Hrushesky William J M, Sothern Robert B, Rietveld Wop J, Du Quiton Jovelyn, Boon Mathilde E
Department of Epidemiology and Biostatistics, Norman J. Arnold of Public Health, University of South Carolina, Columbia, SC 29209, USA.
Cancer Epidemiol Biomarkers Prev. 2005 Aug;14(8):1940-7. doi: 10.1158/1055-9965.EPI-04-0940.
Sunlight's UV B component, a known cellular immunosupressant, carcinogen, and activator of viral infections, is generally seasonally available. Venereal human papillomavirus (HPV) transmission, at least in part, causes cervical cancer. We have previously inspected the monthly rates of venereal HPV infection and sunlight fluency in Southern Holland over 16 consecutive years. Both peak in August with at least 2-fold seasonality. The amount of available sunlight and the rate of Papanicolaou (Pap) smear screen-detected HPV are positively correlated. We now investigate whether premalignant and malignant cervical epithelial changes are also seasonal and related to seasonal sunlight fluency.
We have studied >900,000 consecutive, serially independent, interpretable screening Pap smears obtained by a single cervical cancer screening laboratory in Leiden, Holland, during a continuous 16-year span from 1983 through 1998. The average monthly rates of premalignant and malignant epithelial change were inspected and the annual patterns contrasted to the annual pattern of sunlight fluency at this global location and to monthly average HPV infection rate. Because HPV is venereally transmitted, Dutch seasonal sexual behavior was evaluated by assessment of the annual pattern of Dutch conception frequency as a competing cause for cervical cancer seasonality.
(a) Twice as many premalignant and malignant epithelial changes were found among Pap smears obtained in the summer months, with an August peak concurrent with histopathologic evidence of HPV infection and sunlight fluency in Southern Holland. (b) Monthly sunlight fluency is correlated positively with both the monthly rates of Pap smear-detected cervical epithelial dysplasia and carcinomatous histopathology, as well as HPV. (c) Conception frequency, in this location, peaks in Spring not summer, and has a 4.8% annual amplitude.
(a) Cervical epithelial HPV infection and HPV-induced cervical epithelial dysplasia and carcinomatous change may each be novel sun exposure risks and thereby behaviorably avoidable. (b) Because screening Pap smears uncover many abnormalities that resolve spontaneously (false positives), these data may argue for screening and follow-up Pap smear examinations in seasons other than summer in the Northern Hemisphere, to diminish the false-positive smear rate. Global data are available to confirm and further test each of these conclusions.
阳光中的紫外线B成分是一种已知的细胞免疫抑制剂、致癌物和病毒感染激活剂，其可用性通常具有季节性。性传播的人乳头瘤病毒（HPV）传播至少在一定程度上会引发宫颈癌。我们之前连续16年调查了荷兰南部性传播HPV感染的月度发生率和阳光照射情况。两者均在8月达到峰值，季节性至少为2倍。可获得的阳光量与巴氏涂片筛查检测到的HPV发生率呈正相关。我们现在研究癌前和恶性宫颈上皮变化是否也具有季节性，并与季节性阳光照射情况相关。
我们研究了荷兰莱顿一个宫颈癌筛查实验室在1983年至1998年连续16年期间获得的超过90万份连续、独立、可解读的筛查巴氏涂片。检查了癌前和恶性上皮变化的月度平均发生率，并将年度模式与该地区阳光照射的年度模式以及月度平均HPV感染率进行对比。由于HPV是通过性传播的，通过评估荷兰受孕频率的年度模式作为宫颈癌季节性的一个竞争因素，来评估荷兰的季节性性行为。
（a）在夏季获得的巴氏涂片中发现的癌前和恶性上皮变化数量是其他季节的两倍，8月达到峰值，与荷兰南部HPV感染的组织病理学证据和阳光照射情况一致。（b）月度阳光照射情况与巴氏涂片检测到的宫颈上皮发育异常和癌组织病理学的月度发生率以及HPV均呈正相关。（c）该地区的受孕频率在春季而非夏季达到峰值，年振幅为4.8%。
（a）宫颈上皮HPV感染以及HPV诱导的宫颈上皮发育异常和癌变可能各自都是新的阳光暴露风险，因此在行为上是可以避免的。（b）由于筛查巴氏涂片会发现许多会自行消退的异常情况（假阳性），这些数据可能支持在北半球夏季以外的季节进行巴氏涂片筛查和后续检查，以降低假阳性涂片率。可获取全球数据来证实并进一步检验这些结论。
