Metastatic thymic-enteric adenocarcinoma responding to chemoradiation plus anti-angiogenic therapy: A case report

BACKGROUND: Thymic-enteric adenocarcinoma with positive expression of CDX2 and CK20 is rare in adults, with only 16 reported cases. However, standard treatment options for this type of thymic adenocarcinoma has not yet been established. Therefore, we report a case of stage IV thymic-enteric adenocarcinoma treated with radiotherapy, chemotherapy, and anti-angiogenesis therapy. CASE SUMMARY: We report a case of thymic-enteric adenocarcinoma occurring in a 44-year-old woman. The tumor was considered unresectable owing to its invasiveness. The patient was treated with six cycles of oxaliplatin (130 mg/m(2), day 1) and capecitabine (1000 mg/m(2) BID, days 1-14). During the first three cycles of chemotherapy, concurrent radiotherapy (60 Gy/30 fractions) and anti-angiogenic therapy using apatinib were recommended. The primary tumor achieved partial remission based on the Response Evaluation Criteria in Solid Tumors. During follow-up, there was no evidence of disease relapse, except a high serum CA19-9 level. The patient is alive and regularly followed. Based on the previous literature and the present case, we believe that early diagnosis of thymic-enteric adenocarcinoma is important. CONCLUSION: XELOX (capecitabine plus oxaliplatin) combined with radiotherapy is an optional therapy for inoperable thymic-enteric adenocarcinoma.