THERAPEUTIC AND DIAGNOSTIC FACTORS AS RELATED TO CANCER RISK

这一研究计划的一个主要重点是确定外源性激素与随后的癌症风险的关系。先前的研究表明，使用绝经期雌激素会增加乳腺癌发生的风险。然而，在诊断乳腺癌时使用替代雌激素的女性似乎经历了乳腺癌死亡率的降低。在一项大型筛查计划的背景下进行的分析表明，这并不是由于激素使用者较早发现肿瘤所致。瑞典筛查计划和一项创纪录的连锁研究中对激素替代疗法的分析表明，雌激素-孕激素联合疗法增加了风险，而不是单独使用雌激素。在筛查研究中，早期和晚期疾病的风险增加都很明显，孕激素受体阳性的风险比阴性肿瘤更大。激素使用与其他癌症(包括子宫内膜癌和肺癌)的关系也在探索中。口服避孕药对癌症风险的影响也在几项调查中得到了研究。在一项关于子宫腺癌的研究中，口服避孕药的使用似乎增加了原位肿瘤的风险。还在进行一项回溯性队列研究，以评估不同类型不孕症和暴露于促排卵药物后的癌症风险。在丹麦的一项比较研究中，正在研究使用这些药物后怀孕的儿童的癌症风险。最近完成的一项对接受隆乳手术的女性进行的回顾性队列研究的数据也在分析中。最近的一篇文献综述表明，人们对乳腺癌、肉瘤和包括多发性骨髓瘤在内的几种血液系统恶性肿瘤的可能关系感到担忧。对于乳腺癌，人们担心对发病率和预后的影响，因为乳房植入物已经被证明干扰了乳房X光检查病变的能力。一项对经历过缩胸手术的女性的研究也已经完成。目前正在进行分析，以检查手术中切除的组织数量是否与随后乳腺癌风险的降低有关。最后，正在努力评估与不同类型的妇科手术有关的几种癌症的风险。令人感兴趣的不仅是涉及卵巢切除的手术，还包括那些具有更微妙影响的手术，如输卵管结扎术。虽然这项手术与卵巢癌风险的显著降低有关，但它对其他肿瘤(如乳腺癌)的影响却鲜为人知。在一项基于人群的病例对照研究的背景下进行的初步分析并未证实乳腺癌手术的病因学作用。人类受试者和人类受试者：仅限采访、问卷调查或调查

A major emphasis of this program of research has been to define the relationship of exogenous hormones to subsequent cancer risk. Previous research has demonstrated an increased risk of incident breast cancer following usage of menopausal estrogens. However, women who use replacement estrogens at the time of diagnosis of a breast cancer appear to experience reductions in breast cancer mortality. An analysis within the context of a large screening program showed that this was not due to earlier detection of tumors among hormone users. Analyses of hormone replacement therapy within both the screening program and a record linkage study in Sweden showed that the combined estrogen-progestin regimen increased risk beyond that associated with estrogens alone. In the screening study, increases in risk were evident for both early and late- stage disease and were greater for progesterone receptor- positive than negative tumors. Relationships of hormone use with other cancers (including endometrial and lung) are also being explored. Effects of oral contraceptives on cancer risk have also been pursued in several investigations. In a study of cervical adenocarcinomas, use of oral contraceptives appeared to increase the risk of in situ tumors. Also underway is a retrospective cohort study to evaluate cancer risk following different types of infertility and exposure to ovulation- stimulating drugs. In a comparison study in Denmark, cancer risks among children conceived following use of these drugs is being pursued. Also under analysis are data from a recently completed retrospective cohort study of women who received augmentation mammoplasties. A recent review of the literature indicated concern about possible relationships with breast cancer, sarcomas, and several hematopoietic malignancies, including multiple myeloma. For breast cancer, there are concerns regarding effects on both incidence as well as prognosis, since breast implants have been shown to interfere with the ability to mammographically visualize lesions. A study of women who experienced breast reduction operations has also been completed. Analyses are currently underway to examine whether the amount of tissue removed during the operation relates to subsequent reductions in breast cancer risk. Finally, efforts are being made to assess risk of several cancers in relation to different types of gynecologic operations. Of interest are not only operations involving ovarian ablation but also those with more subtle effects, such as tubal ligation. Although this procedure has been linked with substantial decreases in the risk of ovarian cancers, its effects on other tumors (e.g., breast) are less well known. Preliminary analyses within the context of a population-based case-control study do not confirm an etiologic role for the procedure in breast cancer. Human Subjects & Human Subjects: Interview, Questionaires, or Surveys Only