Urothelial carcinoma with trophoblastic differentiation: Reappraisal of the clinical implication and immunohistochemically features.

Purpose: To investigate the clinical implications of identifying urothelial carcinoma (UC) with trophoblastic differentiation (UCTD).

Materials And Methods: A prospective cohort study was performed from 2010 to 2016 to examine the incidence of UCTD in urinary tract cancer and association with clinicopathological indicators and patient outcome.

Results: UCTD was detected in 47 of 859 (5.5%) cases of UC of the bladder and 65 of 635 (10.2%) cases in the upper urinary tract. UCTD of the bladder was significantly associated with non-papillary, multiple, larger size ( > 3 cm), muscle invasion, and nodal metastasis (P ≤ 0.0001, respectively). A higher risk of recurrence (P = 0.005), progression (P < 0.0001), and patient death (P < 0.0001) was observed for UCTD than those with traditional, high-grade UC of the bladder. Among four patterns of expression, focal expression of β-human chorionic gonadotropin was frequently detected in papillary tumor (P < 0.005) and UCs of smaller than 3 cm (P = 0.03). Significant indicators in predicting poor disease-specific overall survival in multivariate statistical model were tumor staging (P = 0.001), followed by non-focal β-hCG expression (P = 0.049).

Conclusion: UCTD is more often identified in the upper urinary tract than in the bladder. UCTD of the bladder was significantly associated with higher risk of recurrence, progression, and patient death. Expression of β-hCG in non-focal patterns predicts a worse prognosis for patients with UCTD and deserves an individualized treatment planning.