A case of isolated paraaortic lymph node recurrence from colon cancer successfully treated with chemoradiotherapy.

Isolated paraaortic lymph node (PALN) recurrence from colorectal cancer is rare and has no established treatment. A 56-year-old woman was referred to our hospital for the treatment of PALN recurrence in June 2005. She had undergone right hemicolectomy for ascending colon cancer two years earlier. The pathological diagnosis in 2003 was a well-differentiated adenocarcinoma with positive PALN metastasis in 3 of 4 dissected nodes (T3, N1b, M1a, stage IVa). At our hospital, chemoradiotherapy was started, with the radiation field determined from positron emission tomography (PET) images. Oral tegafur/uracil (600 mg/day) plus leucovorin (75 mg/day) therapy was also started. Radiotherapy (1.5 Gy/ fraction, total of 45 Gy) was completed in August 2005, while oral chemotherapy was discontinued 3 weeks after it was started due to diarrhea and epigastric discomfort. The serum carcinoembryonic antigen level was 193 ng/ml (N < 5) before treatment and decreased to within normal limits 3 months after initiation of chemoradiotherapy. Complete remission was confirmed by computed tomography (CT) and PET in December 2005 and has continued for more than 6 years. This case shows that chemoradiotherapy is potentially curative for PALN recurrence from colorectal cancer. To our knowledge, this is the first report of more than 5 years disease-free survival in a patient with PALN recurrence from colon cancer treated with chemoradiotherapy.