[A Case of Long-Term Survival in a Patient with Lung Metastasis of Gastric Cancer Treated Using Curative Surgery].

A 50-year-old man was referred to our hospital with gastric cancer. Esophagogastroduodenoscopy(EGD)revealed an irregular nodular lesion with an ulcer in the esophagogastric junction, the biopsy specimens of which showed moderately differentiated adenocarcinoma. Abdominal computed tomography(CT)showed a lymph node measuring 1.2 cm in the perigastric area. A clinical diagnosis of advanced gastric cancer was made, and the patient underwent total gastrectomy with D2 lymphadenectomy followed by Roux-en-Y reconstruction. Microscopic examination confirmed that the moderately differentiated adenocarcinoma invaded the muscularis propria with 1 lymph node metastasis and lymphovascular invasion. The final diagnosis according to the Japanese classification of gastric carcinoma was UE, Less, Type 2, 3.8×1.7 cm, T2(MP), M0, H0, P0, N1(1/15), tub2, ly1, v2, StageⅡ. The postoperative course was uneventful, and he received postoperative adjuvant chemotherapy with S-1. The patient underwent periodic follow-up physical examinations, and 1 year after the surgery, CT showed a well-defined mass measuring 1.0 cm in diameter located in the middle lobe of the right lung. Because there was no evidence of further metastatic lesions in any other organs, he underwent surgical resection of the solitary pulmonary lesion by video-assisted thoracic surgery. Pathological examination confirmed the presence of moderately differentiated adenocarcinoma, and the proliferating tumor cells were positive for cytokeratin(CK)7 and CK20, and negative for thyroid transcription factor 1, which confirmed metastasis from gastric cancer. After the surgery, the patient received combination chemotherapy with S-1 plus cisplatin, followed by S-1 monotherapy. Five years after pulmonary metastasectomy, we discontinued chemotherapy because of no evidence of recurrence and the patient's wishes. The patient has remained in good health without evidence of recurrence for 7 years following the second surgery. Resection of the metastatic lesion might be a promising treatment for solitary pulmonary metastasis of gastric cancer; however, further investigations involving the accumulation of a large number of cases and prospective cohort studies are required to verify the above issue, and future development of multidisciplinary therapy is expected.