No large previous study had compared c-kit genotype in mastocytosis according to age of onset.
These findings are in accordance with a large previous study by Yang et al. in which 50 patients were enrolled [ 14].
The complete absence of ACA and the occasional presence of ATA described in a large previous study that focused on anti-Ku in patients with SSc [ 17] were nicely reproduced in our cohort (Table 3).
For men, our finding of positive associations for cancers of the colon, rectum, and prostate are consistent with the only large previous study on all-sites cancer that included both women and men, a Korean cohort study of 9,400 female and 23,700 male cancer cases [ 13].
8 Further, differences in healthcare services such as access to antenatal care might limit generalisability of the large previous study from the USA. 2 In Finland, with around 5.5 million residents, healthcare services are mainly publicly funded and all women have free access to antenatal care.
Interestingly, the largest previous studies of genetic risk from GSTM1 (n the Nurese Health Study; Keenan et al (19) was also based on population-based recruitment and was not sensitive to selection on long-time severity, and this study on 549 RA cases and controls, Keenan et al. [20] could not demonstrate any association between GSTM1 and development of RA.
Second, it included 1893 EIA-positive/culture-positive strain-typed cases, approximately double the largest previous studies (n = 1008 [ 5]; n = 715 [ 13]).
The two largest previous studies reported findings similar to ours with subnormal testosterone in 5% (Gerl et al, 2001) and 16% (Aass et al, 1991) of patients.
The two largest previous studies of VEGF polymorphisms and breast cancer [ 15, 19] also included prevalent breast cancer cases, and the extent to which survival bias might have affected their results is unclear.
PIK3CA mutations were identified in 151 (33.4%) of 452 primary breast tumors, in keeping with the results of the largest previous studies, showing mutation rates of 25%to40%0% [ 7, 8, 11, 14, 16, 18, 26- 30].
