Predictors of lymph node metastasis and survival in radically resected rectal neuroendocrine tumors: A Surveillance, Epidemiology, and End Results (SEER) database analysis.

BACKGROUND

Rectal neuroendocrine tumors are uncommon tumor types. Lymph node metastases may occur in up to 40%, potentially impacting decision-making. We aimed to assess risk factors for lymph node metastases of rectal neuroendocrine tumors and their association with overall and cancer-specific survival.

METHODS

This retrospective case-control study involved patients with stage I to III rectal neuroendocrine tumors who underwent radical resection. Data were derived from the Surveillance, Epidemiology, and End Results database (2000-2020). Patients with pathologic evidence of lymph node metastases were compared to those without lymph node metastases for baseline patient and tumor characteristics. The main outcomes were lymph node metastases, overall survival, and cancer-specific survival.

RESULTS

In total, 580 patients (50.9% male; mean age: 58.9 years) were included. The lymph node metastases rate was 37.1%. Independent predictors of lymph node metastases were Grade 2 neuroendocrine tumors (odds ratio: 8.06; P = .001), neuroendocrine carcinoma (odds ratio: 2.59, P = .006), large-cell neuroendocrine carcinoma (odds ratio: 4.89; P = .017), T2 tumors (odds ratio: 6.44; P < .001), T3 tumors (odds ratio: 27.5; P < .001), and T4 tumors (odds ratio: 17.3; P < .001). Lymph node metastases were associated with shorter restricted mean overall survival (40.8 vs 52.7 months; P < .001) and cancer-specific survival (41.3 vs 54.8 months; P < .001). When adjusted for other confounders, the nodal status of rectal neuroendocrine tumors was not independently associated with overall (hazard ratio = 1.56; P = .165) or cancer-specific survival (hazard ratio = 1.69; P = .158). Significant factors associated with worse overall survival and cancer-specific survival were age, tumor size, neuroendocrine carcinomas, large-cell neuroendocrine carcinomas, and the number of positive lymph nodes.

CONCLUSIONS

Lymph node metastases of rectal neuroendocrine tumors were more likely associated with high-grade, large-sized, and T2 to T4 tumors. The number of involved lymph nodes was an independent predictor of overall and cancer-specific survival. Other independent survival predictors were tumor grade, size, and T stage.

Informations de copyright

Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.