Men have a 43% greater risk of dying from lung cancer than women but most of the survival difference can be explained by known prognostic factors, Australian research shows.
Key drivers of sex-related survival disparities in lung cancer mortality included histologic subtype, cancer stage, treatment received and smoking status, according to findings published by researchers from The Daffodil Centre, Sydney University and Cancer Council NSW.
They said it had long been known that women tended to survive a lung cancer diagnosis longer than men but the factors related to sex-related disparities had remained largely elusive until now.
They therefore investigated lung cancer outcomes and prognostic factors for 488 women and 642 men who were enrolled in the 45 and Up Study between 2006–2009.
During follow up to 2015 they found that overall survival for women was significantly longer than for men (median 1.28 versus 0.77 years; HR for men = 1.43, 95% CI: 1.25–1.64, p < 0.0001).
Their initial findings, published in the Journal of Thoracic Oncology, showed that survival disparity remained when each subgroup of major prognostic factors (histologic subtype, stage at diagnosis, treatment received, and smoking status) was evaluated separately.
On multivariable analysis, treatment-related factors explained half of the survival difference, followed by lifestyle and tumour characteristics (explaining 28%, 26%, respectively). After adjusting for all major known prognostic factors, the excess risk for men was reduced by more than 80%.
The researchers said their findings confirmed and extended those of previous Australian studies into sex disparities in lung cancer survival, providing more robust data based on people in community settings rather than just hospital-based patients undergoing treatment with curative intent.
“We found that approximately half of the observed sex survival disparity was explained by differences in receipt of anticancer treatments within six months after diagnosis. This could partly be due to a lower proportion of men having surgery within six months than women (17% versus 25%), which may be due to patient-related factors that also correlate with poorer survival,” they said.