Recurrence patterns and survival outcomes following lymphadenectomy in epithelial ovarian cancer: The impact of lymph node involvement

OBJECTIVE: The role of lymph node (LN) involvement on recurrence patterns and survival in patients with advanced epithelial ovarian cancer (EOC) remains unclear. This study investigates the treatment failure patterns and clinical outcomes in EOC patients with initial LN involvement. MATERIALS AND METHODS: We conducted a retrospective cohort study. Patients with stage IIIC/IV EOC who received standard therapy including cytoreductive surgery with lymphadenectomy and platinum-based adjuvant chemotherapy at our hospital between 2008 and 2018, achieved a complete response, were included. RESULT: Among 310 women with advanced EOC, 130 met the inclusion criteria. Of these, 77 had pathologically confirmed initial LN involvement (LN-positive group), of whom 51 (66.2 %) experienced recurrence. The remaining 53 patients were in the LN-negative group, with 29 (54.7 %) experiencing recurrence. Patients of the LN- positive group were more likely to experience treatment failure in retroperitoneal lymph node (RPLN) compared to those in the LN-negative group (28.6 % [22/77] vs. 11.3 % [6/53], p = 0.02). Out of 22 patients in the LN-positive group with RPLN recurrence, 10 experienced isolated retroperitoneal lymph node (iRPLN) recurrence, while none in the LN-negative group developed such recurrence. The rates of isolated LN-positive (iIP) recurrence and isolated distant recurrence were similar between the two groups. Isolated RPLN recurrence was not associated with better overall survival (OS) compared to iIP recurrence. The 5-year OS rate was 45.5 % for patients with iRPLN recurrence and 46.7 % for patients with iIP recurrence. In the LN-positive group, patients with >5 positive lymph nodes had a higher overall recurrence rate compared to those with ≤5 nodes (82.8 % vs. 55.6 %, p= 0.02), a significantly higher rate of RPLN recurrence (41.4 % vs. 20.0 %, p= 0.046), and poorer OS (p= 0.047). A similar trend was observed in patients with a lymph node ratio (LNR) ≥ 10 %, who showed a higher rate of RPLN recurrence (35.6 % vs. 17.2 %, p= 0.09) and reduced OS (p= 0.07), though these differences did not reach statistical significance. CONCLUSION: This study highlights the significant impact of initial LN involvement on recurrence patterns in patients with advanced EOC. Patients in the LN-positive group were more likely to experience recurrence in the RPLN and had a higher frequency of isolated RPLN recurrence. Isolated RPLN recurrence was not associated with better OS compared to iIP recurrence. The presence of more than five positive LNs was associated with higher recurrence rates, including a significantly higher rate of retroperitoneal recurrence, and poorer OS compared to patients with fewer positive LNs.