Breast cancer risk following radiotherapy for Hodgkin lymphoma: modification by other risk factors.
The importance of genetic and other risk factors in the development of breast cancer after radiotherapy (RT) for Hodgkin lymphoma (HL) has not been determined. We analyzed data from a breast cancer case-control study (105 patients, 266 control subjects) conducted among 3 817 survivors of HL diagnosed at age 30 years or younger in 6 population-based cancer registries. Odds ratios (ORs) and excess relative risks (ERRs) were calculated using conditional regression. Women who received RT exposure (> or = 5 Gy radiation dose to the breast) had a 2.7-fold increased breast cancer risk (95% confidence interval (CI) 1.4-5.2), compared with those given less than 5 Gy. RT exposure (> or = 5 Gy) was associated with an OR of 0.8 (95% CI, 0.2-3.4) among women with a first- or second-degree family history of breast or ovarian cancer, and 5.8 (95% CI, 2.1-16.3) among all other women (interaction P = .03). History of a live birth appeared to increase the breast cancer risk associated with RT among women not treated with ovarian-damaging therapies. Breast cancer risk following RT varied little according to other factors. The additional increased relative risk of breast cancer after RT for HL is unlikely to be larger among women with a family history of breast or ovarian cancer than among other women.
Hill
Deirdre A
DA
Division of Cancer Epidemiology and Genetics and Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA. dahill@salud.unm.edu
Gilbert
Ethel
E
Dores
Graça M
GM
Gospodarowicz
Mary
M
van Leeuwen
Flora E
FE
Holowaty
Eric
E
Glimelius
Bengt
B
Andersson
Michael
M
Wiklund
Tom
T
Lynch
Charles F
CF
Van't Veer
Mars
M
Storm
Hans
H
Pukkala
Eero
E
Stovall
Marilyn
M
Curtis
Rochelle E
RE
Allan
James M
JM
Boice
John D
JD
Travis
Lois B
LB
D000328:Adult; D001943:Breast Neoplasms / Q000209:etiology / Q000401:mortality; D005260:Female; D006689:Hodgkin Disease / Q000150:complications / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000209:etiology / Q000401:mortality; D016609:Neoplasms, Second Primary / Q000209:etiology / Q000401:mortality; D016017:Odds Ratio; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012307:Risk Factors