Late recurrence of CD44 variant 9-positive gastric carcinoma 12 years after surgery: A case report

Background: Late recurrence of gastric cancer of over 10 years post-gastrectomy is extremely rare, and the mechanism of late recurrence is unclear. We report a case of para-aortic lymph node metastasis that recurred 12 years postoperatively. Case presentation A 44-year-old woman who was pathologically diagnosed with moderately to poorly differentiated adenocarcinoma with T2N2M0 Stage IIIA according to the Japanese Classification of Gastric Carcinoma (the 13th Edition) underwent laparoscopic distal gastrectomy with D1 + lymph node dissection. She received adjuvant chemotherapy with tegafur-uracil (400 mg/day) for 2 years. At postoperative year (POY) 5, a swollen lymph node was detected in the No.16b1lat lymph node station. However, positron emission tomography (PET) revealed normal uptake, and tumor markers were within normal limits; hence, the possibility of metastasis was judged to be low, and the patient was placed under observation. At POY 12, computerized tomography revealed an enlargement of the No.16b1lat lymph node station, and PET revealed abnormal uptake. Endoscopic ultrasound-guided fine-needle aspiration revealed a moderately differentiated adenocarcinoma. Hence, a diagnosis of recurrence of gastric cancer was made. She underwent para-aortic nodal dissection (PAND) of No.16b1lat & int stations. Immunochemical staining was similarly consistent with recurrence of gastric cancer. Meanwhile, CD44 variant 9 (CD44v9), a cancer stem cell marker for gastric adenocarcinoma, was attenuated in the recurrent lesions compared with the primary lesions. Postoperatively, she received chemotherapy with tegafur-gimeracil-oteracil (80 mg/day) for 1 year. At POY 4 after PAND, the patient remained well with no evidence of recurrence and distant metastasis. Conclusions The degree of staining for CD44v9 in the recurrent lesions may be related to the timing of recurrence. Hence, it is important to continue to investigate the role of the expression of CD44v9 in gastric cancer and to clarify the details.