原発性肺癌切除例における他臓器重複癌の検討 A Clinical Study on Multiple Primary Cancers in Cases of Resected Lung Cancer

<b>目的</b>．肺癌切除例における重複癌の存在が予後に及ぼす影響について，その臨床的特徴を含めて検討した．<b>方法</b>．1996年1月～2005年12月までに当院にて施行された肺癌手術症例731例中，重複癌を認めた101例（13.8％）を対象とした．臨床的特徴及び予後は多重癌を認めない619例と比較検討した．<b>結果</b>．重複癌は胃癌，大腸癌，乳癌，子宮癌，頭頸部癌などが多く，肺癌単発例と比較して年齢・性別・組織型・分化度・病理病期に有意差を認めなかった．重複悪性腫瘍別の検討では，頭頸部癌・食道癌合併例に肺扁平上皮癌が多く，乳癌・子宮癌・甲状腺癌・前立腺癌合併例に肺腺癌が多い傾向を認めた．重複癌症例での肺癌術後の5年生存率は59.4％で，肺癌単発例の71.3％に対して有意に低かった．同時性・異時性別の5年生存率は，各々57.5％，65.6％で特に同時性で予後不良の傾向にあった．重複癌死亡例を検討すると，肺癌死12例（42.9％），他癌死6例（21.4％）であった．<b>結論</b>．肺癌手術例において重複癌，特に同時性のものは予後不良因子の1つであり，術前・術後の消化管を含めた全身検索が重要と考えられた．<br>

<i><b>Objective</b></i>. We examined the influence of multiple primary cancers and their clinical features on outcome in cases of excised lung cancer. <i><b>Methods</b></i>. We targeted 101 out of 731 cases (13.8%) which presented multiple primary cancers in lung cancer operations performed in our hospital between January 1996 and December 2005. We then conducted comparative analysis with the clinical features and outcome of the 619 cases which did not present multiple primary cancers. <i><b>Results</b></i>. Many of the multiple primary cancers were present in the stomach, large intestine, breast, uterus, head and neck. The cases of lung cancer with multiple primary cancers did not show a significant difference compared to the cases of lung cancer alone in terms of age, sex, histological type, degree of differentiation, or pathological stage. There were many cases of lung squamous cell carcinoma in the patients with existing esophagus, head and neck cancer. Furthermore, there was a high percentage of lung adenocarcinoma in patients with existing breast, uterus, thyroid, or prostate cancer. The 5-year-survival rate after resection of lung cancer in patients with multiple primary cancers was 59.4%, which was significantly lower than the 71.3% 5-year-survival rate of patients with only lung cancer. The 5-year-survival rates after resection of lung cancer in cases of synchronous and metachronous multiple primary cancers were 57.5% and 65.6%, respectively. The cause of death of patients with lung cancer and multiple primary cancers was lung cancer in 12 cases (42.9%) and cancers of other organs in 6 cases (21.4%). <i><b>Conclusion</b></i>. The presence of multiple primary cancers, particularly synchronous cancers, is an adverse prognostic factor in cases of resected lung cancer. Whole body screening including examination of the digestive tract should be performed before and after lung resection.<br>