Malignant breast tumors after radiotherapy for a first cancer during childhood.
OBJECTIVE
To assess the specific role of treatment and type of first cancer (FC) in the risk of long-term subsequent breast cancer (BC) among childhood cancer survivors.


METHODS
In a cohort of 1,814 3-year female survivors treated between 1946 and 1986 in eight French and English centers, data on chemotherapy and radiotherapy were collected. Individual estimation of radiation dose to each breast was performed for the 1,258 patients treated by external radiotherapy; mean dose to breast was 5.06 Gy (range, 0.0 to 88.0 Gy) delivered in 20 fractions (mean).


RESULTS
Mean follow-up was 16 years; 16 patients developed a clinical BC, 13 after radiotherapy. The cumulative incidence of BC was 2.8% (95% CI, 1.0% to 4.5%) 30 years after the FC and 5.1% (95% CI, 2.1% to 8.2%) at the age of 40 years. The annual excess incidence increased as age increased, whereas the standardized incidence ratio decreased. On average, each Gray unit received by any breast increased the excess relative risk of BC by 0.13 (< 0.0 to 0.75). After stratification on castration and attained age, and adjusting for radiation dose, FC type, and chemotherapy, a higher risk of a subsequent BC was associated with Hodgkin's disease (relative risk, 7.0; 95% CI, 1.4 to 30.9).


CONCLUSIONS
The reported high risk of BC after childhood Hodgkin's disease treatment seems to be due not only to a higher radiation dose to the breasts, but also to a specific susceptibility.
Guibout
Catherine
C
National Institute of Health and Medical Research, Cancer Epidemiology Research Unit (U605 INSERM), Physics Department, Institut Gustave Roussy, rue Camille Desmoulins, 94805 Villejuif, France.
Adjadj
Elisabeth
E
Rubino
Carole
C
Shamsaldin
Akthar
A
Grimaud
Emmanuel
E
Hawkins
Mike
M
Mathieu
Marie-Christine
MC
Oberlin
Odile
O
Zucker
Jean-Michel
JM
Panis
Xavier
X
Lagrange
Jean-Léon
JL
Daly-Schveitzer
Nicolas
N
Chavaudra
Jean
J
de Vathaire
Florent
F
D000293:Adolescent; D000328:Adult; D000970:Antineoplastic Agents / Q000009:adverse effects; D001943:Breast Neoplasms / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006689:Hodgkin Disease / Q000532:radiotherapy; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced; D016609:Neoplasms, Second Primary / Q000209:etiology*; D011879:Radiotherapy Dosage; D013997:Time Factors
D000970:Antineoplastic Agents