1. Prognostic and Predictive Impact of Primary Tumor Sidedness for Previously Untreated Advanced Colorectal Cancer.
- Author
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Yin J, Cohen R, Jin Z, Liu H, Pederson L, Adams R, Grothey A, Maughan TS, Venook A, Van Cutsem E, Punt C, Koopman M, Falcone A, Tebbutt NC, Seymour MT, Bokemeyer C, Rubio ED, Kaplan R, Heinemann V, Chibaudel B, Yoshino T, Zalcberg J, Andre T, De Gramont A, Shi Q, and Lenz HJ
- Subjects
- Humans, Antineoplastic Combined Chemotherapy Protocols adverse effects, Cetuximab, Panitumumab therapeutic use, Prognosis, Colorectal Neoplasms drug therapy, Colorectal Neoplasms genetics, Colorectal Neoplasms therapy, Proto-Oncogene Proteins p21(ras) genetics
- Abstract
Background: Unplanned subgroup analyses from several studies have suggested primary tumor sidedness (PTS) as a potential prognostic and predictive parameter in metastatic colorectal cancer (mCRC). We aimed to investigate the impact of PTS on outcomes of mCRC patients., Methods: PTS data of 9277 mCRC patients from 12 first-line randomized trials in the ARCAD database were pooled. Overall survival (OS) and progression-free survival (PFS) were assessed using Kaplan-Meier and Cox models adjusting for age, sex, performance status, prior radiation/chemotherapy, and stratified by treatment arm. Predictive value was tested by interaction term between PTS and treatment (cetuximab plus chemotherapy vs chemotherapy alone). All statistical tests were 2-sided., Results: Compared with right-sided metastatic colorectal cancer patients (n = 2421, 26.1%), left-sided metastatic colorectal cancer patients (n = 6856, 73.9%) had better OS (median = 21.6 vs 15.9 months; adjusted hazard ratio [HRadj] = 0.71, 95% confidence interval [CI] = 0.67 to 0.76; P < .001) and PFS (median = 8.6 vs 7.5 months; HRadj = 0.80, 95% CI = 0.75 to 0.84; P < .001). Interaction between PTS and KRAS mutation was statistically significant (Pinteraction < .001); left-sidedness was associated with better prognosis among KRAS wild-type (WT) (OS HRadj = 0.59, 95% CI = 0.53 to 0.66; PFS HRadj =0.68, 95% CI = 0.61 to 0.75) but not among KRAS mutated tumors. Among KRAS-WT tumors, survival benefit from anti-EGFR was confirmed for left-sidedness (OS HRadj = 0.85, 95% CI = 0.75 to 0.97; P = .01; PFS HRadj = 0.77, 95% CI = 0.67 to 0.88; P < .001) but not for right-sidedness., Conclusions: The prognostic value of PTS is restricted to the KRAS-WT population. PTS is predictive of anti-EGFR efficacy, with a statistically significant improvement of survival for left-sidedness mCRC patients. These results suggest treatment choice in mCRC should be based on both PTS and KRAS status., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
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