Impact of MRI-evaluated neoadjuvant chemotherapy response on change of surgical recommendation in breast cancer.
OBJECTIVE
To investigate how MRI imaging of neoadjuvant chemotherapy (NAC) tumor response affects the recommendation for optimal breast cancer surgery, both before and after NAC.


BACKGROUND
Understanding how imaging findings are incorporated into surgeons' decision-making processes will help establish appropriate imaging guidelines for recommending breast conservation surgery (BCS) after the NAC.


METHODS
Seventy-six breast cancer patients undergoing NAC with MRI follow-up studies were analyzed. Two experienced breast surgeons reviewed all cases. An initial surgical recommendation was made based on the pre-NAC lesion presentation; a subsequent surgical recommendation was made based on the post-NAC tumor response. Finally, the pathology results were disclosed and the surgeons were asked to decide on the optimal definitive surgical procedure. MRI findings throughout the entire course of the NAC were analyzed to understand how they affected different recommendations.


RESULTS
Before the NAC, a large tumor size or extent of disease were the primary determinant factors for mastectomy. In this study, the mean tumor size was 5.3 +/- 3.4 cm (RECIST) in the mastectomy group and 3.2 +/- 1.6 cm in the lumpectomy group (P = 0.0001). After the NAC, based on consensus recommendations, 21 mastectomy candidates remained for mastectomy, with tumor size decreasing from 7.4 +/- 4.5 to 1.5 +/- 2.5 cm, and 22 mastectomy candidates were changed to lumpectomy, with tumor size decreasing from 4.2 +/- 2.1 to 0.4 +/- 0.6 cm. When the final pathology revealed pCR or minimal residual disease, the surgeons agreed that BCS is the optimal procedure. On the other hand, for a large extent of residual disease, mastectomy should be performed.


CONCLUSIONS
In patients who had more extensive pretreatment disease, despite an excellent response to NAC, the surgeons still tended to apply an aggressive approach and recommended mastectomy. Given that the confirmation of pCR or minimal residual disease would change surgeons' recommendations for less aggressive, conservation surgery, the maturity of MRI for NAC response prediction may provide reliable staging information to aid in the recommendation of the optimal surgical procedure.
Chen
Jeon-Hor
JH
Tu and Yuen Center for Functional Onco-Imaging, University of California, Irvine, California 92697-5020, USA.
Feig
Byron A
BA
Hsiang
David J-B
DJ
Butler
John A
JA
Mehta
Rita S
RS
Bahri
Shadfar
S
Nalcioglu
Orhan
O
Su
Min-Ying
MY
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy*; D003657:Decision Making; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008408:Mastectomy; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D012074:Remission Induction
D000970:Antineoplastic Agents