Center for Clinical Genetics and Genomics, Providence St. Joseph Health, Los Angeles, California.
Division of Genetics, Providence John Wayne Cancer Institute, Santa Monica, California.
Cancer Med. 2019 Mar;8(3):1306-1314. doi: 10.1002/cam4.1864. Epub 2019 Feb 7.
Despite a growing body of literature describing the geographic and sociodemographic distribution of cancer genetic testing, work focused on these domains in cancer genetic counseling is limited. Research describing the epidemiology of cancer genetic counseling has mainly focused on isolated populations, a single gender (women) and a single condition (hereditary breast and ovarian cancer). Study findings to date are contradictory, making it unclear what, if any, disparities in receipt of cancer genetic counseling exist.
Utilizing the 2015 National Health Interview Survey (NHIS)-a cross-sectional, in person interview survey collecting self-reported health data for the US population-geographic and sociodemographic factors were compared between those receiving genetic counseling and the national sample. Bivariate analysis and subsequent multivariable logistic regression were performed with stratification by cancer status (affected/unaffected). Reason for (eg, doctor recommended) and focus of (eg, breast/ovarian) genetic counseling were also assessed. To generate nationally representative estimates, all analyses were adjusted for survey weights.
An estimated 4.8 million individuals in the United States had cancer genetic counseling. On bivariate analysis, there were significant differences in proportions undergoing genetic counseling by sex, race/ethnicity, insurance, citizenship, education, age, and cancer status (P < 0.01). After adjustment, however, only female sex (Odds Ratio [OR]: 1.78 [95% CI: 1.18-2.67]) remained a significant predictor of genetic counseling among the affected. Among the unaffected, female sex (OR: 1.70 [1.30-2.21]), non-Hispanic black race (OR: 1.44 [1.02-2.05], reference: non-Hispanic white), graduate education (OR: 1.76 [1.03-2.98], reference: less than high school), and age (OR: 1.06 [1.01-1.11]) predicted higher rates of genetic counseling. An estimated 2.1 million individuals have undergone genetic counseling focused on breast/ovarian cancer, 1.3 million on colorectal cancer, and 1.4 million on "other" cancers. Of those receiving genetic counseling focused on breast/ovarian cancer, 3% were male and 97% female (breast cancer alone-4% male, 96% female); for colorectal cancer, 49% male and 51% female, and for "other" cancers, 60% male and 40% female. The majority of individuals receiving genetic counseling reported they did so because their doctor recommended it (66%), with smaller proportions describing self (12%), family (10%), or media (5%) influences as the primary reason.
This is the first study to depict the sociodemographic and geographic distribution of cancer genetic counseling at the national level. Despite perceived disparities in access, cancer genetic counseling in the United States appears to be accessed by individuals of diverse racial/ethnic backgrounds, with various insurance coverage and educational levels, and across a broad range of ages and geographic regions. The only sociodemographic factor that independently predicted receipt of genetic counseling across both the affected and unaffected population was sex. With physician recommendation as the predominant driver for counseling, targeting physician education, and awareness is crucial to utilization.
尽管越来越多的文献描述了癌症遗传检测的地理和社会人口分布，但在癌症遗传咨询领域的相关工作却很有限。描述癌症遗传咨询流行病学的研究主要集中在孤立的人群、单一的性别（女性）和单一的疾病（遗传性乳腺癌和卵巢癌）上。迄今为止的研究结果相互矛盾，使得是否存在任何差异（如果有的话）接受癌症遗传咨询的情况并不清楚。
利用 2015 年全国健康访谈调查（NHIS）——一项收集美国人口自我报告健康数据的横截面、面对面访谈调查——比较了接受遗传咨询者和全国样本的地理和社会人口统计学因素。采用双变量分析和随后的多变量逻辑回归，并按癌症状况（患病/未患病）进行分层。还评估了（例如，医生推荐）和（例如，乳腺癌/卵巢癌）遗传咨询的原因和重点。为了生成具有全国代表性的估计值，所有分析都根据调查权重进行了调整。
估计有 480 万美国人接受了癌症遗传咨询。在双变量分析中，按性别、种族/民族、保险、公民身份、教育、年龄和癌症状况进行比较，接受遗传咨询的比例存在显著差异（P<0.01）。然而，调整后，只有女性（优势比[OR]：1.78[95%置信区间：1.18-2.67]）仍然是患病者接受遗传咨询的显著预测因素。在未患病者中，女性（OR：1.70[1.30-2.21]）、非西班牙裔黑人（OR：1.44[1.02-2.05]，参考：非西班牙裔白人）、研究生教育（OR：1.76[1.03-2.98]，参考：低于高中学历）和年龄（OR：1.06[1.01-1.11]）预测更高的遗传咨询率。估计有 210 万人接受了针对乳腺癌/卵巢癌的遗传咨询，130 万人接受了针对结直肠癌的遗传咨询，140 万人接受了“其他”癌症的遗传咨询。在接受针对乳腺癌/卵巢癌的遗传咨询者中，3%为男性，97%为女性（乳腺癌单独治疗-4%为男性，96%为女性）；结直肠癌患者中，男性占 49%，女性占 51%，“其他”癌症患者中，男性占 60%，女性占 40%。大多数接受遗传咨询的人表示，他们是因为医生的建议（66%），而比例较小的人表示是因为自己（12%）、家人（10%）或媒体（5%）的影响。
这是第一项描述全国范围内癌症遗传咨询的社会人口统计学和地理分布的研究。尽管在获得机会方面存在差异，但美国的癌症遗传咨询似乎为不同种族/民族背景、各种保险覆盖范围和教育水平的个人提供，并涵盖了广泛的年龄和地理区域。唯一独立预测患病和未患病人群接受遗传咨询的社会人口统计学因素是性别。由于医生的建议是咨询的主要驱动因素，因此针对医生进行教育和提高认识至关重要。
