Children treated for Hodgkin's disease before 1986 have an increased risk of developing another cancer later in life, according to a new study by an international team of researchers including scientists from Cancer Research UK.
They found adults treated for Hodgkin's disease as children between 1955 and 1986 were more likely to develop leukemia and certain solid tumors such as breast, thyroid, lung, bowel and stomach cancer.
Children given radiotherapy to the chest area - one of the standard treatments pre-1986 - were more likely to develop a solid tumor. However, those who received chemotherapy - now the more common way to treat the disease - had an increased risk of leukemia.
Experts from the charity say it is essential survivors of the disease treated before 1986 to receive regular screening for breast and bowel cancer, and receive careful monitoring for the early signs of the other cancers linked to the disease, while children treated after this period, who receive chemotherapy, could be monitored for leukemia.
The news follows a recent Government announcement that young women who have received radiotherapy to the chest for Hodgkin's disease will be offered breast screening, and highlights the importance of long-term follow-up of patients, particularly children and young people.
Since 1986 radiotherapy is being used less and less as a treatment for children with Hodgkin's disease because it is known to interfere with the growth of normal tissue. It is now only used in cases where the disease is localized to one area. Chemotherapy is currently the main treatment for childhood Hodgkin's disease.
The new study found overall survivors of Hodgkin's disease treated with radiotherapy, chemotherapy or a combination of the two were nearly 20 times more likely to develop a second cancer later in life than their peers.
Study author Professor Jillian Birch, from the Cancer Research UK Paediatric and Familial Cancer Group at the University of Manchester, says: "In the past, children with Hodgkin's disease were treated with radiotherapy, chemotherapy or a combination of the two. The treatment was so successful nearly all patients survived the disease but, as a result, we are now uncovering evidence of subsequent cancers developing among survivors."
Researchers had previously tracked the incidence of cancer over an 11-year period in adults who received treatment as children for Hodgkin's disease. They analyzed data from some 1,400 children from Europe and America who were diagnosed with Hodgkin's disease at 16 years or less and received their initial treatment between 1955 and 1986.
In this study they extended the follow-up to 17 years and found the number of second cancers detected in this group nearly doubled, increasing from 109 to 212 cases developing in 173 patients.
Researchers found 30 of the 1,400 children who had received radiotherapy to the chest area developed breast cancer later in life. Altogether there were 42 breast cancers in this group of 30, in some cases cancer occurring in both breasts. This compares to one expected case in the general population.
There were 19 more cases of thyroid cancer than would be expected, eight more cases of bone and bowel cancer, four more cases of lung cancer and three more cases of stomach cancer.
There was also an increased risk of leukemia, which was highest in the first five years of follow-up but declined over the next 10 years.
The team also found that patients who had developed a second cancer were at greater risk of being diagnosed with a third cancer.
Birch says: "Our study shows cancers typically observed among adults are occurring at a much younger age in the survivors of childhood Hodgkin's treated before 1986 and in some cases multiple cancers are developing in patients."
Dr. David Walker, a leading member of the United Kingdom Children's Cancer Study Group, says: "It's crucial that those treated for Hodgkin's disease as children are made aware of their increased risk of other cancers."
SOURCE:
Cancer Research UK (http://www.cancerresearchuk.org)
