Future prospects of neoadjuvant chemotherapy in treatment of primary breast cancer

Progress and Future Trends in PET/CT and PET/MRI Molecular Imaging Approaches for Breast Cancer

Breast cancer is a major disease with high morbidity and mortality in women worldwide. Increased use of imaging biomarkers has been shown to add more information with clinical utility in the detection and evaluation of breast cancer. To date, numerous studies related to PET-based imaging in breast cancer have been published. Here, we review available studies on the clinical utility of different PET-based molecular imaging methods in breast cancer diagnosis, staging, distant-metastasis detection, therapeutic and prognostic prediction, and evaluation of therapeutic responses. For primary breast cancer, PET/MRI performed similarly to MRI but better than PET/CT. PET/CT and PET/MRI both have higher sensitivity than MRI in the detection of axillary and extra-axillary nodal metastases. For distant metastases, PET/CT has better performance in the detection of lung metastasis, while PET/MRI performs better in the liver and bone. Additionally, PET/CT is superior in terms of monitoring local recurrence. The progress in novel radiotracers and PET radiomics presents opportunities to reclassify tumors by combining their fine anatomical features with molecular characteristics and develop a beneficial pathway from bench to bedside to predict the treatment response and prognosis of breast cancer. However, further investigation is still needed before application of these modalities in clinical practice. In conclusion, PET-based imaging is not suitable for early-stage breast cancer, but it adds value in identifying regional nodal disease and distant metastases as an adjuvant to standard diagnostic imaging. Recent advances in imaging techniques would further widen the comprehensive and convergent applications of PET approaches in the clinical management of breast cancer.

Role of 18F-Flurodeoxyglucose Positron-Emission Tomography/Computed Tomography in the Evaluation of Early Response to Neoadjuvant Chemotherapy in Patients with Locally Advanced Triple-Negative Breast Cancer

Background:

Response evaluation in locally advanced breast cancer is done through different methods ranging from clinical examination to magnetic resonance imaging, however evaluation with positron-emission tomography/computed tomography (PET/CT) in now being incorporated for the response evaluation. The aim of the present study is to correlate response to neoadjuvant chemotherapy (NACT) with PET/CT scan.

Materials and Methods:

The present study is a retrospective analysis of 30 locally advanced, triple-negative breast cancer patients. PET/CT scan was done pretreatment and post three and six cycles of NACT and was correlated with pathologic complete response (pCR). Responding disease was considered when there was at least a 50% reduction in the longest diameter.

Results:

The median pretreatment size of the breast lesion in CT scan was 3.9 ± 2.3 cm (2–12 cm) and maximum standardized uptake value (SUVmax) on PET/CT was 8.5 ± 5.5 (2.9–24). Among the responders, the median decrease in size of lesion was 3.2 ± 1.3 cm and median reduction in SUV of the tumor among was −8.1 ± 5.4 and was statistically significant when compared with nonresponders (P < 0.001). CT scan has 66% accuracy and PET has 82% accuracy at post three cycles NACT in predicting the pathological response. PET/CT had higher sensitivity and specificity when compared with CT findings alone in response evaluation.

Conclusion:

PET/CT scan can be considered as a sensitive tool for predicting pCRs and further larger trials are required to establish these findings.

Development of a new subclavian arterial infusion chemotherapy method for locally or recurrent advanced breast cancer using an implanted catheter-port system after redistribution of arterial tumor supply

Locally or recurrent advanced breast cancers can receive arterial blood supply from various arteries, such as the internal thoracic artery (ITA), the lateral thoracic artery, and the other small arterial branches originating from the subclavian artery. Failure to catheterize and subsequent formation of collateral arterial blood supply from various arteries are some of the reasons why the response to conventional selective transarterial infusion chemotherapy is limited and variable. To overcome this problem, we developed a new subclavian arterial infusion chemotherapy method using an implanted catheter-port system after redistribution of arterial tumor blood supply by embolizing the ITA. We named this technique ("redistributed subclavian arterial infusion chemotherapy" (RESAIC)). Using RESAIC, patients can be treated on an outpatient basis for extended periods of time. Eleven patients underwent RESAIC, and the complete remission and partial response rate in 10 evaluable patients was 90%: complete remission [CR] n = 4, partial remission n = 4, stable disease n = 1, and not evaluable n = 1. Three of four patients with CR had no distant metastasis, and modified radical mastectomy was performed 1 month after conclusion of RESAIC. The resected specimens showed no residual cancer cells, and pathologically confirmed complete remission was diagnosed in each of these cases. Although temporary grade-3 myelosuppression was seen in three patients who were previously treated by systemic chemotherapy, there was no other drug-induced toxicity or procedure-related complications. RESAIC produced a better response and showed no major complications compared with other studies despite the advanced stage of the cancers.

Optimal Management of Primary Breast Cancer

The diagnosis and treatment of breast cancer have changed in response to not only new technologies but also cultural and social aspects of the disease. While breast-conserving surgery and adjuvant therapy are the preferred treatments for many breast cancers, neoadjuvant therapy is often used in advanced disease. In this review we examine the treatment options that are influenced by pathologic and clinical factors. Invasive breast cancer is a potentially curable disease if it is regarded and managed by a multidisciplinary approach from the outset.

Positron emission tomography using [(18)F]-fluorodeoxy-D-glucose to predict the pathologic response of breast cancer to primary chemotherapy

PURPOSE

To determine whether [(18)F]-fluorodeoxy-D-glucose ([(18)F]-FDG) positron emission tomography (PET) can predict the pathologic response of primary and metastatic breast cancer to chemotherapy.

PATIENTS AND METHODS

Thirty patients with noninflammatory, large (> 3 cm), or locally advanced breast cancers received eight doses of primary chemotherapy. Dynamic PET imaging was performed immediately before the first, second, and fifth doses and after the last dose of treatment. Primary tumors and involved axillary lymph nodes were identified, and the [(18)F]-FDG uptake values were calculated (expressed as semiquantitative dose uptake ratio [DUR] and influx constant [K]). Pathologic response was determined after chemotherapy by evaluation of surgical resection specimens.

RESULTS

Thirty-one primary breast lesions were identified. The mean pretreatment DUR values of the eight lesions that achieved a complete microscopic pathologic response were significantly (P =.037) higher than those from less responsive lesions. The mean reduction in DUR after the first pulse of chemotherapy was significantly greater in lesions that achieved a partial (P =.013), complete macroscopic (P =.003), or complete microscopic (P =.001) pathologic response. PET after a single pulse of chemotherapy was able to predict complete pathologic response with a sensitivity of 90% and a specificity of 74%. Eleven patients had pathologic evidence of lymph node metastases. Mean pretreatment DUR values in the metastatic lesions that responded did not differ significantly from those that failed to respond (P =.076). However, mean pretreatment K values were significantly higher in ultimately responsive cancers (P =.037). The mean change in DUR and K after the first pulse of chemotherapy was significantly greater in responding lesions (DUR, P =.038; K, P =.012).

CONCLUSION

[(18)F]-FDG PET imaging of primary and metastatic breast cancer after a single pulse of chemotherapy may be of value in the prediction of pathologic treatment response.