"當以超音波優先評估乳房攝影發現之病灶,乳管原位癌術後高比率分期上升"

Abstract

研究目的 原始切片診斷為乳管原位癌的病灶，在完整手術後可能被升期為侵襲性乳癌，但目前沒有共識來預測此升期。在對於此病灶常規併行乳房超音波及乳房攝影的背景之下，此研究之目標為辨識出乳管原位癌術後升期的風險因子，並提出預測模型。 研究方法 在這個單一中心回溯性研究中，收納了初始切片診斷為乳管原位癌的個案 (2016年1月至2017年12月，最終樣本數共272病灶)。診斷方式涵蓋了超音波導引粗針切片檢查、乳房攝影導引真空輔助乳房切片檢查及細針定位乳房切片手術。所有的患者常規性的都會接受乳房超音波檢查；若可疑病灶為超音波可見，將優先考慮超音波導引粗針切片檢查。切片後初始診斷為乳管原位癌的患者，若手術後之最終診斷為侵襲性乳癌，則定義為「升期」。 研究結果 超音波導引粗針切片檢查、乳房攝影導引真空輔助乳房切片檢查及細針定位乳房切片手術診斷之乳管原位癌，術後升期比率分別為70.5%、9.7%及4.8%。分析結果顯示，「以超音波導引粗針切片檢查診斷」、「超音波下之病灶尺寸」及「病理高級別的乳管原位癌 (high-grade DCIS)」為最主要之獨立風險預測因子。我們並以這些因子建立了羅吉斯回歸預測模型，接收者操作特徵曲線 (ROC curve) 分析得到良好的內部驗證結果，曲線下面積為0.88。 結論 我們優先考慮以超音波導引切片檢查可疑病灶，可能因此造成病灶的事前分類。超音波不可見之病灶 (通常以乳房攝影導引相關切片技術進行診斷) 術後升期風險低，在首次治療性手術可以免行前哨淋巴結切片。對於以超音波導引粗針切片診斷之乳管原位癌，在手術前須進行個別討論，預測模型可協助外科醫師決策：是否須在首次手術併行前哨淋巴結切片？或是使用真空輔助乳房切片再次進行取樣診斷？

Rationale and Objectives The initial diagnosis of ductal carcinoma in situ (DCIS) can be upstaged to invasive cancer after definitive surgery, although there is no consensus to predict upstaging. This study aimed to identify risk factors for DCIS upstaging using routine breast ultrasonography (US) and mammography (MG) and propose a prediction model. Materials and Methods In this single-center retrospective study, patients initially diagnosed with DCIS (January 2016–December 2017) were enrolled (final sample size = 272 lesions). Diagnostic modalities included ultrasound-guided core needle biopsy (US-CNB), MG-guided vacuum-assisted breast biopsy (MG-VAB), and wire localized surgical biopsy (WLSB). Breast ultrasonography was routinely performed for all patients. US-CNB was prioritized for lesions visible on ultrasound. Lesions initially diagnosed as DCIS on biopsy with a final diagnosis of invasive cancer at definitive surgery were defined as “upstaged.” Results The postoperative upstaging rates were 70.5%, 9.7%, and 4.8% in the US-CNB, MG-VAB, and WLSB groups, respectively. US-CNB, ultrasonographic lesion size, and high-grade DCIS were independent predictive factors for postoperative upstaging, which were used to construct a logistic regression model. Receiver operating characteristic analysis showed good internal validation (area under the curve = 0.88). Conclusions Prioritization of US-CNB possibly contributes to lesion stratification. The low upstaging rate for ultrasound-invisible DCIS diagnosed by MG-guided procedures suggests that it is unnecessary to perform sentinel lymph node biopsy (SLNB) for lesions invisible on ultrasound. Case-by-case evaluation of DCIS detected by US-CNB can help surgeons determine if repeating biopsy with VAB is necessary or if SLNB should accompany breast-preserving surgery.