Maryam Nemati Shafaee, MD
Clinical trial findings that were presented at the 2018 ASCO Annual Meeting could have a significant impact on patients with early-stage breast cancer in the adjuvant setting, explained Maryam Nemati Shafaee, MD.
For example, in the phase III TAILORx trial, adjuvant endocrine therapy demonstrated noninferiority to adjuvant chemoendocrine therapy in women with hormone receptor (HR)–positive/HER2-negative, nodenegative, early-stage breast cancer with an intermediate risk of distant recurrence (HR, 1.08; 95% CI, 0.94-1.24 P
Following the study, Shafaee said that physicians can “safely say that this patient population does not need chemotherapy.”
Moreover, in the phase III PERSEPHONE trial, 4088 women with HER2-positive early breast cancer were randomized to receive trastuzumab (Herceptin) for 6 months (n = 2043) or 12 months (n = 2045). At a 5-year follow-up, the 4-year disease-free survival (DFS) rate was 89.8% and 89.4% with the 12-month and 6-month schedules, respectively (HR, 1.07; 90% CI, 0.93-1.24; P
Although the trial demonstrated noninferiority with the shorter duration of therapy, Shafaee warned against its adoption into practice since other similar trials were negative.
Additionally, the 72-month follow-up analysis of the ABCSG-18 trial showed a DFS benefit with adjuvant denosumab (Xgeva) for postmenopausal women with early HR-positive breast cancer (HR, 0.823; 95% CI, 0.69-0.98; P = .026) per Cox proportional hazards regression analysis.3
In the trial, 3425 women receiving an aromatase inhibitor were randomized to receive 60 mg of denosumab (n = 1712) or placebo (n = 1713) every 6 months. In the denosumab group, DFS was 89.2% at 5 years (95% CI, 87.6-90.7) and 80.6% at 8 years (95% CI, 78.1-83.1). In patients randomized to placebo, DFS was 87.3% at 5 years (95% CI, 85.7-89.0) and 77.5% at 8 years (95% CI, 74.8-80.2).
Following these studies, Shafaee said that more data are needed if precision oncology is to continue to transform the field of breast cancer.
In an interview during the 2018 OncLive®
State of the Science Summit™ on Breast Cancer, Shafaee, an assistant professor, at the Lester & Sue Smith Breast Center, Duncan Cancer Center, Baylor College of Medicine, discussed the pivotal trials in breast cancer that were reported at the 2018 ASCO Annual Meeting.
OncLive: What were the main updates in breast cancer from the 2018 ASCO Annual Meeting?
The first is the TAILORx trial and the second is the PERSEPHONE trial. There are 2 adjuvant denosumab trials that I also spoke about. TAILORx was a study with a very high clinical impact.
There was an earlier paper of a subgroup in the trial that looked at the Oncotype DX Recurrence Risk Score between 0 and 10 [for those who received] endocrine therapy alone. They reported that if the Oncotype DX results showed a number between 0 and 10 in women with early-stage node-negative estrogen-receptor (ER)– positive breast cancer, then you can omit chemotherapy.
In the trial, they looked at recurrence score in the intermediate range between 11 and 25 in post- and premenopausal women. They looked at chemotherapy plus endocrine therapy versus endocrine therapy alone. The endpoint that they looked at was invasive disease-free survival (iDFS).
In this patient population, they reported that, especially in women aged over 50 years with an intermediate-risk score between 11 and 25, chemotherapy is essentially unnecessary. iDFS was pretty much the same between the group who received endocrine therapy and those who received chemotherapy plus endocrine therapy. We can safely say that this patient population does not need chemotherapy.
When it comes to premenopausal women or those aged 50 years and younger, it is a little bit different. In this patient population, there was improvement in the outcomes seen in that range, especially between 16 and 20 and 20 and 25. There was about a 7% improved outcome or reduced recurrence risk in the range of 20 to 25. It’s not as clear as it is for patients aged over age 50.
What did we learn from the PERSEPHONE trial?
For PERSEPHONE, researchers looked at DFS in patients with early-stage, HER2-positive breast cancer who would need adjuvant trastuzumab therapy. They looked at 12 months versus 6 months of trastuzumab, which comes to 18 doses versus 9 doses of therapy. They wanted to know whether the 6-month duration was noninferior to the 12-month duration. They reported that the 6-month duration was noninferior to the 12-month duration of trastuzumab.