Chemo after surgery best for liver-metastatic colon cancer patients: study

A study has found that even in cases of colon cancer that has metastasized to the liver, surgery ahead of chemotherapy is more beneficial for patients if the cancer is still operable.

Two to three colon cancer patients out of 10 are diagnosed at stage 4 when the cancer has already spread to other organs.

Even then, 6–15 percent of patients are found to be eligible for surgical resection. However, there has been disagreement among medical professionals regarding whether first to remove the visible cancer through surgery or to prioritize systemic treatment with chemotherapy to address the possibility of metastasis to other areas.

On Monday, a research team led by Professors Cho Yong-beom and Kim Se-jeong of the Department of Colorectal Surgery at Samsung Medical Center announced that they had analyzed the effects of the order of surgery and anticancer treatment on survival in patients with operable liver-metastasized colorectal cancer and published their findings in the latest issue of the international academic journal “Surgery.”

The research team analyzed 402 patients diagnosed with operable concurrent liver-metastasized colorectal cancer at Samsung Medical Center from January 2007 to February 2022, dividing them into three groups: the “surgery-first group” (244 patients) who received chemotherapy after surgery; the “chemotherapy-first group” (92 patients) who underwent chemotherapy followed by surgery; and the “no chemotherapy-chemotherapy discontinuation group” (66 patients) who did not undergo chemotherapy or discontinued it before surgery. Outpatient follow-up was conducted every three months for the first two years and every six months thereafter.

According to the study, patients who underwent surgery first had higher five-year disease-free survival rates and overall survival rates. Disease-free survival rate refers to the period from the diagnosis of colon cancer to the recurrence of the disease, excluding any treatment-related deaths. In contrast, the overall survival rate refers to the period from the diagnosis of colon cancer to the time of death.

The five-year disease-free survival rates were 52.5 percent for the surgery-first group, 31.5 percent for the chemotherapy-first group, and 16.7 percent for the chemotherapy group. The overall survival rate was 77.5 percent in the surgery-first group, 72.8 percent in the chemotherapy-first group, and 45.4 percent in the chemotherapy group.

The research team also observed differences in disease-free survival rates depending on whether targeted therapy was used before or after surgery. The disease-free survival rate for patients who did not receive targeted therapy was 53.0 percent, which was higher than the 39.6 percent for patients who received targeted therapy. However, the research team noted that caution is needed in interpreting the results, as targeted therapy was likely used primarily in high-risk patients.

“This study provides encouraging results confirming that a treatment strategy prioritizing surgery followed by chemotherapy for patients with operable synchronous liver metastases at diagnosis may improve patient survival,” Professor Cho said.

Professor Kim said, “Although the disease-free survival rate was higher in the group that did not receive targeted therapy, a multi-center study is needed to confirm this. A cautious approach to treatment strategies is required, and based on this, customized treatment tailored to each patient will be important.”