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2017年8月14日，《美国医学会杂志内科学分册》在线发表德克萨斯大学达拉斯西南医学中心、帕克兰医院的病例分析：早期乳腺癌没有必要为了分期而进行的影像学检查。
病例介绍 患者女性，60多岁，葡萄糖耐量异常、退行性膝关节炎，常规筛查乳腺钼靶见右乳房9点钟位置1cm大小钙化区，右乳房和腋窝超声检查确定相应部位8×6×8mm低回声块，边缘不清，无腋窝淋巴结肿大。患者无其他主诉，无任何个人或家族癌症史，无长期用药史。体检乳房对称，未扪及肿块或淋巴结，皮肤或乳头无变化。组织活检示浸润性导管癌（雌激素受体阳性、人表皮生长因子受体2阳性）。诊断：临床T1N0M0（1A期）乳腺癌。常规实验室化验未见异常。为分期对胸部、腹部、骨盆进行多种影像学检查，包括同位素骨扫描、增强计算机断层扫描（CT），未见明确转移证据，仅见左肾上腺1.8cm大小结节。为了更好地明确该结节，进行腹部磁共振扫描，结果表明可能为腺瘤。为了评估肾上腺功能，进行生化检查（地塞米松抑制试验、血浆肾上腺素水平测定），结果为阴性。 患者接受了乳房切除术，无并发症，无淋巴结病变证据，病理分析切缘阴性。术后接受辅助化疗、曲妥珠单抗、阿那曲唑。6个月后，为了评定肾上腺结节状态，随访CT扫描，示其大小未变。诊断14个月后，患者继续接受阿那曲唑治疗，并保持缓解状态，无转移性疾病。 虽然为分期进行的影像学检查并未改变治疗方案，但是造成患者长期担心偶发病变引起转移性疾病，并接受了不必要的生化检查和影像学检查，所幸并未导致长时间的治疗延迟或不必要的创伤检查。 病例讨论 乳腺癌是全世界女性最常见的癌症。在临床上，使用TNM分期系统（肿瘤大小、累及淋巴结、转移）进行术前分期，包括病史、体检、实验室化验、针对乳腺的影像学检查（通常采用乳腺钼靶或超声检查）。 对于早期疾病仅限于乳腺、无或局限性淋巴结累及的患者，不需为分期进行其他影像学检查。美国临床肿瘤学会（ASCO）明智选择指南不推荐对无症状亚组患者进行其他检查【1】。对于导管原位癌、临床I或II期乳腺癌的无症状患者，缺乏证据支持为分期使用正电子发射断层扫描（PET）、CT或骨扫描。国家综合癌症网络（NCCN）指南【2】推荐对于晚期疾病患者（III～IV期）或有转移性疾病症状、体征或实验室数据（例如骨痛、病理性骨折、神经系统症状、肝功能化验异常）的患者考虑影像学检查。在一项评估2612例乳腺癌女性的英国研究中【3】，为分期进行CT扫描的0～I期乳腺癌患者未检出真正转移，其中假阳性病变占2.2%～2.6%。在ASCO指南发表前收集美国学术型医疗中心数据的另一项研究中【4】，为分期进行多种影像学检查并未使早期乳腺癌患者的分期上调，但是与37%的患者假阳性结果相关，造成其中40%需要进一步影像学检查或活检。 虽然现在的乳腺癌大部分需要进行多学科诊疗，但是首先被初级保健医生怀疑或诊断。他们可能并未意识到对无症状患者为分期进行常规影像学检查的不必要性。密歇根乳腺肿瘤学质量倡议（MiBOQI）分析了2008～2015年超过34000例早期乳腺癌患者，其中20.1%的患者为分期接受了影像学检查【5】。该不必要的影像学检查给每例患者造成直接和间接成本估计达5720美元【4】。除了沉重的经济负担，不必要的影像学检查可使患者无谓接触造影剂和辐射，无关紧要的检查结果还可引起患者严重焦虑。 本例患者被诊断为临床ⅠA期乳腺癌，但是为分期进行了不必要的影像学检查，不仅由于最初莫须有的全身探查转移性癌症引起严重情绪困扰，而且还由于检出偶发良性结节直至随访影像学检查显示毫无变化。该患者一开始不必要的影像学检查（同位素骨扫描、CT）如同瀑布一般引出多种影像学检查和生化检查。除了患者面临的情绪困扰，假阳性扫描结果可能导致抗肿瘤治疗启动延迟，同时进行其他影像学检查和创伤性手术探查异常。该病例表明遵从指南的重要性，以尽量减少对新诊断早期乳腺癌无症状患者的可能损害。 读者调查 参考文献
JAMA Intern Med. 2017 Aug 14. [Epub ahead of print] Unnecessary Staging Imaging in Early-Stage Breast Cancer: A Teachable Moment. Heather R. Wolfe; Arjun Gupta; Navid Sadeghi. University of Texas Southwestern Medical Center, Dallas; Parkland Hospital, Dallas, Texas. This Teachable Moment uses the details of a case report to evaluate the risks and benefits of staging imaging in early-stage breast cancer. STORY FROM THE FRONT LINES A woman in her 60s with impaired glucose tolerance and osteoarthritis of the knees presented to her primary care clinician after routine screening mammography revealed a 1-cm area of calcification at the 9-o'clock position of the right breast. Ultrasonography of the right breast and axilla identified an 8×6×8-mm hypoechoic mass with indistinct margins in the corresponding area, without evidence of axillary lymphadenopathy. She otherwise had no complaints, reported no personal or family history of cancer, and took no scheduled medications. Examination revealed symmetric breasts without palpable masses or lymph nodes, and no skin or nipple changes. A biopsy of this mass revealed invasive ductal carcinoma (estrogen receptor positive and human epidermal growth factor receptor 2 positive). She was diagnosed with clinical T1N0M0 (stage 1A) breast cancer. Routine laboratory analysis noted no abnormalities. Multimodality staging imaging, including a nuclear bone scan and contrast-enhanced computed tomography (CT) scans of the chest, abdomen, and pelvis revealed no clear evidence of metastasis, but a 1.8-cm left adrenal gland nodule was noted. A magnetic resonance scan of the abdomen was performed to better define this nodule, and results indicated a likely adenoma. Results of biochemical testing (dexamethasone suppression test and measured levels of plasma metanephrines), performed to evaluate the functionality of the adrenal lesion, were negative. The patient underwent an uncomplicated mastectomy without evidence of nodal disease and with negative margins on pathologic analysis. Adjuvant chemotherapy, trastuzumab, and anastrozole were administered. A follow-up CT scan was performed 6 months later to assess the status of the adrenal nodule, and it had remained stable in size. Fourteen months after diagnosis, the patient continued to receive anastrozole therapy and remained in remission without evidence of metastatic disease. Initial staging imaging did not alter management, led to prolonged patient anxiety regarding the possibility of metastatic disease due to an incidental lesion, and was followed by a needless cascade of biochemical testing and imaging, which fortunately did not result in prolonged treatment delay or unnecessary invasive investigation. TEACHABLE MOMENT Breast cancer is the most common cancer among women worldwide. It is clinically staged preoperatively with the TNM staging system (tumor size, node involvement, and metastasis) using history, examination, laboratory analysis, and focused breast imaging, usually with a mammogram or ultrasonography. Patients with early disease confined to the breast with no or limited lymph node involvement require no further staging imaging. The American Society of Clinical Oncology (ASCO) Choosing Wisely guidelines recommend against further workup in this subset of asymptomatic patients.[1] There is lack of evidence supporting the use of staging positron emission tomography, CT, or bone scans in asymptomatic patients with ductal carcinoma in situ, or clinical stage I or II breast cancer. The National Comprehensive Cancer Network guidelines[2] recommend reserving imaging in patients with advanced disease (stage III-IV), or in patients with signs, symptoms, or laboratory data concerning for metastatic disease (such as bone pain, pathological fracture, neurological symptoms or abnormal liver function tests). In a British study evaluating 2612 women with breast cancer,[3] staging CT scans detected true metastasis in no patients with stage 0 to I breast cancer, with false-positive lesions identified in 2.2% to 2.6% of these patients. In another study collecting data from an academic US medical center just before the publication of ASCO guidelines,[4] multimodality staging imaging resulted in upstaging of no patients with early-stage breast cancer but was associated with false-positive findings in 37% of patients, 40% of whom required further imaging or biopsies. Although breast cancer care is now largely multidisciplinary, it is often first suspected or diagnosed by primary care physicians. They may be unaware of the needlessness of routine staging imaging in otherwise asymptomatic patients. Analysis of over 34000 patients with early-stage breast cancer between 2008 and 2015 in the Michigan Breast Oncology Quality Initiative demonstrated that 20.1% of patients underwent staging imaging.[5] The direct and indirect costs of this unnecessary imaging has been estimated to be $5720 per patient.[4] Aside from this heavy financial burden, unnecessary imaging exposes patients to contrast and radiation, and incidental findings can induce significant anxiety. The present patient was diagnosed with clinical stage IA breast cancer but was subjected to unnecessary staging imaging. She experienced significant emotional distress not only from the initial unwarranted full-body exploration for metastatic cancer, but also from the detection of an incidentaloma, until follow-up imaging demonstrated stability. The "diagnostic cascade" of unnecessary imaging in this patient extended to further multimodality imaging and biochemical testing. Apart from the emotional distress faced by patients, false-positive scan results can lead to delays in initiating antineoplastic therapy while further imaging and invasive procedures are performed to investigate abnormalities. This case exemplifies the importance of compliance with guidelines to minimize the potential harms in otherwise asymptomatic patients with newly diagnosed early-stage breast cancer. REFERENCES
DOI: 10.1001/jamainternmed.2017.2785 |
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