What is it about?

We have used data from the Swedish Obese Subjects (SOS) study; ClinicalTrials.gov, identifier: NCT01479452 – a prospective controlled intervention study examining weight-loss surgery outcomes – to examine the impact of weight loss surgery on the long-term risk of colorectal cancer. In our study, we could not verify that weight-loss surgery leads to changes in colorectal cancer risk in patients with obesity. Our results rather indicates a possible decreased risk of rectal cancer with weight-loss surgery.

Featured Image

Why is it important?

Obesity is a risk factor for several types of cancer, and intentional weight loss sometimes reduces the risk. Although weight-loss surgery is considered to reduce cancer risk in general, whether the incidence of colorectal cancer increases or decreases after this treatment is debated.


Despite reported positive effects of weight-loss surgery on mortality and health- including reduction of many types of cancer-, the possibility that weight-loss may be associated with colorectal cancer can affect decisions by both patients and health care professionals. Our study reporting unaltered colorectal cancer risk with surgery in a large controlled cohort with long follow-up is therefor important.

Magdalena Taube

Read the Original

This page is a summary of: Long-term incidence of colorectal cancer after bariatric surgery or usual care in the Swedish Obese Subjects study, PLoS ONE, March 2021, PLOS,
DOI: 10.1371/journal.pone.0248550.
You can read the full text:

Open access logo


The following have contributed to this page