No abstract

Our purpose was to assess the risk of developing a second malignant neoplasm (SMN) after cancer in childhood and adolescence associated with different treatment modalities. Our investigation was performed as a nested case‐control study within a Nordic cohort of 25,120 patients younger than 20 years old at first malignant neoplasm (FMN) diagnosed in 1960 through 1987. SMNs were diagnosed in 1960 through 1991. For each case of SMN, 3 controls were sampled, matched by sex, age, calendar year of diagnosis and length of follow‐up. For the final analysis, there were 234 cases and 678 controls. Relative risks (RRs) of various exposures were estimated by means of conditional logistic regression, with non‐exposed as the reference. The RR of developing SMN in the radiated volume was 4.3 (95% confidence interval 3.0–6.2). The risk was highest in children diagnosed before the age of 5 years; it increased with the dose of radiation and with increasing follow‐up time after FMN. Chemotherapy alone was not associated with an increased RR, but it significantly potentiated the effect of radiotherapy. RRs were unchanged between the periods 1960–1973 and 1974–1987, and since the use of chemotherapy increased in the latter period, the number of SMNs may increase. Hereditary factors were important for the occurrence of SMN independently of therapy. We conclude that radiation was the most important treatment‐related risk factor for the development of SMN. Chemotherapy appeared to play only an accessory role during the study period, potentiating the carcinogenic effect of radiotherapy. Int. J. Cancer 88:672–678, 2000. © 2000 Wiley‐Liss, Inc.

ON as determined by MRI was found to be a common complication in children and adolescents after treatment with the Nordic ALL protocols. Revision of the ALL protocols by shortening the single exposure to dexamethasone has diminished the risk for ON remarkably. High BMI was identified as a new significant risk factor for ON.

While the prognosis of acute childhood leukemia has improved, long-term survivors are increasingly experiencing late effects of the treatment. Cranially irradiated survivors are predisposed to the development of CNS tumors. Our aim was to describe the incidence of secondary brain tumors and to define the significance of treatment-related risk factors and host characteristics in a cohort of childhood leukemia survivors. Our cohort consisted of 60 consecutive cranially irradiated adult survivors of childhood leukemia treated in Oulu University Hospital (Oulu, Finland); MRI of the brain was performed on 49. The sites of the tumors, their histology, and details of the leukemia treatment were determined. Of the 49 patients, 11 (22%) 1-8 years of age at the time of diagnosis developed meningioma later in life, while no other brain tumors were seen. In this cohort, the development of meningioma seemed to show undisputable linkage with long latency periods (mean, 25 years; range, 14-34 years) and an increasing incidence 20 years after the treatment (47%). Three patients had multiple meningiomas, two had recurrent disease, and one had an atypical meningioma. Age at the time of irradiation, gender, or cumulative doses of chemotherapeutic agents showed no significant association with the development of meningiomas. The high incidence of meningiomas in this study was associated with long follow-up periods. Although the cohort is small, it seems probable that the increasing incidence of meningioma will shadow the future of cranially irradiated leukemia survivors. Systematic brain imaging after the treatment is therefore justifiable.