How beneficial is chemotherapy after surgery for patients with rectal cancer?

The aim of this study was to investigate the role of chemotherapy (CT) after surgery in patients with rectal cancer. The study suggests that CT after surgery could improve patient outcomes. 

Rectal cancer can be treated with surgery to remove the tumor. In general, patients are given CT before the surgery (neoadjuvant CT; NACT) to shrink the tumor and increase the chance that the surgeon can remove the entire tumor. Sometimes, patients can be given CT after surgery (adjuvant CT; ACT). ACT can kill any cancer cells that have been left behind or have moved to other parts of the body. However, ACT can also cause severe side effects.

It is not yet clear how beneficial ACT is for patients who have had NACT and full removal of the rectal tumor.

This study evaluated data from 17,406 patients in 23 studies. The average follow-up time in these trials ranged from 35 – 120 months.

In patients that achieved full tumor removal after NACT, ACT was associated with a 32% higher chance of an improved overall survival. However, patients who had ACT had no significant increase in survival without the progression of the disease or without relapse.

The study concluded that ACT may improve the survival rate of patients with rectal cancer that have had complete removal of the tumor after NACT. 

The study included data from a very wide range of trials. There were many differences in the types of ACT patients received. The study did not consider whether tumor size or type responded differently to ACT. Most of the studies analyzed were considered of low quality. Further studies are needed.