Forkhead box protein P3 (Foxp3) expression serves as an early chronic inflammation marker of squamous cell differentiation and aggressive pathology of urothelial carcinomas in neurological patients

OBJECTIVE

To establish whether the expression of forkhead box protein P3 (Foxp3) provides specific diagnostic information about neurological patients with urothelial carcinoma of the bladder (UCB).

PATIENTS AND METHODS

UCB tissue samples from neurological patients were retrieved and compared with control samples. The expression of Foxp3 was analysed via immunohistochemistry of microarray tissue sections. The correlation between Foxp3 expression, histological parameters and tumour stage was assessed.

RESULTS

Overall, 20 UCB tissue samples and 20 others without UCB from neurological patients, and 46 UCB tissue samples from non-neurological patients were analysed. The distribution of pT of UCB in the neurological patients was as follows: one low-grade pTa (5%), three high-grade pTa (15%), three pT1(15%), one pT2(5%), seven pT3(35%) and five pT4(25%). Squamous cell differentiation was seen in nine UCB samples (45%). Foxp3 expression was detected in tumour tissues, including one pTa high grade, one pT1, one pT2, five pT3 and five pT4 tumours. Foxp3 was expressed in 11/13 muscle-invasive tumours. All tumours displaying squamous cell differentiation expressed Foxp3. Foxp3 was not expressed in the pT3 tumours that displayed sarcomatoid and micropapillary properties. Among the bladder samples without UCB from neurological patients, no expression of Foxp3 was observed. Among the UCB samples from the non-neurological patients, only seven displayed squamous cell differentiation. All tumours that displayed squamous cell differentiation expressed Foxp3, including one pTa high grade, four pT3 and two pT4 tumours. Other tumours displaying urothelial differentiation did not express Foxp3. The expression of Foxp3 correlated to squamous cell differentiation in neurological (P = 0.004) and non-neurological UCB tissue (P < 0.001). In neurological, but not non-neurological UCB tissue, the expression of Foxp3 correlated with the muscle-invasive stage (P = 0.022).

CONCLUSIONS

Elevated expression of Foxp3 appears to be a characteristic of neurological patients presenting with aggressive UCB and squamous cell differentiation. Targeting Foxp3 may represent a novel strategy to improve anti-tumour immunotherapy for UCB.