Log odds of positive lymph nodes predicts survival in metaplastic breast cancer based on SEER analysis.

[PURPOSE] To investigate, for the first time, the association between LODDS and survival outcomes in MBC patients after surgery.

[METHODS] This retrospective analysis included 1,776 patients diagnosed with MBC recorded during 2010-2017 through the Surveillance, Epidemiology, and End Results (SEER) database. The optimal LODDS cutoff was determined. using maximally selected rank statistics, with patients subsequently categorized into low (L1) and high (L2) groups of LODDS. Cox models, Kaplan-Meier, and restricted cubic splines analyzed OS and BCSS.

[RESULTS] After adjusting for demographic and tumor-related characteristics, LODDS remained significantly associated with OS and BCSS, both as a continuous and categorical variable. In adjusted model, the L2 group exhibited mortality increases of 25% for all causes (HR: 1.25, 95% confidence interval [CI]: 1.06-1.48, P = 0.009) and 29% for breast cancer-specific causes (HR: 1.29, 95% CI: 1.05-1.58, P = 0.015) compared to the L1 group. The Log-rank analysis (P = 0.003) confirmed superior survival outcomes in the L1 group compared to L2 group. RCS analysis revealed a nonlinear U-shaped correlation between LODDS and OS (P < 0.001), while a linear correlation was observed between LODDS and BCSS (P = 0.443).

[CONCLUSION] These findings provide the first evidence that LODDS has a significant non-linear association with OS and a significant linear association with BCSS in patients with MBC after surgery. Higher LODDS values were associated with elevated risks of all-cause mortality and breast cancer-specific mortality.