Weight loss that began as far as 2 years before a lung cancer diagnosis was associated with a risk of cancer.
Significant weight loss may be associated with incident lung cancer, according to an analysis of electronic health records (EHR) from University of Washington Medicine (UWM) that was published in JAMA Network Open. Patients in the case-control study who experienced 10% to 50% weight loss had a 2-times higher likelihood of being diagnosed with lung cancer.
Further, 6 months of continued weight loss prior to cancer diagnosis was significantly associated with incident cancer diagnosis. This includes weight loss recorded as a symptom by the clinician or weight loss based on changes seen in routinely measured weight.
Weight loss, loss of appetite, and fatigue are nonspecific symptoms of lung cancer; however, they are also associated with other conditions. To further complicate the issue, weight loss is difficult to assess because it can either be subjectively measured by the patient or objectively measured by a clinician. For example, it is routinely measured in visits to ambulatory care facilities.
Prior studies suggest weight loss can be significantly associated with various cancers; however, there is no clear association between weight loss and incident lung cancer. Investigators conducted a study to collect evidence that weight loss is associated with incident lung cancer.
The study included a large cohort of 625 patients, aged 40 years and older, diagnosed with lung cancer between 2012 and 2019 and part of the US ambulatory care medical system. Investigators enrolled 4606 controls who were matched on age, sex, smoking status, and in a similar type of ambulatory clinic.
The EHR data suggest that 3 or more months of weight loss prior to lung cancer diagnosis is associated with lung cancer. Further, patients with lung cancer were more likely to have increased weight loss than matched controls in the 2 years prior to diagnosis.
Weight loss ranging between 1% and 10% did not have as much of a risk on lung cancer diagnosis compared to patients who maintained a steady weight. In addition, weight loss recorded by the clinician was a better tool to estimate risk of incident lung cancer than measuring weight change, although clinicians often missed or did not make noteworthy records of objective weight changes.
Limitations include control and study arms being chosen based on different criteria; some cases and controls were excluded during analysis due to clinically implausible data; certain aspects of data collection relied on patient interactions with the health care system; and smoking was not directly included in models.
Lung cancer is the top cause of cancer death and third most common cancer in the United States. Lung cancer screenings remain low despite it being an effective means of improving patient outcomes. The findings support further research on the implementation and impact of clinical decision-making and identifying other serious illnesses to improve patient outcomes.
Kessler L, Nicholson B, Burkhardt H, et al. Association of Weight Loss in Ambulatory Care Settings With First Diagnosis of Lung Cancer in the US. JAMA Netw Open. 2023, DOI: 10.1001/jamanetworkopen.2023.12042