Adjuvant Therapy for Postmenopausal Patients with Operable Breast Cancer who have Estrogen Receptor or Progesterone Receptor Positive Tumors. Tamoxifen vs. Letrozole vs. Tamoxifen followed by Letrozole vs. Letrozole followed by Tamoxifen

A phase III study to evaluate letrozole as adjuvant endocrine therapy for postmenopausal women with receptor (ER and/or PgR) positive tumours

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12607000012471

Acronym

IBCSG 18-98 / BIG 1-98(Letrozole)

Enrollment

6193

Registered

2003-12-17

Start date

1999-04-01

Completion date

Unknown

Last updated

2020-01-13

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

Conditions

None listed

Brief summary

Tamoxifen is a hormone tablet that improves cure rates in women with early breast cancer. Letrozole is a new hormone tablet that has recently been shown to work in advanced breast cancer. This international trial will determine if in women with early breast cancer, Letrozole is as good or better than tamoxifen, and whether taking both together is better still.

Interventions

Patients are randomised to one of the following treatment arms: Tamoxifen (20mg orally once a day) for 5 years Vs Letrozole (2.5mg orally once a day) for 5 years Vs Tamoxifen (20mg orally once a day) for 2 years, followed by letrozole (2.5mg orally once a day) for 3 years. Vs Letrozole (2.5mg orally once a day) for 2 years, followed by tamoxifen (20mg orally once a day) for 3 years.

Study design

Allocation

Randomised controlled trial

Intervention model

Parallel

Primary purpose

Treatment

Masking

Blinded (masking used)

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

Compliant postmenopausal women with histologically proven breast cancer who have had either a total mastectomy or a lesser procedure who are classified as pT1-3 or pT4b, Nx, Nsentinel-ve, N0-2, M0, and have oestrogen receptor and/or progesterone receptor positive tumours (ER/PR=10 fmol/mg cytosol protein or =10% of tumour cells positive by immunocytochemical assay); judged suitable for endocrine treatment; adequate marrow function, adequate renal and hepatic function; written and dated informed consent; geographically accessible for follow up; informed of data and material transfer and handling.

Exclusion criteria

Patients with distant metastases. Bilateral breast cancer except in situ lesions of the contralateral breast. Patients with prior ipsilateral in situ breast cancer. Patients with previous history of concomitant other (not breast) malignancy within the past 5 years except adequately treated basal or squamous cell carcinoma of the skin or in situ carcinoma of the cervix. Patients who have had a previous malignancy must have been disease free for five years. Patients receiving adjuvant chemotherapy at randomisation. Patients with other non-malignant systemic diseases. Patients treated with systemic investigational drugs within the past 30 days or topical investigational drugs within the past 7 days. History of non-compliance to medical regimens and patients who are considered potentially unreliable. Patients known to be HIV positive.

Outcome results