Asan Medical Center researchers have developed a treatment guideline that can reduce the recurrence rate of rectal cancer by adjusting the intensity of adjuvant chemotherapy after radiation or surgery according to the cancer cell decrease.
|From left, Professors Kim Tae-won, Hong Yong-sang, and Kim Sun-young|
Currently, hospitals conduct surgery on rectal cancer patients after reducing the cancer size through chemotherapy or anticancer treatment. After surgery, adjuvant chemotherapy to prevent recurrence is underway. However, patients are concerned because cancer often recurs locally after treatment.
To help ease such worries, the AMC team, led by Professors Kim Tae-won, Hong Yong-sang, and Kim Sun-young at the hospital, confirmed the reduced risk of recurrence rate and increased the survival rate for patients after adjusting the intensity of adjuvant chemotherapy according to the cancer cell decrease after radiation or surgery.
The team analyzed 321 patients with stage 2 or 3 rectal cancer who had undergone surgery at six medical institutions in Korea from 2008 to 2012 and applied adjuvant chemotherapy that fit the patient’s condition. As a result, the group treated with two anticancer drugs had a 37 percent lower risk of rectal cancer recurrence and an 11.4 percent increase in recurrence-free survival for six years compared to the group receiving only one anticancer agent.
In detail, the group that received only one anticancer drug (fluoropyrimidine) had a six-year overall survival and recurrence-free survival rate of 76.4 and 56.8 percent, respectively, while the group that received two drugs (fluoropyrimidine and oxaliplatin) showed a six-year overall survival and recurrence-free survival rate of 78.1 and 68.2 percent.
“The study demonstrated that high-intensity adjuvant chemotherapy was effective for patients with high-risk rectal cancer,” the team said. “Also, when we designated the risk of relapse in the one drug group as 1, the risk of relapse in the two-drug group was 0.63, indicating a 37 percent reduction in the risk of relapse.”
To date, adjuvant chemotherapy with two drugs has not been used in clinical practice as it was not clear whether it will lower the risk of cancer recurrence, the team added. As the result of this study, however, the adjuvant chemotherapy with two drugs was cited in the U.S. National Comprehensive Cancer Network guidelines, which is the standard treatment guideline for clinicians worldwide and is increasingly being used in Korea.
“In Korea, there are more than 10,000 cases of rectal cancer every year, and the problem of locally recurring cancer is reducing the quality of life of many patients with rectal cancer,” Professor Kim Tae-won said.
The study demonstrates the efficacy of adjuvant chemotherapy in combination with drugs, and the possibility of applying the new chemotherapy to postoperative stages in patients at high risk who have not had a definite effect in managing their cancer, he added.
Journal of Clinical Oncology published the results of the study in its October issue,.