Weight loss might be an early clinical manifestation of undiagnosed cancer: a nation-based cohort study

Background/Aim: No published nation-based study has examined the relationship between weight loss and cancer in Taiwan. The aim of this study was to investigate whether weight loss is an early clinical manifestation of cancer in Taiwan. Methods: We conducted a nation-based, retrospective cohort study that analyzed the database of the Taiwan National Health Insurance Program. There were 8210 subjects aged 20 to 84 years with newly diagnosed weight loss selected as the weight loss group from 2000 to 2012, and 32826 randomly selected subjects without weight loss as the non-weight loss group. The weight loss and non-weight loss groups were matched along sex, age, and comorbidities. The incidence of cancer at the end of 2013 was examined in both groups. Results: The weight loss group had a significantly higher incidence of cancer than the non-weight loss group during the first 3 months of follow-up (25.1 vs. 8.39 per 1000 person-years, with an incidence rate ratio 2.99, 95% CI 2.82, 3.18). The multivariable Cox proportional hazards regression model revealed that the adjusted HR of cancer was 1.05 for the weight loss group (95% CI 1.04, 1.05) as compared with the non-weight loss group. Conclusion: Weight loss is associated with a small but statistically significant increase in the hazard of cancer. Weight loss might be an early clinical manifestation of undiagnosed cancer. Physicians should keep in mind the possibility of cancer when people present with weight loss and other possible cancer-related symptoms, particularly during the first 3 months of follow-up.