Prognostic factors in lung cancer in a defined geographical area over two decades with a special emphasis on gender.

Introduction: Many studies over recent decades report an increasing incidence of lung cancer in female patients. Female gender is often reported as a good prognostic factor.

Objectives: The aim of the present study was to investigate prognostic factors with a special emphasis on gender.

Methods:   During 1989-2008, 1497 patients in eastern Scania, a part of southern Sweden with 202,000 inhabitants, were referred to one Central Hospital and prospectively registered. All patients were grouped into four 5-year periods and were analysed for occurrence of lung cancer, patient performance status, types and stages of lung cancer and the relation to gender.

Results: The incidence of lung cancer more than doubled in women. The proportion of adenocarcinomas increased in females and in males to 57% (P=0.028) and 42% (P=0.001), respectively, while the frequency of small cell lung carcinomas (SCLCs) decreased in both genders to approximately 14%. Females had significantly more frequent stage 1 (16.6%) and higher surgery rate (23.1%) than males (12% and 18.2%, respectively). Females showed a higher 5-year survival rate than males (20.1% and 11.5%, respectively; P<0.001). Patients with non-small cell lung carcinoma (NSCLC) had a higher 5-year survival rate than those with SCLC (16.5% and 7.5%, respectively; P<0.01); however, there was no significant survival difference in females between NSCLC and SCLC.

Conclusion: Female patients exhibited longer survival than males for both NSCLC and SCLC, and this was not explained by a higher frequency of stage 1 or surgery in NSCLC.