CERVICAL CANCER SCREENING EFFICACY IN OLDER WOMEN

通过巴氏涂片筛查宫颈癌，明显减轻了育龄妇女患宫颈癌的负担。不幸的是，在超过育龄的妇女中，宫颈筛查的有效性还不确定。我们建议使用病例对照研究设计来评估高龄妇女宫颈筛查的有效性。我们将比较在美国西北部两个大型健康维护组织之一登记的两组老年女性(55-79岁)之前使用巴氏涂片的情况。这项建议的总体目标是评估在老年妇女中，通过巴氏涂片对宫颈进行筛查可以在多大程度上降低宫颈癌的发病率。具体目标是：(1)确定筛查阴性后老年妇女浸润性宫颈癌的发生率；(2)比较患有浸润性宫颈癌的老年妇女和其他类似组没有这种情况的妇女的宫颈筛查史。病例将包括那些在1980-1997年间在团体健康合作社或Kaiser Permanente Northwest登记时患上浸润性宫颈癌的妇女。资格将仅限于连续注册七年的女性。对于每个病例，将从以前没有做过子宫切除的参与者中随机抽样三个对照，并在年龄和参加医疗计划的时间方面与病例匹配。将审查研究对象的医疗记录，以确定是否收到了巴氏涂片筛查和其他与患宫颈癌(即吸烟)风险有关的信息。将比较病例和对照组在肿瘤侵袭前可检测阶段的筛查历史。在一定程度上，筛查可以降低这一人群中宫颈癌的发病率，在先兆病变出现期间，但在癌症发生之前，在对照组中筛查的历史将比病例更常见。拟议研究的结果应该为建议继续(或扩大)对老年妇女进行宫颈筛查提供更坚实的基础，或者建议降低筛查水平，并将节省的成本分配给更有成效的健康促进手段。

Screening for cervical cancer, by means of the Pap smear, has demonstrably reduced the burden of cervical cancer among women of reproductive ages. Unfortunately, in women beyond the reproductive years the usefulness of cervical screening is uncertain. We propose to evaluate the efficacy of cervical screening in older women using a case-control study design. We will compare the prior use of the Pap smear in two groups of older women (55-79 years of age) enrolled at one of two, large, health maintenance organizations in the northwestern United States. The overall goal of this proposal is to assess, in older women, the degree to which screening of the uterine cervix, by means of a Pap smear, can reduce the incidence of cancer of the cervix. The specific aims are: (1) to determine the incidence of invasive cervical cancer in older women following a negative screening exam; and (2) to compare older women who develop invasive cervical cancer and an otherwise similar group of women without this condition for a history of cervical screening. Cases will consist of those women who developed invasive cervical cancer during 1980-1997 while enrolled at either Group Health Cooperative or Kaiser Permanente Northwest. Eligibility will be restricted to women with seven years of continuous enrollment. For each case, three controls will be randomly sampled from enrollees who have not previously had a hysterectomy and matched to cases on age and duration of enrollment in the health plan. Medical records of the study subjects will be reviewed to ascertain receipt of Pap smear screening and other information relevant to the risk of developing cervical cancer (i.e., smoking). Cases and controls will be compared for a history of screening during the pre-invasive detectable phase of the tumor. To the extent that screening leads to a reduced incidence of cervical cancer in this population, a history of screening - during the time period in which the precursor lesion is present, but prior to the development of cancer - will be more common in controls than cases. The results of the proposed study should provide a more solid basis either for recommending continued (or expanded) cervical screening of older women, or instead for a reduced level of screening and an allocation of the cost savings to more productive means of health promotion.