Better survival among women after lung cancer surgery
STOCKHOLM, Sweden: There are known differences in the survival rates of women and men with lung cancer. Researchers at Karolinska Institutet have set out to investigate potential reasons behind this disparity, such as the presence of other underlying diseases and smoking status. The study showed that women have better survival rates after lung cancer surgery than men, independent of other factors.
Previous studies have shown a link between female sex and a lower overall disease risk, as well as better survival in many forms of cancer that affect both sexes. However, lung cancer is an exception, for which female sex could be a risk factor.
Previous studies on sex differences in survival after lung cancer treatment have yielded conflicting results. Therefore, the research team set out to further investigate the link between sex and survival after lung cancer surgery.
“The healthcare sector is always striving to offer all patients equal treatment tailored to their individual needs,” said lead-author Erik Sachs, doctoral student at the Department of Molecular Medicine and Surgery at Karolinska Institutet. “This kind of study can help shed light on systematic differences that ultimately affect patient outcomes.”
In a national population-based registry study, researchers analysed sex differences in survival in women and men after lung cancer surgery, taking into account a wide range of factors such as socioeconomic differences, age, smoking status, comorbidities, tumour characteristics and the type and extent of surgery. Follow-ups were carried out one, five and ten years after surgery.
The sample consisted of 6,536 patients, of which just over half were women, who underwent lung cancer surgery in Sweden between 2008 and 2017. The mean age was 67 years for women and 68 years for men. More women were non-smokers, and women had a lower incidence of comorbidities than men.
Women showed lower mortality
The results showed that women have a 27% lower mortality compared to men, independent of factors such as comorbidities, age, socioeconomic status, lifestyle factors, physical function, type and extent of surgery, tumour characteristics and tumour stage. The pattern of better survival in women was observed across all age categories except in the youngest patients, where the difference was not as pronounced.
“Our findings are significant, as they suggest that the prognosis for lung cancer can likely be improved, but more research is needed in this area,” said co-author Dr Veronica Jackson, researcher at the Department of Molecular Medicine and Surgery, Karolinska Institutet. “Further studies that specifically investigate the effects of lifestyle, sociocultural conditions and the presence of any inequalities in the delivery of care would likely be of value.”
The journal pre-proof of the study, titled “Sex and survival after surgery for lung cancer: A Swedish nationwide cohort”, was published online on 16 November 2020 in CHEST.