Secondary malignancies among mantle cell lymphoma patients.

PURPOSE: With modern treatments, mantle cell lymphoma (MCL) patients more frequently experience long-lasting remission resulting in a growing population of long-term survivors. Follow-up care includes identification and management of treatment-related late-effects, such as secondary malignancies (SM). We conducted a population-based study to describe the burden of SM in MCL patients. METHODS: All patients with a primary diagnosis of MCL, aged ≥ 18 years and diagnosed between 2000 and 2017 in Sweden were included along with up to 10 individually matched population comparators. Follow-up was from twelve months after diagnosis/matching until death, emigration, or December 2019, whichever occurred first. Rates of SM among patients and comparators were estimated using the Anderson-Gill method (accounting for repeated events) and presented as hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age at diagnosis, calendar year, sex, and the number of previous events. RESULTS: Overall, 1 452 patients and 13 992 comparators were followed for 6.6 years on average. Among patients, 230 (16%) developed at least one SM, and 264 SM were observed. Relative to comparators, patients had a higher rate of SM, HRadj= 1.6 (95%CI:1.4-1.8), and higher rates were observed across all primary treatment groups: the Nordic-MCL2 protocol, R-CHOP, R-bendamustine, ibrutinib, lenalidomide, and R-CHOP/Cytarabine. Compared to Nordic-MCL2, treatment with R-bendamustine was independently associated with an increased risk of SM, HRadj= 2.0 (95%CI:1.3-3.2). Risk groups among patients were those with a higher age at diagnosis (p < 0.001), males (p = 0.006), and having a family history of lymphoma (p = 0.009). Patients had preferably higher risk of melanoma, other neoplasms of the skin and other hematopoietic and lymphoid malignancies. CONCLUSIONS: MCL survivors have an increased risk of SM, particularly if treated with R-bendamustine. The intensive treatments needed for long-term remissions are a concern, and transition to treatment protocols with sustained efficacy but with a lower risk of SM is needed.

Lympho-hematopoietic malignancies risk after exposure to low dose ionizing radiation during cardiac catheterization in childhood.

Pediatric patients with congenital heart disease (CHD) often undergo low dose ionizing radiation (LDIR) from cardiac catheterization (CC) for the diagnosis and/or treatment of their disease. Although radiation doses from a single CC are usually low, less is known about the long-term radiation associated cancer risks. We aimed to assess the risk of lympho-hematopoietic malignancies in pediatric CHD patients diagnosed or treated with CC. A French cohort of 17,104 children free of cancer who had undergone a first CC from 01/01/2000 to 31/12/2013, before the age of 16 was set up. The follow-up started at the date of the first recorded CC until the exit date, i.e., the date of death, the date of first cancer diagnosis, the date of the 18th birthday, or the 31/12/2015, whichever occurred first. Poisson regression was used to estimate the LDIR associated cancer risk. The median follow-up was 5.9 years, with 110,335 person-years. There were 22,227 CC procedures, yielding an individual active bone marrow (ABM) mean cumulative dose of 3.0 milligray (mGy). Thirty-eight incident lympho-hematopoietic malignancies were observed. When adjusting for attained age, gender and predisposing factors to cancer status, no increased risk was observed for lympho-hematopoietic malignancies RR/mGy = 1.00 (95% CI: 0.88; 1.10). In summary, the risk of lympho-hematopoietic malignancies and lymphoma was not associated to LDIR in pediatric patients with CHD who undergo CC. Further epidemiological studies with greater statistical power are needed to improve the assessment of the dose-risk relationship.

Early life ionizing radiation exposure and cancer risks: systematic review and meta-analysis.

BACKGROUND: Ionizing radiation use for medical diagnostic purposes has substantially increased over the last three decades. Moderate to high doses of radiation are well established causes of cancer, especially for exposure at young ages. However, cancer risk from low-dose medical imaging is debated. OBJECTIVE: To review the literature on cancer risks associated with prenatal and postnatal medical diagnostic ionizing radiation exposure among children and to assess this risk through a meta-analysis. MATERIALS AND METHODS: A literature search of five electronic databases supplemented by a hand search was performed to retrieve relevant epidemiological studies published from 2000 to 2019, including patients younger than 22 years of age exposed to medical imaging ionizing radiation. Pooled odds ratio (ORpooled) and pooled excess relative risk (ERRpooled) representing the excess of risk per unit of organ dose were estimated with a random effect model. RESULTS: Twenty-four studies were included. For prenatal exposure (radiographs or CT), no significant increased risk was reported for all cancers, leukemia and brain tumors. For postnatal exposure, increased risk was observed only for CT, mostly for leukemia (ERRpooled=26.9 Gy-1; 95% confidence interval [CI]: 2.7-57.1) and brain tumors (ERRpooled=9.1 Gy-1; 95% CI: 5.2-13.1). CONCLUSION: CT exposure in childhood appears to be associated with increased risk of cancer while no significant association was observed with diagnostic radiographs.