Myelodysplastic syndromes in Chernobyl clean-up workers

[Environmental and occupational risk factors for myelodysplastic syndrome]

Chemotherapy and radiotherapy for a previous cancer can lead to subsequent myelodysplastic syndrome (MDS). However, these therapy-related cases are hypothesized to explain only 5 % of diagnosed MDS cases. Environmental or occupational exposure to chemicals or radiations has also been reported to be associated with higher risk of MDS. The present review analyses those studies evaluating the association of MDS with environmental or occupational risk factors. There is sufficient evidence that environmental or occupational exposure to ionizing radiation or benzene can cause MDS. Tobacco smoking is also a sufficiently documented riskfactor for MDS. A positive association has been reported between exposure to pesticides and MDS. However, there is only limited evidence that this association could be causal.

Clinical features and prognosis of patients with myelodysplastic syndromes who were exposed to atomic bomb radiation in Nagasaki

There is evidence that radiation exposure is a causative factor of myelodysplastic syndromes (MDS). However, little is known about whether radiation exposure is also a prognostic factor of MDS. We investigated the impact of radiation exposure on the prognosis of MDS in Nagasaki atomic bomb survivors using the International Prognostic Scoring System (IPSS) and the revised version (IPSS‐R). Subjects were 140 patients with primary MDS diagnosed between 1985 and 2011 and evaluable for IPSS, IPSS‐R, and exposure distance. Of those, 31 were exposed at <1.5 km, 35 at 1.5–2.99 km, and 74 at ≥3.0 km. By the end of March 2014, 47 patients (34%) progressed to overt leukemia and 106 (75.7%) died. By comparing with patients exposed at ≥3.0 km, those exposed at <1.5 km had significantly higher frequencies of abnormal chromosome (P = 0.02), intermediate/poor IPSS, and intermediate/poor/very poor IPSS‐R cytogenetic category (P = 0.0001, and P < 0.0001, respectively). As with de novo MDS, multivariate Cox regression analyses revealed that cytogenetic abnormalities, IPSS karyotype, and IPSS‐R cytogenetics were significantly associated with poor survival, and cumulative incidence of leukemic transformation in MDS among atomic bomb survivors, but exposure distance was not associated with any poor outcomes. These suggest that exposure to the greater dose of atomic bomb radiation is associated with developing poor cytogenetic abnormalities in MDS, which might consequently lead to overt leukemia among atomic bomb survivors.

Myeloid neoplasms after chemotherapy and PRRT: myth and reality

Peptide receptor radionuclide therapy (PRRT) with (90)Y-octreotide or (177)Lu-octreotate is an effective treatment for inoperable or metastatic neuroendocrine tumors (NETs), particularly well-differentiated gastroenteropancreatic or bronchopulmonary NETs. PRRT is generally extremely well tolerated, with modest toxicity to target organs, kidney and bone marrow. Nevertheless, a priori concerns regarding long-term effects lead clinicians such as Brieau and coworkers, in this ERC issue, to ascribe to the combination of alkylating agents and PRRT the apparently high occurrence (n=4) of myeloproliferative events (therapy-related myeloid neoplasms (t-MNs)) in a small cohort of 20 progressive, advanced digestive NETs treated with PRRT after chemotherapy. Anecdotal reports of myelotoxic events should be placed in the correct perspective of larger series, where the reported incidence of these events is ~2%, with the aim of promoting a balanced awareness of the issue and unbiased and reasonable overall conclusions. For a comprehensive definition of the issue, we provide an evaluation of the occurrence of t-MN in patients treated with various myelotoxic treatments.