Objective:To investigate the clinical and pathological characteristics, prognostic factors, and treatment outcomes of bladder adenocarcinoma.Methods:The data of 177 bladder adenocarcinoma patients treated at Renji Hospital, Shanghai Jiaotong University School of Medicine from January 2003 to December 2023, and 2 687 bladder adenocarcinoma patients from the SEER database (2000—2021) were reviewed retrospectively. The clinicopathological and prognostic characteristics were compared between the two cohorts. Patients with urachal adenocarcinoma or primary bladder adenocarcinoma were included, while metastatic bladder adenocarcinoma from other sites and urothelial carcinoma with glandular components were excluded. The Chi-square test was used for comparison of categorical data, and propensity score matching (1∶1) was applied to match baseline data between the Renji and SEER cohorts. Kaplan-Meier survival curves were generated, and log-rank tests were used for comparisons. Univariate and multivariate Cox regression analyses were performed using the survival R package, with P-values calculated via Wald tests. Results:The proportion of localized bladder adenocarcinoma was significantly higher in the Renji cohort than in the SEER cohort [61.0% (108/177) vs. 19.4% (521/2 687), P<0.001], and mucinous adenocarcinoma was more common in Renji cohort [33.3% (59/177) vs. 22.6% (607/2 687), P<0.001]. After matching for baseline factors, including SEER stage and pathological grade, survival analysis revealed that the Renji cohort patients had slightly better survival compared to the SEER cohort [median survival: 55.4 (24.1, 196.2) months vs. 39.2 (13.6, 137.4)months, P=0.033]. Multivariate Cox analysis identified SEER stage [Renji cohort: HR=3.83 (95% CI 1.62-9.07), P=0.002; SEER cohort: HR=3.67 (95% CI 3.13-4.31), P<0.001] and pathological grade [Renji cohort: HR = 2.76 (95% CI 1.54-4.95), P=0.001; SEER cohort: HR=1.46 (95% CI 1.29-1.65), P<0.001] as independent prognostic factors. In the Renji cohort, no significant differences were observed in the median progression-free survival [40.1 (19.5, 91.6) months vs. 40.9 (12.8, not reached)months, P=0.976] and overall survival [79.3 (37.1, 195.8) months vs. 53.9 (16.4, 129.5)months, P=0.374] between patients receiving adjuvant chemotherapy and those not receiving it. However, among patients with lymph node-positive bladder adenocarcinoma, adjuvant chemotherapy significantly improved both progression-free survival [40.1 (38.2, 75.4) months vs. 12.2 (3.1, 12.2)months, P=0.004] and overall survival [68.2 (46.2, 84.5)months vs. 28.1 (4.3, 28.3)months, P=0.006]. Conclusions:Bladder adenocarcinoma is rare and associated with poor prognosis. Compared to the SEER cohort, Renji cohort patients had more localized disease, with no significant differences in other features. SEER stage and pathological grade were independent prognostic factors in both cohorts. Lymph node-positive bladder adenocarcinoma patients in the Renji cohort benefited significantly from adjuvant chemotherapy.

Objective:To investigate the clinical and pathological characteristics, prognostic factors, and treatment outcomes of bladder adenocarcinoma.Methods:The data of 177 bladder adenocarcinoma patients treated at Renji Hospital, Shanghai Jiaotong University School of Medicine from January 2003 to December 2023, and 2 687 bladder adenocarcinoma patients from the SEER database (2000—2021) were reviewed retrospectively. The clinicopathological and prognostic characteristics were compared between the two cohorts. Patients with urachal adenocarcinoma or primary bladder adenocarcinoma were included, while metastatic bladder adenocarcinoma from other sites and urothelial carcinoma with glandular components were excluded. The Chi-square test was used for comparison of categorical data, and propensity score matching (1∶1) was applied to match baseline data between the Renji and SEER cohorts. Kaplan-Meier survival curves were generated, and log-rank tests were used for comparisons. Univariate and multivariate Cox regression analyses were performed using the survival R package, with P-values calculated via Wald tests. Results:The proportion of localized bladder adenocarcinoma was significantly higher in the Renji cohort than in the SEER cohort [61.0% (108/177) vs. 19.4% (521/2 687), P<0.001], and mucinous adenocarcinoma was more common in Renji cohort [33.3% (59/177) vs. 22.6% (607/2 687), P<0.001]. After matching for baseline factors, including SEER stage and pathological grade, survival analysis revealed that the Renji cohort patients had slightly better survival compared to the SEER cohort [median survival: 55.4 (24.1, 196.2) months vs. 39.2 (13.6, 137.4)months, P=0.033]. Multivariate Cox analysis identified SEER stage [Renji cohort: HR=3.83 (95% CI 1.62-9.07), P=0.002; SEER cohort: HR=3.67 (95% CI 3.13-4.31), P<0.001] and pathological grade [Renji cohort: HR = 2.76 (95% CI 1.54-4.95), P=0.001; SEER cohort: HR=1.46 (95% CI 1.29-1.65), P<0.001] as independent prognostic factors. In the Renji cohort, no significant differences were observed in the median progression-free survival [40.1 (19.5, 91.6) months vs. 40.9 (12.8, not reached)months, P=0.976] and overall survival [79.3 (37.1, 195.8) months vs. 53.9 (16.4, 129.5)months, P=0.374] between patients receiving adjuvant chemotherapy and those not receiving it. However, among patients with lymph node-positive bladder adenocarcinoma, adjuvant chemotherapy significantly improved both progression-free survival [40.1 (38.2, 75.4) months vs. 12.2 (3.1, 12.2)months, P=0.004] and overall survival [68.2 (46.2, 84.5)months vs. 28.1 (4.3, 28.3)months, P=0.006]. Conclusions:Bladder adenocarcinoma is rare and associated with poor prognosis. Compared to the SEER cohort, Renji cohort patients had more localized disease, with no significant differences in other features. SEER stage and pathological grade were independent prognostic factors in both cohorts. Lymph node-positive bladder adenocarcinoma patients in the Renji cohort benefited significantly from adjuvant chemotherapy.