Survivors of Hodgkin's lymphoma, a form of cancer that tends to affect the young, face a higher risk of developing other forms of cancer later in life, researchers have found.

Nearly 20,000 people who had successfully beaten Hodgkin's lymphoma were tracked for up to 30 years after treatment by Canadian, U.S. and European researchers, whose study appears in the April 20 issue of the Journal of Clinical Oncology.

Survivors of Hodgkin's lymphoma in their mid-30s had risks of breast and colorectal cancer like those of someone 20 years older, said Dr. David Hodgson.
(CBC)

The younger patients were when treated, the higher their risks of developing breast, lung or colorectal cancers. Women treated in their 20s had the greatest risk.

"By the time they're aged 50, about 25 per cent per cent of those young women will have experienced a second cancer — whereas in the general population, we'd expect that rate to be under five per cent," said the study's lead researcher, Dr. David Hodgson, a radiation oncologist at Toronto's Princess Margaret Hospital.

An estimated 850 Canadians are diagnosed with Hodgkin's lymphoma each year and more than 100 die of the disease. The average age of diagnosis is 30, although it can also affect adolescents.

Old treatments likely contributed to later cancers

Survivor Chaya Katrensky is philosophical about her increased risk of a second cancer.
(CBC)

The researchers suggested that treatments used decades ago for Hodgkin's likely contributed to the later cancers.

Many of the people in the study were treated 20 to 30 years ago, when doctors used higher doses of radiation. Those treatments targeted lymph nodes in the neck, chest and abdomen, where many of the later tumours surfaced.

As well, two commonly used chemotherapy drugs in the '60s and '70s have been linked to development of later cancers.

These days, doctors limit or avoid radiation therapy and chemotherapy drugs are safer, said Dr. Joseph Connors, the head of lymphoma treatment at the B.C. Cancer Agency.

"I think that we've reduced the risk," said Connors. "I don't think we've been able to completely eliminate it because it still is quite important to cure the Hodgkin's lymphoma. If one doesn't do that, then a person will lose their life to the primary disease."

Connors and Hodgson both recommended that people who were treated more than five years ago for Hodgkin's lymphoma should have regular screenings for breast and colorectal cancers.

The five-year survival rates after treatment are now 80 to 90 per cent.

Hodgkin's survivor not overly concerned

Chaya Katrensky, a 25-year-old Vancouverite who underwent chemotherapy after being diagnosed with Hodgkin's lymphoma a year ago, said she wasn't overly concerned to hear she could face a higher risk.

"So if my chances used to be five per cent and now they're 25 per cent, I really don't think that that is that significant, said Katrensky.

"I think that if it's meant to happen it's going to happen."

Doctors have told Katrensky she is now cancer free, but she said she is careful to eat well, exercise and see her doctor regularly sure to help lower her chances of developing cancer again.

With files from the Canadian Press