儿童时期癌症治疗好后有复发癌症的危险

    近期在美国癌症研究协会会议上发表的一项研究指出：儿童时期患过癌症经治疗后幸存下来的人，在以后复发另一种癌症的几率比其他人多6倍。

    Child's cancer therapy can lead to tumors later onNEW ORLEANS, Mar 28 (Reuters Health) - Children who survive a bout of cancer are about six times more likely to develop a second type of cancer later in life, according to a report presented here at the American Association for Cancer Research meeting.The excess cancer risk appears to be due to the effects of cancer treatment, such as chemotherapy and radiation, although some cases may be due to an increased genetic susceptibility to cancer. Dr. Joseph Neglia of the University of Minnesota presented the findings.The results showed that 282 of 13,581 people studied (3%) who had cancer as children, developed a secondary cancer later in life that seemed unrelated to the original cancer. Study participants were followed an average of 15 years after initial cancer treatment, with some followed up to 20 years.The average age of those studied was 23, but some were in their mid- to late-40s, said Neglia.The most common secondary tumor was breast cancer, found in 60 women. Forty-three people had thyroid tumors and 36 had brain tumors.Neglia said it was difficult to separate out if the tumors were partly caused by some underlying genetic defect, but that he was confident that children treated with radiation had a high risk of later tumor development.Children treated for Hodgkin's disease are also at higher risk, partly because the standard treatment 20 years ago was aggressive radiation. That is not true any longer.Women, especially, seem to be at risk. But Neglia said that getting radiation therapy during puberty was not an additional risk factor for later breast cancer development.He urged women who had radiation treatment at any point in childhood to get a baseline mammogram in their 20s.Neglia said anyone who received childhood cancer treatment should talk with a physician about their risk factors and potential monitoring strategies.Doctors walk a fine line in balancing the benefit of treating a childhood cancer with the risk that the therapy itself could lead to later cancers in adulthood.With so much of their lives ahead, the stakes are high, said oncologists, who also noted there has been a slight rise in pediatric cancer cases over the past several decades. There are about 8,000 to 10,000 new cases a year in the US, with leukemias and brain tumors leading in incidence, said Dr. Barton Kamen, a pediatric oncologist affiliated with the Robert Wood Johnson Medical School in New Jersey. He addressed reporters at the meeting.Noting that cancer is the leading disease-related cause of death in children, and that pediatric cancer usually doesn't respond to multiple therapeutic attempts, Kamen said oncologists must err on the side of aggressive initial treatment, despite more data showing that therapies can cause other cancers later in life."You don't get a second chance to treat a child with cancer," Kamen stated. "You have to win the first time out."Both Kamen and Neglia cautioned that oncologists should not pull back in their treatment of childhood tumors, noting that some 70% of children diagnosed with cancer today will be cured of their initial disease."The progress we've made in pediatric oncology has been just astonishing," said Neglia. "We just need to understand the ramifications," he added.