The nodal cancer index (NCI): An objective approach for systematic lymph node dissection in ovarian carcinomatosis

Ovarian cancer is the deadliest gynaecological malignancy, often diagnosed at an advanced stage with widespread peritoneal dissemination and lymph node involvement, particularly in retroperitoneal and pelvic regions. The Peritoneal Cancer Index(PCI) is used to assess peritoneal disease but does not address nodal metastasis, an important prognostic factor. The Nodal Cancer Index(NCI) was developed to quantify lymph node burden, improving surgical precision.

The primary aim was to assess the NCI as a score for objectively evaluating systemic lymph node dissection in ovarian cancer. Secondary objectives included evaluating its prognostic value and survival outcomes.

This study included 211 patients with advanced ovarian cancer(FIGO stages III and IV) who underwent cytoreductive surgery(CRS) from 2015 to 2020. The NCI divided the abdomen and pelvis into 13 nodal zones zones(6 retroperitoneal and 6 pelvic, plus an extra-abdominal zone). Each zone was scored based on lymph node size, with higher scores indicating more extensive disease. The NCI score was correlated with clinical outcomes, including survival rates.

The cohort's median age was 51 years, with most patients at advanced stages (FIGO III: 73.9 %, IV: 26.1 %). Histologically, 83.4 % had serous carcinoma. Treatment included 23.7 % upfront surgery and 76.3 % neoadjuvant chemotherapy (NACT) with interval cytoreductive surgery (CC-0: 88.1 %). Lymph node involvement occurred in 46.4 % of cases. Survival analysis showed that patients with low, moderate, and severe NCI scores had median OS of 57.70, 47.58, and 36.37 months, respectively, with lower NCI scores linked to better survival.

The NCI provides an objective framework for assessing lymph node metastasis in ovarian cancer, aiding in surgical planning, prognostication, and treatment decisions.