Gender dimorphism in survival of patients with lymph node metastasis of bladder cancer

Background: The effect of gender on the prognosis of bladder cancer (BCa) in different metastatic sites is insufficiently understood. We aimed to assess the impact and potential mechanisms of a combination of gender dimorphism and BCa metastasis sites on the risk of death. Methods: Independent predictors of overall survival and cancer-specific survival were analyzed after stratification by gender and metastasis sites from the Surveillance, Epidemiology, and End Results database. Furthermore, gender-differentially expressed genes (DEGs) and function-enriched annotations for patients with lymph node metastasis (LNM) were identified from The Cancer Genome Atlas (TCGA) database. A gender-associated signature was constructed in TCGA and validated in the IMvigor210 trial, and the magnetic resonance imaging-based radiomics signature was developed in our center to predict the gender-associated signature. Results: In patients with metastatic BCa, the most common site of metastasis is bone in men and lung in women. Moreover, stratified by sex, LNM had a better prognosis in men than visceral metastasis, which was not observed in female. Similarly, stratified by the metastasis site, the prognosis of men in patients with LNM is better than that of women, which was not observed in visceral metastasis patients. Enrichment of DEGs between sexes in patients with LNM may be related to metastasis and tumor immunity, especially the role of neutrophils. Moreover, the gender-associated signature is related to the clinicopathological characteristics of patients, and patients in the high-risk group had worse survival outcomes, and higher susceptibility to cisplatin, docetaxel, camptothecin, and paclitaxel. A nomogram combined with the signature and clinical staging showed significant predictive power in survival prediction. Furthermore, patients with high radiomics scores had a strong tendency for high-risk group. Conclusion: These results may improve the understanding of the differences in tumor biology between sexes and thus provide additional evidence for individualized treatment in BCa.