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
427P - Sahai: A restorative support to address unmet needs of women with cancer – impact on quality of life
Presenter: Poonam Maurya
Session: Poster display session
Resources:
Abstract
428P - A pilot study on comparative efficacy of tramadol or eutectic mixture of local anaesthetics (prilocaine plus lignocaine) in preventing bone marrow aspiration associated pain
Presenter: Bipinesh Sansar
Session: Poster display session
Resources:
Abstract
429P - Skin pathologic change evaluation of the patients who had EGFR inhibitor-related skin adverse events
Presenter: Sung Yong Oh
Session: Poster display session
Resources:
Abstract
430P - Emetic risk of carboplatin plus pemetrexed is higher than that of carboplatin plus paclitaxel in patients with lung cancer: A propensity score-matched analysis
Presenter: Koichi Matsuo
Session: Poster display session
Resources:
Abstract
431P - An in vitro evaluation of CYP2D6 enzymatic inhibition activities of a Chinese herbal medicine formulation (Xiang Bei Yangrong Tang) for the management of cancer-related fatigue
Presenter: Ning Yi Yap
Session: Poster display session
Resources:
Abstract
432P - Chemotherapy induced extravasation: Incidence and possible predictors
Presenter: Shalaka Somayaji
Session: Poster display session
Resources:
Abstract
433P - Prospective outcomes of adolescent and young adult (AYA) patients received treatment from a tertiary cancer hospital in Bangladesh
Presenter: Abdullah Al Mamun Khan
Session: Poster display session
Resources:
Abstract
434P - Pneumonitis induced antineoplastic agents: Mortality and risk factors in 129 consecutive cases
Presenter: Sawako Kaku
Session: Poster display session
Resources:
Abstract
435P - Telephonic communication in palliative care for better management of terminal cancer patients in rural India: An NGO based approach
Presenter: NABANITA MANDAL
Session: Poster display session
Resources:
Abstract
436P - Assessing the quality of life of Filipino cancer patients: A survey of Filipino oncologists
Presenter: Frederic Ivan Ting
Session: Poster display session
Resources:
Abstract