DNA Mismatch Repair and 5-FU: What's the Connection?

Some colon cancer patients don’t benefit from treatment with 5-FU based chemotherapy and may even have worse outcomes than if they no chemo at all. Of every 100 people with colon cancer, about 15 will have cancers that arise when mistakes in DNA during cell division are not caught and fixed.  Scientists call this defective mismatch…  Read More

Some Colorectal Cancers Not Connected to Obesity

Although being obese increases risk for most colon and rectal cancers, the connection isn’t true in all types of colorectal cancer. Cancers that are linked to microsatellite instability (MSI) don’t appear to be influenced by obesity, strengthening the belief that MSI cancers come about differently than the average colorectal cancer. Overall, in a recent study, body…  Read More

FOLFOX Effectiveness Not Related to DNA Mismatch Repair or MSI

Colon cancers that are caused by defects in genes that repair damaged DNA don’t respond well to 5-FU treatment after surgery. However, a new analysis of patients treated with FOLFOX (oxaliplatin, leucovorin, and 5-FU) found no differences between patients with deficient mismatch repair tumors and those with normal gene expression. In this small study of 135…  Read More

Biomarkers Predict Colorectal Cancer Survival

Two gene changes that occur in some colorectal cancers can forecast chances for good or poor survival. Patients whose cancers had high microsatellite instability (MSI) had significantly better outcomes at every stage, but mutations in the KRAS gene predicted poorer survival.

Stage III MSI High Colon Cancer May Benefit from Irinotecan

About 15 percent of people with stage III colon cancer may have fewer recurrences and better survival when they are treated with irinotecan. Although all stage III colon cancers don’t have an additional benefit when irinotecan is added to bolus 5-FU and leucovorin in a treatment called IFL, this smaller group does. About 15 percent of colon…  Read More