Murphy Caitlin, Mukaro Violet, Tobler Robert, Asher Rebecca, Gibbs Emma, West Linda, Giuffre Bruno, Baron-Hay Sally, Khasraw Mustafa
University Hospital Geelong, Geelong, Victoria, Australia.
Department of Medicine, Deakin University, Geelong, Victoria, Australia.
Intern Med J. 2018 Jun;48(6):699-705. doi: 10.1111/imj.13617.
Magnetic resonance imaging (MRI) accuracy after neoadjuvant systemic therapy (NST) for breast cancer varies according to hormone receptor (HR), human epidermal growth factor receptor type-2 (HER2) subtype and Ki-67 proliferation index. Whether MRI accuracy varies by genomic signatures is unknown. We examined the accuracy of MRI in the NEONAB trial (Clinicaltrials.gov #: NCT01830244).
To examine the accuracy of MRI to predict pathological response to neoadjuvant therapy for breast cancer in the NEONAB trial.
Patients with stages II-III breast cancer received sequential epirubicin, cyclophosphamide and nab-paclitaxel and trastuzumab if they were HER2+. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated to assess the utility of preoperative MRI to predict pathological complete response (pCR). Bland-Altman plots were used to assess agreement between MRI and pathological assessment of residual disease.
MRI correctly predicted pCR in 64.1% of the cohort. Sensitivity and specificity were 52% and 78%, respectively; PPV 73% and NPV 58%. MRI predicted pCR most accurately in HER2-positive patients; sensitivity 58%, specificity 100%, PPV 100% and NPV 38%. MRI had higher PPV and NPV in tumours with Ki-67 ≥ 15% than tumours with Ki-67 < 15%, 75% versus 50% and 57.5% versus 50%, respectively. In this study, MRI underestimated residual tumour size by 1.65 mm (limits of agreement: 43.07-39.77 mm).
MRI appears more accurate for predicting pCR in HER2+ disease than other subtypes and in cancers with Ki-67 ≥ 15% compared to those with Ki-67 < 15%. Accuracy of MRI in our HR+, RS ≥ 25 cohort is comparable to previous reports of unselected HR+ disease. MRI post-NST should be interpreted in conjunction with HER2 status and Ki-67 index of the primary.
乳腺癌新辅助全身治疗（NST）后的磁共振成像（MRI）准确性因激素受体（HR）、人表皮生长因子受体2型（HER2）亚型和Ki-67增殖指数而异。MRI准确性是否因基因组特征而异尚不清楚。我们在NEONAB试验（Clinicaltrials.gov编号：NCT01830244）中研究了MRI的准确性。
在NEONAB试验中研究MRI预测乳腺癌新辅助治疗病理反应的准确性。
II-III期乳腺癌患者接受表柔比星、环磷酰胺和白蛋白结合型紫杉醇序贯治疗，HER2阳性患者加用曲妥珠单抗。计算敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV），以评估术前MRI预测病理完全缓解（pCR）的效用。采用Bland-Altman图评估MRI与残留疾病病理评估之间的一致性。
MRI正确预测了队列中64.1%的pCR。敏感性和特异性分别为52%和78%；PPV为73%，NPV为58%。MRI在HER2阳性患者中预测pCR最准确；敏感性58%，特异性100%，PPV 100%，NPV 38%。与Ki-67<15%的肿瘤相比，Ki-67≥15%的肿瘤中MRI的PPV和NPV更高，分别为75%对50%和57.5%对50%。在本研究中，MRI将残留肿瘤大小低估了1.65 mm（一致性界限：43.07-39.77 mm）。
与其他亚型相比，MRI在预测HER2阳性疾病的pCR方面似乎更准确，与Ki-67<15%的癌症相比，在Ki-67≥15%的癌症中更准确。我们HR+、RS≥25队列中MRI的准确性与先前未选择的HR+疾病报告相当。NST后的MRI应结合原发灶的HER2状态和Ki-67指数进行解释。
