Medline ® Abstracts for References 43-45

Myelodysplastic syndromes (MDS) incidence is unclear because of historical lack of population-based registration and possibly because of underdiagnosis. We conducted a study to evaluate completeness of MDS registration in the Seattle-Puget Sound region of the Surveillance, Epidemiology, and End Results (SEER) program-which has reported the highest rates among the SEER registries since mandatory reporting of MDS began in 2001. We identified incident MDS cases of any age that occurred within a nonprofit healthcare system in western Washington State in 2005 or 2006 through the local SEER registry or by relevant diagnostic code followed by medical chart review to classify these patients as unlikely, possible, or definite/probable MDS. We calculated age-standardized incidence rates for all identified MDS cases and for case groups based on identification method, and we summarized medical histories of the MDS patients. MDS incidence in our study population was estimated as 7.0 per 100,000 person-years in 2005-2006 when combining MDS cases identified by SEER and definite/probable cases identified by chart review, which was similar to the rate of 6.9 reported by our local SEER registry. The addition of possible MDS cases identified from chart review increased the rate to 10.2 per 100,000. MDS patients frequently had previous cancer diagnoses (25%) and comorbidities such as high blood pressure and diabetes. Our investigation suggests that although reporting of confirmed MDS diagnoses in our region appears complete, MDS incidence is likely underestimated because of omission of cases who are symptomatic but do not receive definitive diagnoses.

The myelodysplastic syndromes (MDSs) are hematologically diverse hematopoietic stem cell malignancies primarily affecting older individuals. The incidence of MDS in the United States is estimated at 3.3 per 100 000; however, evidence suggests underreporting of MDS to centralized cancer registries. Contrary to clinical recommendations, registry guidelines from 2001-2010 required the capture of only one malignancy in the myeloid lineage and did not require blood count (BC) or bone marrow (BM) biopsy for MDS confirmation. To address these potential limitations, we constructed 4 claims-based algorithms to assess MDS incidence, applied the algorithms to the 2000-2008 Surveillance Epidemiology and End Results (SEER)-Medicare database, and assessed algorithm validity using SEER-registered MDS cases. Each algorithm required one or more MDS claims and accounted for recommended diagnostic services during the year before the first claim: 1+, 2+, 2 + BC, and 2 + BCBM (ordered by sensitivity). Each had moderate sensitivities (78.05%-92.90%) and high specificities (98.49%-99.84%), with the 2 + BCBM algorithm demonstrating the highest specificity. Based on the 2 + BCBM algorithm, the annual incidence of MDS is 75 per 100 000 persons 65 years or older-much higher than the 20 per 100 000 reported by SEER using the same sample.

BACKGROUND: Myelodysplastic syndromes (MDS) appear to be underreported to cancer registries, with important implications for cancer and transfusion support service planning and delivery. Two population-based databases were linked to estimate MDS incidence more accurately.

METHODS: Data from the statewide Victorian Cancer Registry (VCR) and Victorian Admitted Episode Dataset (VAED, capturing all inpatient admissions), in Australia, were linked. Incidence rates were calculated based on VCR reported cases and using additional MDS cases identified in VAED. Differences between reported and nonreported cases were assessed. A multivariate capture-recapture method was used to estimate missed cases.

RESULTS: Between 2003 and 2010, 2692 cases were reported to VCR and an additional 1562 cases were identified in VAED. Annual incidence rate for those aged 65 years and older based on VCR was 44 per 100,000 (95% confidence interval [CI] = 43-45 per 100,000) and 68 per 100,000 (95% CI = 67-70 per 100,000) using both data sets. Cases not reported to VCR were more likely to have had previous malignancies recorded in VAED (23% versus 19%, P = .003) and to require red cell transfusion (59% versus 54%, P = .003). Using the multivariate model, an estimated 1292 cases were missed by both data sources: the re-estimate was 5546 (95% CI = 5438-5655) MDS cases, with an annual incidence in those aged 65 or older of 103 per 100,000 (95% CI = 100-106).

CONCLUSIONS: This study reports a higher incidence of MDS using 2 data sources from a large and well-defined population than reported using cancer registry notifications alone. Cancer 2014;120:1686-1694.©2014 American Cancer Society.