[Quantitative method to describe the inner characteristics of hereditary nonpolyposis colorectal cancer family].

OBJECTIVE: To establish a quantitative method to describe the inner characteristics of hereditary nonpolyposis colorectal cancer (HNPCC) family.

METHODS: All members of 25 HNPCC families with assembly of malignant tumors therein [with at least one patients with colorectal cancer (CRC)] in China underwent questionnaire survey. Other 32 HNPCC families with complete clinical data were collected from the published Chinese and foreign literatures related to clinical phenotype of Chinese HNPCC family. Altogether 57 HNPCC families fulfilling the Amsterdam Criteria (AC) I or II underwent analysis of the inner characteristics cumulatively. The following parameters were analyzed: familial median age when diagnosed as with the first malignant tumor (FMA-DFMT), familial median age when diagnosed as with the first CRC (FMA-DFCRC), familial proportion of CRC in first malignant tumors (FPCRC-FMT), familial proportion of CRC patients (FP-CRCP), number of involved generations, number of cancer patients, and type of family.

RESULTS: In the ACI HNPCC families, the distribution patterns of both FMA-DFMT and FMA-DFCRC were not normal distribution. Most of the FMA-DFMT and FMA-DFCRC were from 35 years to 50 years with the medians of 44.0 years and 43.5 years respectively. The FPCRC-FMT and FP-CRCP were less than 0.6 in 13.2% (7/53) and 7.5% (4/53) of the families respectively. The FMA-DFMT and FMA-DFCRC were not correlated with FPCRC-FMT, FP-CRCP, number of involved generations and cancer patients, and type of family (all P > 0.05).

CONCLUSION: Compared to the traditional methods, the features of HNPCC families can be accurately described by a series of quantitative parameters.