrometastases, 126 received inguinofemoral radiotherapy, with an ipsilateral isolated groin recurrence rate at 2 years of 1.6%. Among 162 patients with SN macrometastases, the isolated groin recurrence rate at 2 years was 22% in those who underwent radiotherapy, and 6.9% in those who underwent IFL ( P = .011). Treatment-related morbidity after radiotherapy was less frequent compared with IFL. CONCLUSION: Inguinofemoral radiotherapy is a safe alternative for IFL in patients with SN micrometastases, with minimal morbidity. For patients with SN macrometastasis, radiotherapy with a total dose of 50 Gy resulted in more isolated groin recurrences compared with IFL.
5501 Background: The role of secondary cytoreductive surgery in recurrent ovarian cancer (OC) has not been defined by level-1 evidence. Methods: Pts with OC and 1st relapse after 6+ mos platin-free interval (TFIp) were eligible if they presented with a positive AGO-score (PS ECOG 0, ascites ≤500 ml, and complete resection at initial surgery) and were randomized to 2nd-line chemotherapy alone vs cytoreductive surgery followed by chemo. Chemo regimens were selected according to the institutional standard. We report here results of the predetermined interim analysis. Results: 407pts were randomized 2010-2014. The TFIp exceeded 12 mos in 75% and 76% pts in both arms. 8.9% of 203 pts were operated despite of randomization to the no-surgery arm, whereas 6.9% of 204 pts in the surgery arm did not undergo operation. Complete resection was achieved in 67% of pts; 87% and 88% received a platinum-containing 2nd-line therapy. Median PFS was 14 mos without and 19.6 mos with surgery (HR: 0.66, 95%CI 0.52-0.83, p<0.001). Median time to start of first subsequent therapy (TFST) was 21 vs 13.9 mos in favor of the surgery arm (HR 0.61, 95%CI 0.48-0.77, p=p<0.001). PFS-2 between 1st and 2nd relapse equaled or even exceeded PFS-1 before 1strelapse in 26% after surgery and only 16% without-surgery. Analysis of the primary endpoint OS is kept blinded due to immaturity and will be evaluated after extended follow-up (the observed pooled unblinded 2-YSR was 83% instead of the initially in the protocol assumed 55-66%). 60d mortality rates were 0 and 0.5% in the surgery and no-surgery arm. Re-laparatomies were performed in 7 pts (3.5%) in the surgery arm.With the exception of myelosuppression which occurred more frequently in the no-surgery arm no further significant differences were observed with respect to grade 3+ acute adverse events. Conclusions: Surgery in pts with 1st relapse of OC after a TFIp of 6+ mos and selected by a positive AGO-Score resulted in a clinically meaningful increase of PFS and TFST with acceptable treatment burden. Until final OS data will definitively define the role of secondary cytoreductive surgery it should at least be considered as valuable option in pts with a positive AGO-Score. Clinical trial information: NCT01166737.