Especially for women, lung cancer screening with low-dose CT (LDCT) reduces all-cause mortality, increases disease survival rates, and decreases coronary artery calcification burden, according to a group led by Dr. Margherita Ruggirello, of Fondazione IRCCS Istituto Nazionale dei Tumori, in Milan, Italy. The team's findings were published on 4 October in Lung Cancer.
LDCT has been shown to reduce lung cancer mortality rates among heavy smokers -- a benefit that appears to be greater among women, the authors noted. Previous studies regarding the benefits of lung cancer screening have focused on factors such as tumor characteristics (histological type and location) and lifestyle (that is, awareness of risk and screening behavior). Yet reasons for the difference between women and men aren't clear.
To address the knowledge gap, Ruggirello and colleagues conducted a study that compared overall mortality rates and lung cancer survival among women and men, focusing on the predictive value of coronary artery calcification (CAC) at baseline LDCT. The research included 6,495 heavy smokers enrolled in the Multicentric Italian Lung Detection (MILD) and the BioMILD trials between 2005 and 2016; the authors assessed sex differences in 12-year cause-specific mortality rates stratified by age, pack years, and CAC score.
The group found that 12-year all-cause mortality rates were lower for women compared with men, at 4.1 % and 7.7 %, respectively (p < 0.0001). The median CAC score was 8.7 in women and 41 in men (with scores of 1 to 10 equal to minimal risk; those of 11 to 100, mild risk; scores of 101 to 400 equal to moderate risk; and those of more than 400, high risk).
Incidence of lung cancer and the percentage of stage I disease was not statistically significant between the sexes, but women had significantly lower 12-year mortality rates and higher disease survival rates, the team found.
12-year follow-up effect of LDCT lung cancer screening by sex |
|||
|---|---|---|---|
| Outcome |
Men |
Women |
p-value |
| Lung cancer mortality rate |
1.9% |
1% |
0.0052 |
| Lung cancer survival from diagnosis rate |
51.7% |
72.3% |
0.0005 |
| Proportion of Stage I disease |
51.2 % |
58.1 % |
0.2782 |
| Incidence of lung cancer |
4.7% |
4.4% |
0.6216 |
Why does it appear that women benefit from lung cancer screening more than men? The answer is likely related to CAC scores, according to the authors.
"The lower CAC burden observed in women at all ages might … explain their lower rates of all-cause mortality and better lung cancer survival," they concluded.
The complete study can be found here.
