Long-Term Follow-Up Continues to Support Trastuzumab in HER2+ Breast Cancer

3d rendered medically accurate illustration of a breast cancer: © SciePro - stock.adobe.com

According to long-term findings from a study which evaluated the safety and activity of the combination of docetaxel, carboplatin, and trastuzumab (Herceptin), a subset of patients (10%) with metastatic HER2-positive breast cancer achieved long-term survival beyond 20 years.¹

At a follow-up of 20 years, the response rate (RR) for complete response (CR) or partial response (PR) was 72.5% (n = 29), and the RR for CR was 42.5% (n = 17). The median response duration (RD) was 8 months (95% CI, 116-1741) and the median time to progression (TTP) was 10.8 months (95% CI, 263-525).

Patients achieved a median overall survival (OS) of 39.8 months (95% CI, 791-2415). Additionally, 37 of 40 patients survived for at least a year making for a1-year survival rate of 92.5%.

Between November 1999 and October 2002, 40 women were enrolled in the phase 2, single-arm, open-label study. The majority of patients (67.5%) had visceral metastasis upon enrollment, the most frequent site being the liver (47.5%), and the median age of those enrolled was 56.5 years (range, 33-79). Most patients (95%) were White, had an ECOG performance status of 0 (95%), received 0 lines of prior therapy (67.5%), and had estrogen receptor--negative disease (77%).

Between non-survivors and survivors, the frequency of liver involvement was 51% (n = 18) and 20% (n = 1), respectively (P =.4). The degrees of lung involvement between non-survivors and survivors were 37% (n = 13) and 60% (n = 3), respectively (P =.6). Among all survivors, they had ≤2 metastatic sites involved compared with only 83% of nonsurvivors.

After 20 years and 3 months from the time of first enrollment, 4 (10%) patients were alive with a median follow-up of 3.2 years. In 18 of the patients (50%), the cause of death was linked with malignant disease while it was attributed to other causes in 3 patients (8.3%), and was unknown in 15 (42%) patients.

In this follow-up, investigators evaluated the primary end point of activity from the treatment combination in terms of RR, and secondary end points of RD, TTP, OS, and 1-year survival.

At this long-term follow-up, the adverse events observed were similar to those that were previously reported.

Overall, trastuzumab continues to hold its place as the backbone of therapy for the first-line management of HER2-positive metastatic breast cancer.

REFERENCES:

Gomez Marti JL, Nasrazadani A, Ding Y, Normolle D, Brufsky AM. Twenty-Year Follow-Up of a Phase II Trial of Taxotere/Carboplatin/Herceptin in Patients With Metastatic HER2-Positive Breast Cancer. Oncologist. 2023;28(11):e1123-e1126. doi:10.1093/oncolo/oyad258