Systematic Review and Cumulative Analysis of the Combination of Mitomycin C plus Bacillus Calmette-Guérin (BCG) for Non-Muscle-Invasive Bladder Cancer

This systematic review and cumulative analysis aimed to explore the efficacy and safety of the combination of intravesical mitomycin C (MMC) plus bacillus Calmette-Guerin (BCG) for non-muscle-invasive bladder cancer (NMIBC) patients. A comprehensive literature search using Pubmed, Embase, Medline, Cochrane Library, CBM, CNKI and VIP databases was performed to identify studies applying intravesical MMC plus BCG therapy on NMIBC patients up to June 2016. Summarized unadjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the efficacy and safety of the combination therapy. A total of 25 studies containing 2749 NMIBC patients were included in this systematic review. Compared with BCG monotherapy, the combination therapy could significantly reduce the tumor recurrence rate (OR = 0.64, 95% CI: 0.44-0.94, P = 0.02) and cancer-specific mortality (OR = 0.54, 95% CI: 0.34-0.87, P = 0.01), without more toxicities (OR = 0.58, 95% CI: 0.17-1.94, P = 0.37). The combination therapy could also lead to significant lower tumor recurrence rate than MMC monotherapy (OR = 0.41, 95% CI: 0.24-0.69, P = 0.0009). Our study indicates that the combination of MMC plus BCG instillation is an effective and safe adjuvant treatment for NMIBC patients.

CIS is a surrogate marker of genetic instability and field carcinogenesis in the urothelial mucosa

OBJECTIVE

To investigate whether carcinoma in situ (CIS) lesion could be considered a surrogate marker of urothelium genetic instability and field carcinogenesis or not, we evaluated DNA content, p53 overexpression, and proliferative index (Ki-67 expression) in primary tumor, in tumor-adjacent mucosa, and distant urothelial mucosa with and without presence of CIS.

PATIENTS AND METHODS

A retrospective study in radical cystectomy specimens from 49 patients was carried out. All the lesions present in each cystectomy specimen were studied, including the tumor area and the adjacent mucosa (AM). Whenever possible, the distant mucosa (DM) was also studied. When CIS was detected, this lesion and the surrounding normal mucosa were also studied. The 49 tumor areas included high grade papillary urothelial carcinoma (HGP) in 19 cases (38.8%) and invasive urothelial cell carcinomas in 30 cases (61.2%). The nuclear DNA content of cancer cells was evaluated using image cytometry allowing the determination of the DNA ploidy and 5cER parameters. The p53 and Ki-67 immunoexpression was evaluated by immunohistochemistry.

RESULTS

CIS lesions were observed in the AM and DM of both tumor groups: 15.8% and 15.4% in AM and DM, for each one of them, in HGP group and 26.7% and 22.2% in AM and DM, for each one of them, in invasive tumors group. In CIS lesion aneuploid DNA content, p53 overexpression and high proliferative labeling index were observed. The so-called normal mucosa (AM and DM) with and without focus of CIS lesions were compared for genetic instability and molecular alterations profile. Statistical differences were observed between the normal mucosa with and without CIS: the so-called normal mucosa areas with focus of CIS revealed significantly higher frequencies of DNA content alterations, p53 overexpression, and higher proliferative index. These differences were significantly different in the invasive UCC group, but this profile it is also present in HPG group.

CONCLUSION

This study points out that CIS is a marker of genetic instability of the urothelium mucosa. The CIS surrounding morphologically normal urothelium showed a high frequency of abnormal DNA content, with high percentage of clear aneuploid cells (high 5cER), p53 mutated protein expression, and a proliferative status underlying a field carcinogenesis. These alterations in normal mucosa were not found when CIS was not present.

Tumourigenic effect of Schistosoma haematobium total antigen in mammalian cells

Schistosoma haematobium is endemic in several regions of Africa and has been shown to be associated with predominantly squamous cell bladder carcinoma. The mechanisms underlying the association between S. haematobium and bladder squamous cell carcinoma is largely unknown. All the reports so far, demonstrate exclusively an epidemiological evidence linking S. haematobium infection with squamous cell bladder carcinoma. We hypothesized that these parasite antigens might induce tumourigenesis. For this, we used normal mammalian cells of Chinese hamster ovary (CHO) and treated the cells in culture with S. haematobium total antigen (Sh). Our results showed increased proliferation in Sh-treated cells in comparison with the controls. The CHO cells exposed to Sh were inoculated subcutaneously into male nude mice and formed sarcomas (n = 5/5). The cells from the sarcomas expressed vimentin filaments and were negative to cytokeratin. Our results demonstrate for the first time that S. haematobium antigens induce tumour development in nude mice.