To improve the success of surgery for advanced rectal cancer, physicians are using a combination of chemotherapy before surgery with radiation therapy before or after surgery. The goal of this approach is to shrink the tumor, making it possible to remove it surgically with less damage to surrounding tissues.
This therapy is becoming a standard for very large cancers that still can be removed surgically, and for locally advanced disease or tumors that cannot be removed surgically.
Preoperative chemoradiation may offer several advantages: Patients may be able to tolerate higher doses of chemotherapy before surgery, with less severe side effects. By giving chemotherapy at the earliest possible time, the metastases may be fewer or smaller, making chemotherapy more effective.
Kathleen L. Schneekloth, MD – “…radiation and chemotherapy shrink the cancer before surgery…”
Other possible advantages include reducing the chance of tumor cells spreading to new locations, and improving the chance of sphincter preservation by decreasing the size of the tumor.
A possible disadvantage of using preoperative chemoradiation is that during surgery, some patients may turn out to have early-stage disease, which did not need chemoradiation.
Your doctor will discuss with you the pros and cons of chemoradiation in your particular case.