Patients with triple-negative breast cancer (TNBC) who received a more intensive adjuvant chemotherapy regimen following classification into a high-risk category using a multigene signature had better survival outcomes compared with patients randomized to a less intensive regimen, according to research from the 2024 ASCO Annual Meeting. 

In the phase 3 study researchers classified 504 patients with TNBC into high- and low-risk groups using a multigene signature. Patients received either intensive adjuvant treatment or standard treatment based on their classification. Median patient age was 52 years, 488 patients had T1 or T2 tumors, and 263 had node-positive disease. 

Overall, 336 patients were deemed high risk, and 168 were deemed low risk. In the high-risk group, patients were randomized to receive an intensive regimen consisting of four cycles of docetaxel, epirubicin, and cyclophosphamide which was followed up with four cycles of gemcitabine and cisplatin (group A) or four cycles of epirubicin and cyclophosphamide followed with four cycles of docetaxel (group B). 

In the low-risk group, patients received four cycles of epirubicin and cyclophosphamide and then four cycles of docetaxel (group C). The researchers evaluated disease-free survival (DFS) as a primary endpoint and relapse-free survival (RFS) between groups. 

The researchers found a 3-year DFS rate of 90.9% for patients in group A compared with 80.6% of patients in group B at median 45.1 months of follow-up, with patients in group A benefitting from the intensive regimen “irrespective of tumor size and nodal status” compared with patients who received standard therapy. 

Among patients in group A, the 3-year RFS was 92.6% compared with 83.2% in group B, but there were no significant differences between either group regarding overall survival (OS) or 3-year OS (98.2% vs 91.3%). 

Compared with patients in group B, the researchers said patients in group C who received a standard regimen had a significantly higher DFS with a 3-year DFS of 90.1% compared to 80.6% among patients in group B. Patients in group C also had a significantly higher RFS at 3 years and OS at 3 years compared with group B. 

The researchers noted the most common grade 3 or grade 4 treatment-related adverse events were thrombocytopenia, febrile neutropenia, anemia, nausea, vomiting, and myalgia, which occurred more often in group A compared with groups B and C. 

“The multigene signature showed potential for tailoring adjuvant chemotherapy for patients with operable TNBC.”

- Min He, MD, of the department of breast surgery at Fudan University Shanghai Cancer Center.

References:

https://meetings.asco.org/abstracts-presentations/238972

https://clinicaltrials.gov/study/NCT02641847

Disclosures: No authors declared financial ties to drugmakers.

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