Study results presented at this month’s San Antonio Breast Cancer Symposium highlighted several advances in the treatment of breast cancer.
CURE® selected some of the top stories from our coverage of the breast cancer meeting, which included topics such as advanced breast cancer, side effects in older patients, circulating tumor DNA (ctDNA) detection and more.
Time to Next Treatment Slightly Higher With Orserdu in Breast Cancer Subset
A real-world analysis found that Orserdu (elacestrant) yielded comparable or slightly better time to treatment discontinuation and time to next treatment than the progression-free survival (PFS) reported in the phase 3 EMERALD trial for patients with HR-positive/HER2-negative advanced breast cancer and ESR1 mutations.
An analysis of 742 patients receiving Orserdu (mean age, 63 years) showed a median real-world time to next treatment (rwTTNT) of 6.43 months and a median real-world time to treatment discontinuation (rwTTD) of 4.6 months.
Although most patients received Orserdu in the third or fourth line of treatment, the treatment line did not substantially affect outcomes. Median rwTTNT ranged from 5.9 to 8.8 months, and median rwTTD ranged from 4.5 to 5.3 months across the second, third and fourth lines.
Older Patients With Early Breast Cancer May Have Worse Immune Side Effects
Researchers presented findings from a multi-institutional study suggesting a potential link between prior immune checkpoint inhibitor use in early-stage breast cancer and an increased risk of high-grade immune-related side effects in older patients.
In patients with early-stage breast cancer treated with immune checkpoint inhibitors, 72.6% experienced any-grade immune-related side effects, and 18.9% experienced high-grade effects. While the majority (81%) experienced no high-grade events, 17% experienced one and 1.7% experienced two. No patients experienced more than two high-grade side effects. The distribution of any-grade events was as follows: none (27%), one (43%), two (23%), three (5.7%), four (1.2%) and five (0.2%).
Ultra-Sensitive Testing Can Detect ctDNA in HR-Positive Breast Cancer
Findings from a phase 2 trial demonstrated ctDNA detection using an ultra-sensitive tissue-free method in patients with HR-positive early breast cancer.
Baseline ctDNA was associated with larger pathological tumor size and higher residual cancer burden scores after neoadjuvant endocrine therapy. Dr. Albert Grinshpun and colleagues also reported that detectable ctDNA after treatment correlated with higher recurrence rates.
In the phase 2 PELOPS trial, 49 patients with stage 1 to 3 HR-positive, HER2-negative breast cancer were randomly assigned to receive either neoadjuvant endocrine therapy in combination with Ibrance (palbociclib; 35 patients) or neoadjuvant endocrine therapy alone (13 patients).
Postoperative Radiation Offers Higher Quality of Life, Fewer Side Effects in Some with Breast Cancer
Study results from the phase 3 EUROPA trial demonstrated that, at 24 months, older patients with stage 1 luminal-like breast cancer had better health-related quality of life (HRQOL) and fewer treatment-related side effects with postoperative radiation therapy than with exclusive endocrine therapy.
Regarding HRQOL, the radiation therapy group experienced a smaller decline from baseline to 24 months compared to the endocrine therapy group. The mean change from baseline was -1.1 versus -10, respectively. After adjusting for age and G8 score, the median change was -3.4 versus -9.79, respectively. Baseline median scores were 71.9 (radiation therapy) and 75.5 (endocrine therapy).
Enhertu Improves Progression-Free Survival in HR-Positive, HER2-Low/Ultralow Metastatic Breast Cancer
Enhertu (fam-trastuzumab deruxtecan-nxki) improved PFS compared to physician's choice (TPC) in patients with HR-positive, HER2-low/-ultralow metastatic breast cancer, regardless of time to progression (TTP) on frontline endocrine therapy with CDK4/6 inhibition or the type of endocrine resistance, according to results from the DESTINY-Breast06 trial.
Median PFS with Enhertu was 14 months versus 6.5 months with TPC for patients with TTP less than 6 months, 13.2 months versus 6.9 months for TTP between 6 and12 months and 12.9 months versus 8.2 months for TTP greater than 12 months.
In patients with primary endocrine resistance, median PFS was 12.4 months with Enhertu versus 6.6 months with TPC. For those with secondary endocrine resistance, median PFS was 13.2 months with Enhertu versus 9.5 months with TPC.
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