Rectal Cancer Transcriptomes Provide Treatment Response, Survival Clues

For a paper appearing in JAMA Network Open, Japanese researchers turn to transcriptomics to search for survival-related markers that can be detected prior to treatment in individuals with advanced rectal cancers, while also tracking response to neoadjuvant chemoradiotherapy (CRT). The team turned to RNA sequencing to retrospectively profile pretreatment biopsy samples collected from 298 rectal cancer patients receiving neoadjuvant chemoradiotherapy from the spring of 2004 to fall 2020, using consensus molecular subtype classification and microenvironment cell populations counter scoring approaches to cluster the cases into four transcriptomic subtypes and characterize tumor immune cell infiltration. The results suggest neoadjuvant chemoradiotherapy response, recurrence-free survival, and overall survival were linked to cytotoxic lymphocyte scores. "In this case series of patients with rectal cancer treated with neoadjuvant CRT, the cytotoxic lymphocyte score in pretreatment biopsy samples, as computed by RNA sequencing, was associated with response to CRT and survival," the authors report. "This finding suggests that the cytotoxic lymphocyte score might serve as a biomarker in personalized multimodal rectal cancer treatment."