Lung cancer detected on coronary artery calcium scoring computed tomography: factors delaying diagnosis and predictors of survival

Lung cancers are occasionally detected on coronary artery calcium (CAC)-scoring computed tomography (CT). However, the cause of delayed diagnosis and prognostic factors have not been studied.

To investigate the causes of delayed diagnosis of lung cancer in patients who undergo CAC-scoring CT and to identify predictors of mortality.

A total of 151 patients who were diagnosed with lung cancer and had undergone CAC-scoring CT from January 2010 to December 2014 were retrospectively enrolled. The reasons for delayed diagnosis were reviewed. Follow-up data on all-cause mortality were obtained. Cox proportional hazards regression analysis was used to identify predictors of mortality. Analyses of solid and subsolid subgroups were performed.

Among the 151 patients, 86 lesions (56.9%) were solid and 63 (41.7%) were subsolid. The main causes of delayed diagnosis were detection (48%) and interpretation (22%) errors. Age, size, unresectable stage at the time of diagnosis, and stage shift were independent prognostic factors throughout the entire and in the solid subgroup (all P < 0.2). There were no significant prognostic factors in the subsolid subgroup.

In conclusion, avoidance of detection and interpretation errors may prevent delayed diagnosis of lung cancer on CAC-scoring CT. Older age, larger tumor size, unresectable stage at the time of diagnosis, and stage shift were associated with poor survival in patients with solid lung cancers but not in those with subsolid lung cancers.