Lymph node metastasis from colon carcinoma at 11 years after the initial operation managed by lymph node resection and chemoradiation: A case report and a review of the literature.

INTRODUCTION: Lymph node metastasis from colorectal cancer after a disease-free interval (DFI) of >5years is extremely rare, and occurs in <0.6% cases. PRESENTATION OF CASE: A 60-year-old man underwent low anterior resection for sigmoid colon cancer. The lesion was an adenocarcinoma with no lymph node metastasis of Stage II. At 9years after the colectomy, he was diagnosed with prostate cancer and was treated with radiation and hormonal therapies; at 11years, he exhibited suddenly elevated carcinoembryonic antigen levels. Computed tomography (CT) and positron emission tomography-CT revealed a 2.0-cm para-aortic lymph nodes swelling invading the small intestine. These lymph nodes and the affected segment of the small intestine were resected, and histopathology of the resected specimen confirmed a metastatic tumor. The patient was administered radiation therapy after 22 cycles of 5-fluorouracil, oxaliplatin and leucovorin. He however presented with a residual lesion in the para-aortic lymph node, but currently, he has been symptom free for 4years. DISCUSSION: A review of the literature indicates that the median survival of all previously reported patients is 12months, and that colon cancer with a long DFI might be a slow growing. One of these patients and our patient both had received radiation and/or hormonal therapy for another cancer, which probably impaired their immune systems, thus resulting in metastatic tumors.
CONCLUSION: We report a case of lymph node metastasis after a DFI of >5years and review relevant literature to assess the significance and possible reasons for delayed colorectal cancer metastases.