According to a new study published in the journal Gastroenterology, a certain subset of stage 3 colon cancer patients had increased survival rates when treated with irinotecan, leucovorin, and fluorouracil (5-FU) compared with leucovorin and 5-FU alone.
In the study, researchers from the Fred Hutchinson Cancer Research Center in Seattle, Washington, analyzed data from patients with stage 3 colon adenocarcinoma randomly assigned to groups given irinotecan-based therapy or leucovorin and 5-FU from 1999 to 2001. Researchers identified 145 patients whose colon cancer had the CpG island methylator phenotype (CIMP), defined by an increased frequency of aberrantly methylated genes.
Researchers found that patients with CIMP-positive colon cancer had a shorter duration of overall survival compared with patients with CIMP-negative tumors. Furthermore, CIMP-positive patients treated with irinotecan-based therapy trended toward an increased overall survival versus those treated with leucovorin and 5-FU (P=0.07); however, this trend was not observed in patients with CIMP-negative colon cancer.
In addition, researchers observed the most benefit of irinotecan-based therapy in patients with CIMP-positive, mismatch repair (MMR)-intact tumors (P=0.01). They also found KRAS or BRAF mutation status did not affect the effectiveness of treatment.
A subset of patients with stage III colon cancer had improved survival rates when treated with irinotecan-based therapy, according to a new study in Gastroenterology, the official journal of the American Gastroenterological Association.
When added to the standard chemotherapy treatment—fluorouracil and leucovorin—adjuvant irinotecan therapy improved overall survival rates for patients with the CpG island methylator phenotype (CIMP).
CIMP is seen in about 10 to 20 percent of colorectal cancers. Patients with CIMP-negative tumors, however, exhibited significant harm from the addition of irinotecan—overall survival was 68 percent compared with 78 percent for those receiving the standard treatment alone.