THERAPEUTIC AND DIAGNOSTIC FACTORS AS RELATED TO CANCER RISK

这个研究项目的一个主要重点是确定外源性激素与随后癌症风险的关系。先前的研究表明，使用绝经期雌激素会增加患乳腺癌的风险。然而，在诊断出乳腺癌时使用替代雌激素的妇女似乎经历了乳腺癌死亡率的降低。一项大型筛查项目的分析表明，这并不是因为在激素使用者中更早发现肿瘤。在筛查项目和瑞典的一项记录关联研究中对激素替代疗法的分析表明，雌激素-黄体酮联合治疗方案增加的风险超过了单独使用雌激素的风险。在筛查研究中，早期和晚期疾病的风险都明显增加，孕激素受体阳性的肿瘤比阴性的肿瘤风险更大。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进行了探讨。在一项宫颈腺癌的研究中，使用口服避孕药似乎增加了原位肿瘤的风险。同时正在进行的是一项回顾性队列研究，以评估不同类型的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患癌症的风险。最近完成的一项关于接受隆胸手术的女性的回顾性队列研究的数据也在分析之中。最近对文献的回顾表明了对乳腺癌、肉瘤和几种造血恶性肿瘤（包括多发性骨髓瘤）可能存在的关系的关注。对于乳腺癌而言，由于乳房植入物已被证明会干扰乳房x光检查显示病变的能力，因此人们担心其对发病率和预后的影响。一项针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卵巢消融手术，还有那些影响更细微的手术，如输卵管结扎。尽管这一过程与卵巢癌风险的大幅降低有关，但其对其他肿瘤（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该手术在乳腺癌中的病因学作用。人类受试者&人类受试者：仅采访、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