Phenotypic characteristics of colo-rectal cancer in I1307K APC germline mutation carriers compared with sporadic cases

The 11307K APC germline mutation is associated with an increased risk to co lo-rectal cancer (CRC). Whether and to what extent the phenotype of CRC in mutation carriers differs from sporadic cases, remains unknown. To gain ins ight into this issue, we analysed 307 unselected Israeli patients with CRC, who were treated in a single medical centre, for harbouring the 11 307K mu tation. Twenty-eight mutation carriers (9.1%) were detected. Two of 28 muta tion carriers (7.1%) and 93/277 (33.6%) of non-carriers, were of non-Ashken azi origin (P < 0.01). In 74/278 (26.6%) of the sporadic cases, and only 1/ 28 (3.6%) of mutation carriers (3.6%) the tumour was located in the right c olon (P < 0.01). Mutation carriers had a more advanced disease stage (114/2 8 - 50% Dukes C), as compared with 60 (19.5%) of non-carriers (P = 0.02). T he mean age at diagnosis was similar: 65 (+/- 9.7) years and 66.3 (+/- 11.6 ) years, for mutation carriers and noncarriers, respectively. No statistica l differences were noted between the two groups in sex distribution, tumour grade, and family history of cancer. We conclude that early age at diagnos is and family history of cancer cannot be used to predict who is likely to harbour the 11 307K APC germline mutation carriers. However, the tumours in patients with this mutation appear different than those without, are less likely to be proximal and more likely to be advanced than tumours in non-ca rriers. (C) 2001 Cancer Research Campaign.