Estimated prevalence of hereditary cancers and the need for surveillance in a Norwegian county, Telemark.
OBJECTIVE
The aim of the study was to estimate the prevalence of hereditary cancers and the need for surveillance in Telemark county, Norway.


METHODS
All persons attending the Norwegian Colorectal Cancer Prevention (NORCCAP) trial in Telemark were interviewed about cases of cancer in the family. Diagnoses were verified, pedigrees constructed and families classified according to preset criteria aiming at identifying hereditary cancer. Mutation analyses were performed in kindreds at risk for breast cancers when possible. Immunohistochemistry of tumors in assumed inherited colorectal cancer families was undertaken.


RESULTS
The screening examination was attended by 7,224 persons among whom 2,866 had cancer in the family. Of these, 2,479 had no suspicion of any known inherited cancer syndrome. Family information questionnaires were mailed to 387 persons and returned by 191. Sixty-four of these 191 met the clinical criteria for familial cancer by family history after verification of diagnoses. Observed prevalences for being at risk for hereditary breast and breast-ovarian cancer (HBOC) or hereditary non-polyposis colorectal cancer (HNPCC) were 2.8 per thousand and 0.77 per thousand, respectively.


CONCLUSIONS
The number of colonoscopies and mammograms obtained per year serving those who needed them was limited and reduced by clinical genetic work-up from 2,866 with a family history of cancer to 64 proven cases. Continued surveillance of an unnecessarily high number leads to unjustified cancer worry, is costly and uses up health-care facilities. Genetic work-up is a one-time job that reduces input numbers to surveillance programs, provides a starting-point for mutation testing and is economically cost beneficial if inherited cancers are prevented or cured by the health-care programs offered.
Stormorken
Astrid T
AT
Section of Genetic Counselling, Department of Cancer Genetics, The Norwegian Radium Hospital, Oslo, Norway.
Hoff
Geir
G
Norstein
Jarle
J
Bowitz-Lothe
Inger Marie
IM
Hanslien
Eldbjørg
E
Grindedal
Eli
E
Møller
Pål
P
D048868:Adaptor Proteins, Signal Transducing; D001943:Breast Neoplasms / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics; D009154:Mutation; D009369:Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000517:prevention & control; D009664:Norway / Q000453:epidemiology; D009687:Nuclear Proteins / Q000235:genetics; D010051:Ovarian Neoplasms / Q000235:genetics; D011159:Population Surveillance; D015995:Prevalence
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein