To look for any difference in disease characteristics and oncological outcome between bladder cancer patients with and without carcinoma-in-situ (CIS) after radical cystectomy of curative intent.

This is a retrospective cohort study of patients who had radical cystectomy performed as a curative treatment for non-metastatic bladder cancer. Their demographic information, pre-operative disease status such as the previous treatment received and pathology, pathological result and post-operative disease outcome were retrieved from the electronic health system. Patients were excluded if there was no residual bladder carcinoma on cystectomy pathology. The pathological record was reviewed to stratify patients into CIS and non-CIS group. For analysis, chi-square test and t-test were performed to compare the baseline disease characteristics between CIS and non-CIS group, while log-rank test were performed to compare their post-operative survival outcome.

From August 2008 to October 2022, a total of 131 patient have undergone open radical cystoprostatectomy or open anterior exenteration as a curative treatment for bladder cancer in Tuen Mun Hospital in Hong Kong. After excluding patients without residual bladder carcinoma on cystectomy pathology, there were 114 patients included for analysis, including 92 male and 22 female. Their mean age was 77.9+/-9.8 years. Most (75%) patients had the surgery for muscle invasive disease while 16% for tumour not amenable to endoscopic resection. Pre-operatively, 45% patients had hydronephrosis with 47% having suspicious or malignant urine cytology. On pathological staging, over 50% patients had T3 disease or above and 24% had positive lymph node. CIS was present in 28.9%. It was found that the CIS group is less likely to have pre-operative hydronephrosis (51% vs 30%, p=0.048) but more likely to have ureteric involvement (4.9% vs 22%, p=0.023). There was no statistical difference in disease staging between the two groups. In terms of oncological outcome, the CIS and non-CIS group had a similar overall survival (p=0.778), cancer-specific survival (p=0.414), metastasis (p=0.934) and recurrence (p=0.909).

There is less pre-operative hydronephrosis but more ureteric involvement in bladder cancer patients who had CIS. The oncological outcome was however similar between the CIS and non-CIS group.