Phase III trial evaluating the role of continuous letrozole versus intermittent letrozole following 4 to 6 years of prior adjuvant endocrine therapy for postmenopausal women with hormone-receptor positive, node positive early stage breast cancer

Phase III trial evaluating the role of continuous letrozole versus intermittent letrozole following 4 to 6 years of prior adjuvant endocrine therapy for postmenopausal women with hormone-receptor positive, node positive early stage breast cancer - JBCRG(SOLE study)

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000004458

Enrollment

4800

Registered

2010-11-01

Start date

2007-08-01

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Postmenopausal patients with breast cancer

Interventions

A: Continuous letrozole 2.5 mg daily for 5 years B: Intermittent letrozole 2.5 mg daily for the first 9 months of years 1 through 4, followed by 12 months in year 5

Eligibility

Sex/Gender

Female

Inclusion criteria

Inclusion criteria: 1. Completely resected, non-inflammatory breast cancer 2. ER and/or PgR positive 3. postmenopausal 4. Axillary and/or internal mammary lymph nodes positive 5. Any (neo-)adjuvant treatment 6. 4 to 6 years of SERM or AI treatment Last dose of SERM/AI within 1 year prior to randomization 7. No evidence of recurrence at any time 8. No bilateral breast cancer 9. No bone fracture due to osteoporosis during SERM/AI treatment 10. Pathology material from primary tumor available 11. No previous or concomitant malignancy 12. Signed informed consent

Exclusion criteria

Exclusion criteria: 1. Patients must have clinically adequate hepatic function. 2. Patients who have had a bone fracture due to osteoporosis at any time during the 4-6 years of prior endocrine SERM/AI therapy. 3. Patients who have had any previous or concomitant malignancy EXCEPT adequately treated: basal or squamous cell carcinoma of the skin, in situ carcinoma of the cervix or bladder, contra- or ipsilateral in situ breast carcinoma. 4. Patients who have had any other non-malignant systemic diseases (cardiovascular, renal, lung, etc.) that would prevent prolonged follow-up. 5. Patients with psychiatric, addictive, or any disorder which compromises compliance with protocol requirements.

Design outcomes

Primary

Measure	Time frame
Disease-free survival (DFS): time from randomization to local (including invasive recurrence restricted to the breast after breast conserving treatment), regional or distant relapse, contralateral breast cancer, appearance of a second (non-breast) malignancy, or death from any cause, whichever occurs first.	—

Secondary

Measure	Time frame
Overall survival (OS), distant disease-free survival (DDFS), breast cancer free interval (BCFI), sites of first failure, second (non-breast) malignancies, deaths without prior cancer events, and adverse events.	—

Countries

Japan,Asia(except Japan),North America,South America,Australia,Europe,Africa

Contacts

Public ContactJun Fukase

Japan Breast Cancer Research Group (JBCRG) Administrative office

office@jbcrg.jp+81-3-6264-8873

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026