The role of molecular breast imaging in predicting complete tumor response to treatment and residual tumor extent following neoadjuvant therapy

Abstract

The aim of the present study was to investigate the usefulness of molecular breast imaging (MBI) in predicting complete tumor response to treatment and residual tumor extent following neoadjuvant therapy. A consecutive series of 43 female patients with large or locally advanced primary breast cancer, scheduled for surgery following neoadjuvant therapy, was retrospectively reviewed. Prior to surgery, all patients underwent MBI using a high-resolution semiconductor-based device for image acquisition. MBI data were correlated with surgical histopathological findings. Spearman's correlation coefficient was calculated to assess differences in residual tumor size with MBI and histopathological examination. From the images obtained using MBI, 7 patients were negative for residual tumors with pathological complete response (specificity, 100%) and positive in 34/36 patients with residual disease (sensitivity, 94.4%), including 26/27 patients with unifocal and 8/9 patients with multicentric/multifocal tumors, 5 of which exhibited multiple microscopic foci scattered in a fibrotic area. Overall accuracy was 95.3% and the positive predictive value (PPV) and negative predictive value (NPV) were 100 and 77.8%, respectively. MBI was false-negative in one patient with a 2.5-cm invasive ductal carcinoma located close to the chest wall and in one patient with microscopic foci of epithelial carcinoma. In the patients with unifocal residual tumors, correlation of tumor size between MBI and histopathology was r=0.981 (P<0.0001); however, MBI overestimated the number of lesions in one of these cases. In the patients with multifocal/multicentric tumors, MBI adequately assessed residual tumor extent in 5/8 positive cases, overestimating the number of lesions in one case and underestimating tumor extent in 2 further cases with microscopic foci scattered in a fibrotic area. MBI proved to be a highly accurate diagnostic tool in predicting complete tumor response to neoadjuvant therapy and residual tumor extent, correlating with surgical histopathological findings in 86% of overall cases. A positive result was always associated with the presence of residual disease and MBI tumor size was strongly correlated with histopathological analysis mainly in unifocal residual tumors.

Radionuclide-Based Imaging of Breast Cancer: State of the Art

“…The results indicated that BSGI is highly sensitive for the detection of BI-RADS 4 category lesions, achieving good positive/negative predictive values, and is superior to ultrasound and mammography for invasive ductal carcinomas. A recent retrospective review summarized that MBI with 99m Tc-tetrofosmin using a high-resolution, solid-state dedicated breast camera was a highly accurate diagnostic tool in predicting the complete tumor response to neoadjuvant therapy and residual tumor extent [ 140 ].…”

The residual cancer burden index as a valid prognostic indicator in breast cancer after neoadjuvant chemotherapy

“…Currently, Neoadjuvant chemotherapy (NAC) is recognized as an indispensable treatment option for locally advanced breast cancer [ 6 , 7 ].The principal role of NAC is to downstage cancers, so that inoperable patients can undergo surgery, or patients who are not suitable for breast-conserving surgery (BCS) can obtain breast-conserving opportunities to satisfy their aesthetic needs. In addition, the response to NAC can be used to evaluate drug sensitivity and guide follow-up adjuvant therapy [ 8 – 10 ]. Patients who achieve pathologic complete response (pCR) after NAC may have a long-term survival benefit, although differences have been observed among breast cancer subtypes [ 11 ].…”

The Residual Cancer Burden index as a valid prognostic indicator in breast cancer after Neoadjuvant chemotherapy

“…Currently, Neoadjuvant chemotherapy (NAC) is recognized as an indispensable treatment option for highrisk breast cancer [6,7].The principal role of NAC is to downstage cancers, so that inoperable patients can undergo surgery, or patients who are not suitable for breast-conserving surgery (BCS) can obtain breastconserving opportunities to satisfy their aesthetic needs. In addition, the response to NAC can be used to evaluate drug sensitivity and guide follow-up adjuvant therapy [8][9][10]. Patients who achieve pathologic complete response (pCR) after NAC may have a long-term survival bene t, although differences have been observed among breast cancer subtypes [11].…”