Researchers seek to determine the ideal duration between radiation treatment and the actual surgical removal of cancerous cells.
A recent study evaluated the most successful time to undergo a cancer operation after patients receive chemoradiotherapy.
During a 6-year study published in the Journal of the American College of Surgeons, investigators evaluated at 11,760 patients with either stage 2 or stage 3 localized rectal cancer administered chemotherapy and surgical treatments from 2006 to 2012.
The goals of the study included determining the ideal waiting time between chemotherapy and radiation treatment and the actual surgical removal of the cancer. Researchers also sought to evaluate the amount the tumor decreased in size and penetration into surrounding tissue.
During the study, researchers divided patients into a short interval group, which includes patients who had an operation within 55 days of chemoradiotherapy, and a long interval group, which includes patients who had an operation 56 days or more after therapy.
Patients in the long-interval group were slightly older (59 vs 58-years old), were more likely to be black (9.5% vs 8%), treated at an academic hospital, have stage 3 cancer (51.4% vs 54.2%), and were less likely to have private insurance (50.2% VS 55.4%).
It was also found that extending the delay past 56 days did not have a greater effect on down-staging the tumor. However, it did have a higher likelihood of positive resection margins and long-term survival.
Although this group of patients had a worse long-term survival rate, they did have a lower risk for returning to the hospital within 30 days post-surgery. There were no apparent differences in death rates during that period of time.
The results of the study confirmed that the median time between chemoradiotherapy and surgery was 56 days or 8 weeks, with the actual time ranging from 43 to 63 days.
In the United States, colon and rectal cancers are the third most common cancers. According to the Centers for Disease Control and Prevention, there are approximately 135,000 new cases and 51,000 deaths per year.
"The real significant thing we found was that long-term mortality was significantly higher after 56 days," said lead author Christopher Mantyh, MD, FACS. "In the global picture, there's a lot of discussion about if waiting longer for surgery is better, and if you don't wait as long there's less chance of tumor spreading, but none of it is backed up on good modeling data like we have in this study. This kind of analysis is what we need in medicine and surgery. We need to have good population based data."