[Weight loss as a presenting clinical feature of malignancy].

Unexpected weight loss presents a diagnostic challenge as it is associated with a wide range of benign and serious conditions. Although it is readily associated with malignancy, the risk of cancer in adults with unexpected weight loss presenting to primary care is 2% or less. In male patients aged 60 years or older and in patients with concurrent clinical symptoms, signs and abnormal blood test, the risk of cancer increases. Initial testing should include a history including medication review, physical examination and blood tests. Recommended blood tests include a complete blood count, basic metabolic panel, liver function tests, thyroid function tests, C-reactive protein level, erythrocyte sedimentation rate and lactate dehydrogenase measurement. Imaging and invasive testing may be considered based on initial evaluation. When the initial evaluation is unremarkable, an observation period is recommended for young patients in particular.