A recent study identified a copy number gain that was associated with increased risk of late recurrence in postmenopausal women with hormone receptor–positive early breast cancer.
The study sampled 598 primary breast cancers from the SOLE trial, and next-generation sequencing of gene mutations and copy-number gains was conducted. The researchers correlated genomic aberrations with clinicopathologic factors and distant recurrence-free intervals.
The most frequent alterations were PIK3CA mutations, which occurred in 42% of samples. There was no association between PIK3CA mutations and clinical outcomes.
More than one-third of samples (36%) harbored at least 1 copy number gain. The most frequent copy number gains were CCND1 (15%), ERBB2 (10%), FGFR1 (8%), and MYC (8%). Presence of PIK3CA mutations was associated with lower tumor grade (P =.03), and copy number gain in MYC was associated with higher tumor grade (P =.0004).
Importantly, copy number gain of FGFR1 was associated with about 3 times an increased risk for late events in a univariate and multivariate analyses (hazard ratio for breast cancer free intervals, 3.2; 95% CI, 1.48-6.92; P =.0003 and HR for distant recurrence-free interval, 3.5; 95% CI, 1.61-7.75; P =.002).
“These women might benefit from intensive monitoring and different treatment strategies,” the researchers wrote. “Further studies are needed to evaluate whether the genomic aberrations of FGFR1 are clonal and still preserved in the recurrent tumors where they might represent potential actionable targets.”
Guerini-Rocco E, Gray KP, Fumagalli C, et al. Genomic aberrations and late recurrence in postmenopausal women with hormone receptor-positive early breast cancer: results from the SOLE trial. Clin Can Research. Published online December 2, 2020. doi:10.1158/1078-0432.CCR-20-0126.