Primary Tumor Resection Offers Higher Survival Advantage in KRAS Mutant Metastatic Colorectal Cancer Patients.

BACKGROUND/AIMS: Colorectal cancer is the fourth most common cancer diagnosed in the United States, and the third most common cause of death from cancer. Approximately 20% of the patients with colorectal cancer have distant metastasis during diagnosis. Primary tumor resection is controversial in unresectable metastatic colorectal cancer (CRC). We studied the survival effect of primary tumor resection in unresectable metastatic CRC according to kirsten ras (KRAS) mutation status.

METHODOLOGY

Seventy eight CRC cases with unresectable metastasis were included in the study. The KRAS status was known in all patients. 34 patients had undergone primary tumor resection before 1st chemotherapy.

RESULTS

ThE median time from primary tumor resection to first chemotherapy was 6 (3-17) weeks. The survival was better in the unresectable metastatic colon patients with resected primary tumor, but it was statistically non-significant (P = 0.07). The median OS was similar (P = 0.91) in the KRAS wild patients with or without primary tumor resection. The median OS was 28 months in KRAS mutant patients with primary tumor resection, 14 months in KRAS mutant patients without primary tumor resection (P = 0.002).

CONCLUSION

Primary tumor resection offers survival advantage in KRAS mutant patients, but randomized prospective studies are required.