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Purpose Lymph-node metastasis is considered as critical prognostic factor in colorectal cancer. A preoperative evaluation of lymph-node metastasis can also help to determine the range of distant lymph node dissection. However, the reliability of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the detection of lymph-node metastasis is not fully known. Methods The medical records of 433 patients diagnosed with colorectal cancer were reviewed retrospectively. FDG-PET/CT and CT were performed on all patients. Lymph nodes were classified into regional and distant lymph nodes according to the American Joint Committee on Cancer (AJCC) Cancer Staging Manual, 7th edition. Results The patients included 231 males (53.3%) and 202 females (46.7%), with a mean age of 64.7 ± 19.0 years. For regional lymph nodes, the sensitivity of FDG-PET/CT was lower than that of CT (57.1% vs. 73.5%, P < 0.001). For distant lymph nodes, the sensitivity of FDG-PET/CT was higher than that of CT (64.7% vs. 52.9%, P = 0.012). The sensitivity of FDG-PET/CT for regional lymph nodes was higher in patients with larger primary tumors. The positivity of lymph-node metastasis for FDG-PET/CT was affected by carcinoembryonic antigen levels, tumor location, and cancer stage for regional lymph nodes and by age and cancer stage for distant lymph nodes (P < 0.05). Conclusion The sensitivity of FDG-PET/CT for regional lymph-node metastasis was not superior to that of CT. However, FDG-PET/CT provides helpful information for determining surgical plan especially in high risk patients group.

Purpose The assurance of a negative resection margin is significant in rectal cancer as it indicates a reduced risk of local recurrence; thus, sufficient length of the resection margin is strongly required. The purpose of this study was to analyze the relationship between the length of the distal resection margin (DRM) and local recurrence or survival rate and to evaluate the possibility of performing sphincter-conserving surgery. Methods The medical records of 218 rectal cancer patients were analyzed. Patients were classified into three groups according to the length of the DRM as follows: group 1, DRM < 1 cm; group 2, 1 cm ≤ DRM ≤ 2 cm; and group 3, DRM > 2 cm. Results Of 218 patients enrolled, 81 were in group 1, 66 in group 2, and 71 in group 3. The 5-year survival rates were 78.2%, 78.2%, and 76.8% for groups 1, 2, and 3, respectively, and there were no statistically significant differences in survival (P = 0.913). Local recurrence was found in 2 patients in group 1, 1 patient in group 2, and 1 patient in group 3; there were no statistically significant differences in local recurrence (P = 0.908). Conclusion A DRM of < 1 cm did not impair the oncologic outcomes of rectal cancer patients. Our results indicated that surgeons should keep in mind to consider the option of sphincter-conserving surgery with adjuvant chemoradiotherapy even in very low rectal cancer.

5-Fluorouracil (5-FU) based chemotherapy has been commonly used to treat metastatic or advanced colon cancer as an adjuvant chemotherapy. Although the side effects of 5-FU such as gastrointestinal problems and neutropenia and thrombocytopenia are common, not many cases of 5-FU related encephalopathy are reported. Hyperammonemic encephalopathy is a rare central nervous system toxicity following 5-FU chemotherapy manifesting as altered mental status with elevated ammonia levels with no radiologic abnormality. We report one case of 5-FU induced hyperammonemic encephalopathy occurring after Folfox4 (oxaliplatin, folinic acid and 5-fluorouracil) chemotherapy in a colon cancer patient who presented with confused mental status soon after the chemotherapy and review the 5-FU related encephalopathy.