Clinicopathological Characteristics of Tumor Doubling Time in Primary Lung Cancer

A total of 174 cases with primary lung cancer which were detected in local municipalities during a limited period were examined with regard to their distribution and the clinicopathological characteristics of tumor doubling time (DT). 1) After logarithmic conversion of DT in lung cancer, a small skew (0.7204) and a small kurtosis (—0.0643) showed a normal distribution. DT was found to have a log-normal distribution. 2) The minimum DT was 30 days, and the maximum 1077 days in the present study. Arithmetic mean±standard deviation of DT was 163.7±177.5 days, and geometric mean was 113.3 days. 3) Mean DT in males was significantly shorter than that in females, and that in cases with a smoking history was significantly shorter than that in cases without a smoking history. In cases with symptoms, DT was also significantly shorter than that in cases without symptoms. The mean DT in cases with adenocarcinoma was significantly longer than that in cases with squamous cell carcinoma, small cell carcinoma and large cell carcinoma. The mean DT in cases with T1 lung cancer was significantly longer than that in cases with T2, T3, and T4 lung cancer, and that in cases with stage I lung cancer was significantly longer than that in cases with stage III lung cancer.