Abstract 7648: COL6A1 expression as a potential prognostic biomarker for risk stratification of T1HG bladder cancer: Unveiling the aggressive nature of a distinct non-muscle invasive subtype

Abstract Introduction and Objectives: T1 high grade (T1HG) bladder cancer (BC) is a type of non-muscle invasive BC (NMIBC) that is recognized as an aggressive subtype with a heightened propensity for progression. Current risk stratification methods for NMIBC rely on clinicopathological indicators; however, these approaches do not adequately capture the aggressive nature of T1HG BC. Thus, new, more accurate biomarkers for T1HG risk stratification are needed. Here, we enrolled three different patient cohorts and investigated expression of COL6A1, a key component of the extracellular matrix, at different stages and grades of BC, with a specific focus on T1HG BC. Materials and Methods: Samples from 298 BC patients were subjected to RNA sequencing and real-time PCR. Results: We found that T1HG BC and muscle invasive BC (MIBC) exhibited comparable expression of COL6A1, which was significantly higher than that by other NMIBC subtypes. In particular, T1HG patients who later progressed to MIBC had considerably higher expression of COL6A1 than Ta, T1 low-grade patients, and patients that did not progress, highlighting the aggressive nature and higher risk of progression associated with T1HG BC. Moreover, Cox and Kaplan-Meier survival analyses revealed a significant association between elevated expression of COL6A1 and poor progression-free survival of T1HG BC patients (multivariate Cox hazard ratio, 16.812; 95% confidence interval, 3.283-86.095; P=0.001 and P=0.0002 [log-rank test]). Conclusion: These findings suggest that COL6A1 may be a promising biomarker for risk stratification of T1HG BC, offering valuable insight into disease prognosis and guidance of personalized treatment decisions. Citation Format: Xuan-Mei Piao, Young Joon Byun, Chuang-Ming Zheng, Seon-Kyu Kim, Seong-Hwan Park, Kyungchan Min, Hansoo Park, Sungmin Moon, Kyeong Kim, Ho Won Kang, Won Tae Kim, Seok Joong Yun. COL6A1 expression as a potential prognostic biomarker for risk stratification of T1HG bladder cancer: Unveiling the aggressive nature of a distinct non-muscle invasive subtype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7648.