Intermittent Letrozole Therapy

Efficacy and Safety

• The American Society of Clinical Oncology supported study, the SOLE trial, found that intermittent letrozole administration was non-inferior to continuous therapy in terms of disease-free survival (HR, 1.08; 95% CI, 0.93 to 1.26; P = .31) 1, 2
• Intermittent letrozole administration showed comparable efficacy to continuous administration while providing quality of life benefits 1, 3

Benefits of Intermittent Therapy

• Patients on intermittent letrozole reported significantly less vaginal problems (P = .017), improved sleep (P = .0073), better physical well-being (P = .0080), and improved mood (P = .026) compared to continuous administration 1, 2
• Taking breaks from letrozole may reduce cumulative side effects while maintaining therapeutic efficacy 3

Monitoring and Recommendations

• Upon restarting letrozole after a break, monitor for common side effects including hot flashes, fatigue, arthralgia, and myalgia 1, 3
• Long-term letrozole use is associated with increased risk of osteoporosis and bone fractures, but these risks are unlikely to be significantly affected by a 1-2 month break 5