Second primary tumors in children and young adults in the North of England (1968-99).

摘要

BACKGROUND: This study describes the risk of second malignancy in patients diagnosed with cancer under the age of 25 years, registered on the Northern Region Young Person's Malignant Disease Registry. PROCEDURE: Incidence rates were calculated to describe the occurrence of second malignancies, rate ratios were estimated to compare rates between subgroups. Standardized incidence ratios (SIRs) were calculated for comparison with a reference population. RESULTS: There were 4,072 children and young adults diagnosed with a first malignancy from 1968 to 1999, of whom 68 had a second malignancy (including basal cell carcinomas and meningiomas). The incidence rate of second malignancy is 1.7 per 1,000 survivor person-years (95% CI: 1.4, 2.2), reflecting a four-fold increased risk of malignancy compared with the general population. The rate of second malignancy was non-significantly higher for those diagnosed during young adulthood rather than childhood (RR = 1.2, 95% CI: 0.7, 2.0), significantly higher in females than males (RR = 1.8, 95% CI: 1.1, 3.0) and significantly lower for those diagnosed in more recent years (RR = 0.4, 95% CI: 0.2, 0.8). In contrast, the SIRs indicated that children were at substantial increased risk; whilst males and females, and those diagnosed in earlier and later time periods, were at equivalent risks. CONCLUSIONS: There is evidence of a sustained increased risk of second malignancy in those treated for primary cancer, especially those diagnosed in childhood; with no evidence that this risk is reducing.