The efficacy of neoadjuvant chemotherapy and morphological classification of invasive bladder cancer according to chemoresponse

Abstract

(Background) We investigate the propriety of neoadjuvant chemotherapy and the possibility of bladder preservation based on clinical and pathological responses in invasive bladder cancer. (Method) Nineteen cases of invasive bladder cancer which had been subjected to two courses of neoadjuvant chemotherapy followed by radical cystectomy were analyzed. (Results) The overall response rate was 79% (5/19), and 7 cases (37%) had a pathological complete response (pCR). Many cases showed degeneration or necrosis of cancer cells and infiltration of lymphocytes around the original cancer sites. Foamy macrophage or fibrous change was observed in high response cases. Thickening of the bladder wall were found after chemotherapy in such cases, which led to over-staging of the CT scan. We divided invasive bladder cancers into four types based on gross tumor appearance and histology from TUR biopsy specimen: Type 1 which has an nodularly elevating nonpedunculated structure: Type 2A which has an elevating nonpedunculated structure with papillary component and no lymph vessel invasion: Type 2B which has an elevating nonpedunculated structure with partly papillary component and marked lymph vessel invasion: and Type 3 which has a nonelevating diffuse invasive structure with CIS lesion. The therapeutic effect was greater than grade 2 in 7 cases out of 8 (88%) Type 1, 2 cases out of 3 (67%) Type 2A, no case out of 6(0%) type 2B, and 1 case out of 2 (50%) type 3. (Conclusion) This classification will indicate the appropriate preoperative treatment for invasive bladder cancer, and will be useful when formulating criteria for bladder preservation. In particular, Type 1 or Type 2A is chemosensitive and may be considered for bladder preservation.