Muñoz N, Hayashi M, Bang L J, Wahrendorf J, Crespi M, Bosch F X
Unit of Field and Intervention Studies, International Agency for Research on Cancer, Lyon, France.
J Natl Cancer Inst. 1987 Oct;79(4):687-91.
A randomized double-blind intervention trial was done in Huixian, People's Republic of China, a population with a high incidence of esophageal cancer. The aim of the trial was to determine whether a once-a-week treatment with retinol (15 mg or 50,000 IU), riboflavin (200 mg), and zinc (50 mg) could result, after 1 year, in a lower prevalence of precancerous lesions of the esophagus in the group receiving the active treatment as compared with the prevalence in the group receiving a placebo. The results of the trial, published elsewhere, indicated that the treatment had no effect on the prevalence of precancerous lesions of the esophagus. In determining whether an effect could be detected when earlier end points are used, the prevalence of micronuclei was evaluated in exfoliated cells from the esophagus and from the buccal mucosa in the present study. In a subsample of 200 out of the original 610 study subjects, smears were taken from the buccal mucosa before and after treatment, and in 170 subjects esophageal smears were obtained during endoscopy only after treatment. The smears were fixed and kept at room temperature over 1 year before being evaluated for the presence of micronuclei by means of 4'-6-diamidino-2-phenylindole fluorescent staining. Smears from approximately half of the subjects were considered suitable for evaluation. No statistically significant difference in the prevalence of micronuclei in the buccal mucosa cells was observed before and after treatment (the mean percentage of micronucleated cells in the vitamin group upon first examination, before treatment started, 0.35%; 1 year after treatment, 0.31%) or between the treatment and the placebo group at the final examination. (The mean percentage of micronucleated cells in the vitamin-treated group was 0.31 and 0.39% in the placebo group.) However, a statistically significant reduction (P = .04) was observed in the prevalence of micronuclei in esophageal cells in the treatment group as compared to the placebo. (The mean percentage of micronucleated cells in the vitamin-treated group was 0.19%; it was 0.31% in the placebo group.
在中国食管癌高发地区辉县进行了一项随机双盲干预试验。该试验的目的是确定每周一次服用视黄醇（15毫克或50,000国际单位）、核黄素（200毫克）和锌（50毫克）治疗1年后，接受活性治疗组食管的癌前病变患病率是否低于接受安慰剂组。该试验结果已在其他地方发表，表明该治疗对食管的癌前病变患病率没有影响。在本研究中，为了确定使用更早的终点时是否能检测到效果，对食管和颊黏膜脱落细胞中的微核患病率进行了评估。在最初的610名研究对象中的200名子样本中，在治疗前后采集颊黏膜涂片，在170名研究对象中，仅在治疗后通过内窥镜检查获取食管涂片。涂片固定后在室温下保存1年以上，然后通过4′-6-二脒基-2-苯基吲哚荧光染色评估微核的存在情况。大约一半受试者的涂片被认为适合评估。治疗前后颊黏膜细胞微核患病率没有统计学上的显著差异（维生素组在治疗开始前首次检查时微核细胞的平均百分比为0.35%；治疗1年后为0.31%），在最终检查时治疗组和安慰剂组之间也没有差异。（维生素治疗组微核细胞的平均百分比为0.31%，安慰剂组为0.39%。）然而，与安慰剂组相比，治疗组食管细胞中的微核患病率有统计学上的显著降低（P = 0.04）。（维生素治疗组微核细胞的平均百分比为0.19%；安慰剂组为0.31%。
