Higher risk of death with endocrine therapy nonadherence

TOPLINE:

Patients with early-stage breast cancer who do not adhere to adjuvant endocrine therapy as prescribed or stop early may face as much as a twofold higher risk of relapse or death, a new systematic review found.

METHODOLOGY:

• The investigators conducted a systematic literature search of five databases, looking for studies involving patients with nonmetastatic hormone receptor–positive breast cancer that were published between 2010 and 2020.
• Adequate adherence was defined as a medical possession ratio – the percentage of days the prescribed treatment dose of adjuvant endocrine therapy was available to the patient – of at least 80%.
• Medication nonpersistence was defined as a period in which no new adjuvant endocrine therapy prescriptions were filled before the scheduled end of treatment of 90-180 days, depending on the study.
• The impact of both parameters on event-free survival, which included breast cancer recurrence, disease-free survival, breast cancer–specific survival, and overall survival cancer was calculated.
• Of 2,026 articles retrieved, 14 studies, with sample sizes ranging from 857 to 30,573 patients, met the eligibility and quality criteria; 11 examined patient adherence, and 6 examined patient persistence.

TAKEAWAY:

• Of 10 studies that assessed event-free survival, 7 showed significantly worse survival for nonadherent or nonpersistent patients, at hazard ratios of 1.39-2.44.
• Of nine studies that examined overall survival, seven demonstrated a significantly higher risk for mortality in the groups with nonadherence and nonpersistence, at HRs of 1.26-2.18.
• The largest study, which included data on more than 30,000 patients in Taiwan, found that nonadherence and nonpersistence were associated with a significantly increased risk for mortality, at HRs of 1.98 and 2.18, respectively.

IN PRACTICE:

“The available data highlight the dangers of nonadherence and nonpersistence, showing an up to twofold higher risk of relapse or death for patients who do not use endocrine treatment as prescribed,” the researchers said. “Importantly, improving adherence and persistence represents a low-hanging fruit for increasing survival in luminal breast cancer.”

SOURCE:

The study, led by Finn Magnus Eliassen, MD, department of surgery, Stavanger (Norway) University Hospital, was published online on July 4 in BMC Cancer.

LIMITATIONS:

• The review is limited by the relatively small number of studies that met the eligibility criteria and by their heterogeneity, which ruled out a meta-analysis.
• There are no gold-standard definitions of adherence and persistence.

DISCLOSURES:

• No funding was declared. No relevant financial relationships were declared.
• A version of this article first appeared on Medscape.com.