Volume 333:1594-1599           December 14, 1995           Number 24

Cancer in the Parents of Children with Cancer

http://content.nejm.org/cgi/content/abstract/333/24/1594

Jørgen H. Olsen, M.D., John D. Boice, Sc.D., Niels Seersholm, M.D., Andrea Bautz, and Joseph F. Fraumeni, M.D.

Background Certain types of cancer in children and young adults have been linked with an increased risk of cancer in close relatives. However, the relation between childhood cancer and familial risk remains to be fully assessed in population-based studies.

Methods We conducted a nationwide study in Denmark of 11,380 parents of children with cancer. The children were identified from records in the Danish Cancer Registry; their parents were identified from population registers. The occurrence and rate of cancer in the parents were determined with use of the Cancer Registry's files and compared with national incidence rates for various categories of tumor.

Results Overall, 1445 cancers were diagnosed in the parents, as compared with 1496 expected from national incidence rates, to yield standardized incidence ratios of 1.0 (95 percent confidence interval, 0.9 to 1.0) for all parents, 1.0 for mothers, and 0.9 for fathers. The lower rate of cancer among fathers reflected their lower standardized incidence ratio for lung cancer (0.8; 95 percent confidence interval, 0.6 to 0.9), as calculated from 114 observations.

Conclusions Genetic determinants are important in several types of childhood cancer, but the genetic susceptibility to tumors does not generally extend to the parents of children with cancer, nor do the patterns of incidence point to the influence of shared environmental factors. Thus, cancer in children should not be viewed as a general marker for an increased risk of cancer in the patients' parents.


Source Information

From the Division for Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark (J.H.O., N.S., A.B.); and the Epidemiology and Biostatistics Program, National Cancer Institute, Bethesda, Md. (J.D.B., J.F.F.).

Address reprint requests to Dr. Olsen at the Danish Cancer Society, Division for Cancer Epidemiology, Strandboulevarden 49, DK-2100 Copenhagen, Denmark.