Mammograms are advised at a younger age
The risk is three times greater, compared to the general population, according to findings presented to delegates at the 3rd European Breast Cancer Conference in Barcelona.
If the women were younger than 30 when they received the treatment, the threat rose to eight times the normal risk.
If these younger women had their spleen removed as part of the treatment, they were 10 times more likely than the general population to contract the disease.
Professor Dietlind Wahner-Roedler, who presented the findings, said this risk was so high that these women might want to consider prophylactic double mastectomy.
However, she said radiotherapy techniques have improved in recent years and she thinks the risk may have decreased with modern treatments.
Professor Wahner-Roedler and her colleagues from the Mayo Clinic, Rochester, USA, reviewed the records of more than 2,000 women with Hodgkin's disease who visited the centre between 1950 and 1993.
They studied the records of 653 women who were treated with radiation therapy.
They found 30 women had developed breast cancer, of whom, four had developed cancer at different times in both breasts.
Four patients who were diagnosed with breast cancer prior to the diagnosis of Hodgkin's disease, were excluded from the analysis.
Regular examinations
Women aged 30 and over who received radiation had only a slightly higher than normal risk of developing breast cancer.
Hodgkin's disease tends to occur either in young adulthood, mid-teens to late twenties, or after the age of 45.
Professor Wahner-Roedler said: "It is important to realise breast cancer diagnosed now reflects treatment methods for Hodgkin's disease from more than 10 years ago.
"During the past several years, splenectomy has been abandoned by many centres.
"Modern combined therapy with improved techniques, reduced fields and reduced doses of radiation is expected to lower the increased risk of breast cancer."
However, she recommends women who have been treated for Hodgkin's disease should have professional breast examinations every six months.
She suggests patients who received radiation under the age of 20, should start having mammograms 10 years after the treatment, but not before the age of 25.
For patients treated after the age of 20, she recommends routine screening to start after radiation therapy or at age 35, whichever comes first.
Kate Law, head of clinical trials at Cancer Research UK, said women should not be frightened by this study, but should ask for mammograms if they have any concerns.
She said: "Those who had treatment that long ago should now be in the age group where they're being called for mammograms.
"But radiation therapy has changed out of all recognition since the 1950s.
"Now it is much more targeted to the area and dosages are much more controlled."