Comparison of longevity and common tumor profiles between Sprague-Dawley and Han Wistar rats

The Sprague Dawley (SD) and Han Wistar (HW) are the two most commonly used rat strains in Europe and the US, with the Han Wistar increasing in popularity because of its greater longevity and lower tumor burden. This survey was undertaken at Covance CRS (Huntingdon and Eye) to compare in-house longevity and common spontaneous tumor profiles of the two strains with published data. Data were compiled from 104-week studies started between 2010 and 2017. Mean survival was greater for both sexes of HWs when compared with SDs. Pituitary tumors were the commonest in both strains, with slightly higher incidences and more malignant tumors in SDs of both sexes. Mammary tumors were the second most common tumor in both strains; the incidence being greater in SDs compared to HWs. Benign pheochromocytomas of the adrenal and fibromas of the skin/subcutis were commoner in male SDs than in HWs. Granular cell tumors of the uterine tract were recorded only in SDs, but uterine stromal and glandular tumors were more common in HWs, which also displayed a higher incidence of granulosa cell tumors of the ovaries. Vascular tumors of the mesenteric lymph nodes, thymomas and follicular cell tumors of the thyroids were recorded at a higher incidence in HWs than in SDs. Tumor profiles of other common tumors were broadly similar between the two strains. The results of this survey correlate closely with similar comparisons made at other laboratories, and with data compiled at our laboratories 10 years ago and published as a poster.