The more tumors shrink during chemotherapy and radiation before rectal cancer surgery, the better the chance that patients will survive and be cancer-free five years later.
Doctors in Ireland developed a simple, three point, tumor regression grade or TRG, to measure the amount of change during chemoradiotherapy before surgery to remove rectal cancer. After five years, all patients with the best tumor regression grade — complete or near complete response to chemoradiation — were alive and disease-free.
In a series of 126 patients with locally advanced rectal cancer (T3/T4 or spread into nearby lymph nodes), five year disease-free survival after chemoradiotherapy followed by surgery was 72 percent. Seven percent of patients had cancer recur locally in or near the rectum.
After pathologists examined the surgical specimen, a standard score was used grade response to chemoradiation: complete or near-complete response (TRG1), partial response (TRG2), or no response (TRG3).
Patients with near or complete response (TRG1) had 100 percent disease-free survival at five years. For those with partial (TRG2) response, five year DFS was 71 percent. No response (TRG3) led to a 66 percent disease-free survival. Six in ten patients had some response to the presurgical chemoradiotherapy.
D. Beddy and colleagues concluded,
Tumor regression grade measured on a 3-point system predicts outcome after chemoradiotherapy and surgery for locally advanced rectal cancer.
SOURCE: Beddy et al., Annals of Surgical Oncology, Volume 15, Number 12, December 2008.