Is delay of surgery after neo-adjuvant chemo-radiotherapy an effective treatment procedure?

The meta-analysis assessed whether a longer interval between the end of neo-adjuvant chemo-radiotherapy and surgery leads to better outcomes in treatment of rectal cancer.

Rectal cancer involves the final part of the large intestine, or rectum. The first choice for treatment of rectal cancer is usually surgery. However, in more advanced stages chemotherapy with radiation is given before surgery (neo-adjuvant chemo-radiation) to shrink the cancer so that it can be completely removed by surgery.

 Neo-adjuvant chemo-radiotherapy can cause side effects independent of the surgery itself (such as loss of bowel control, bladder or sexual problems) or can extend the recovery period for patients with rectal cancer.  However, previous studies have indicated that delaying the time between neo-adjuvant chemo-radiotherapy and surgery can improve the pathological complete response rate. This meta-analysis (pooled analysis) assessed previous studies on this topic.

The meta-analysis involved thirteen trials with a total of 3,584 rectal cancer patients. Patients had either undergone surgery within eight weeks (short waiting interval patients) or after eight weeks (delayed patients) from completion of neo-adjuvant chemo-radiotherapy. The main parameter of analysis was pathological complete response (no residual cancer cells found).

Results showed that delayed patients were 42% more likely to achieve pathological complete response. Only 13.7% of patients who underwent surgery within eight weeks after neo-adjuvant chemo-radiotherapy experienced pathological complete response compared to 19.5% of delayed patients.

Overall survival and disease-free survival (the length of time after a specific cancer treatment that a patient survives with no sign of the disease) were similar in the two groups.  

In summary, longer interval between the end of neo-adjuvant chemo-radiotherapy and surgery improves the likelihood of achieving complete pathological response in the treatment of rectal cancer.

This was a study of non-randomized clinical trials, therefore the pCR association with sugrical delay cannot be correlated with other clinical variables.