The detection of pCR after PST by contrast-enhanced ultrasonography for breast cancer.
BACKGROUND
Primary systemic therapy (PST; such as chemotherapy) has been approved as the standard therapy. Breast-conserving surgery is involved in 60-70% of breast cancer operations, and cancer can spread in the period between the initial treatment and preoperative chemotherapy. To reduce the residual tumor in persistent disease of breast tissue, determining the margin including normal tissue when removing the tumor is very difficult. With the development of the color Doppler method, contrast-enhanced ultrasonography (CEUS) allows visualization of the tumor bloodstream. The availability and efficacy of CEUS for setting the resection margin in breast-conserving surgery were examined and compared with MRI imaging as tools for making decisions for breast-conserving surgery.


METHODS
One hundred seventy patients underwent breast cancer operations: 59 were PST(+) and 111 PST(-). Imaging studies, ultrasonography and MRI, to measure the size of the tumor were performed twice, before and after chemotherapy, for PST patients. This was carried out not only to measure the residual tumor size after PST, but also to detect whether pathologically complete response (pCR) had been achieved or not. Fifty-nine patients received CEUS after PST, and we determined the precision of CEUS and conventional US.


RESULTS
The sensitivity of CEUS for pCR was 80.0% (95% CI 0.571-0.88), specificity 98.0% (95% CI 0.933-0.996), positive predictive value 88.9% (95% CI 0.635-0.978) and negative predictive value 96.0% (95% CI 0.914-0.976). The difference between the pathological examination and ultrasonography, conventional ultrasonography and CEUS was -4.455 ± 2.02 and 2.582 ± 2.298 cm (95% CI -13.11 to -0.96, p = 0.0235); CEUS was near the diameter of the actual pathological examination.


CONCLUSIONS
Contrast-enhanced ultrasonography is suitable for the preoperative examination, especially after PST, to determine the resection margin before breast-conserving surgery and detects pCR, which can help to avoid surgical procedures in the future.
Department of Breast Oncology, Gunma Prefectural Cancer Center, 617-1 Takabayashi-nishi cho, Ota, Gunma, 373-8550, Japan. fujisawa@gunma-cc.jp
Tomomi
T
Fujisawa
Tomoko
T
Hirakata
Yasuhiro
Y
Yanagita
Misa
M
Iijima
Hiroyuki
H
Horikoshi
Koji
K
Takeuchi
Yumi
Y
Saitoh
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D003287:Contrast Media; D005260:Female; D005290:Ferric Compounds; D006801:Humans; D007501:Iron; D008279:Magnetic Resonance Imaging; D015412:Mastectomy, Segmental; D008875:Middle Aged; D010087:Oxides; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D016217:Ultrasonography, Mammary / Q000379:methods*
D003287:Contrast Media; D005290:Ferric Compounds; D010087:Oxides; C069727:Sonazoid; D007501:Iron