Thyroid dysfunction, manifested by primary hypothyroidism, hyperthyroidism, goiter, or nodules, is a common delayed effect of radiation therapy fields that include the thyroid gland incidental to treating Hodgkin lymphoma (HL), brain tumors, head and neck sarcomas, and acute lymphoblastic leukemia.
Of children treated with radiation therapy, most develop hypothyroidism within the first 2 to 5 years posttreatment, but new cases can occur later. Reports...
Revised text to state that patients without any of the adverse features have a median survival of more than 10 to 15 years, but the presence of any two of the adverse features lowers the median survival to less than 4 years (cited 2012 Tefferi et al. as reference 14). Also added text to state that international prognostic scoring systems incorporate the aforementioned prognostic factors (cited Gangat et al. as reference 15).
Revised text on karyotype abnormalities to state that in a retrospective series, the 13q and 20q deletions and trisomy 9 correlated with improved survival and no leukemia transformation compared with the worse prognosis with trisomy 8, complex karyotype, -7/7q-, i(17q), inv(3), -5/5q-, 12p-, or 11q23 rearrangement (cited Caramazza et al. as reference 16).
Added text to state that asymptomatic low-risk patients should be followed with a watchful-waiting approach; also added that development of symptomatic anemia, marked leukocytosis, drenching night sweats, weight loss, fever, or symptomatic splenomegaly would warrant therapeutic intervention.
Expanded text on therapies for disease-associated anemia (cited Cervantes et al. as reference 20, Huang et al. as reference 21, Thomas et al. as reference 22, 2007 Tefferi et al. as reference 23, 2010 Mesa et al. as reference 24, Begna et al. as reference 26).
Added text to state that ruxolitinib can reduce the splenomegaly and debilitating symptoms of weight loss, fatigue, and night sweats for patients with primary myelofibrosis, post–essential thrombocythemia myelofibrosis, or post–polycythemia vera myelofibrosis (cited 2010 Verstovsek et al. as reference 27). Also added text about two prospective, randomized trials in which 528 higher-risk patients were randomly assigned to ruxolitinib or to best available therapy or placebo; at 48 weeks, patients on ruxolitinib had a decrease of 40% to 60% in mean palpable spleen length or in spleen volume compared with an increase of 1% to 4% with best available therapy (cited Harrison et al. as reference 28 and level of evidence 1iiDiv; 2012 Verstovsek et al. as reference 29 and level of evidence 1iDiv). Ruxolitinib improved overall quality-of-life measures with low toxic effects in both studies but with no benefit in overall survival; discontinuation of ruxolitinib resulted in a rapid worsening of splenomegaly and recurrence of systemic symptoms (cited 2011 Tefferi et al. as reference 30). Other JAK2 inhibitors are currently being studied in clinical trials (cited 2011 Verstovsek as reference 31).