叶酸与宫颈癌关系的病例对照研究

目的探讨膳食叶酸、血清叶酸与宫颈癌的关系以及叶酸和人乳头瘤病毒(HPV)16在宫颈癌发生中的相互作用。方法采用以医院为基础的病例对照研究方法,对111例经病理学确诊的宫颈鳞癌新发病例和111例子宫肌瘤患者进行年龄、籍贯、居住地匹配,在收集宫颈癌相关因素的同时,采用食物频数问卷(FFQ)调查膳食叶酸摄入情况,利用特异PCR检测HPV16 DNA,血清叶酸采用RIA定量测定。结果官颈癌组HPV16感染率(61．26％)显著高于对照组(28．83％),调整OR 值4．95(95％CI:2．49-9．83);病例组膳食叶酸摄入量(5．00μg/kcal±0．41 μg／kcal)和血清叶酸水平 (1．79 ng／ml±1．42 ng／ml)均低于对照组(5．14μg／kcal±0．35μg/kcal,2．59 ng／ml±2．81 ng／ml),差异有统计学意义,特别是随着血清叶酸水平的降低,患宫颈癌的危险性增加(X2=17．37,P=0．000);血清叶酸水平较低同时伴有HPV16感染患宫颈癌的危险明显高于两者单独作用之和,交互作用检验有统计学意义(G=5．56,P=0．02)。结论叶酸缺乏可增加宫颈癌发生的危险。

A case-control study on the associatlou between folate and cervical cancer

OBJECTIVE: To evaluate the possible effects of folate on cervical carcinogenesis and the interaction of folate and human papillomaviruses 16 (HPV16). METHODS: A hospital-based case-control study was conducted. 111 hospitalized cases who were pathologically diagnosed of having cervical cancer and 111 controls identified with hysteromyoma that frequency-matched to cases on age, birth place and residential area. A 60-item food-frequency questionnaire (FFQ) were administered to estimate the consumption of dietary folate. HPV16 DNA in exfoliated cervical cell and serum folate were detected by special PCR and radioimmunoassay respectively. RESULTS: HPV16 infection rate in cases (61.26%) was significantly higher than that in controls (28.83%), with adjusted OR of 4.95(95% CI:2.49-9.83).The levels of dietary folate in cases (5.00 microg/kcal +/- 0.41 microg/kcal) were significantly lower than that in controls (5.14 microg/kcal +/- 0.35 microg/kcal), but the adjusted OR showing no statistical significance. However, serum folate in cases (1.79 ng/ml +/- 1.42 ng/ml) was significantly lower than that in controls(2.59 ng/ml +/- 2.81 ng/ml),and there were significantly increasing trend in the risk of cervical cancer with reducing level of serum folate (chi-squared trend test of P = 0.000). Meanwhile, low-level of serum folate and HPV16-infection showed significant interaction in the development of cervical cancer, with likelihood ratio test of G = 5.56, P = 0.02. CONCLUSION: Results indicated that low levels of folate might increase the risk of cervical cancer, and potential synergistic action might exist between low level of serum folate and HPV16 in the development of cervical cancer.