RESUMEN
OBJECTIVES: To assess whether extended surveillance with repeated computed tomography (CT) scans for patients with clinical stage IIA (CS IIA; <2 cm abdominal node involvement) and negative markers (Mk-) non-seminomatous germ cell tumours (NSGCTs) can identify those with true CS I. To assess the rate of benign lymph nodes, teratoma, and viable cancer in retroperitoneal lymph node dissection (RPLND) histopathology for patients with CS IIA Mk- NSGCT. PATIENTS AND METHODS: Observational prospective population-based study of patients diagnosed 2008-2019 with CS IIA Mk- NSGCT in the Swedish and Norwegian Testicular Cancer Group (SWENOTECA) registry. Patients were managed with surveillance, with CT scans, and tumour markers every sixth week for a maximum of 18 weeks. Patients with radiological regression were treated as CS I, if progression with chemotherapy, and remaining CS IIA Mk- disease with RPLND. The end-point was the number and percentage of patients down-staged to CS I on surveillance and rate of RPLND histopathology presented as benign, teratoma, or viable cancer. RESULTS: Overall, 126 patients with CS IIA Mk- NSGCT were included but 41 received therapy upfront. After surveillance for a median (range) of 6 (6-18) weeks, 23/85 (27%) patients were in true CS I and four (5%) progressed. Of the remaining 58 patients with lasting CS IIA Mk- NSGCT, 16 received chemotherapy and 42 underwent RPLND. The RPLND histopathology revealed benign lymph nodes in 11 (26%), teratoma in two (6%), and viable cancer in 29 (70%) patients. CONCLUSIONS: Surveillance with repeated CT scans can identify patients in true CS I, thus avoiding overtreatment. The RPLND histopathology in patients with CS IIA Mk- NSGCT had a high rate of cancer and a low rate of teratoma.