Long non-coding RNA C20orf56 as predictor for response to neoadjuvant CCRT and survival rates of rectal cancers

Abstract

Introduction: Colorectal cancers are the third most prevalent malignant neoplasms and the second leading cause of cancer mortality globally. The introduction of neoadjuvant concurrent chemoradiotherapy (CCRT) for patients with resectable rectal cancer not only improves survival rates but also increases the likelihood of curative surgeries. C20orf56, a long non-coding RNA, has been extensively documented as a tumor suppressor across various cancer types, participating in numerous cellular processes. However, no comprehensive evaluation has been conducted on the relationship between C20orf56 expression, response to neoadjuvant CCRT, and survival in patients with rectal cancer. Materials and Methods: A comparative analysis of gene expression profiles from the transcriptomic dataset (GSE35452) identified C20orf56 as the most significantly up-regulated lncRNA. Tumor samples were collected from 343 primary rectal cancer patients who underwent neoadjuvant CCRT followed by surgical resection. The expression level of C20orf56 was semi-quantitatively assessed using in situ hybridization. Subsequently, statistical analyses were conducted to examine the relationship between C20orf56 expression, various clinicopathological features, and survival outcomes. Results: Decreased expression of C20orf56 showed significant correlations with less advanced post-treatment tumor invasiveness, negative post-treatment nodal metastasis, absence of vascular invasion and perineural invasion, and improved response to neoadjuvant CCRT (all p ≤ 0.024). Diminished expression of C20orf56 was associated not only with favorable disease-specific survival (DSS), local recurrence-free survival (LRFS) and metastasis-free survival (MeFS) (all p < 0.0001) in univariate analysis but also functioned as an independent predictor signifying enhanced clinical outcomes, including DSS, LRFS, and MeFS (all p < 0.001). Conclusion: C20orf56 may play a significant role in rectal cancer progression and response to neoadjuvant CCRT, serving as a novel prognostic factor.