Cumulative absolute breast cancer risk for young women treated for Hodgkin lymphoma.
BACKGROUND
Many women develop breast cancer after treatment for Hodgkin lymphoma (HL) at a young age. We estimated this future risk, taking into account age and calendar year of HL diagnosis, HL treatment information, population breast cancer incidence rates, and competing causes of death.


METHODS
Relative risks of breast cancer for categories defined by radiation dose to the chest (0, 20- < 40 Gy, or > or = 40 Gy) and use of alkylating agents (yes or no) were estimated from a case-control study conducted within an international population-based cohort of 3817 female 1-year survivors of HL diagnosed at age 30 years or younger from January 1, 1965, through December 31, 1994. To compute cumulative absolute risks of breast cancer, we used modified standardized incidence ratios to relate cohort breast cancer risks to those in the general population, enabling application of population-based breast cancer rates, and we allowed for competing risks by using population-based mortality rates in female HL survivors.


RESULTS
Cumulative absolute risks of breast cancer increased with age at end of follow-up, time since HL diagnosis, and radiation dose. For an HL survivor who was treated at age 25 years with a chest radiation dose of at least 40 Gy without alkylating agents, estimated cumulative absolute risks of breast cancer by age 35, 45, and 55 years were 1.4% (95% confidence interval [CI] = 0.9% to 2.1%), 11.1% (95% CI = 7.4% to 16.3%), and 29.0% (95% CI = 20.2% to 40.1%), respectively. Cumulative absolute risks were lower in women treated with alkylating agents.


CONCLUSIONS
Breast cancer projections varied considerably by type of HL therapy, time since HL diagnosis, and age at end of follow-up. These estimates are applicable to HL survivors treated with regimens of the past and can be used to counsel such patients and plan management and preventive strategies. Projections should be used with caution, however, in patients treated with more recent approaches, including limited-field radiotherapy and/or ovary-sparing chemotherapy.
Travis
Lois B
LB
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA. travisl@mail.nih.gov
Hill
Deirdre
D
Dores
Graça M
GM
Gospodarowicz
Mary
M
van Leeuwen
Flora E
FE
Holowaty
Eric
E
Glimelius
Bengt
B
Andersson
Michael
M
Pukkala
Eero
E
Lynch
Charles F
CF
Pee
David
D
Smith
Susan A
SA
Van't Veer
Mars B
MB
Joensuu
Timo
T
Storm
Hans
H
Stovall
Marilyn
M
Boice
John D
JD
Gilbert
Ethel
E
Gail
Mitchell H
MH
D000328:Adult; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005387:Finland / Q000453:epidemiology; D006689:Hodgkin Disease / Q000188:drug therapy* / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D007484:Iowa / Q000453:epidemiology; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology; D016609:Neoplasms, Second Primary / Q000453:epidemiology* / Q000209:etiology; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D009864:Ontario / Q000453:epidemiology; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D018570:Risk Assessment; D012307:Risk Factors; D018426:SEER Program; D013548:Sweden / Q000453:epidemiology
D018906:Antineoplastic Agents, Alkylating