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, Prof. Dietlind Wahner-Roedler told the 3rd European Breast Cancer Conference, March 23, 2002.

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 10 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.

According to Prof. Wahner-Roedler, assistant professor and consultant in Internal Medicine at the Mayo Clinic, Rochester, the increased risk was even greater in the past, prior to "improvements" in radiotherapy techniques.

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.

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), of developing breast cancer increased significantly after 15 years of follow-up and that this increase continued through 30 years of follow-up.

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."