Prioritising primary care patients with unexpected weight loss for cancer investigation: diagnostic accuracy study
Unexpected weight loss (WL) is recorded for about 1.5% of adults attending primary care. The likelihood of a cancer diagnosis in such people is increased in the three to six months after the first record of unexpected WL compared with people without unexpected WL. A diagnostic accuracy study using routinely collected electronic health records in UK primary care established the predictive value of unexpected WL for cancer, given the patient’s age, sex, smoking status, concurrent symptoms, signs, and blood test results. They found male regular smokers aged 50 years or older had a positive predictive value for cancer of above 3% – greater than the threshold recommended by the National Institute for Health and Care Excellence, warranting urgent referral for invasive investigation. Clinical features thought to be specific to an individual cancer site were also found to be markers of several different types of cancer when they co-occur with unexpected WL. Future research could address broader investigative approaches for patients with unexpected WL, which could lead to a more comprehensive investigation of cancer symptoms for different cancer types and thus, result in earlier diagnosis.