Distribution according to histologic type and outcome by gender and age group in Taiwanese patients with lung carcinoma

Abstract

Background: The results from previous studies suggested that the clinical characteristics and outcomes of patients with lung carcinoma vary between gender and age groups. The objective of the current study was to assess the trend in the evolution of the histologic types in Taiwan and to compare the outcomes of patients with lung carcinoma between different gender and age groups.

Methods: Patients with primary lung carcinoma were identified through the cancer registry system. Clinical records were reviewed and analyzed for age, gender, disease stage, histology, treatment modalities, and survival. A multivariate analysis using a Cox proportional hazards model was applied for gender, age (by decade), histologic type, disease stage, and treatment modality.

Results: Between 1991-1999, 2714 patients with histologically or cytologically proven lung carcinoma were included. Adenocarcinoma was the major cell type of lung carcinoma (52.5%), with a significant trend toward an increase in adenocarcinoma during the study period. A significantly high percentage of adenocarcinoma was demonstrated in female patients (73.5%), who also had better survival compared with male patients (P = 0.002), especially in the group age 50-69 years. Patients age < 40 years also had a poor prognosis, which was worse compared with the prognosis for patients age 40-59 years. patients who had adenocarcinoma had a better survival rate compared with patients who had other histologic types (relative risk, 0.78; 95% confidence interval, 0.69-0.87).

Conclusions: Adenocarcinoma was predominant in female patients and emerged as a greater problem than other histologic types in Taiwan, potentially raising the importance of studies regarding the benefit of population diversity in new antitumor therapies, such as gefitinib. Female patients with lung carcinoma had a better prognosis than male patients in the group age 50-69 years, warranting further studies on potential prognostic factors associated with middle age, such as hormone status.