Malhotra S L
Med Hypotheses. 1976 Nov-Dec;2(6):279-81. doi: 10.1016/s0306-9877(76)80010-2.
Environmental rather than genetic factors appear to be responsible for the causation of cancers involving epithelial surfaces, especially oropharyngeal cancers, cancers of the gastro-intestinal tract, cancers of the liver and gall-bladder, cancers of the cervix uteri and lung cancers. Epithelial surfaces which have mucus-bearing cells are particularly prone, because if these mucus cells are surrounded by an alkaline milieu over a prolonged period, the mucous of the epithelial cells is rendered fluid and is removed from the cells, of which it forms an integral part. This leads to proliferative changes with metaplasia, cell-atypia and a very significant increase in mitotic activity. Such changes are a prelude to carcinogenesis. In the case of many oropharyngeal cancers in Asia and Africa it is the alkaline slaked lime in the betel quid which is responsible; in the case of gastric cancers it is the reflux of the alkaline duodenal contents into the stomach; in the case of colon it is the absence of roughage, cellulose and vegetable fibres from the diet; in the case of the cervix uteri it is the frequency of coitus which gives rise to a highly alkaline seminal fluid; and in the case of cancer lung it is the alkaline cigarette smoke.
环境因素而非遗传因素似乎是导致涉及上皮表面的癌症的原因，尤其是口咽癌、胃肠道癌、肝癌和胆囊癌、子宫颈癌和肺癌。具有含黏液细胞的上皮表面特别容易发生这种情况，因为如果这些黏液细胞长期处于碱性环境中，上皮细胞的黏液就会变成液体并从细胞中被清除，而黏液是细胞不可或缺的一部分。这会导致化生、细胞异型性以及有丝分裂活性显著增加的增殖性变化。这些变化是致癌作用的前奏。在亚洲和非洲，许多口咽癌是由槟榔中的碱性熟石灰导致的；胃癌是由十二指肠碱性内容物反流至胃引起的；结肠癌是由于饮食中缺乏粗粮、纤维素和植物纤维；子宫颈癌是由于性交频繁导致精液碱性过高；肺癌则是由碱性香烟烟雾引起的。
