The Association of KRAS Mutation With Primary Tumor Location and Survival in Patients Undergoing Resection of Colorectal Cancers and Synchronous Liver Metastases

Niccolo Allievi; Paolo Goffredo; Alan F. Utria; Michele Pisano; Elia Poiasina; Alessandro Lucianetti; Paige Zhou; Imran Hassan

Disclosures

Chin Clin Oncol. 2019;8(5) 

In This Article

Results

Patient Characteristics

A total number of 806 patients with colorectal cancer and synchronous liver metastases and documented KRAS mutational status who underwent surgical treatment of their primary tumor and liver metastases were retrieved in the SEER Database. m-KRAS was present in 321 cases (39.8%). Overall m-KRAS was associated with older age (59.4 vs. 57.3 years, P=0.038; Table 1) and African-American ethnicity (19.0% vs. 11.3%, P=0.01), but was not related to gender, insurance status or year of diagnosis. Furthermore, m-KRAS was more commonly found in right-sided primary lesions, when compared to left-sided lesions (54.7% vs. 31.3%, P<0.001). Clinicopathologic variables, such as primary tumor size, lymph node involvement and radio-chemotherapy administration were not significantly associated with m-KRAS. On multivariable analysis, right-sided lesions (OR 2.56, 95% CI: 1.90–3.44, P<0001) and African-American ethnicity (OR 1.58, 95% CI: 1.05–2.40, P=0.03) were significantly associated with m-KRAS status (Table 2).

Survival Analyses

Compared to wt-KRAS, m-KRAS status was associated with decreased DSS; 3- and 5-year DSS were 59% vs. 50%, and 29% vs. 21%, respectively (P=0.024; Figure 1). Similarly, patients with right-sided lesions demonstrated an increase in disease-specific mortality, with a 5-year DSS of 19%, as compared to 29% for left-sided lesions (P<0.001).

Figure 1.

DSS by KRAS mutational status. Log-rank test: P=0.024. DSS, disease-specific survival.

After adjusting for the available confounders, patients with right-sided lesions had a decreased DSS (HR 1.68, 95% CI: 1.32–2.12, P<0.001; Table 3). Furthermore, m-KRAS demonstrated a trend toward decreased DSS (HR 1.15, 95% CI: 0.91–1.46, P=0.24).

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