Retrospective study of impact of tumor stroma immune interactions on survival and response to neoadjuvant chemotherapy in bladder cancer

The tumor stroma is associated with unfavorable prognosis in diverse solid tumors, but its prognostic and predictive value in bladder cancer (BCa) is unclear. A multicenter retrospective study in China investigated the impact of tumor stroma ratio (TSC) in 830 BCa patients from six independent cohorts. Compared to low-TSR tumors, high TSR-tumors were significantly associated with worse overall survival (HR 1.193; p=0.008) and cancer-specific survival (HR 1.337; p<0.001) and lower rate of pathologic complete response to neoadjuvant chemotherapy (7.8% versus 82.4%; p<0.001). High-TSR tumors exhibited higher infiltration of immunosuppressive cells. Based on 567 radiomics features, a TSR prediction model for pathological complete response to neoadjuvant chemotherapy (NAC) was developed, with AUCs 0.871 (95% CI 0.821-0.921) in the training cohort, 0.821 (0.731-0.911) in the internal validation cohort, and 0.801 (0.737-0.865) in the external validation cohort. The authors conclude that the TSR was significantly associated with clinical outcomes of patients with BCa, whereas the prediction model provided non-invasive evaluation of TSR and was able to predict pCR in patients receiving NAC for BCa.