Cancer sidedness in CRC

Q: Left-sided primary Colorectal Cancer (CRC) is associated with a significantly reduced risk of death.

A) True

B) False

Answer: A

Primary tumor location is one of the essential prognostic factors in Colorectal Cancer (CRC). Left-sided primary tumor location (at or beyond the splenic flexure) is found to be associated with a significantly reduced risk of death. This mortality benefit is independent of any variable such as stage, race, use of adjuvant chemotherapy, year of study, and quality of the included studies!

This advantage is attributed to different kinds of gene mutations. "Cancer sidedness" is also considered a predictive factor for response to therapies.

#oncology

References:

1. Holch JW, Ricard I, Stintzing S, et al. The relevance of primary tumour location in patients with metastatic colorectal cancer: A meta-analysis of first-line clinical trials. Eur J Cancer 2017; 70:87.

2. Petrelli F, Tomasello G, Borgonovo K, et al. Prognostic Survival Associated With Left-Sided vs Right-Sided Colon Cancer: A Systematic Review and Meta-analysis. JAMA Oncol 2016; 3:211.

3. Tejpar S, Stintzing S, Ciardiello F, et al. Prognostic and Predictive Relevance of Primary Tumor Location in Patients With RAS Wild-Type Metastatic Colorectal Cancer: Retrospective Analyses of the CRYSTAL and FIRE-3 Trials. JAMA Oncol 2016.

4. Loree JM, Pereira AAL, Lam M, et al. Classifying Colorectal Cancer by Tumor Location Rather than Sidedness Highlights a Continuum in Mutation Profiles and Consensus Molecular Subtypes. Clin Cancer Res 2018; 24:1062.