ABSTRACT
Carcinoma in situ (CIS) is a non-papillary high-grade, potentially aggressive, and unpredictable manifestation of bladder urothelial carcinoma. The aim of this study was to assess patterns of Cyclin D3 gene amplification in Bacillus Calmette-Guerin (BCG)-treated CIS and correlate gene status with recurrence-free and progression-free survival. A sequential cohort series of 28 primary (isolated) or secondary (concomitant) bladder CIS samples in which there was enough tissue material to assess Cyclin D3 gene status by fluorescent in situ hybridization was the study group. Cyclin D3 gene amplification was present in 29% of secondary CIS; none of primary CIS samples had Cyclin D3 gene amplification. Cyclin D3 amplification was related to recurrence- (p = 0.046) and progression-free survival (p = 0.002). Type of bladder CIS (primary vs. secondary) was unrelated to recurrence- or progression-free survival in the current series. Cox's regression analysis selected Cyclin D3 as an independent predictor of progression-free survival (p = 0.041, relative risk = 61.503, 95% confidence interval = 1.1-274.710). None of primary CIS cases recurred on follow-up; nine secondary CIS recurred and four of them progressed to invasive bladder carcinoma HG T1 (n = 1), T2b N0M0 (n = 1), T3b N1M0 (n = 1) and T4aN1M1 (n = 1). Mean recurrence ± SD (months) occurred at 19.5 ± 2.06 (95% (confidence interval (CI)), 15.5-23.6); mean progression (months) occurred at 23.8 ± 1.46 (95% (CI), 20.9-26.7). Our study suggests that Cyclin D3 gene amplification might be a predictor of aggressiveness in BCG-treated CIS.
Subject(s)
Biomarkers, Tumor/genetics , Carcinoma in Situ/genetics , Carcinoma, Transitional Cell/genetics , Cyclin D3/genetics , Gene Amplification , Gene Expression Regulation, Neoplastic , Urinary Bladder Neoplasms/genetics , Aged , Aged, 80 and over , BCG Vaccine/therapeutic use , Blotting, Western , Carcinoma in Situ/drug therapy , Carcinoma in Situ/mortality , Carcinoma, Transitional Cell/drug therapy , Carcinoma, Transitional Cell/mortality , Disease-Free Survival , Female , Humans , In Situ Hybridization, Fluorescence , Kaplan-Meier Estimate , Male , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/mortality , Proportional Hazards Models , Tissue Array Analysis , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/mortalityABSTRACT
PURPOSE: Human epidermal growth factor receptor 2 (HER-2) overexpression has been associated with the genesis and progression of a subset of breast cancers. The function of HER-2 may be upregulated by overexpression or by the availability of neuregulins (NRGs), a group of transmembrane growth factors. Transmembrane NRGs strongly activated HER-2 and cell proliferation in breast cancer cells that did not overexpress HER-2, and treatment with trastuzumab prevented the proliferative action of transmembrane NRG. This raised the relevant clinical question of whether patients considered as HER-2 negative, but expressing transmembrane NRG, may benefit from treatment with trastuzumab. PATIENTS AND METHODS: MCF7 cells expressing transmembrane NRG (MCF7-NRG2c) were injected into mice, and their sensitivity to trastuzumab was assessed. A retrospective study of 124 patients with early-stage or metastatic breast cancer was conducted. Expression of transmembrane NRG was evaluated by immunohistochemistry. In 11 patients, Western blot for NRGs was also carried out. Statistics were performed to analyze possible correlations between NRG expression and response to trastuzumab-based therapies, event-free survival, and overall survival (OS). RESULTS: Trastuzumab inhibited tumor growth in mice injected with MCF7-NRG2c cells. Transmembrane NRG was frequently expressed in breast cancer patients. Overexpression of transmembrane NRG significantly correlated with a longer event-free survival and OS in patients with low or normal HER-2 expression who were treated with trastuzumab-based therapies but not in patients with HER-2 overexpression. CONCLUSION: We suggest that the spectrum of patients who may benefit from trastuzumab-based therapies may be widened to include patients with metastatic breast cancer without HER-2 amplification but who express transmembrane NRGs.
