There was also a difference in coding between invasive and in situ melanomas. Of the 87 melanomas with a 663 code, 68 were in situ. Of the 106 melanomas with a national-level code, 11 were in situ. The odds of being assigned a local code were much higher for the in situ melanomas than they were for the invasive melanomas (OR, 30.9; CI, 13.8-69.1; P ≤ .0001).
Since 2000, the SNOMED code for melanoma in situ has been 87202, but no melanomas in situ were assigned this code. The 87202 code was not available in VistA for pathology laboratories to assign to melanomas at the time this study was conducted. Instead, most melanomas in situ were assigned a locally generated code. However, OncoTraX cannot recognize local codes, so melanomas assigned a local code might not have been accessionable.
The remaining 5 unreported melanomas were assigned WHO standardized codes. Secondary analysis revealed clerical errors, 4 made by the pathology laboratory and 1 by the registrar.
Discussion
Data from central cancer registries are used in a variety of fields, from research studies to health policymaking. They are used to “monitor cancer trends over time, show cancer patterns in various populations, identify high-risk groups, guide planning and evaluation of cancer control programs, help set priorities for allocating health resources, and advance clinical, epidemiologic, and health services research.” 1
Melanoma underreporting has been demonstrated in previous studies, with the percentage of underreported cases varying from 10.4% 11 to 70%.9 A longitudinal study of melanomas in Washington state found that underreporting of cutaneous melanomas increased from 2% to 21% over a 10-year period. 10 This trend prompted examination of this study’s data for a similar temporal trend, and none was found.
A 2008 study found that more melanoma cases were being diagnosed or treated at outpatient facilities. 9 Such facilities are prone to problems in reporting because they lack in-house reporting systems and knowledge of melanoma reporting requirements. 9 A 2011 study of
practicing dermatologists found that many failed to report melanomas to a registry, and more than half were unaware of the requirement. 12 Accordingly, underreporting is likely to continue. Results of the present study showed that melanoma underreporting was a major issue at VAPSHCS and that it could occur even in facilities that used in-house reporting systems and were aware of reporting requirements. The primary cause of underreporting was generation and use of local SNOMED codes that were unrecognizable by OncoTraX. A secondary cause was clerical error.
Discovery of unreported cases prompted facility review of procedures for reporting melanomas and expansion of current methods for melanoma discovery. All unreported cases have been entered into the VACCR, the Washington state registry, and the NCDB, which populate the national cancer registries. Contract registry staff were educated regarding melanoma reporting requirements, particularly requirements for melanoma in situ. The 87202 SNOMED code for melanoma in situ also has been added to VistA at VAPSHCS. A follow-up study will be conducted to ascertain whether the interventions have corrected the underreporting of melanoma.
