Neoadjuvant chemotherapy-related histological changes in radical cystectomy: assessment accuracy and prediction of response

• Published in: Human pathology
• Main Authors: Wang, Hui Jun, MD, Solanki, Shraddha, MsC, Traboulsi, Samer, MD, Kassouf, Wassim, MD, Brimo, Fadi, MD
• Format: Journal Article
• Language: English
• Published: 2016
• Subjects: Pathology; neoadjuvant; histology; carcinoma; response; effect; chemotherapy; urothelial
• ISSN: 0046-8177; 1532-8392
• DOI: 10.1016/j.humpath.2016.02.011

Summary We evaluated the spectrum of histological changes associated with neoadjuvant chemotherapy (NAC) and compared them with those resulting from transurethral resection (TUR). 25 patients who received NAC were divided based on both their pre-operative clinical/radiographic findings (clinical stage; hydronephrosis; palpable mass) and the cystectomy (RC) findings into NAC-respondents (advanced clinical stage and < pT2 + pN0), possible NAC-respondents (non-advanced clinical stage and < pT2 + pN0) and NAC-non-respondents (≥ pT2and/or ≥ pN1). In addition, 14 patients who received TUR alone and had < pT2 + pN0 on RC were included. Presence/absence of the following histological features was assessed: fibrosis/myofibroblastic reaction, hyalinisation in the bladder wall, inflammatory reaction, calcification, foreign-body giant cells, necrosis, sheets of foamy macrophages, and fibrosis/hyalinisation/necrosis in the lymph nodes (LN). Overall, there was a significant histological overlap between all groups. However, patients who received NAC had significantly higher likelihood of showing hyalinisation and less giant cells and inflammatory reaction than those who received TUR only. Moreover, the only significantly different histological features in NAC-respondents versus TUR-respondents were hyalinisation and LN changes with those two features in 25% and 0% of the possible NAC-respondents group, respectively. Lastly, there was no significant difference in the possible NAC-respondents group in comparison to the TUR-only arm. It appears that TUR and NAC result in overlapping histological changes. In cases with no/minimal residual disease on RC, it is difficult to attribute the changes to NAC-effect-only except if: 1- hyalinisation of the bladder wall or LN changes are present, or 2-if the pre-operative clinical stage was beyond what could be resected by TUR.