美国癌症学会（ACS）公布乳腺癌筛查指南更新

　　美国癌症学会（ACS）建议女性在45岁时每年做一次乳腺癌筛查，如过了55岁，应每两年做一次筛查。

　　《美国医学会杂志》（JAMA）在10月20日发布了该新指南。这个指南与美国联邦预防医学工作组（USPSTF）发布的指南有很多共同点，后者是美国政府支持的专家小组，也建议50岁以上的女人每两年做一次乳腺癌筛查。

　　联邦医学工作组曾于2009年发布建议书，指出应减少乳腺癌筛查的频率，推迟筛查的年龄，因为他们的研究发现，早做乳腺癌筛查未必就更有好处，有可能被误诊为阳性，导致女性做不必要的额外检查，比如活组织切片检查。

　　当联邦医学工作组建议将乳腺癌筛查的年龄从40岁推迟到50岁时，很多团体，包括美国癌症学会，都对此提出了激烈的反对意见，谴责这个变动。有些专家认为这将导致很多女性死于乳腺癌。

　　今年4月，联邦医学工作组重新拟定了建议书，但是并没有指出女性应在40多岁时就开始筛查乳腺癌，而是建议根据本人及医生协商的结果来考虑是否进行筛查。

　　“这也就是说，建议书改变了那种‘放之四海而皆准’的统一建议，变得更加个人化，更加个性化了。这也就是医药未来的走向。”凯文·奥芬格尔博士说。他是纽约纪念斯隆-凯特琳癌症医院的主治医生，是该小组的负责人，负责新的美国癌症学会指南的制定工作。

　　新的癌症学会指南对乳腺癌筛查的好处与害处做了综合调查。调查发现，54岁以前的女性，如果每年做一次筛查，比两年做一次受益更多。奥芬格尔博士说，55岁以上的女性更适合做两年一次的筛查，因为这个年纪以上的女人乳房组织没那么致密了，当癌症进入终止期，其活动也就没那么活跃了。

　　美国癌症学会也建议，女性们只要仍旧健康，就应持续进行乳腺癌筛查。阿维斯·奥·康奈尔博士说，他是纽约罗切斯特医学中心大学的女性影像专业主任，他认为新的指南更加合理，替50岁以下的女人考虑得更加细致。“这些新指南为诊所和公共医学服务部门提供了更好的指南。”

　　两个指南都没有指出女性该何时去做筛查，也没有指出检查的次数。波士顿布莱汉姆女子医院的南希·基廷博士说。

　　布莱汉姆博士是新指南的合作者之一，她说，两个指南的差异表明，必须跟患者交谈，倾听她们自己对乳腺癌筛查的意愿。

　　新的美国癌症学会指南也建议，不要仅仅相信临床乳房检查，这是项人工检查，医生只检查乳房是否有硬块。他们强调做乳腺癌筛查的成本并不高。对于未保险过的女性来说，一次乳腺癌筛查的费用是300美金。

　　美国联邦预防医学工作组（USPSTF）对美国癌症学会出台的新指南所持的态度是，他们会复审此指南。

JAMA. 2015 Oct 20;314(15):1599-614

Breast Cancer Screening for Women at Average Risk: 2015 Guideline Update From the American Cancer Society.

Oeffinger KC, Fontham ET, Etzioni R, Herzig A, Michaelson JS, Shih YC, Walter LC, Church TR, Flowers CR, LaMonte SJ, Wolf AM, DeSantis C, Lortet-Tieulent J, Andrews K, Manassaram-Baptiste D, Saslow D, Smith RA, Brawley OW, Wender R.

Memorial Sloan Kettering Cancer Center, New York, New York.

Louisiana State University School of Public Health, New Orleans.

University of Washington and the Fred Hutchinson Cancer Research Center, Seattle.

Patient advocate, Troy, New York.

Massachusetts General Hospital and Harvard Medical School, Boston.

University of Texas MD Anderson Cancer Center, Houston.

University of California, San Francisco, and San Francisco VA Medical Center.

Masonic Cancer Center and the University of Minnesota, Minneapolis.

Emory University School of Medicine and Winship Cancer Institute, Atlanta, Georgia.

Independent retired physician and patient advocate.

University of Virginia School of Medicine, Charlottesville.

American Cancer Society, Atlanta, Georgia.

IMPORTANCE: Breast cancer is a leading cause of premature mortality among US women. Early detection has been shown to be associated with reduced breast cancer morbidity and mortality.

OBJECTIVE: To update the American Cancer Society (ACS) 2003 breast cancer screening guideline for women at average risk for breast cancer.

PROCESS: The ACS commissioned a systematic evidence review of the breast cancer screening literature to inform the update and a supplemental analysis of mammography registry data to address questions related to the screening interval. Formulation of recommendations was based on the quality of the evidence and judgment (incorporating values and preferences) about the balance of benefits and harms.

EVIDENCE SYNTHESIS: Screening mammography in women aged 40 to 69 years is associated with a reduction in breast cancer deaths across a range of study designs, and inferential evidence supports breast cancer screening for women 70 years and older who are in good health. Estimates of the cumulative lifetime risk of false-positive examination results are greater if screening begins at younger ages because of the greater number of mammograms, as well as the higher recall rate in younger women. The quality of the evidence for overdiagnosis is not sufficient to estimate a lifetime risk with confidence. Analysis examining the screening interval demonstrates more favorable tumor characteristics when premenopausal women are screened annually vs biennially. Evidence does not support routine clinical breast examination as a screening method for women at average risk.

RECOMMENDATIONS: The ACS recommends that women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 years (strong recommendation). Women aged 45 to 54 years should be screened annually (qualified recommendation). Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually (qualified recommendation). Women should have the opportunity to begin annual screening between the ages of 40 and 44 years (qualified recommendation). Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer (qualified recommendation). The ACS does not recommend clinical breast examination for breast cancer screening among average-risk women at any age (qualified recommendation).

CONCLUSIONS AND RELEVANCE: These updated ACS guidelines provide evidence-based recommendations for breast cancer screening for women at average risk of breast cancer. These recommendations should be considered by physicians and women in discussions about breast cancer screening.

PMID: 26501536

DOI: 10.1001/jama.2015.12783

JAMA. 2015 Oct 20;314(15):1615-34

Benefits and Harms of Breast Cancer Screening: A Systematic Review.

Myers ER, Moorman P, Gierisch JM, Havrilesky LJ, Grimm LJ, Ghate S, Davidson B, Mongtomery RC, Crowley MJ, McCrory DC, Kendrick A, Sanders GD.

Duke Clinical Research Institute, Durham, North Carolina.

Duke University School of Medicine, Durham, North Carolina.

Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical.

IMPORTANCE: Patients need to consider both benefits and harms of breast cancer screening.

OBJECTIVE: To systematically synthesize available evidence on the association of mammographic screening and clinical breast examination (CBE) at different ages and intervals with breast cancer mortality, overdiagnosis, false-positive biopsy findings, life expectancy, and quality-adjusted life expectancy.

EVIDENCE REVIEW: We searched PubMed (to March 6, 2014), CINAHL (to September 10, 2013), and PsycINFO (to September 10, 2013) for systematic reviews, randomized clinical trials (RCTs) (with no limit to publication date), and observational and modeling studies published after January 1, 2000, as well as systematic reviews of all study designs. Included studies (7 reviews, 10 RCTs, 72 observational, 1 modeling) provided evidence on the association between screening with mammography, CBE, or both and prespecified critical outcomes among women at average risk of breast cancer (no known genetic susceptibility, family history, previous breast neoplasia, or chest irradiation). We used summary estimates from existing reviews, supplemented by qualitative synthesis of studies not included in those reviews.

FINDINGS: Across all ages of women at average risk, pooled estimates of association between mammography screening and mortality reduction after 13 years of follow-up were similar for 3 meta-analyses of clinical trials (UK Independent Panel: relative risk [RR], 0.80 [95% CI, 0.73-0.89]; Canadian Task Force: RR, 0.82 [95% CI, 0.74-0.94]; Cochrane: RR, 0.81 [95% CI, 0.74-0.87]); were greater in a meta-analysis of cohort studies (RR, 0.75 [95% CI, 0.69 to 0.81]); and were comparable in a modeling study (CISNET; median RR equivalent among 7 models, 0.85 [range, 0.77-0.93]). Uncertainty remains about the magnitude of associated mortality reduction in the entire US population, among women 40 to 49 years, and with annual screening compared with biennial screening. There is uncertainty about the magnitude of overdiagnosis associated with different screening strategies, attributable in part to lack of consensus on methods of estimation and the importance of ductal carcinoma in situ in overdiagnosis. For women with a first mammography screening at age 40 years, estimated 10-year cumulative risk of a false-positive biopsy result was higher (7.0% [95% CI, 6.1%-7.8%]) for annual compared with biennial (4.8% [95% CI, 4.4%-5.2%]) screening. Although 10-year probabilities of false-positive biopsy results were similar for women beginning screening at age 50 years, indirect estimates of lifetime probability of false-positive results were lower. Evidence for the relationship between screening and life expectancy and quality-adjusted life expectancy was low in quality. There was no direct evidence for any additional mortality benefit associated with the addition of CBE to mammography, but observational evidence from the United States and Canada suggested an increase in false-positive findings compared with mammography alone, with both studies finding an estimated 55 additional false-positive findings per extra breast cancer detected with the addition of CBE.

CONCLUSIONS AND RELEVANCE: For women of all ages at average risk, screening was associated with a reduction in breast cancer mortality of approximately 20%, although there was uncertainty about quantitative estimates of outcomes for different breast cancer screening strategies in the United States. These findings and the related uncertainty should be considered when making recommendations based on judgments about the balance of benefits and harms of breast cancer screening.

PMID: 26501537

DOI: 10.1001/jama.2015.13183