Survival of patients with rectal cancer followed-up by the watch and wait method after chemoradiotherapy

This study investigated the outcomes of patients with rectal cancer who were followed up with the watch and wait method after chemoradiotherapy (CRT). Researchers suggested that this strategy can effectively identify patients who can have a less frequent follow-up if they maintain response for the first 3 years after treatment.

Rectal cancer is present in a third of patients with colorectal cancer in the US. The recommended treatment in patients who responded well to CRT is no immediate surgery. This method is known as the watch and wait and avoids the risks associated with a major surgery. However, with the watch and wait, there is a risk for the rise of local recurrence (when the cancer comes back). Therefore, long-term and intensive follow-up protocols have been recommended for patients managed by a watch and wait method. 

The chances of survival and risk of recurrence after cancer treatment are measured for each patient. The identification of risk factors for disease recurrence that change over time helps to predict the survival of each patient. However, studies of large populations of patients with rectal cancer who received CRT and were managed by the watch and wait method are still lacking.

This study included information about 793 patients from a large watch and wait database. The main outcomes measured were local recurrence-free survival (time from treatment to recurrence) at 3 years and metastasis-free (time from treatment to cancer spread at distant places) survival at 5 years. The average follow-up was 55.2 months.

If patients had no recurrence after the first year, the chances of remaining free from local recurrence for another 2 years was 88.1%. This chance was 97.3% for those who remained free of recurrence after 3 years and 98.6% if they did not have recurrence after 5 years.

The chances of remaining free from metastasis for another 2 years was 93.8% for those without metastasis after 1 year. This chance was 97.8% after 3 years and 96.6% after 5 years of metastasis-free status. 

This study concluded that patients with rectal cancer who maintain a complete response for 3 years after CRT have a 5% or lower risk of local recurrence and less than 2% risk of a metastasis. The authors suggest that for these patients, the intensity of the follow-up by the watch and wait method could be reduced. 

This study was based on information from medical records, therefore information might be missing. Moreover, both near and full complete response patients were grouped together which might change the interpretation of data. Further studies are necessary.