Abstract 29P
Background
Early prediction of tumor response to therapy is essential for individualized treatment and sparing non-responders needless harm. A relationship has recently been found between pathologic response in breast cancer (BC) and a measure of cell loss based on serum levels of thymidine kinase 1 (sTK1), a macromolecule released when proliferating tumor cells are disrupted, and tumor volume. Objective: To establish whether the predictive power of this cell-loss metric can be further improved by baseline tumor characteristics.
Methods
Fifty-eight women with localized BC received neoadjuvant epirubicin/docetaxel in 6 cycles, supplemented with bevacizumab in cycle 3-6. The cell-loss metric, defined as the ratio between sTK1 (ng/ml) and tumor volume (cm3), was obtained prior to and 48h after cycle 2. The predictive value of this metric, and the improvement by adding routine baseline markers, was evaluated using pathologic response as endpoint (16 complete responses (pCR); 42 remaining tumors).
Results
Compared to baseline (median = 0.285 ng / ml), sTk1 increased 2-fold before cycle 2 and 3-fold 48h after cycle 2 while tumor volume (baseline 105 cm3) decreased by 70%. The cell loss method increased from 0.0032 units (IQR 0.0015-0.0099) to 0.0166 (0.0064-0.0423) and 0.0232 (0.0095-0.053), respectively, showing a strong association with pathological response (p = 0.002). Combination with histological markers, and especially the progesterone receptor, significantly improved the prediction of pCR, achieving positive and negative predictive values of 81% and 93%.
Conclusions
The usefulness of tumor markers in blood can be increased by combining them with other tumor properties. Thus, in neoadjuvant treatment of BC the cell-loss metric, which relates sTK1 to tumor volume, has been noticed as a predictor of pathologic response. Here we found that adding certain established tumor markers significantly improved the predictive power of the metric. Early prediction of tumor response makes the cell-loss metric potentially useful in personalized oncology and in the evaluation in new therapeutic modalities.
Clinical trial identification
PROMIX: NCT00957125.
Editorial acknowledgement
Legal entity responsible for the study
Thomas Hatschek, MD, PhD, Karolinska University Hospital.
Funding
Has not received any funding.
Disclosure
B. Tribukait: Shareholder / Stockholder / Stock options, minor stock owner: AroCell Ab.
Resources from the same session
65P - Updated efficacy and safety of entrectinib in patients with NTRK fusion-positive tumours: Integrated analysis of STARTRK-2, STARTRK-1 and ALKA-372-001
Presenter: Christian Rolfo
Session: Poster display session
Resources:
Abstract
66P - Brain metastases, treatment patterns and outcomes in ROS1-positive NSCLC patients from US oncology community centers
Presenter: Matthew Krebs
Session: Poster display session
Resources:
Abstract
67P - Pooled safety analysis of tepotinib in Asian patients with advanced solid tumours
Presenter: Kentaro Yamazaki
Session: Poster display session
Resources:
Abstract
68P - A novel anti-EGFR antibody HLX07 for potential treatment of squamous cell carcinoma of the head and neck
Presenter: Ming Mo Hou
Session: Poster display session
Resources:
Abstract
69P - Irinotecan and cisplatin therapy-induced neutropenia as a prognostic factor in patients with extensive-disease small cell lung cancer
Presenter: Hiroshi Ishikawa
Session: Poster display session
Resources:
Abstract
70P - Is safe and efficient by intraoperative endoscopic nasobiliary drainage over primary closure of the common bile duct for cholecystolithiasis combined with common bile duct stones: A meta-analysis
Presenter: Jiasheng Cao
Session: Poster display session
Resources:
Abstract
71P - Irreversible electroporation versus radiotherapy after induction chemotherapy on survival in patients with locally advanced pancreatic cancer: A propensity score analysis
Presenter: Chaobin He
Session: Poster display session
Resources:
Abstract
72P - Novel technique of near-focus mode for accurate operation during endoscopic submucosal tunneling procedure: A two-center comparative study
Presenter: Wei Peng
Session: Poster display session
Resources:
Abstract
73P - Cabozantinib in combination with anti-PD1 immune checkpoint inhibitor in syngeneic tumour mouse models
Presenter: Rachel Sparks
Session: Poster display session
Resources:
Abstract
74TiP - Phase I study of BI 836880, a VEGF/Ang2-blocking nanobody®, as monotherapy and in combination with BI 754091, an anti-PD-1 antibody, in Japanese patients (pts) with advanced solid tumours
Presenter: Kentaro Yamazaki
Session: Poster display session
Resources:
Abstract