Due to major developments in genetics over the past decade, molecular biology tests are serving promising tools in early diagnosis and follow-up of cancer patients. Recent epidemiological studies revealed that the risk for each individual to develop cancer is closely linked to his/her own genetic potentialities. Some populations that are defective in DNA repair processes, for example in Xeroderma pigmentosum or in the Lynch syndrome, are particularly prone to cancer due to the accumulation of mutations within the genome. Such populations would benefit from the development of tests aimed at identifying people who are particularly at risk. Here, we review some data suggesting that the inactivation of mismatch repair is often found in endometrial cancer and we discuss molecular-based strategies that would help to identify the affected individuals in families with cases of glandular malignancies.