Is the presence of edema and necrosis on T2WI pretreatment breast MRI the key to predict pCR of triple negative breast cancer?

• Published in: European radiology 2020-06, Vol.30 (6), p.3363-3370
• Main Authors: Harada, Taiyo L., Uematsu, Takayoshi, Nakashima, Kazuaki, Sugino, Takashi, Nishimura, Seiichirou, Takahashi, Kaoru, Hayashi, Tomomi, Tadokoro, Yukiko, Watanabe, Junichiro, Nakamoto, Shogo, Ito, Takahiro
• Format: Article
• Language: English
• Subjects: Adult; Aged; Antineoplastic Agents - therapeutic use; Biopsy; Breast; Breast - diagnostic imaging; Breast - pathology; Breast cancer; Breast Neoplasms - diagnostic imaging; Breast Neoplasms - drug therapy; Breast Neoplasms - pathology; Carcinoma, Ductal, Breast - diagnostic imaging; Carcinoma, Ductal, Breast - drug therapy; Carcinoma, Ductal, Breast - pathology; Chemotherapy; Classification; Correlation; Diagnostic Radiology; Edema; Edema - diagnostic imaging; Edema - pathology; Evaluation; Female; Humans; Imaging; Internal Medicine; Interventional Radiology; Invasiveness; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Medical imaging; Medicine; Medicine & Public Health; Middle Aged; Necrosis; Necrosis - diagnostic imaging; Necrosis - pathology; Neoadjuvant Therapy; Neuroradiology; Prognosis; Radiography; Radiology; Retrospective Studies; Triple Negative Breast Neoplasms - diagnostic imaging; Triple Negative Breast Neoplasms - drug therapy; Triple Negative Breast Neoplasms - pathology; Tumors; Ultrasound
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-020-06662-7

Purpose Given that a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) is an important prognostic factor, evaluating pretreatment imaging findings is important. Outcomes for triple negative breast cancer (TNBC) vary with the histological classification, indicating that this classification is clinically significant. In this study, we focus on the most common histological subtype of TNBC, invasive carcinoma of no special type (NST), to evaluate whether intramammary edema (intra-E) and intratumoral necrosis (intra-N) on T2-weighted magnetic resonance imaging (T2WI) is a useful predictor of pCR. Method We retrospectively included patients with biopsy-diagnosed TNBC-NST who received NAC between January 2014 and December 2017. Intra-E and intra-N were evaluated on T2WI before NAC. We grouped intra-E into no edema, peritumoral edema, prepectoral edema, and subcutaneous edema, and we defined intra-N as water-like signal intensity without enhancement on T2WI. We also evaluated tumor size, Ki-67 expression, and histological/nuclear grade, as well as their correlation with intra-E and intra-N. Results Fifty-seven patients with TNBC-NST were enrolled. There was no correlation with the rate of pCR and the presence of either intra-E or intra-N before NAC. Only intra-E and tumor size showed a positive correlation. Conclusions In patients with TNBC-NST, intra-E and intra-N did not correlate with pCR, but intra-E did positively correlate with tumor size. NST may exhibit a greater response to NAC, regardless of whether intra-E or intra-N is present or not on the pretreatment MRI. Key Points • Pathological complete response in TNBC-NST had no correlation with intramammary edema or intratumoral necrosis. • NAC may be justified in TNBC-NST even in the presence of edema or necrosis. • The extension of edema correlated with tumor size of TNBC-NST.