Upper Gastrointestinal Research (UGIR), Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
Eur J Cancer. 2010 Apr;46(6):1093-100. doi: 10.1016/j.ejca.2010.01.029. Epub 2010 Feb 24.
Oesophageal and gastric adenocarcinoma share a male predominance not seen for other adenocarcinomas of the gastrointestinal tract. These sex differences are not explained by known risk factors. An endogenous factor, such as premenopausal oestrogen exposure, may act protectively in favour of women and might be detected by scrutinising sex ratios and incidence rates stratified by age.
The Swedish Cancer Register was used to collect primary oesophageal, gastric cardia, non-cardia gastric, colonic and pancreatic adenocarcinoma cases aged 25-84, during the study period of 1970-2006. Cases were divided into five-year age groups and crude incidence rates and male: female ratios were calculated. Evaluating potential time period effect, the corresponding results from 1970-1986 and 1987-2006 were also derived.
The sex ratio for oesophageal adenocarcinoma ranged from approximately 10:1 to 4:1, presenting a seemingly consistent decline with age. The sex ratio for non-cardia gastric adenocarcinoma, however, increased with age to reach 2:1 at a point one to two decades after menopause, where the ratio levelled off and eventually declined. There was no discernible time period effect concerning any type of adenocarcinoma. The ratios for gastric cardia, colonic and pancreatic adenocarcinoma were stable with age.
This study indicates separate patterns of age-dependency of the sex difference in oesophageal and non-cardia gastric adenocarcinoma incidence. The non-cardia gastric adenocarcinoma pattern might be due to a protective effect during premenopausal years for the female population, while the seemingly steady decline in sex ratio in oesophageal adenocarcinoma indicates a mechanism independent of menopause.
食管和胃腺癌与胃肠道其他腺癌不同，其发病率男性高于女性。这些性别差异不能用已知的危险因素来解释。一种内源性因素，如绝经前雌激素暴露，可能对女性有保护作用，可以通过仔细观察按年龄分层的性别比例和发病率来发现。
利用瑞典癌症登记处收集了 1970 年至 2006 年期间年龄在 25-84 岁的原发性食管、胃贲门、非贲门胃、结肠和胰腺腺癌病例。病例分为 5 岁一个年龄组，计算了粗发病率和男女比例。为评估潜在的时间效应，还得出了 1970-1986 年和 1987-2006 年相应的结果。
食管腺癌的性别比约为 10:1 至 4:1，随着年龄的增长呈明显下降趋势。然而，非贲门胃腺癌的性别比随着年龄的增长而增加，在绝经后一到二十年达到 2:1，之后该比例趋于稳定，最终下降。任何类型的腺癌都没有明显的时间效应。胃贲门、结肠和胰腺腺癌的比例随年龄变化而稳定。
本研究表明食管和非贲门胃腺癌发病率性别差异的年龄依赖性存在不同模式。非贲门胃腺癌的模式可能是由于女性在绝经前有保护作用，而食管腺癌性别比例的稳定下降则表明存在与绝经无关的机制。
