RSNA: Ground-glass lung nodules point to greater cancer risk for women

CHICAGO—A new review of CT scans in the National Lung Screening Trial has revealed that women are as much as 50 percent more likely than men to have “ground-glass” nodules. Moreover, when these nodules are present, women seem to be at greater risk than men of developing lung cancer.

Ground-glass nodules are characterized by subsolid density properties that render their appearance hazy. They may be wholly nonsolid (in which case they completely obscure no areas of adjacent lung tissue) or part-solid (part of the ground-glass opacity completely obscures tissue).

Nonsolid ground-glass nodules are referred to as “pure ground glass.”

Part-solid nodules are most strongly associated with lung cancer detected in screening.

Phillip Boiselle, MD, of Harvard will present the new study on differences in actions of these nodules by sex at RSNA.

According to a pre-conference news release, Boiselle and colleagues found that, of 26,455 participants, some 9,994, or 37.8 percent, had a positive screen at one or more points during the trial.

The team characterized all CT-detected nodules measuring 4 to 30 millimeters by consistency using the NLST database. They calculated the relative risk of developing a lung cancer for each nodule consistency subtype—solid, part-solid (partial ground glass) and pure ground glass.

Women with pure ground-glass nodules “had a significantly higher relative risk of lung cancer than men with the same type of nodules, and a similar trend was observed for part-solid nodules,” according to RSNA.

By contrast, the relative risk of lung cancer for solid nodules was comparable for both sexes.

More than 40 percent of subjects in the National Lung Screening Trial (NLST) were women, “giving the research team a rare opportunity to look for statistically significant differences in lung nodules and lung cancer between the sexes,” RSNA noted.

In prepared remarks, Boiselle said that, by looking at the rate at which lung cancers grow on serial CT scans, “we can develop a better understanding of how often to obtain follow-up CT scans in men and women.”