Radiotherapy instead of inguinofemoral lymphadenectomy in vulvar cancer patients with a metastatic sentinel node: results of GROINSS-V II

• Published in: International journal of gynecological cancer Vol. 29; no. Suppl 4; p. A14
• Main Authors: Oonk, MHM, Slomovitz, B, Baldwin, P, van Doorn, H, van der Velden, J, de Hullu, J, Slangen, B, Gaarenstroom, K, Vergote, I, Brannstrom, M, van Dorst, E, van Driel, W, Hermans, R, Nunns, D, Widschwendter, M, Nugent, D, Holland, C, DiSilvestro, P, Sharma, A, Mannel, R, Boll, D, Covens, A, Cibula, D, Provencher, D, Luesley, D, Ellis, P, Duncan, T, Tjiong, M, Cruickshank, D, Kjolhede, P, Levenback, C, Bouda, J, Kieser, K, Runnebaum, I, Palle, C, Spirtos, N, O’Malley, D, Leitao, M, Geller, M, Tamussino, K, Dhar, K, Tobias, D, Borgfeldt, C, Myers, T, Lea, J, Bailey, J, Persson, P, Monk, B, Creutzberg, C, van der Zee, A
• Format: Journal Article
• Language: English
• Published: Oxford BMJ Publishing Group LTD 01.11.2019
• Subjects: Genital cancers; Metastasis; Radiation therapy
• ISSN: 1048-891X; 1525-1438
• DOI: 10.1136/ijgc-2019-ESGO.16

Introduction/Background Introduction: GROINSS-V II investigated whether radiotherapy is a safe alternative for inguinofemoral lymphadenectomy (IFL) in vulvar cancer patients with a metastatic sentinel node (SN).Methodology Methods: In GROINSS-V II, a prospective multicentre phase II trial, patients were included with early-stage squamous cell carcinoma (SCC) of the vulva (diameter <4cm) without suspicious lymph nodes at imaging, who had primary surgery with SN-procedure. In case of a metastatic SN (metastasis of any size), radiotherapy was given to the groin(s) (50Gy). In case of a negative SN, patients were followed-up for ≥2 years. Stopping rules were defined for both groups to monitor groin recurrence rate.ResultsFrom December 2005 until October 2016, 1552 eligible patients were registered. SN-metastasis occurred in 324/1552 (21%) patients. After 54 months of inclusion the stopping-rule for SN-positive patients was activated; interim analysis showed an increased risk for groin recurrence in case of SN-metastasis >2 mm and/or extranodal extension (ENE). After amendment of the protocol only patients with SN-micrometastasis ≤2 mm received radiotherapy, while those with SN metastasis >2 mm underwent IFL (with radiotherapy if >1 metastasis or ENE). Final analysis after ≥2 years of follow-up revealed six isolated groin recurrences in 157 patients with a SN-micrometastasis (3.8%). Four could not be considered radiotherapy failures: two developed recurrence in the contralateral (SN-negative) groin, two refused radiotherapy. Twenty-eight patients did not get radiotherapy (2 recurrences;7.1%). Among 129 patients who received radiotherapy to the groin(s) only two isolated groin recurrences were diagnosed (1.6%: 95%CI:0–3.8%). The combination of radiotherapy with SN was associated with minimal toxicity: 5/118(4.2%) grade 3 toxicity, no grade 4 or 5 toxicity. In 38/1222 SN-negative patients (3.1%: 95%CI:2.1–4.1%) isolated groin recurrences were diagnosed with clear protocol violations in 6 patients: incomplete treatment of the groin (n=3); primary tumor >4cm (n=1); not all SNs visualized on the lymphoscintigram removed (n=2). After exclusion of these protocol violations an isolated groin recurrence rate of 2.6% (95%CI:1.7–3.5%) was observed.ConclusionRadiotherapy to the groins is a safe alternative for IFL in patients with SN metastasis ≤2 mm, with minimal toxicity. We further established the safety of omitting IFL in patients with SCC of the vulva <4cm and a negative SN. For patients with SN metastasis >2 mm, radiotherapy with a total dose of 50Gy was no safe alternative for IFL; dose escalation and/or chemoradiation should be investigated in these patients.DisclosureFunded by Dutch Cancer Society.