Association of Log Odds of Positive Lymph Nodes with Overall Survival in Patients with Primary Malignant Anorectal Melanoma: A Population-Based Study.

Background: Malignant anorectal melanoma (AM) is a rare tumor characterized by its aggressive behavior. To date, there has been no comprehensive investigation into the association between the log odds of positive lymph nodes (LODDS) and the prognosis of patients with malignant AM who have undergone surgical intervention.

Methods: Data were extracted from the Surveillance, Epidemiology and End Results (SEER) database for patients diagnosed with primary malignant AM who have undergone surgical intervention between 2000 and 2021. The Kaplan-Meier (KM) method with the log-rank test was used to compare survival curves between different LODDS groups. Multivariate Cox models were employed to evaluate the independent association between LODDS and overall survival (OS). An analysis to explore the potential influence of unmeasured confounders on the relationship between LODDS and OS was conducted using the E value.

Results: The study included a total of 126 eligible patients. KM analysis revealed that patients with low LODDS exhibited significantly improved OS compared to those with high LODDS ( < 0.001). The multivariate Cox analysis demonstrated that LODDS was independently associated with OS. The calculated E value suggested that the potential impact of unmeasured confounders on the association between LODDS and OS was likely minimal.

Conclusion: The findings indicate that LODDS is independently associated with the prognosis of patients with AM undergoing surgical intervention. These results may enhance clinicians' understanding of the prognosis of this rare malignancy and provide a basis for guiding therapeutic decisions.