膵癌肺転移切除例における胸膜播種の予測因子とメカニズム

Factors and Mechanisms of Pleural Dissemination in Surgically Treated Cases of Lung Metastasis Originated from Pancreatic Cancer

遠隔転移を伴う膵癌は予後不良の疾患であるが，膵癌肺転移は予後がよいとされる1）．しかし膵癌肺転移には胸膜播種を伴う症例が報告されており2，3），根治切除を達成するための胸膜播種の予測因子が不可欠と考えられる．また，膵癌肺転移における胸膜播種のメカニズムは不明である．

Pancreatic cancer with distant metastasis typically results in a poor prognosis, but patients with only pulmonary metastasis are reported to have a relatively good prognosis. In this study, we investigated the clinicopathological data and prognosis of 15 patients who underwent surgery for lung metastasis of pancreatic cancer at our hospital between April 2010 and December 2021. The median disease-free interval after pancreatic cancer treatment was 24.5 （9.6-71.8） months. Ten of the 15 patients underwent successful radical resection, while the remaining 5 had pleural dissemination and underwent non-radical resection. The median follow-up duration was 13.5 months, with the median survival time for radical resection and non-radical resection cases being 49.5 months and 31.2 months, respectively. This indicates significantly worse prognosis for non-radical resection cases （p＝0.010）. Furthermore, the median CA19-9 levels before lung resection were 22 U/ml for radical resection and 2,181 U/ml for non-radical resection cases, significantly higher in the latter （p＝0.049）. Immunostaining of resected specimens revealed that MMP-2 was positive in 11 of 15 cases, particularly in 4 of 5 cases with pleural dissemination. CA19-9 levels before lung resection may be a predictive factor for pleural dissemination, and MMP-2 may play a role in the mechanism of pleural dissemination.