Microsurgery for rectal cancer: how successful is transanal endoscopic microsurgery?

The authors examined the outcomes of rectal cancer patients after transanal endoscopic microsurgery (TEM).

Cancers are often described in terms of grades and stages. The T grades of rectal cancer describe how far the cancer has spread through the layers of the rectum. A T1 grade indicates that the cancer has grown through the inner layers of the bowel. A T2 grade indicates that the cancer has grown into the thick outer layer of muscle. A T3 grade indicates that the cancer has grown through the outer muscle layer of the bowel and into the outer layer of the colon.

TEM is a procedure used to remove small portions of bowel without any incision into the abdomen. It is useful for patients with T1 to T3 rectal cancer who have no cancer in their lymph nodes. TEM reduces the risk of complications compared to major surgery.

This study examined the outcomes of 425 rectal cancer patients who underwent TEM. Patients with grade T1 cancer only underwent TEM. Patients with grade T2 to T3 cancer received radiotherapy or radiotherapy plus chemotherapy before TEM. Patient survival and relapse rates were recorded. The number of patients who experienced complications was also recorded.

28% of patients were diagnosed with T1 cancer, 43.5% with T2 cancer, and 28% with T3 cancer. The cancer relapsed close to the original site (local recurrence) in 4.2% of patients after TEM. The cancer relapsed in a distant organ in 3.8% of patients.

After an average follow-up time of 253 months 100% of patients with T1 cancer were still alive. After an average follow-up time of 255 months 93% of patients with T2 cancer were still alive and after 239 months 89% of patients with T3 cancer were still alive.

No patients died as a result of the operation and no complications occurred during surgery. Minor complications occurred in 9.9% of patients after TEM. These included partial opening of the wound, rectal bleeding, and loss of bowel control. Major complications occurred in 1.4% of patients. These included inflammation behind the lining of the abdomen, inflammation around the anus, and an abnormal connection forming between the vagina and the rectum. 

The authors concluded that TEM is a safe and effective procedure to treat rectal cancer in selected patients. They highlight that for patients with grade T2-T3 cancer pre-treatment with chemotherapy and radiotherapy is needed.