Risk of Second Cancer Weighed for Kids

New research shows that cancer risk may be higher for children who have already faced a type of cancer called soft tissue sarcoma.

Over the last 25 years, more children have survived soft tissue sarcoma. In light of that encouraging trend, researchers examined the risk of second cancers in children who had survived this type of cancer.

The risk of second cancers was about six to eight times higher than normal, according to the study in the April 25 online edition of Cancer.

However, that's the big picture, comparing survivors with the general public. The real risk to a survivor is "quite low," say the researchers.

Of course, cancer survivors are advised to stay in touch with their doctors, asking questions, getting checkups, and raising any concerns.

The Survivors

Data came from the National Cancer Institute and included 1,500 child survivors of soft tissue sarcoma, a cancer of connective tissues, such as muscle.

All were younger than 18 years, were diagnosed from 1973 to 2000, and had survived for at least one year. Some had survived for a decade or longer.

A total of 27 children developed another cancer. Among the general public, the expected number of cancers would have been 4.5, say the researchers.

Twenty years after the initial diagnosis with childhood soft tissue sarcoma, 2.9% of kids had developed a second cancer.

Second Cancers

The higher risk was seen with all forms of childhood soft tissue sarcoma.

The risk of developing a second cancer was highest during the first five years of follow-up, say the researchers. During those early years, the risk was almost 12 times higher than normal but fell to fivefold for the rest of the study.

Second cancers included leukemia, melanoma, breast cancer, oral cancers, and sarcomas of the bone and soft tissue.

Treatment Type Affects Risk

Risk of second cancers was higher in children who had had radiation combined with chemotherapy, compared with those who only had surgery.

The risk was also higher with radiation alone for one type of soft tissue sarcoma (fibromatous neoplasms) but not for another type (rhabdomyosarcoma).

Chemotherapy alone was not linked to a higher risk of second cancers.

Genetics May Be a Factor

The data didn't include family history of cancer. However, three patients with multiple second cancers involving soft tissue sarcomas might have had underlying genetic conditions, say researchers.

"We conclude that both treatment effects and genetic factors contributed to the increased risk of second cancers in this series of children with soft tissue sarcoma," write the researchers, who included Randi J. Cohen, MS, a Howard Hughes Medical Institute-National Institutes of Health research scholar.

By Miranda Hitti, reviewed by Michael W. Smith, MD

SOURCES: Cohen, R. Cancer, April 25, 2005; online edition. News release, John Wiley & Sons, Inc.