CORRELATION OF THE SERUM LEVEL OF VITAMIN D AND RISK OF OVARIAN CANCER IN LAGOS
Introduction: Ovarian cancer is a very lethal gynaecological cancer with poorly understood preventive and prognostic outcome. Conflicting evidence exists among caucasians and other populations about the role of vitamin D deficiency in the evolution of ovarian cancer. However, little is known about the relationship of vitamin D levels and ovarian cancer in Nigeria.
Aim: To determine the relationship between serum vitamin D level and risk of ovarian cancer.
Study Design/Method: It was a case control study in which thirty five women with primary epithelial ovarian cancer and 35 apparently healthy women with no gynaecological cancer diagnosis were recruited as cases and controls respectively from 1st August 2016 to 31st May 2017. Their serum levels of 25-hydroxyvitamin D [25(OH)D] were determined using theCalbiotech 25(OH) vitamin D ELISA kit. Student’s t-test, Mann-Whitney U test andPearson’s Chi square were used to compare the mean, median and incidence of vitamin D levelsamong the cases and controls. Univariate and multivariate logistic regressions were utilised to further determine the relationship between vitamin D levels and the risk of ovarian cancer after controlling for confounding variables. The outcome measured was vitamin D deficiencydefined as: vitamin D ≤20ng/ml, insufficient: 21-29ng/ml; sufficient≥30ng/ml: Stata Version 13 statistical package (Stata I/C, StataCorp LP, Texas, USA) was used for the statistical analysis.
Result: The overall mean age of the cohort was 50.6(±11.1) years. The majority of ovarian cancer participants had serous cystadenocarcinoma (80%) and presented with late stage disease (94.3%). The incidence of vitamin D deficiency was high (62.9%) and it was found that theodds of developing ovarian cancer among women with vitamin D deficiency (≤20ng/ml) was
about four fold higher than in women with adequate vitamin D levels (p-value =0.049). It was also found that the median vitamin D level was lower in the cases as compared with the median vitamin D level of the controls. (13.5, 95%CI: 9.2 –21.2ng/ml Vs 20.0, 95% CI: 13 - 37.2, p- value = 0.0061).
Conclusion: This study revealed that low circulating 25(OH)D levels may be associated with the risk of epithelial ovarian cancer. The study also found a relatively high incidence of vitamin D deficiency among all the participants.
A future large prospective longitudinal study is recommended to further evaluate the association between serum vitamin D levels and epithelial ovarian cancers in women in Nigeria.