Reappraisal of uterine sarcoma diagnosis in the Swedish Cancer Registry.

An investigation of over- and under-registration of uterine sarcomas in the Swedish Cancer Registry during the period 1958-1980 was carried out. A histopathologic review of a 10% sample (159 cases) revealed that 18% of the cases, the majority of which were benign leiomyomas, could not be reclassified as sarcomas. All 186 cases of uterine sarcoma treated at Radiumhemmet during the period 1958-1980 were found in the Cancer Registry, but only 90% as sarcomas. As a consequence of over- and under-registration of the sarcoma tumors, the estimated incidences will be affected. In this study, however, we could not find any time trend in the erroneous registration, which implies that comparisons in incidence over time would still be valid.