Dr Roy on Polygenic Scores and the Risk of Recurrence in Breast Cancer

Arya Mariam Roy, MBBS, fellow, Hematology/Oncology, Roswell Park Comprehensive Cancer Center, discusses findings from the Pathway trial—a prospective cohort study—evaluating the association between polygenic scores (PGS) and survival outcomes in patients with breast cancer.

The study utilized genome-wide genotype data from 3995 patients, enrolled from 2006 to 2013, to calculate four different PGS: PGS313, PGS4k, PGS5k, and PGS6m), and evaluated their associations with various survival outcomes, including recurrence, contralateral second primary breast cancer, other second primary cancers, and death.

Findings presented at the 2024 ASCO Annual Meeting showed that at a median follow-up of 10.5 years (range, 0.2-14.2), 504 patients experienced disease recurrence, 146 had contralateral second primary breast cancer, 237 had non-breast second primary cancers, and 762 patients died, including 352 with breast cancer–specific deaths.

Data demonstrated that compared with patients with low (T1) PGS313, patients with medium (T2) PGS313 risk scores were associated with a higher risk of recurrence (HR, 1.28; 95% CI, 1.02-1.61; P = .04), all-cause death (HR, 1.12; 95% CI, 0.96-1.31; P = .03), total breast cancer events (HR, 1.27; 95% CI, 1.04-1.54; P = .02), and invasive disease (HR, 1.33; 95% CI, 1.09-1.63; P = .006). Patients with high (T3) PGS313 scores also had worse outcomes vs patients with T1 scores in regards to recurrence (HR, 1.29; 95% CI, 1.02-1.61; P = .04), all-cause death (HR, 1.28; 95% CI, 0.96-1.31; P = .03), total breast cancer events (HR, 1.29; 95% CI, 1.04-1.54; P = .02), and invasive disease (HR, 1.34; 95% CI, 1.09-1.63; P = .006). However, these increased risks were not observed with the other PGS variants assessed in the study.

Previously, it was known the PGS was associated with the risk of developing breast cancer, Roy explains. Findings from this study help further that understanding by showing the PGS313 scores are linked to worse survival outcomes and a higher risk of recurrence in patients who have already developed breast cancer, she concludes.