Bolus versus Continuous Intravenous Delivery of Doxorubicin in Soft-Tissue Sarcomas: Post Hoc Analysis of a Prospective Randomized Trial (SARC021/TH CR-406).

PURPOSE: Continuous intravenous infusion (CIV) of doxorubicin (DOX) versus bolus (BOL) may minimize dose-dependent DOX cardiomyopathy, but it is unclear whether this advantage is evident as employed in typical soft-tissue sarcoma (STS) treatment. The impact of administration mode on adverse events (AE) and efficacy were compared using data from a randomized trial of DOX-based therapy (SARC021/TH CR-406). EXPERIMENTAL DESIGN: In this post hoc analysis, CIV versus BOL was at discretion of the treating physician. Likelihood of AEs, and objective responses were assessed by adjusted logistic regression. Progression-free (PFS) and overall survival (OS) were compared using Kaplan-Meier, log-rank test, and adjusted Cox regression. RESULTS: DOX was administered by BOL to 556 and by CIV to 84 patients. Proportions experiencing hematologic, non-hematologic, or cardiac AEs did not differ by administration mode. Hematologic AEs were associated with age, performance status, and cumulative DOX. Non-hematologic AEs were associated with age, performance status, and cumulative evofosfamide. Cardiac AEs were only associated with cumulative DOX; there was no interaction between DOX dose and delivery mode. PFS and OS were similar (median PFS 6.14 months BOL vs. 6.11 months CIV, P = 0.47; median OS 18.4 months BOL vs. 21.4 months CIV, P = 0.62). PFS, OS, and objective responses were not associated with delivery mode. CONCLUSIONS: CIV was not associated with superior outcomes over BOL within DOX dosing limits of SARC021. Cardiac AEs were associated with increasing cumulative DOX dose. While not randomized with respect to DOX delivery mode, the results indicate that continued investigation of AE mitigation strategies is warranted.

Development and testing of a polygenic risk score for breast cancer aggressiveness.

Aggressive breast cancers portend a poor prognosis, but current polygenic risk scores (PRSs) for breast cancer do not reliably predict aggressive cancers. Aggressiveness can be effectively recapitulated using tumor gene expression profiling. Thus, we sought to develop a PRS for the risk of recurrence score weighted on proliferation (ROR-P), an established prognostic signature. Using 2363 breast cancers with tumor gene expression data and single nucleotide polymorphism (SNP) genotypes, we examined the associations between ROR-P and known breast cancer susceptibility SNPs using linear regression models. We constructed PRSs based on varying p-value thresholds and selected the optimal PRS based on model r2 in 5-fold cross-validation. We then used Cox proportional hazards regression to test the ROR-P PRS's association with breast cancer-specific survival in two independent cohorts totaling 10,196 breast cancers and 785 events. In meta-analysis of these cohorts, higher ROR-P PRS was associated with worse survival, HR per SD = 1.13 (95% CI 1.06-1.21, p = 4.0 × 10-4). The ROR-P PRS had a similar magnitude of effect on survival as a comparator PRS for estrogen receptor (ER)-negative versus positive cancer risk (PRSER-/ER+). Furthermore, its effect was minimally attenuated when adjusted for PRSER-/ER+, suggesting that the ROR-P PRS provides additional prognostic information beyond ER status. In summary, we used integrated analysis of germline SNP and tumor gene expression data to construct a PRS associated with aggressive tumor biology and worse survival. These findings could potentially enhance risk stratification for breast cancer screening and prevention.