New clinical criteria for hereditary nonpolyposis colorectal cancer (HNPCC, Lynch syndrome) proposed by the International Collaborative Group on HNPCC☆

One of the first successful efforts of the International Collaborative Group on HNPCC (ICG-HNPCC) at its meeting in Amsterdam in 1990 was the establishment of a set of selection criteria for families with hereditary nonpolyposis colorectal cancer (HNPCC, Lynch syndrome) to provide a basis for uniformity in collaborative studies (Table 1).1 Until 1990, such criteria were lacking and the descriptions of the syndrome in the literature varied widely. In the absence of a common nomenclature it was impossible to compare the results of different studies on HNPCC. The wide acceptance of the ICG criteria is reflected by the fact that almost all investigators currently make use of them. However, the criteria have also been criticized. Some investigators feel that the criteria exclude some classic HNPCC families because they do not take into account the extracolonic cancers that are part of the syndrome. There is also concern that the criteria are being used inappropriately for the diagnosis of HNPCC. As criteria for the selection of families for research, they were originally aimed at specificity more than sensitivity. It is now considered that many true HNPCC families would be missed if the criteria are applied to clinical diagnosis, and that families not meeting the criteria might be falsely reassured and excluded from genetic counseling, DNA testing, or surveillance. To resolve these problems, many investigators have developed additional criteria.2–6 At the ninth meeting of the ICG-HNPCC held in Noordwijk, the Netherlands, in 1997, a definition of HNPCC was proposed that was aimed at helping clinicians to identify families. This provided a detailed description of the specific features of HNPCC rather than the rigid criteria required for collaborative studies. In addition, at the ninth meeting, and also at the tenth held in Coimbra, Portugal, in 1998, new selection criteria for collaborative studies were proposed that included the extracolonic cancers associated with HNPCC. Definition of HNPCC