Predictive values of upper gastrointestinal cancer alarm symptoms in the general population: a nationwide cohort study

BACKGROUND: Survival rates for upper gastrointestinal (GI) cancer are poor since many are diagnosed at advanced stages. Fast track endoscopy has been introduced to prompt diagnosis for patients with alarm symptoms that could be indicative of upper GI cancer. However, these symptoms may represent benign conditions and little is known about the predictive values of alarm symptoms of upper GI cancer in the general population. METHODS: The study is a nationwide cohort study of 60,562 individuals aged 45 years or above randomly selected from the Danish general population. Participants were invited to complete a survey comprising of questions on several symptom experiences, including alarm symptoms for upper GI cancer within the past four weeks. The participants were asked about specific symptoms (repeated vomiting, difficulty swallowing, signs of upper GI bleeding or persistent and recent-onset abdominal pain) and non-specific symptoms (nausea, weight loss, loss of appetite, feeling unwell and tiredness). We obtained information on upper GI cancer diagnosed in a 12-month period after completing the questionnaire from the Danish Cancer Registry. We calculated positive predictive values and positive likelihood ratios for the association between alarm symptom and subsequent upper GI cancer. RESULTS: A total of 33,040 individuals above 45 years completed the questionnaire, yielding a response rate of 54.6%. Respondents were fairly respresentative of the study sample. During the follow-up period, 18 people were diagnosed with upper GI cancer. The number of incident cancers was similar among eligible non-respondents. Two thirds of the respondents with an upper GI malignancy had experienced one or more alarm symptoms. The positive predictive value for being diagnosed with upper GI cancer after reporting a least one alarm symptom was 0.1% (95% CI:0.0–0.1%). The positive likelihood ratio was 4.4 for specific alarm symptoms and 1.1 for non-specific alarm symptoms. CONCLUSIONS: We found that positive predictive values of alarm symptoms of upper GI cancer experienced in the general population are low. It is important knowledge that despite denoted alarm symptoms even patients with specific alarm symptoms of upper GI cancer have a low risk of being diagnosed with upper GI cancer.