重複癌を伴う前立腺癌の臨床的特徴

Abstract

1)重複癌は, 前立腺癌610例中93例(15.2%)にみられた.2)前立腺癌に伴う重複癌の種類は, 胃癌が最多で, 以下膀胱癌, 結腸癌, 肺癌の順であった.第一, 二, 三癌の診断時年齢の中央値は各々72, 74, 75歳で, 第一～二癌の診断間隔(中央値20ヵ月)は第二～三癌の診断間隔(中央値8ヵ月)よりも長かった.3)死因の明らかな37例のうち癌死は29例(78.4%)で, 前立腺癌が死因となったものは6例と少なかった.4)重複癌群と単発癌群の前立腺癌の比較では, 診断時年齢, 分化度に統計学的な有意差は無かった

We analyzed the clinical features of multiple primary cancers (MPCs) that included prostate cancer. MPCs were observed in 93 (15.2%) of the patients suffering from prostate cancer. In the MPC group, the organ most commonly involved was the stomach, followed by bladder, colon and lungs. The median age at diagnosis of the first, second and third cancers was 72, 74, and 75 years old, respectively, and the duration between the first and second cancers (median: 20 months) was longer than that between the second and third cancers (median: 8 months). In the 37 MPC patients whose cause of death was obvious, 29 (78.4%) died of a cancer; prostate cancer was not so common (6 patients) as the cause of death. Age at diagnosis and grade distribution of prostate cancer were not significantly different between the MPC and single primary cancer (SPC) groups. However, the proportion of earlier stage was significantly (p < 0.01) higher in the MPC group than in the SPC group, and this trend was more obvious in patients whose prostate cancer was diagnosed as the second cancer. The prostate cancer-specific survival rates were significantly higher in the patients with MPC, and this trend was more obvious in the patients with stage D or moderately differentiated cancer. It is important in the follow up of prostate cancer patients to be aware of the possibility of the occurrence of a second cancer.