While patients with metastatic colorectal cancer are undergoing less surgery for the removal of their primary tumors, survival rates for the disease are improving, according to a new study.
According to The University of Texas MD Anderson Cancer Center, with new chemotherapeutic and biologic agents available for managing metastatic colorectal cancer, patients are having less surgery. The study found that although this patient population is having less surgery to remove their primary tumors, there has been an increase in overall survival among patients with metastatic colorectal cancer.
Yet researchers are questioning whether the rates of primary tumor resection (PTR) have not kept up with chemotherapy benefits and whether PTR rates should be even lower. According to the study’s corresponding author, George Chang, MD, associate professor, Surgical Oncology and Health Services Research, the primary indication for PTR in metastatic colorectal cancer is for patients who develop symptoms such as obstruction and bleeding. He said that in a select but small group of patients PTR should be performed in the context of treatment plans that include surgical resection of both primary and metastatic sites. However, several physicians and patients are concerned individuals whose primary tumors are intact may develop such symptoms on chemotherapy.
“We know from a previous phase II, cooperative group study that it’s safe to give chemotherapy even with biologics to patients with metastatic disease. Yet there’s still controversy about the role of primary tumor resection because some believe that there’s a survival association,” Chang said. “The purpose of our study was to evaluate the use of primary tumor resection among patients with metastatic colorectal cancer in everyday practice and nationally by examining trends in the proportion of metastatic patients undergoing PTR.”
Additionally, Chang and his team wanted to evaluate the trends in survival outcomes in patients with advanced disease over the same time period to show that despite the decreased use of surgery, survival is improving.
For the retrospective, population-based study, researchers used the National Cancer Institute’s (NCI) database to identify 64,157 patients who were diagnosed with metastatic colon cancer between 1988 and 2010. Among these, 43,273 underwent PTR. Those receiving the surgery were more likely to be female, younger than 50 years old and married, and to have colon cancer and a high tumor grade. Researchers found that the annual surgery rate decreased from 74.5 percent in 1988 to 57.4 percent in 2010. The most dramatic annual changes in PTR rates occurred after 2001. Chang said that the more dramatic PTR changes correlate with the availability of new chemotherapy drugs.
Additionally, the researchers found that independent of receiving PTR, the median relative survival rate of metastatic colon cancer patients improved from 8.6 percent in 1988 to 17.8 percent in 2009. Chang said that the study, which was published in JAMA Surgery, does not directly compare survival among those who did and did not get PTR nor did the researchers have information about the receipt of systemic chemotherapy.
“Our findings tell us that it is increasingly recognized that chemotherapy may be safely given to patients with tumors intact,” said Chang. “Although fewer people are getting primary tumors resected, a large proportion of patients with metastatic disease at diagnosis are still having them removed. Together with the observation that primary tumor resection was more likely performed in younger patients who have colon rather than rectal cancers suggests that there may still be an overutilization of PTR and that careful consideration of the indication for such surgery should be made.”
Source: MD Anderson