Is chemoradiotherapy before surgery needed for patients with stage II-III colorectal cancer?

This study evaluated whether chemoradiotherapy (CRT) before surgery improves the outcomes of patients with stage II-III colorectal cancer (CRC). The study found that CRT before surgery may not be needed in certain patients with low-risk disease.

CRC is the third most common cancer worldwide. The standard therapy for CRC is CRT to shrink the tumor, followed by surgery to remove the tumor. Add-on chemotherapy (CT) is often given to ensure that any remaining cancer cells are destroyed.

Both CT after surgery and CRT before surgery can increase the risk of severe side effects. 30% of patients who are treated with CRT followed by surgery will experience recurrence and spread (metastasis) of the disease and will need further treatments. Magnetic resonance imaging (MRI) scanning before treatment can help doctors decide the best treatment for a patient with CRC. Some patients may not need CRT before surgery and they can be identified by MRI. These patients could be treated with upfront surgery (US) to remove the tumor followed by add-on CT if needed.

It is not known whether US gives patients an equally good outcome compared to CRT followed by surgery in patients with stage II-III CRC.

 This study evaluated data from 202 patients with CRC. Patients were divided into two groups. Group 1 received CRT followed by surgery (101 patients). Group 2 included 101 patients that were identified by MRI as not needing pre-surgery treatment and had US. Patients in both groups were given add-on CT after surgery as decided by their doctor. The average follow-up time was 62 months.

There were similar recurrence rates between group 1 (17%) and group 2 (12%) after 3 years. Survival without signs of cancer after 3 years was similar between group 1 (83%) and group 2 (88%). There was also a similar 3-year overall survival between group 1 (89%) and group 2 (91%).

Patients in both groups reported side effects. The most reported were fatigue and diarrhea. Patients in group 1 reported more severe side effects.

The study found that patients who were treated with US had an equally good response to therapy as those treated with CRT followed by surgery. 

The study was based on medical records data. Patients were given CRT followed by surgery or US based on their doctor’s choice. The sample size was small. All patients came from the same treatment center. Further studies are needed to evaluate whether US alone is a good treatment option for CRC.