The relationship between unexpected weight loss & cancer

New research will help GPs to identify the signs, symptoms, and blood test results they should look for to swiftly diagnose cancer in people with unexpected weight loss. The findings have implications for existing health policy and guidelines.

Researchers Brian Nicholson and Paul Aveyard from the Nuffield Department of Primary Care & Health Sciences, University of Oxford have examined the patient records of 63,973 adults who visited their GP with unexpected weight loss over a two-year period. They then linked these records with a national cancer registry to work out how many went on to be diagnosed with a cancer and what type.

The researchers looked for additional clinical features in patient records, such as recent blood test results or changes in bowel habit, that might be positive or negative indicators for cancer when combined with unexpected weight loss.

The team found that, of the almost 64,000 people, 908 (1.4%) received a cancer diagnosis within six months of reporting unexpected weight loss. Several symptoms, signs and tests when combined with unexpected weight loss increased the risk of a cancer further and could be used by GPs to identify different cancer types for priority investigation with further tests.

Symptoms that were associated with a cancer diagnosis in patients with unexpected weight loss included abdominal pain, appetite loss, iron deficiency anaemia, jaundice and enlarged lymph nodes. The team were also able to distinguish symptoms that were more important in men, such as difficulties in swallowing (dysphagia) or non-heart related chest pain, and women, such as back pain and indigestion (dyspepsia), that were associated with cancer.

The study highlights where guidelines focussed on investigating individual cancers have the potential to miss other types of cancer. For example, guidelines suggest that patients with unexpected weight loss and abdominal pain should be investigated for colorectal cancer, however, in this study there were over ten additional cancers with these two symptoms that would be missed by colonoscopy.

For more information about the findings of this research, please check out the Nuffield Department of Primary Care & Health Sciences website.