Jieun Kim1,2, Boo-Kyung Han3, Eun Young Ko1, Eun Sook Ko1, Ji Soo Choi1, Ko Woon Park1. 1. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea. 2. Department of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, South Korea. 3. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea. bkhan@skku.edu.
Abstract
OBJECTIVES: This study aimed to investigate the predictability of breast MRI for pathologic complete response (pCR) by molecular subtype in patients with breast cancer receiving neoadjuvant chemotherapy (NAC) and investigate the MRI findings that can mimic residual malignancy. METHODS: A total of 506 patients with breast cancer who underwent MRI after NAC and underwent surgery between January and December 2018 were included. Two breast radiologists dichotomized the post-NAC MRI findings as radiologic complete response (rCR) and no-rCR. The diagnostic performance of MRI predicting pCR was evaluated. pCR was determined based on the final pathology reports. Tumors were divided according to hormone receptor (HR) and human epidermal growth factor receptor (HER) 2. Residual lesions on post-NAC MRI were divided into overt and subtle which classified as nodularity or delayed enhancement. Pearson's χ2 and Wilcoxon rank-sum tests were used for MRI findings causing false-negative pCR. RESULTS: The overall pCR rate was 30.04%. The overall accuracy for predicting pCR using MRI was 76.68%. The accuracy was significantly different by subtypes (p < 0.001), as follows in descending order: HR - /HER2 - (85.63%), HR + /HER2 - (82.84%), HR + /HER2 + (69.37%), and HR - /HER2 + (62.38%). MRI in the HR - /HER2 + type showed the highest false-negative rate (18.81%) for predicting pCR. The subtle residual enhancement observed only in the delayed phase was associated with false-negative findings (76.2%, p = 0.016). CONCLUSIONS: The diagnostic accuracy of MRI for predicting pCR differed by molecular subtypes. When the residual enhancement on MRI after NAC is subtle and seen only in the delayed phase, overinterpretation of residual tumors should be performed with caution. KEY POINTS: • In patients with breast cancer after completion of neoadjuvant chemotherapy, the diagnostic accuracy of MRI for predicting pathologic complete response (pCR) differed according to molecular subtype. • When residual enhancement on MRI is subtle and seen only in the delayed phase, this finding could be associated with false-negative pCR results.
OBJECTIVES: This study aimed to investigate the predictability of breast MRI for pathologic complete response (pCR) by molecular subtype in patients with breast cancer receiving neoadjuvant chemotherapy (NAC) and investigate the MRI findings that can mimic residual malignancy. METHODS: A total of 506 patients with breast cancer who underwent MRI after NAC and underwent surgery between January and December 2018 were included. Two breast radiologists dichotomized the post-NAC MRI findings as radiologic complete response (rCR) and no-rCR. The diagnostic performance of MRI predicting pCR was evaluated. pCR was determined based on the final pathology reports. Tumors were divided according to hormone receptor (HR) and human epidermal growth factor receptor (HER) 2. Residual lesions on post-NAC MRI were divided into overt and subtle which classified as nodularity or delayed enhancement. Pearson's χ2 and Wilcoxon rank-sum tests were used for MRI findings causing false-negative pCR. RESULTS: The overall pCR rate was 30.04%. The overall accuracy for predicting pCR using MRI was 76.68%. The accuracy was significantly different by subtypes (p < 0.001), as follows in descending order: HR - /HER2 - (85.63%), HR + /HER2 - (82.84%), HR + /HER2 + (69.37%), and HR - /HER2 + (62.38%). MRI in the HR - /HER2 + type showed the highest false-negative rate (18.81%) for predicting pCR. The subtle residual enhancement observed only in the delayed phase was associated with false-negative findings (76.2%, p = 0.016). CONCLUSIONS: The diagnostic accuracy of MRI for predicting pCR differed by molecular subtypes. When the residual enhancement on MRI after NAC is subtle and seen only in the delayed phase, overinterpretation of residual tumors should be performed with caution. KEY POINTS: • In patients with breast cancer after completion of neoadjuvant chemotherapy, the diagnostic accuracy of MRI for predicting pathologic complete response (pCR) differed according to molecular subtype. • When residual enhancement on MRI is subtle and seen only in the delayed phase, this finding could be associated with false-negative pCR results.
Authors: Bryan T Hennessy; Gabriel N Hortobagyi; Roman Rouzier; Henry Kuerer; Nour Sneige; Aman U Buzdar; Shu Wan Kau; Bruno Fornage; Aysegul Sahin; Kristine Broglio; S Eva Singletary; Vicente Valero Journal: J Clin Oncol Date: 2005-12-20 Impact factor: 44.544
Authors: Jennifer F De Los Santos; Alan Cantor; Keith D Amos; Andres Forero; Mehra Golshan; Janet K Horton; Clifford A Hudis; Nola M Hylton; Kandace McGuire; Funda Meric-Bernstam; Ingrid M Meszoely; Rita Nanda; E Shelley Hwang Journal: Cancer Date: 2013-02-21 Impact factor: 6.860
Authors: Joseph J Weber; Maxine S Jochelson; Anne Eaton; Emily C Zabor; Andrea V Barrio; Mary L Gemignani; Melissa Pilewskie; Kimberly J Van Zee; Monica Morrow; Mahmoud El-Tamer Journal: J Am Coll Surg Date: 2017-09-15 Impact factor: 6.113
Authors: Laura S Dominici; Viviana M Negron Gonzalez; Aman U Buzdar; Anthony Lucci; Elizabeth A Mittendorf; Huong T Le-Petross; Gildy V Babiera; Funda Meric-Bernstam; Kelly K Hunt; Henry M Kuerer Journal: Cancer Date: 2010-06-15 Impact factor: 6.860
Authors: J A van der Hage; C J van de Velde; J P Julien; M Tubiana-Hulin; C Vandervelden; L Duchateau Journal: J Clin Oncol Date: 2001-11-15 Impact factor: 44.544
Authors: D A Cameron; E D Anderson; P Levack; R A Hawkins; T J Anderson; R C Leonard; A P Forrest; U Chetty Journal: Br J Cancer Date: 1997 Impact factor: 7.640
Authors: Judy C Boughey; Vera J Suman; Elizabeth A Mittendorf; Gretchen M Ahrendt; Lee G Wilke; Bret Taback; A Marilyn Leitch; Henry M Kuerer; Monet Bowling; Teresa S Flippo-Morton; David R Byrd; David W Ollila; Thomas B Julian; Sarah A McLaughlin; Linda McCall; W Fraser Symmans; Huong T Le-Petross; Bruce G Haffty; Thomas A Buchholz; Heidi Nelson; Kelly K Hunt Journal: JAMA Date: 2013-10-09 Impact factor: 56.272
Authors: Priya Rastogi; Stewart J Anderson; Harry D Bear; Charles E Geyer; Morton S Kahlenberg; André Robidoux; Richard G Margolese; James L Hoehn; Victor G Vogel; Shaker R Dakhil; Deimante Tamkus; Karen M King; Eduardo R Pajon; Mary Johanna Wright; Jean Robert; Soonmyung Paik; Eleftherios P Mamounas; Norman Wolmark Journal: J Clin Oncol Date: 2008-02-10 Impact factor: 44.544
Authors: Julie R Gralow; Harold J Burstein; William Wood; Gabriel N Hortobagyi; Luca Gianni; Gunter von Minckwitz; Aman U Buzdar; Ian E Smith; William F Symmans; Baljit Singh; Eric P Winer Journal: J Clin Oncol Date: 2008-02-10 Impact factor: 44.544