A prospective study of a total material of lung cancer from a county in Sweden 1997-1999: gender, symptoms, type, stage, and smoking habits

Abstract

The epidemiology of lung cancer is changing in many parts of the world. In the industrialized countries, there is a trend that the incidence in men is declining, while it is increasing for women. Also, adenocarcinomas are becoming relatively more common, especially among men. The purpose of this study was to investigate whether such trends also occur in Sweden and also to describe other aspects of an unselected lung cancer material today, such as symptoms, stage and smoking habits. In the county of Gaevleborg, Sweden, practically all patients with lung cancer are referred to the lung department, and thus a total material of lung cancer patients with only a minimal selection bias can be studied. All patients with lung cancer in the county from January 1, 1997 to December 31, 1999, were investigated prospectively regarding stage, type of cancer, and symptoms. In all, there were 364 patients, 237 (65.1%) men and 127 (34.9%) women. The mean age for men was 69.8 and for women, 68.1 years. 91.9% of the men and 78.6% of the women were smokers or ex-smokers. In general the men were heavier smokers than were the women (P<0.0001). Adenocarcinoma was the most common subtype found in women and squamous cell carcinoma in men. The excess of adenocarcinoma in women was due to never-smoking women; for smoking and ex-smoking men and women, the proportion of adenocarcinomas was the same. In all, 240 patients (68.0%) were diagnosed at Stage IIIb (27.2%) or IV (40.8%), with no significant differences between the sexes. The most common first symptom was cough. Only 7.0% of patients were asymptomatic. In conclusion, the trend of an increasing proportion of adenocarcinoma in lung cancer is seen also in Sweden. A depressingly high percentage of patients present in late stages and are thus inoperable.