Significance of lymphovascular invasion in pT1 squamous differentiated bladder urothelial carcinoma

Objective To systematically evaluate the prognostic significance of lymphovascular invasion (LVI) in pT1 stage bladder urothelial carcinoma with squamous differentiation. Methods The clinical and patho-logical data of 105 patients with pT1 stage urothelial carcinoma with squamous differentiation and transurethral re-section of bladder tumor (TURBT) were retrospectively analyzed. Hematoxylin-eosin staining and immunohisto-chemical staining were used to determine the presence of LVI in tumor tissues. All patients were divided into LVI-negative group and LVI-positive group according to LVI. The relationship between LVI and clinicopathological fea-tures and 5-year cancer-specific survival (CSS) rate was analyzed. Patients with relapse were divided into TURBT group and radical cystectomy (RC) group according to the surgical method, and the effects of the methods on CSS were compared. Results There are 57 patients (27.6%) had LVI. In the LVI-negative group, the 5-year CSS was 84.9%, while that in the LVI-positive group was 58.4%, the difference was statistically significant(P<0.05). Univari-ate analysis showed that tumor multiple appearance, tumor size, recurrence and LVI were significantly correlated with CSS (all P<0.05). Multivariate analysis showed that tumor size and LVI had significant effects on CSS (all P<0.05). In the relapsed patients with LVI-positive, RC had a higher CSS than TURBT (P=0.042). In the relapsed pa-tients with LVI-negative, the difference between the two methods was not statistically significant(P=0.692). Conclusions LVI is an important prognostic factor in pT1 stage urothelial carcinoma with squamous differentiation. Pa-tients with LVI and tumor size >3 cm have a higher risk of death. Patients with pT1 stage urothelial carcinoma with squamous differentiation, especially those with LVI, should be treated with RC as soon as possible. Key words: Bladder neoplasms; Lymphovascular invasion; Squamous metaplasia; Prognosis; Radical cystectomy