High Risk on Breast Cancer Risk Prediction Tools Associated With More Favorable Disease Characteristics
In a Swedish study reported in the Journal of Clinical Oncology, Holm et al found that high risk on the Tyrer–Cuzick predicted 10-year breast cancer risk score (TCRS) and a 77-single nucleotide polymorphism polygenic risk score (PRS) tended to be associated with favorable prognostic features in women with breast cancer.
Study Details
The study was a case-only analysis in a population-based cohort of 5,500 Swedish patients with breast cancer. Logistic and multinomial logistic regression of outcomes, estrogen receptor status, lymph node involvement, and tumor size and grade was performed using TCRS, PRS, and percent mammographic density. Separate PRSs were used to reflect weighting of analyses in breast cancer overall, estrogen receptor–negative disease, and estrogen receptor–positive disease.
Better Prognostic Features
High risk on TCRS was associated with reduced risks for estrogen receptor–negative disease (odds ratio [OR] = 0.80, 95% confidence interval [CI] = 0.72–0.90), lymph node–positive disease (OR = 0.77, 95% CI = 0.68–0.87), and grade 3 disease (OR = 0.79, 95% CI = 0.69–0.90), with no association with tumor size being observed; on age stratification, the associations with favorable prognostic features were restricted to women younger than age 50.
Among estrogen receptor–positive cases, a high score was more common for patients with low-grade, lymph node–negative disease, as in the overall analysis. No significant associations were observed among patients with estrogen receptor–negative disease.
For the overall PRS, each 1-standard deviation increase in score was associated with reduced risks for estrogen receptor–negative disease (OR = 0.80, 95% CI = 0.74–0.87), tumor size > 40 mm (OR = 0.86, 95% CI = 0.76–0.99), and grade 3 disease (OR = 0.86, 95% CI = 0.77–0.95); the associations were similar in older and younger women. PRS weighted on estrogen receptor–positive tumors yielded estimates similar to the main PRS analysis, whereas PRS weighted on estrogen receptor–negative disease was associated with increased risk of estrogen receptor–negative disease.
High scores on both TCRS and PRS were associated with a lower risk of distant metastasis (hazard ratio = 0.69, 95% CI = 0.49–0.98). Mammographic density was not significantly associated with any of the prognostic features.
The investigators concluded: “Women at high risk for breast cancer based on genetic and lifestyle factors were significantly more likely to be diagnosed with breast cancers with a favorable prognosis. Better knowledge of subtype-specific risk factors could be vital for the success of prevention programs aimed at lowering mortality.”
The study was supported by the Swedish Research Council, Swedish Cancer Society, and Cancer Society in Stockholm.
Johanna Holm, MSc, of Karolinska Institutet, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
