ABSTRACT
Exposure to ionizing radiation increases the risk of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN), but such risks are not known in well-differentiated thyroid cancer (WDTC) patients treated with radioactive iodine (RAI). A total of 148 215 WDTC patients were identified from Surveillance, Epidemiology and End Results registries between 1973 and 2014, of whom 54% underwent definitive thyroidectomy and 46% received adjuvant RAI. With a median follow-up of 6.6 years, 77 and 66 WDTC patients developed MDS and MPN, respectively. Excess absolute risks for MDS and MPN from RAI treatment when compared to background rates in the US population were 6.6 and 8.1 cases per 100 000 person-years, respectively. Compared to background population rates, relative risks of developing MDS (3.85 (95% confidence interval, 1.7-7.6); P=0.0005) and MPN (3.13 (1.1-6.8); P=0.012) were significantly elevated in the second and third year following adjuvant RAI therapy, but not after thyroidectomy alone. The increased risk was significantly associated with WDTC size ⩾2 cm or regional disease. Development of MDS was associated with shorter median overall survival in WDTC survivors (10.3 vs 22.5 years; P<0.001). These data suggest that RAI treatment for WDTC is associated with increased risk of MDS with short latency and poor survival.
Subject(s)
Iodine Isotopes/adverse effects , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/etiology , Myeloproliferative Disorders/etiology , Thyroid Neoplasms/radiotherapy , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Risk Factors , Thyroidectomy/methods , Young AdultABSTRACT
BACKGROUND: There is symptom overlap between gastro-esophageal reflux disease (GERD) and functional dyspepsia (FD). We aimed to test the hypothesis that FD cases are now more likely mislabeled as GERD. METHODS: In subjects from Olmsted County, MN seen at Mayo Clinic: (i) Investigation of GERD and FD diagnosis rates between 1985 and 2009. (ii) Assessment of survey-based upper gastrointestinal symptoms between 1988 and 2009. (iii) Analysis of patients reporting GERD and/or FD symptoms and subsequently receiving a consistent diagnosis of GERD and/or FD during a medical encounter. (iv) Assess the association between PPI use and GERD and/or FD symptoms and between actual diagnoses received. KEY RESULTS: (i) Yearly GERD diagnosis rates rose between 1985 and 2009 (325-1866 per 100 000). FD diagnosis rates rose from 45 in 1985, to 964 in 1999 but decreased to 452 per 100 000 in 2009. (ii) Reported GERD symptoms did not significantly change between three survey waves in the years 1988-2009 (p = 0.052), whereas FD symptoms slightly increased (p = 0.01). (iii) 62.9% of subjects reporting GERD symptoms received a GERD diagnosis, however only 12.5% of subjects reporting FD symptoms received a FD diagnosis. (iv) PPI use was associated with documented GERD diagnosis (p < 0.001), however there was no significant association between GERD symptoms and PPI use (p = 0.078). CONCLUSIONS & INFERENCES: We have found evidence supporting a systematic bias away from diagnosing FD, favoring a GERD diagnosis.
