Adjuvant chemotherapy in early-stage colon cancer may improve survival

Researchers and physicians have grappled with the role of “adjuvant,” or post-surgery, chemotherapy for patients with early-stage colon cancer, even for cancers considered high risk. Now researchers from the University of Illinois at Chicago have found an association between the use of adjuvant chemotherapy in stage 2 colon cancer and improved survival — regardless of a patient’s age or risk, or even of the specific chemotherapy administered.

The findings are published in the journal Cancer.

The American Cancer Society estimates that more than 95,000 people in the U.S. will be diagnosed with colon cancer this year, making it the third-most common cancer diagnosis in men and women in the U.S. It is the second-leading cause of cancer-related deaths.

Adjuvant chemotherapy has long been proven to help patients fighting advanced colon cancer. However, its benefit for patients with stage 2 colon cancer remains unknown, and current clinical guidelines only recommend that physicians discuss this treatment option with stage 2 patients whose cancer is considered high-risk and likely to return after surgery.

“The results of this study are exciting, and certain aspects not entirely expected,” says lead author Dr. Ajay Maker, associate professor of surgery in the UIC College of Medicine and director of surgical oncology for the Advocate Creticos Cancer Center. “For many years, studies have included, but not focused on, stage 2 colon cancer patients. This study, which looks at the largest group of stage 2 colon cancer patients to date, set out to better understand the role of adjuvant chemotherapy in treating patients that are fighting this specific type and stage of cancer.”

Maker and his colleagues looked at health information on 153,110 patients with stage 2 colon cancer in the National Cancer Data Base. They found that patients who received adjuvant chemotherapy survived longer — in some cases, years longer — than those who did not.

“Certainly, we expected to see differences in the data,” Maker said. “But to find a clinically relevant association with overall survival across all subgroups of patients, including low-risk patients, is noteworthy and very relevant to future research on the potential use of adjuvant chemotherapy as a treatment for stage 2 colon cancer,” he said.

Maker noted that any look-back study of treatment and effect has limitations.

“We have to be careful when looking for associations retrospectively,” Maker said. “However, our research validates the need for prospective studies to identify the specific subgroups of stage 2 colon cancer patients who may benefit most from the use of adjuvant chemotherapy.”

Co-authors on the study are Dr. Leigh Casadaban, Garth Rauscher and Sally Freels of UIC and Dr. Mebea Aklilu and Dana Villenes of Advocate Illinois Masonic Medical Center.

This research was funded in part by the the National Cancer Institute, one of the National Institutes of Health, under grant K08CA190855.