Factors that impact the survival rates of chemotherapy patients include the length of elapsed time between surgery and the beginning of treatment and the duration of the treatment period, according to PubMed. Study results published in 2013 show that the eight-year survival rates are higher for stage 3 colorectal cancer patients who begin chemotherapy within five weeks after curative resection and continue treatment more than four months than those who begin after five weeks and continue less than four months.
The eight-year survival rate was 62.9 percent for colorectal cancer patients who began chemotherapy between one and four weeks after their surgery, explains PubMed. Patients who waited more than five weeks after surgery to start chemotherapy had an eight-year survival rate of 52.3 percent. Colorectal cancer patients who underwent more than four months of chemotherapy had an eight-year survival rate of 63 percent, compared to 49.4 percent for those who treated for one to four months. There was no difference in survival rates between patients who underwent one to four months of chemotherapy, who did not begin chemotherapy until five weeks after surgery, and who did not undergo chemotherapy.
As of 2015, of the cancers that affect men and women in the United States, colorectal cancer is the second leading cause of cancer deaths and is the third most common cancer in both genders, according to the Centers for Disease Control and Prevention.