Role of microsatellite instability in the management of colorectal cancers.

Microsatellite instability is the consequence of a deficient mismatch repair system. It has a key role in the diagnostic strategy of Lynch syndrome, where tumours are all characterized by the presence of this phenotype. Microsatellite instability is therefore essential in the selection of colorectal cancer patients in whom a germline analysis of Mismatch Repair genes is possibly indicated. Moreover, microsatellite instability tumours are associated with a good prognosis and a resistance to fluorouracil-based adjuvant chemotherapy, which has a clinical application mainly in stage II colon cancer patients in whom adjuvant chemotherapy has a less beneficial effect than in stage III and outcome in presence of microsatellite instability is excellent. Recent data suggest that impact of microsatellite instability on benefit to fluorouracil-based adjuvant chemotherapy is dependent of the molecular mechanism involved in this genetic instability since an improved survival has been reported with adjuvant fluorouracil in microsatellite instability colorectal cancers of germline origin but not in sporadic cases. Predictive value of microsatellite instability on response to fluorouracil/oxaliplatin adjuvant chemotherapy has been less evaluated but recent studies suggest that the favorable outcome of Microsatellite instability tumours is maintained in patients receiving FOLFOX.

Chemotherapy in the treatment of anal canal carcinoma.

Squamous cell carcinomas of the anal canal are generally diagnosed at a localized or locally advanced stage and only 5% are metastatic at the time of diagnosis. Advanced forms are therefore much rarer than localized forms and usually correspond to metachronous metastases of initially localized disease. Systemic chemotherapy is indicated for the treatment of both localized disease, in combination with radiotherapy, and metastatic disease. The purpose of this article is to define the current indications and modalities of chemotherapy in the treatment of these cancers based on a review of the published data and in the light of available guidelines.

[Appropiateness of colonoscopy in a gastrointestinal unit in 2001: a prospective study using criteria established by a European panel of experts]. / Pertinence des indications de la coloscopie dans un service de gastroentérologie de l'AP-HP en 2001. Application de critères établis par un panel d'experts européens.

UNLABELLED: Criteria for appropriateness of colonoscopy have been elaborated by an European Panel (EPAGE). OBJECTIVES: 1) To assess the feasibility of EPAGE criteria in clinical practice, 2) to assess colonoscopy appropriateness using EPAGE criteria, 3) to compare colonoscopy appropriateness and findings. PATIENTS AND METHODS: Four hundred and six consecutive examinations were included. The referral indication was judged using a scoring system on the basis of the EPAGE criteria. RESULTS: Appropriateness could be assessed in 94% of the colonoscopies. Fifty-four percent were appropriate, 40% equivocal, and 6% inappropriate. Rate of abnormal colonoscopy was not different between the 3 groups, however endoscopic findings were more severe when the indication was appropriate. In the appropriate group, adenomatous polyps were more frequent (24%) than in the two other groups (13% and 12%; P<0.05) and tended to be larger in size. In the inappropriate group, patients were significantly younger, and no cancer was found. There were 5 colonic cancers in the inappropriate group and 12 in the appropriate group. CONCLUSION: Colonoscopy is generally not overused according to EPAGE guidelines. However, on an individual basis it could be rather difficult to determine colonoscopy appropriateness using a scoring system. Indeed, a third of the indications was judged equivocal and the endoscopic findings were no different whether indication was appropriate or equivocal.