Symptom Prevalence and Impact on Lung Cancer Risk in the SUMMIT Study

Lung cancer screening is now widely adopted across health care systems. Screening typically occurs in asymptomatic individuals. Because symptoms of lung cancer overlap with those of chronic conditions, defining asymptomatic screening is challenging. This study outlines the frequency of symptomatic participants in a lung cancer screening trial.

How common are respiratory and red flag symptoms in lung cancer screening participants, and how do these symptoms impact screening outcomes?

SUMMIT is a prospective observational cohort study to assess the implementation of low-dose CT screening for lung cancer. Baseline clinical assessments collected self-reported symptoms, medical history, demographics, and spirometry. Hemoptysis (in last year) and unintentional weight loss (≥ 5 kg in 3 months) were classified as red flag symptoms, and cough (acute: onset < 6 weeks; chronic: > 6 weeks) and dyspnea (modified Medical Research Council scale score ≥ 1) were classified as nonspecific symptoms. Lung cancer diagnoses within 1 year were ascertained. Multivariable logistic regression was used to assess associations between symptoms and lung cancer.

Among 13,035 participants eligible for a baseline LDCT scan, 76% (n = 9,859) reported at least 1 symptom. Cough was present in 36% (n = 4,707), and 66% of participants reported dyspnea. Only 6% of participants reported red flag symptoms, including hemoptysis and weight loss. The presence of any of these symptoms was associated with higher likelihood of lung cancer diagnosis in the year after assessment (OR, 1.45; P = .03, adjusted for other baseline factors).

Our results show that symptoms are commonly reported in those undergoing lung cancer screening and those with symptoms are more likely to be diagnosed with lung cancer.