The risk of cervical cancer in relation to serum concentrations of folate,vitamin B-12, and homocysteine

Due to its role in the synthesis and repair of DNA, folate may protect agai nst the development of cervical cancer. Prospective data on the possible as sociation between folate and cervical cancer have been lacking, There is al so a paucity of prospective evidence concerning the possible associations b etween cervical cancer and vitamin B-12, which shares pathways with folate, and homocysteine, a marker of low B vitamin concentrations. A nested case control study was conducted to prospectively evaluate the associations betw een cervical cancer and serum concentrations of folate, vitamin B-12, and h omocysteine, Among a community-based cohort of women who donated blood in 1 974 for a serum bank in Washington County, Maryland, 39 cases of cervical c ancer diagnosed between 1975 and mid-1990 were included in the study (13 ca ses of invasive cervical cancer and 26 cases of carcinoma in situ). Two con trols were matched to each case by age, race, and sex. Stored serum from th e cases and controls was assayed for folate, B-12, and homocysteine concent rations. For folate, adjusted odds ratios were 1.0, 0.62, and 0.60 for the low to high thirds of the serum concentrations, respectively, a trend in th e protective direction that was not statistically significant (P for trend = 0.42). Overall, the results for vitamin B-12 tended to mimic those for fo late, whereas the associations for homocysteine tended to be in the opposit e direction. None of the results of this study were statistically significa nt, but patterns of the associations are in accord with hypothesized mechan istic pathways concerning B vitamins and cervical cancer.