Wang L D, Qiu S L, Yang G R, Lipkin M, Newmark H L, Yang C S
Henan Institute of Medical Sciences, Henan Medical University, Zhengzhou, China.
Cancer Epidemiol Biomarkers Prev. 1993 Jan-Feb;2(1):71-8.
To determine whether dietary calcium supplementation affects esophageal precancerous lesions, 200 subjects with esophageal lesions in a high-risk area for esophageal cancer in China (Huixian, Henan) were randomly divided into 2 groups (100 subjects/group). Subjects in one group received an oral supplementation of calcium carbonate tablets (1200 mg of calcium daily), and subjects in the other group received placebo pills for 11 months. At the entry and the end of the trial, esophagoscopy was performed, and 2 or 3 biopsy specimens were taken from the middle and lower thirds of the esophagus and from macroscopic lesions, if any, of each subject for histopathology and cell proliferation analysis with deoxythymidine labeling. In comparison to normal epithelium, increased proliferative compartment size was observed in epithelia with hyperplasia or dysplasia. After the intervention, the percentage of individuals with "normal epithelium," "basal cell hyperplasia," "basal cell hyperplasia II," and "basal cell hyperplasia III and dysplasia" were 44, 31, 13, and 11% in the calcium group and 35, 39, 17, and 6% in the placebo group, respectively. The labeling index was 0.046 in the calcium group and 0.044 in the placebo group. After the intervention, the labeling index in basal cell layers 1 to 5, the major zone of cell proliferation, fell 38% in the calcium group and 44% in the placebo group from before the intervention. Therefore, in this study, calcium supplementation was not shown to have beneficial effects in alleviating precancerous lesions and abnormal cell proliferation patterns.
为了确定膳食补充钙是否会影响食管癌前病变，在中国食管癌高发地区（河南辉县）的200例食管病变患者被随机分为两组（每组100例）。一组患者口服碳酸钙片（每日补充1200毫克钙），另一组患者服用安慰剂，为期11个月。在试验开始时和结束时，进行食管镜检查，从每位受试者食管中下段以及肉眼可见病变部位（如有）采集2或3份活检标本，进行组织病理学检查和用脱氧胸苷标记法进行细胞增殖分析。与正常上皮相比，增生或发育异常的上皮中增殖区大小增加。干预后，钙组中“正常上皮”、“基底细胞增生”、“基底细胞增生II级”和“基底细胞增生III级及发育异常”的个体百分比分别为44%、31%、13%和11%，安慰剂组分别为35%、39%、17%和6%。钙组的标记指数为0.046，安慰剂组为0.044。干预后，细胞增殖主要区域即基底细胞层1至5层的标记指数在钙组中较干预前下降了38%，在安慰剂组中下降了44%。因此，在本研究中，未显示补充钙对缓解癌前病变和异常细胞增殖模式有有益作用。
