Key points are not available for this paper at this time.
The treatment of patients with metastatic colorectal cancer (mCRC) is complex and impacted by the location of the primary tumor (LPT). Our study aims to emphasize the importance of LPT as a prognostic and predictive marker, as well as to examine the significance of HER2 overexpression in patients with mCRC, particularly in relation to response to anti-EGFR therapy. In this study, 181 patients with KRAS wild-type mCRC who received anti-EGFR therapy were included. Among them, 101 had left colon cancer (LCC) and 80 had right colon cancer (RCC). Results demonstrated that patients with KRAS wild-type LCC had better median overall survival (OS) (43 vs. 33 months, p = 0.005) and progression-free survival (PFS) (6 vs. 3 months, p lt; 0.001) compared to those with RCC. Multivariate analysis identified mucinous adenocarcinoma (p lt; 0.001), RCC location (p = 0.022), perineural invasions (p = 0.034), and tumors at the resection margin (p = 0.001) as independent predictors of OS, while mucinous adenocarcinoma (p = 0.001) and RCC location (p = 0.004) independently correlated with significantly shorter PFS. In addition, HER2 positive expression was significantly associated with worse PFS compared to HER2 negative results (p lt; 0.001). In conclusion, LPT is an important marker for predicting outcomes in the treatment of wild-type mCRC using anti-EGFR therapy, since patients with RCC have a statistically significantly shorter PFS and OS. Further investigation is needed to understand the role of HER2 overexpression in wild-type mCRC, as these patients also exhibit shorter survival.
Radić et al. (Tue,) studied this question.