Researchers reported a number of important findings in colorectal cancer treatment at the 2017 Annual Meeting of the American Society of Clinical Oncology:

Shorter course of chemotherapy post-surgery nearly as effective in certain patients

A study called the IDEA Collaboration, which looked at data from 6 prior studies, showed that 3 months of chemotherapy after surgery was nearly as effective as the current standard of 6 months of chemotherapy in patients with stage lll lymph node-positive colon cancer who have a relatively lower risk of recurrence. Additionally, the shorter course of therapy caused fewer side effects than the longer course.

The standard chemotherapy after colon cancer surgery is a combination of leucovorin, fluorouracil, and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (CAPOX).

What Patients Need to Know

In patients considered to have a low risk of recurrence, 83.1 percent of patients who received a 3-month course of chemotherapy were free of colon cancer after three years, compared with 83.3 percent who received the standard 6-month course.

No significant difference between cetuximab and bevacizumab in treatment for advanced KRAS wild-type colorectal cancer

A phase lll trial concluded that when cetuximab or bevacizumab were added to a first-line chemotherapy regimen for patients with advanced or metastatic KRAS wild-type colorectal cancer, there was no significant difference in overall survival. In the open-label trial, 1,137 patients chose to receive one of two standard chemotherapy regimens: leucovorin, fluorouracil, and oxaliplatin (FOLFOX) or leucovorin, fluorouracil, and irinotecan (FOLFIRI). They were then randomized to receive cetuximab or bevacizumab.

What Patients Need to Know

Median overall survival was 30 months in the cetuximab group vs. 29 months in the bevacizumab group.

Results of phase lll trial showed benefit of 3-drug combination for BRAF-mutated colorectal cancer

Patients with BRAF-mutated colorectal cancer often do not respond to some of the currently available treatments.

The randomized phase III BEACON trial evaluated the combination of binimetinib, encorafenib, and cetuximab vs. encorafenib and cetuximab in patients with BRAF-mutated colorectal cancer, whose disease had progressed after one or two prior treatment regimens.

What Patients Need to Know

Preliminary trial data supported the benefit of adding binimetinib to encorafenib and cetuximab, and the 3-drug combination was found to be well tolerated.

Nivolumab studied in the treatment of MSI-H metastatic colorectal cancer

About 4 percent of patients with metastatic colorectal cancer have a type called microsatellite instability high (MSI-H), caused by a deficiency in the DNA mismatch repair system. These patients may be less responsive to conventional chemotherapy than patients who do not have this type of metastatic colorectal cancer.

According to updated results from the CheckMate 142 trial, nivolumab, an immunotherapy treatment, provided a long-lasting positive response, disease control, and long-term survival in patients with MSI-H who had received at least one prior treatment.

What Patients Need to Know

A recent amendment to the National Comprehensive Cancer Network (NCCN) guidelines recommended that all metastatic colorectal cancer patients be tested for MSI-H, and that patients with MSI-H colorectal cancer be considered, after initial treatment, for either nivolumab or pembrolizumab (another immunotherapy treatment).