Clin Cancer Res. 2021 Jun 2:clincanres.0641.2021. doi: 10.1158/1078-0432.CCR-21-0641. Online ahead of print.
ABSTRACT
PURPOSE: Patient derived xenografts (PDXs) are a research tool for studying cancer biology and drug response phenotypes. While engraftment rates are higher for tumors with more aggressive characteristics, it is uncertain whether engraftment is prognostic for cancer recurrence.
EXPERIMENTAL DESIGN: In a prospective study of breast cancer patients treated with neoadjuvant chemotherapy (NAC) with taxane+/-trastuzumab followed by anthracycline-based chemotherapy, we report the association between breast cancer events and PDX engraftment using tumors derived from treatment naïve (pre-NAC biopsies from 113 patients) and treatment resistant (post-NAC at surgery from 34 patients). Gray’s test was used to assess whether the cumulative incidence of a breast cancer event differs with respect to either pre-NAC PDX engraftment or post-NAC PDX engraftment.
RESULTS: With a median follow up of 5.7 years, the cumulative incidence of breast cancer relapse did not differ significantly according to pre-NAC PDX engraftment (5-year rate: 13.6% versus 13.4%; p=0.89). However, the incidence of a breast event was greater for patients with post-NAC PDX engraftment (5-year rate: 50.0% versus 19.6%), but this did not achieve significance (p=0.11).
CONCLUSIONS: In treatment-naive breast cancer receiving standard NAC, PDX engraftment was not prognostic for breast cancer recurrence. Further study is needed to establish whether PDX engraftment in the treatment-resistant setting is prognostic for cancer recurrence.
PMID:34078650 | DOI:10.1158/1078-0432.CCR-21-0641
