Polygenic risk score blood test could indicate future risk of breast cancer
A PRS313 blood test could help predict if abnormal cells are likely to become breast cancerous or not.
A retrospective study utilizing the 313-SNP breast cancer polygenic risk score (PRS313) blood test has revealed that women diagnosed with abnormal cells were more likely to be diagnosed with breast cancer in the future. This finding could help identify patients who would benefit from future treatment and reduce the risk of overtreatment.
Abnormal cells that develop in breast ducts and lobules, known as ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS), can sometimes develop into breast cancer; however, it’s not yet possible to predict which cases of DCIS and LCIS will progress and which won’t.
“It is therefore very important that we find ways to predict which women with DCIS and LCIS are most likely to develop invasive breast cancer in the future so they can be given the most appropriate treatment and avoid unnecessary treatment,” explained study senior author Elinor J. Sawyer, King’s College London (UK).
Reviewing PRS313 scores
Sawyer, along with study lead author Jasmine Timbres (King’s College London), turned to PRS313, a blood test that assesses breast cancer risk by identifying which of 313 single nucleotide polymorphisms a patient has. They then reviewed PRS313 scores from over 2000 DCIS and LCIS cases in the ICICLE and GLACIER studies.
This analysis demonstrates that for DCIS, patients with elevated PRS313 scores were 2.03 times more likely to develop cancer in the contralateral breast when compared with patients in the lowest PRS313 quartile. In LCIS, patients with a higher PRS313 score were 2.16 times more likely to develop ipsilateral disease per increase in PRS313. This risk was increased further if a patient had a family history of breast cancer.
“LCIS is not always surgically removed or treated with hormone therapies, as it is considered lower risk than DCIS. However, these results indicate that those with a family history may benefit from such additional treatments, which could reduce their risk of further cancer,” Timbres commented.
Informing sensitive decisions
Although this study doesn’t consider as-yet-unknown genetic changes associated with in situ breast disease, the team are hopeful that PRS313 could eventually guide clinical decisions, improving outcomes and efficient use of healthcare resources.
“The associations found in this study could be useful in helping women decide their treatment options after a diagnosis of DCIS or LCIS,” Timbres added. “By looking at the full picture, rather than just how cells look under a microscope, we can give women more accurate information about their personal risk of recurrence. This could help them make more informed choices about their treatment options and what’s right for them.”
Sawyer noted, “Although more work still needs to be done to confirm the results of this study in other groups of patients or assess additional genetic changes, the results are very promising and have the potential to influence treatment decisions.”
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