Women diagnosed with Hodgkin Lymphoma under the age of 35 are at high risk of developing breast cancer later in life. However, in a ground-breaking Breakthrough Breast Cancer-funded study, scientists have found that the FGFR2 gene puts those patients at even higher risk of developing breast cancer.

Professor Anthony Swerdlow, from The Institute of Cancer Research in Sutton, who led the study, said:

“Patients diagnosed with Hodgkin Lymphoma at a young age are already screened as part of the NHS Breast Screening Programme. However, this finding could give patients and doctors more information to make decisions about their care tailored to their needs. “It is so important we know each woman’s individual risk of breast cancer and this is a step towards helping us do that.”

Every year, nearly 1,500 people are diagnosed with Hodgkin Lymphoma in the UK, according to NHS figures. People aged from 15 to 35 are most at risk, followed by people over 50. Hodgkin Lymphoma is a type of cancer that affects the lymphatic system, which means it spreads quickly through the body. It’s one of the easiest types of cancer to treat. But a common treatment, radiotherapy, puts patients at an extra risk of developing another cancer later in life.

The highest risk is of breast cancer, caused by radiotherapy to the chest. Because this is a known risk, young women given radiotherapy as part of their treatment for Hodgkin Lymphoma can have breast cancer screening if they had radiotherapy to the chest for Hodgkin Lymphoma. The scientists looked at DNA taken from blood samples from 693 Hodgkin’s patients from both the UK and the Netherlands, who had radiotherapy.

These patients were split into two groups. The first group was 449 people who had radiotherapy in England between 1963 and 2003 before they were 36 years old. Among these, 140 developed breast cancer and 309 did not. The second group was made up of 244 patients who had radiotherapy in the Netherlands between 1965 and 1997 before they were 41 years old. And in this group, 92 developed breast cancer and 152 did not. And even though all 693 of them were already at high risk of developing breast cancer, those with the FGFR2 gene were at an extra high risk of breast cancer, especially women first treated before their 20th birthday and those who hadn’t had chemotherapy.

The study was published in the journal, Blood, last month.