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
412P - The evaluation of chromosomal changes in patients with osteosarcoma
Presenter: Nargiza Karimova
Session: Poster display session
Resources:
Abstract
413P - The state of molecular biological markers in osteosarcoma
Presenter: Djamilya Polatova
Session: Poster display session
Resources:
Abstract
414P - Clinical profile of gastrointestinal stromal tumour in Yangon General Hospital
Presenter: Khin Mu
Session: Poster display session
Resources:
Abstract
415P - Adult soft tissue myoepithelial carcinoma: Treatment outcomes and efficacy of chemotherapy
Presenter: Florence Chamberlain
Session: Poster display session
Resources:
Abstract
417P - Clinicopathological profile and survival outcomes of sarcomas from a regional cancer centre in South India
Presenter: Divya Bharathi
Session: Poster display session
Resources:
Abstract
418P - Lessons learnt from treatment of foot sarcomas: Analysis from dedicated sarcoma clinic in North India
Presenter: Satyajit Pawar
Session: Poster display session
Resources:
Abstract
423P - Effectiveness of first-generation 5HT3 receptor antagonist plus dexamethasone plus aprepitant in controlling delayed chemotherapy-induced nausea and vomiting in patients with colorectal cancer: A propensity score-matched analysis
Presenter: Toshinobu Hayashi
Session: Poster display session
Resources:
Abstract
424P - Cancer worry, genetic knowledge, and attitudes towards NGS multigene panel testing among Korean breast cancer patients
Presenter: Ji Soo Park
Session: Poster display session
Resources:
Abstract
425P - Economic and safety evaluation of 5-HT3 recepter antagonist conversion from palonosetron to granisetron in highly and moderately emetogenic chemotherapy: A prospective study
Presenter: Keisuke Yamakita
Session: Poster display session
Resources:
Abstract
426P - Impaired quality of life of caregivers of patients with gastrointestinal cancer undergoing palliative chemotherapy
Presenter: Nobumichi Takeuchi
Session: Poster display session
Resources:
Abstract