肺区域切除術の長期成績の解析

Long-term Outcome of Pulmonary Segmentectomy for Lung Cancer

肺癌に対する標準手術は，肺葉切除と肺門部および縦隔リンパ節郭清とされてきた1）．しかし，最近20年ほどの画像診断の進歩により小型肺癌が発見される頻度が増加し2～4），肺葉切除と縮小手術の後方視的解析の結果5～8）から，実臨床においては症例を選択したうえで肺癌に対する縮小切除が行われるようになってきた．特に区域切除においては術式を行ううえでさまざまな工夫がなされている．しかし，区域切除と肺葉切除を比較する無作為化比較試験の結果が得られていないため，わが国のガイドラインにおいては小型肺癌に対して区域切除が推奨されているものの9），科学的根拠はない．さらに長期予後に関しては，区域切除は小型肺癌か全身状態が不良である肺癌例に対して多く行われている現状を鑑みると，区域切除後の長期予後についてはまだ検討する余地があると推察される．

Objective：Pulmonary segmentectomy has been performed for patients with radiographic early-stage lung cancer. This retrospective study investigated the validity of choice of procedures at our institute by examining the survival outcomes of lung cancer patients who underwent surgery.

Method：Data from 354 consecutive patients with pT1a～c N0 M0 stages ⅠA1～3 non-small cell lung cancer who underwent surgery between 2004 and 2014 were extracted （segmentectomy group：84 patients, lobectomy group：270 patients）. Overall, recurrence-free and cancer-specific survival of patients operated by segmentectomy and lobectomy was compared using the Cox proportional hazard model.

Result：The segmentectomy group had a higher average age and frequency of history of another cancer and smaller lung cancers and its diameter and solid components than the lobectomy group. By univariate and multivariate analyses, surgical procedures were not identified as independent risk factors for overall, recurrence-free and cancer-specific survival.

Conclusion：In this study cohort, the mode of surgical procedure between segmentectomy and lobectomy did not affect relapse and prognosis in pathological stages ⅠA1～3 lung cancer. The choice of procedures at our institute seemed to be appropriate in this study period.