Importance of Early Follow-up Colonoscopy in Patients at High Risk for Colorectal Polyps

PURPOSE: Minimizing the polyp miss rate during colonoscopy is important for patients at high risk for colorectal polyps. We investigated the polyp miss rate and the factors associated with it in high-risk patients. METHODS: The medical records of 163 patients who underwent follow-up colonoscopy between January 2001 and April 2010, which was within 9 months after a polypectomy, because the index colonoscopy had shown multiple (more than 3) adenomas or advanced adenoma were retrospectively reviewed. Miss rates were calculated for all polyps, for neoplastic polyps and for advanced adenomas. Factors associated with the miss rates in these patients, such as the location, shape and size of the polyp, were analyzed. RESULTS: The miss rates for polyps, adenomas, adenomas or =5 mm and advanced adenomas were 32.6%, 20.9%, 17.7%, 3.2%, and 0.9%, respectively. No carcinoma, except for one small carcinoid tumor, was missed. Flat shape and small size (<5 mm) were significantly associated with adenoma miss rate. The miss rate was significantly higher for flat-type advanced adenomas than for protruded-type advanced adenomas (27.7% vs 4.1%). CONCLUSION: The polyp miss rate in patients at high risk for colorectal polyps was higher than expected. Efforts are needed to reduce miss rates and improve the quality of colonoscopy. Also, early follow-up colonoscopy is mandatory, especially in patients at high risk.

Gene Expression Profiling in C57BL/6 Mice Treated with the Anorectic Drugs Sibutramine and Phendimetrazine and Their Mechanistic Implications

Recently, obesity has become a worldwide public health concern and the use of anorectic drugs has drastically increased. In this study, sibutramine and phendimetrazine, representative marketed anorectics, were repeatedly administered per os on a daily basis into C57BL/6 mice and the effects of these drugs on food intakes, body weight changes and gene expression profiles were monitored for up to following 7 days. Methamphetamine, which has a potent anorectic effect, was used as a positive control. Anorectic effects were sustained only for two days by phendimetrazine or methamphetamine, but for six days by sibutramine. The modulations of gene expressions in the hypothalamus and the striatum were investigated using microarrays on day 2 and day 7 post-administration, which corresponded to the anorectic period and a return of appetite respectively, for all three drugs tested. Differences in overall gene expression profiles in the stratum on day 2 for sibutramine and phendimetrazine seems to reflect difference between the two in terms of the onsets of drug tolerance. According to microarray findings, the Ankrd26 gene appears to have an important anorectic role, whereas the up-regulation of the olfaction system appeared to be involved in the drug tolerance of anorectics. The microarray data presented in this study demonstrates the usefulness of gene expression analysis for gathering information on the efficacy and safety of anorectic drugs.

Epidermoid Carcinoma of the Anal Canal: Treatment Outcome and Prognostic Factor

PURPOSE: During recent two decades, therapeutic strategy for epidermoid carcinoma of anal canal has been changed on basis of the knowledge of the natural course and biologic features. The current study evaluated the treatment outcome and prognostic factors in epidermoid carcinoma of the anal canal. METHODS: Fifty-seven cases with epidermoid carcinoma of anal canal were treated curatively in Seoul National University College of Medicine from 1976 to 1997. The sex ratio was 1.5 to 1 with male predominance, with a median age of 57.0 years. The histology consisted of 59.6% (34 cases) in squamous cell carcinoma and 40.4% (23 cases) in cloacogenic carcinoma. According to UICC/AJCC staging system, there were 24.6% in stage I, 28.1% in stage II, 31.6% in stage IIIa and 15.8% in stage IIIb. Operation- based treatment was performed in 96.6% of 29 cases during period I (1976~1988) and in 60.7% of 28 cases during period II (1989~1997). Forty-five cases were treated on the basis of operation: 13 cases, operation only; 20, operation plus radiation; 12, operation plus chemoradiotherapy. And 12 cases were managed by combined radiation and chemotherapy. RESULTS: On median follow-up of 52.0 months (range, 1~160 months), there were 19.3% in local recurrence and 8.8% in systemic recurrence. Recurrence rates were not significantly related to therapeutic strategy (P=0.37). The overall 5-year survival rate was 74.9%. The 5-year survival rates according to therapeutic strategy were 73.3% in the operation-based treatment and 80.0% in the combined radiation and chemotherapy. Survival rates were not significantly related to therapeutic strategy (P=0.48). Three cases, whose sizes were 1 cm, 2 cm and 2.5 cm without lymph node metastasis, were excised locally and are still alive without recurrence. In the multivariate analysis, the metastatic status of lymph nodes had the only independent significant influence on survival. CONCLUSIONS: Combined radiation and chemotherapy in epidermoid carcinoma of anal canal is the preferred treatment for sphincter-preservation, and local excision in early lesion have good outcome without morbidity associated with chemotherapy or radiation therapy. In this study, lymph node status was the only prognostic variable.