According to results recently presented at the plenary session of the 2003 annual meeting of the American Society for Therapeutic Radiation and Oncology, neoadjuvant therapy consisting of chemotherapy and radiation appears to be superior to adjuvant therapy in the treatment of locally advanced rectal cancer.
The rectum is the last 8 to 10 inches of the large intestine. Locally advanced rectal cancer refers to cancer that has spread from its site of origin to nearby tissues, but not to distant sites in the body. Historically, the surgical removal of cancer followed by chemotherapy and/or radiation therapy (adjuvant therapy) was the standard treatment approach for locally advanced rectal cancer. Adjuvant therapy is often used to kill any cancer cells that may remain in the body following surgery. Unfortunately, a significant portion of patients, particularly those who have cancer that is located near to the anus, are left with no sphincter control following surgery for rectal cancer. The sphincter is a circular muscle that controls defecation. Surgeons have addressed the issue of sphincter preservation in rectal surgery by attempting different types of surgical approaches, and lately with the use of neoadjuvant therapy.
Neoadjuvant therapy refers to therapy that is administered prior to surgery. Neoadjuvant therapy is being evaluated in several types of cancers in clinical trials and is emerging as an accepted therapeutic approach in some situations. The reasons for neoadjuvant therapy appear to be at least 2-fold: to immediately treat cancer that may have spread from the site of origin, increasing chances of preventing further spread or growth, and to shrink the cancer before surgery, improving chances that the cancer can be completely removed by surgery. The issue of neoadjuvant therapy has remained controversial in the treatment of rectal cancer.
Researchers from the German Rectal Cancer Group recently conducted a clinical trial to directly compare neoadjuvant to adjuvant therapy in the treatment of rectal cancer. This trial involved nearly 800 patients with locally advanced rectal cancer; approximately half of whom were treated with neoadjuvant chemotherapy (5-fluorouracil) plus radiation therapy and approximately half of whom were treated with adjuvant chemotherapy plus radiation therapy. The outcomes between the two groups were directly compared. At 5 years, cancer-free survival and overall survival were comparable between the 2 groups. However, cancer recurrence occurring within the pelvis occurred in 7% of patients treated with neoadjuvant therapy, compared to 11% of those treated with adjuvant therapy. In addition, the rate of sphincter-sparing surgery was significantly improved in the group of patients treated with neoadjuvant therapy. Complications related to surgery were not increased in the group of patients treated with neoadjuvant therapy.
These researchers suggested that neoadjuvant chemotherapy and radiation therapy should become the standard of care for locally advanced rectal cancer, as sphincter function following surgery was improved and recurrence rates in the pelvis were reduced compared to adjuvant therapy. Furthermore, surgery-related side effects were not increased in the group of patients treated with neoadjuvant therapy. Patients with locally advanced rectal cancer may wish to discuss the risks and benefits of neoadjuvant therapy with their physician.
Reference: Sauer, R, et al. Adjuvant versus neoadjuvant combined modality treatment for locally advanced rectal cancer: first results of the German Rectal Cancer Study (CAO/ARO/AIO-94). Proceedings from the 45th annual meeting of the American Society for Therapeutic Radiation and Oncology. Salt Lake City, UT. 2003. Abstract #2.
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