News Release

Women face high risk of developing breast cancer following radiotherapy for Hodgkin’s Disease

Peer-Reviewed Publication

ECCO-the European CanCer Organisation

Women who have received radiotherapy for Hodgkin’s Disease have a three times higher relative risk of developing breast cancer than women from the general population, Professor Dietlind Wahner-Roedler told the 3rd European Breast Cancer Conference on Saturday 23 March.

If the women were younger than 30 when they received the treatment their relative risk was even higher at eight times the normal risk. If the spleen had been removed from these younger women as part of the treatment (splenectomy), then they faced a ten times higher relative risk than the general population, while a family history of breast cancer increased their chances of developing the disease 11-fold above the general population. This risk is so high that the professor said these women might want to consider prophylactic double mastectomy.

However, Prof Wahner-Roedler, assistant professor and consultant in Internal Medicine and Breast Clinic at the Mayo Clinic, Rochester, USA, said that radiotherapy techniques have improved in recent years and she would expect the risk to have decreased with modern treatments.

Prof Wahner-Roedler and her colleagues reviewed the records of 2,202 women with Hodgkin’s Disease who were seen at Mayo Clinic between 1950 and 1993 and studied the records of 653 women, who were treated at the Mayo Clinic with supradiaphragmatic radiation therapy (SDRT)1. Four patients who were diagnosed with breast cancer prior to the diagnosis of Hodgkin’s Disease were excluded from the analysis. They found that 30 women had developed breast cancer, of whom four had developed cancer at different times in both breasts.

They found that the relative risk, expressed as SMR (standard morbidity ratio)2, of developing breast cancer increased significantly after 15 years of follow-up and that this increase continued through 30 years of follow-up.

Women aged 30 and over at the time of SDRT had only a slightly higher than normal relative risk of developing breast cancer. The relative risk of breast cancer in this age group was significantly higher in women with a positive family history of breast cancer compared to those with a negative family history; similarly the women in this age group who had undergone a splenectomy had a significantly increased relative risk compared to those who had not undergone a splenectomy. In contrast, in women who received SDRT under the age of 30, the risk in those with a family history was not significantly higher than in those without a family history; similarly the risk in this age group was not significantly higher in those with a splenectomy compared to those without a splenectomy. SDRT posed the greatest danger of causing subsequent breast cancer to women under 30 at the time of treatment.

Prof Wahner-Roedler said: “The impact of radiation therapy on younger women is so severe that it makes the impact of having a family history of breast cancer not significant.”

Half of the tumours were found by the women themselves during self-examination, 13 were found by mammographic screening and four by clinical examination.

Prof Wahner-Roedler said: “It is important to realise that breast cancer diagnosed now reflects treatment methods for Hodgkin’s Disease from more than ten years ago. During the past several years, splenectomy has been abandoned by many centres. Modern combined modality therapy with improved techniques, reduced fields and reduced doses of radiation is expected to lower the increased risk of breast cancer. Further studies will be required to assess the effect of current treatment methods for Hodgkin’s Disease.”

She recommended vigilance for women who have been treated for Hodgkin’s Disease. “We recommend that they should have professional breast examinations every six months. For patients treated under the age of 20, we recommend annual mammography starting ten years after SDRT, but not before the age of 25 as the majority of breast cancers have been reported after the age of 25. For patients treated at age 20 or older, we recommend routine screening to start 10 years after SDRT or at age 35, which ever comes first. Bilateral prophylactic mastectomy should be discussed with patients who have a strong family history.”

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1 Supradiaphragmatic Radiation Therapy (SDRT) means that radiation was given to the lymph node regions in the body above the diaphragm. Parts of the breasts are included in this area and therefore receive direct radiation.

2 SMRs were calculated by comparing the number of breast cancers observed to the numbers expected in this cohort during their follow-up. Expected numbers of breast cancer were derived by applying age-specific incidence rates from the total SEER (Surveillance, Epidemiology and End Results Program) female population for breast cancer to age-specific person-years of follow-up in the Hodgkin’s disease cohort.

For further information, contact Emma Mason, Margaret Willson, or Maria Maneiro at the EBCC3 press office in Barcelona, tel: +34 93 364 4487, or Emma Mason's mobile +44 (0)7711 296 986, or Margaret Willson's mobile + 44 (0)7973 853 347.


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