Diagnosis of pathological complete response to neoadjuvant chemotherapy in breast cancer by minimal invasive biopsy techniques.

BACKGROUND: Neoadjuvant chemotherapy (NACT) is widely used as an efficient breast cancer treatment. Ideally, a pathological complete response (pCR) can be achieved. Up to date, there is no reliable way of predicting a pCR. For the first time, we explore the ability of minimal invasive biopsy (MIB) techniques to diagnose pCR in patients with clinical complete response (cCR) to NACT in this study. This question is of high clinical relevance because a reliable pCR prediction could have direct implications for clinical practice. METHODS: In all, 164 patients were included in this review-board approved, multicenter pooled analysis of prospectively assembled data. Core-cut (CC)-MIB or vacuum-assisted (VAB)-MIB were performed after NACT and before surgery. Negative predictive values (NPV) and false-negative rates (FNR) to predict a pCR in surgical specimen (diagnose pCR through MIB) were the main outcome measures. RESULTS: Pathological complete response in surgical specimen was diagnosed in 93 (56.7%) cases of the whole cohort. The NPV of the MIB diagnosis of pCR was 71.3% (95% CI: (63.3%; 79.3%)). The FNR was 49.3% (95% CI: (40.4%; 58.2%)). Existence of a clip marker tended to improve the NPV (odds ratio 1.98; 95% CI: (0.81; 4.85)). None of the mammographically guided VABs (n=16) was false-negative (FNR 0%, NPV 100%). CONCLUSIONS: Overall accuracy of MIB diagnosis of pCR was insufficient to suggest changing clinical practice. However, subgroup analyses (mammographically guided VABs) suggest a potential capacity of MIB techniques to precisely diagnose pCR after NACT. Representativity of MIB could be a crucial factor to be focused on in further analyses.

Using a New Marker Clip System in Breast Cancer: Tumark Vision® Clip - Feasibility Testing in Everyday Clinical Practice.

BACKGROUND: This study presents first feasibility experiences with a new 3-dimensional (3D) marker clip system in clinical practice. The rate of clinical complete responses in the treatment of breast cancer patients is increasing; additionally, a change to targeted axillary dissection is being considered after neoadjuvant chemotherapy (NACT). Consequently, marker clips are needed which are reliable and easy to handle even in the axillary lymph node system. METHODS: A total of 50 patients from the Breast Care Unit of the Kliniken Essen Mitte were included. Clip marking of all 50 primary breast cancer lesions as well as 23 lymph nodes was performed using the Tumark Vision® clip. Following application, the position and visibility of the marker clip were monitored and documented in 2 axes. RESULTS: The feasibility of the Tumark Vision clip was excellent in everyday clinical practice as none of the markers dislocated. After clip marking of the tumor region and/or suspicious lymph nodes, all Tumark Vision clips could be detected in both axes. The 3D shape could be observed in all cases after application. CONCLUSION: The new 3D-shaped marker clip seems to be a promising tool for marking breast cancer lesions and even lymph nodes before NACT. As there are many studies ongoing to prove the feasibility of a shift from standard axillary dissection after NACT towards targeted axillary dissection, the Tumark Vision clip seems to provide good visibility even in lymph nodes after NACT. Further studies are warranted.