Retroperitoneal lymph node dissection in patients with advanced non-seminomatous germ cell testicular tumors and incomplete radiological and serological response to chemotherapy: results

Objective: To evaluate the results of retroperitoneal lymph node dissection (RPLND) in patients with advanced non-seminomatous germ cell testicular tumors (NSGCT) and incomplete serological and radiological response to chemotherapy (CT). Materials and methods: The study included 96 patients with advanced NSGCT who underwent RPLND in N. N. Blokhin Russian Cancer Research Center in 1983-2020. The median age was 27 (15-57) years. All patients (n = 96, 100,0 %) received first-line cisplatin-based CT. Fifty-eight patients (60,4%) received second-line CT. After completion of CT, all patients presented with elevated levels of AFP and/or hCG and detectable tumor lesions (retroperitoneal metastases only in 77 cases (80,2 %), metastases in the retroperitoneal space and other sites in 19 cases (19,8%)). All patients underwent the follow-up surgery after CT completion: RPLND in 96 cases (100,0%) and resection of extra-retroperitoneal lesions in addition to RPLND in 8 cases (8,3%). In total, 29 (30,2%) of 96 patients received CT following surgery. The median follow-up was 39,4 (1-284) months. Results: Postoperative complications were reported in 10 (10,6%) patients, including grade 3-4 in 3 patients (3,1%). The mortality rate was 1,1%. The complete resection of retroperitoneal tumor lesions was performed in 80 cases (83,3 %), resection of all detectable tumor lesions in 69 cases (71,9%). None of the patients achieved complete response to postoperative CT. Pathological examination of retroperitoneal lesions revealed necrosis and fibrosis, teratomas, and malignant non-seminomatous tumors in 25 (26,0 %), 29 (30,2 %), and 42 (43,8 %) cases, respectively. The long-term overall survival (OS) and cancer-specific survival rates were 60,9 % and 61,7 %, respectively. The relapse-free survival rate in patients who underwent complete resection reached 65,2 %, the progression-free survival rate in patients who underwent incomplete resection was 35,9 %. A multivariate analysis revealed the following independent predictors of unfavorable OS: RPLND after second-line CT (odds ratio [OR] 4,667 (95% confidence interval [CI]: 1,987-10,961)), presence of a residual retroperitoneal mass of a malignant non-seminomatous tumor (OR 3,081 (95% CI: 1,178-8,055), and incomplete removal of residual lesions after CT (OR 4,445 (95% CI: 1,813-10,899)). Conclusion: Post-CT RPLND may be considered a viable option in the selected group of advanced NSGCT patients with an incomplete serological response to CT eligible for complete resection of all detectable tumor lesions.