Nodules detected on CT scan may predict lung malignancy

Lung nodules detected during baseline CT scan in combination with specific patient characteristics may serve as prognostic factors for lung cancer, study results suggest.

Management of lung nodules identified on scans, as well as defining a positive result, are complications associated with low-dose CT scanning for lung cancer.

In the population-based, prospective study, researchers aimed to investigate the probability that lung nodules detected on an initial scan would lead to malignancy.

The analysis included two cohorts: 1,871 participants from the Pan-Canadian Early Detection of Lung Cancer Study, and a validation set of 1,090 patients from the British Columbia Cancer Agency.

The analysis included 7,008 nodules — 102 of which were malignant — from the Pan-Canadian cohort, as well as 5,021 nodules — 42 of which were malignant — from the British Columbia group.

The rate of cancer among those with nodules was 5.5% in the Pan-Canadian set vs. 3.7% in the British Columbia set.

The following factors predicted cancer in the cohort: older age, female sex, family history of lung cancer, emphysema, larger nodule size, location of the nodule in the upper lobe, part-solid nodule type, lower nodule count and spiculation.

“Our final parsimonious and full models showed excellent discrimination and calibration, with areas under the receiver-operating-characteristic curve of more than 0.90, even for nodules that were 10 mm or smaller in the validation set,” the researchers wrote.

They concluded that patient and nodule characteristics detected by baseline low-dose CT scanning may have clinical utility in predicting malignancy.

Disclosure: The study was funded by the Terry Fox Foundation. Researchers report financial relationships with Pfizer, Roche, Siemens and other companies.