Change in tumor size at week 8 may predict overall survival during first-line therapy in patients with metastatic breast cancer, according to a study published in the European Journal of Cancer.1
In order to evaluate treatment effect earlier and increase study power, clinical trials may use change in tumor size as a primary end point instead of progression-free survival, leading to more timely regulatory approval for patients with cancer.
Therefore, researchers sought to assess the relationship between change in tumor size and overall survival in first-line metastatic breast cancer.
For the study, investigators analyzed data from 3 randomized phase 3 trials that evaluated the clinical benefit of gemcitabine combination in patients with metastatic breast cancer. Patients had received either gemcitabine with paclitaxel or docetaxel.
Results showed that change in tumor size at week 8, baseline tumor size, and ECOG performance status predict for overall survival.
Among patients with asymptomatic disease and 6-cm tumor burden, first-line treatment with gemcitabine and paclitaxel confers a median overall survival of 28.6 months compared with 26.0 months for paclitaxel alone.
“This work further supports the use of early change in tumor size as a go/no-go decision point during phase 2 clinical evaluation of treatments for metastatic breast cancer,” the authors conclude.
1. Tate SC, Andre V, Enas N, Ribba B, Gueorguieva I. Early change in tumor size predicts overall survival in patients with first-line metastatic breast cancer. Eur J Cancer. 2016;66:95-103.