SABCS 2022: Longer-Term Follow-Up Confirms Many With Early-Stage Breast Cancer Can Skip Chemotherapy
Endocrine therapy alone OK for certain cancers and gene recurrence scores
THURSDAY, Dec. 15, 2022 (HealthDay News) – Endocrine therapy is noninferior to chemotherapy plus endocrine therapy in hormone receptor-positive, human epidermal growth factor receptor 2-negative, lymph node-negative early breast cancer with a 21-gene recurrence score of 11 to 25, according to findings from an updated, longer-term analysis presented at the San Antonio Breast Cancer Symposium, held from Dec. 6 to 10.
Joseph Sparano, M.D., from Mount Sinai Health System in New York City, and colleagues from the ECOG-ACRIN Cancer Research Group provided an updated analysis of the Trial Assigning Individualized Options for Treatment (TAILORx) using data from 10,253 women enrolled between April 7, 2006, and Oct. 6, 2010, and followed for a median of 10.4 years. Recurrence scores were determined using the 21-gene Oncotype DX panel.
At this longer follow-up point, the researchers identified substantially more events than in the primary analysis (median 7.5 years of follow-up), including invasive disease-free survival events (1,819 versus 1,210), distant recurrences (561 versus 384), locoregional +/- distant recurrences (764 versus 543), and deaths (910 versus 499). However, the primary trial conclusions remained consistent with endocrine therapy remaining noninferior to chemotherapy plus endocrine therapy in the randomized group with a recurrence score of 11 to 25.
Compared with endocrine therapy alone, chemotherapy plus endocrine therapy showed continued benefit in the 12-year invasive disease-free survival event rate for women aged 50 years and younger with a recurrence score of 21 to 25 (82.4 versus 75.0 percent) and 16 to 20 (84.8 versus 77.2 percent), but outcomes were similar for women with a recurrence score of 11 to 15 with or without chemotherapy (83.9 versus 82.3 percent).
“It remains unclear whether this benefit is driven by chemotherapy-induced early menopause, especially since the benefit was largely in premenopausal women ages 46 to 50 who were much more likely to develop chemotherapy-induced menopause than younger women,” Sparano told Elsevier’s PracticeUpdate.
By 12 years, recurrence occurred in <10 percent of those with a recurrence score of ≤25, and late recurrence events (more than five years) were more common than earlier recurrence. Invasive disease-free survival events were substantially driven by nonrecurrence events that occurred in about 13 percent at 12 years (about 1 percent/year).
“There are new technologies that allow detection of minute amounts of circulating tumor DNA or circulating tumor cells in women prior to developing clinical evidence or relapse,” Sparano told Elsevier’s PracticeUpdate. “Studies are ongoing and being planned to determine whether these tests can identify those destined to have a recurrence and whether changing adjuvant endocrine therapy before clinical evidence of recurrence can delay or even prevent disease recurrence.”
This updated analysis also showed an increasing divergence between rates of distant recurrence and invasive disease-free survival (composite of recurrence, death, and second primary cancers), indicating that new development of second primary cancers dominated this cohort. However, distant recurrence rates remained high for those with a recurrence score ≥26 despite the use of chemotherapy plus endocrine therapy.
Several authors disclosed financial ties to the pharmaceutical industry.
Click on any of these tags to subscribe to Topic Alerts. Once subscribed, you can get a single, daily email any time PracticeUpdate publishes content on the topics that interest you.
Visit your Preferences and Settings section to Manage All Topic Alerts