Hodgkin's Treatment Increases Secondary Breast Cancer Risk

Patients treated for Hodgkin’s disease during childhood or adolescence have a greater risk of developing secondary breast cancer later in life, particularly if they receive radiotherapy during puberty.

Women treated for Hodgkin’s disease during childhood or adolescence have a significantly increased risk of developing secondary breast cancer later in life, particularly if they are treated during puberty, according to a study published in the January edition of Deutches Ärztezblatt International.

The incidence of breast cancer in women aged 25 to 45 who were previously treated for Hodgkin’s disease was 24 times higher than that of the age-matched general population, the researchers determined.

In the 26 participants who developed secondary breast cancer, half were diagnosed at a locally or generally advanced stage, researchers added. The secondary cancer presented within the irradiated field in 25 of the 26 participants, and 6 participants developed synchronous or metachronous bilateral disease.

Participants who received radiotherapy between the ages of 9 and 16 tended to develop radiotherapy-associated secondary cancer later in life, whereas participants who received radiotherapy prior to puberty did not, researchers noted.

Researchers used information from the long-term Late Effects of Hodgkin’s Disease project of the Society of Paediatric Oncology and Hematology to find 590 female participants from a field of 1406 total participants. All participants were younger than 18 years at the onset of their primary cancer, and 95% survived more than 10 years.

Each of the trials in the project combined chemotherapy and radiotherapy as treatment for Hodgkin’s disease, the researchers noted.

The researchers found no visible difference in overall survival between boys and girls treated for Hodgkin’s disease, and found overall survival rates exceeded 90% for 20 years. Within the next 10 years, however, those rates dropped to 80% and 81% due to deaths from various causes.

By the study’s completion date, 26 women from the original cohort had been diagnosed with secondary breast cancer. The disease caused the death of only 3 participants, however. The median interval between primary and secondary cancers was 20.7 years, and participants’ median age was 35.3 years at the time of their breast cancer diagnosis, according to the study.

The researchers noted that their findings confirm the results of previous research into secondary malignancies, and support the consensus of a causal relationship between radiation fields and secondary tumors. In addition, the results showed that all radiotherapy-associated secondary breast cancer occurred in women who received radiotherapy when they were between the ages of 9 and 16 years, but no secondary breast cancer was recorded in women who received radiation therapy before age 9, which also supports the existing consensus.