Phase 3
Completed N=1,918
Letrozole in Breast Cancer Who Have Received 5 Years of Aromatase Inhibitor Therapy
Source: ClinicalTrials.gov NCT00754845 ↗Enrolled (actual)
1,918
Serious AEs
1.8%
Results posted
Nov 2018
Primary outcomePrimary: Disease-free Survival (DFS) — 0.95; 0.91 probability of DFS at 5 years — p=0.01
◆ Published Evidence
Highly cited
645citations · ~65 / year
Extending Aromatase-Inhibitor Adjuvant Therapy to 10 Years.
Summary
RATIONALE: Estrogen can cause the growth of breast cancer cells. Hormone therapy using letrozole may fight breast cancer by lowering the amount of estrogen the body makes. It is not yet known whether letrozole is more effective than a placebo in treating in women with breast cancer who have already received 5 years of aromatase inhibitor therapy.
PURPOSE: This randomized phase III trial is studying letrozole to see how well it works compared with a placebo in treating women with primary breast cancer who have received 5 years of aromatase inhibitor therapy.
Linked Publications (4)
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Extending Aromatase-Inhibitor Adjuvant Therapy to 10 Years.
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Quality of Life From Canadian Cancer Trials Group MA.17R: A Randomized Trial of Extending Adjuvant Letrozole to 10 Years.
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Influence of the competing risk of death on estimates of disease recurrence in trials of adjuvant endocrine therapy for early-stage breast cancer: A secondary analysis of MA.27, MA.17 and MA.17R.
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Predicting the clinical outcomes and benefit from letrozole after 5 years of treatment with aromatase inhibitors for early breast cancer: analysis from CCTG MA.17R.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Disease-free Survival (DFS) |
0.95; 0.91 | 0.01 sig |
| SECONDARY Incidence of Contralateral Breast Cancer |
2.1; 4.9 | 0.007 sig |
| SECONDARY Overall Survival (OS) |
0.93; 0.94 | 0.83 |
| SECONDARY Change From Baseline in Role Function- Physical Scale on SF(Short Form)-36 Health Survey |
-7.74; -6.28 | <0.01 sig |
Eligibility Criteria
DISEASE CHARACTERISTICS:
- Previously diagnosed with primary breast cancer
- Must have received 4½ - 6 years of aromatase inhibitor therapy (e.g., letrozole, anastrozole, or exemestane), either as initial therapy or after prior tamoxifen citrate, including treatment received as part of clinical trial CAN-NCIC-MA17
- Completed aromatase inhibitor therapy ≤ 2 years ago
- No metastatic or recurrent disease, contralateral breast cancer, or ductal carcinoma in situ in either breast, as determined by the following:
- Clinical examination of the breast area, axillae, and neck within the past 60 days
- Mammogram within the past 12 months*
- Chest x-ray within the past 60 days
- Bone scan, if alkaline phosphatase > 2 times normal and/or there are symptoms of metastatic disease AND confirmatory x-ray, if bone scan results are questionable, within the past 60 days
- Abdominal ultrasound, liver scan, or CT scan of the abdomen within the past 60 days, if ALT, AST, or alkaline phosphatase > 2 times normal NOTE: *A baseline mammogram is not required for patients who have undergone bilateral complete mastectomy
- Hormone-receptor status:
- Estrogen receptor positive (ER+) and/or progesterone receptor positive (PR+) primary tumor at the time of diagnosis, defined as a tumor receptor content of > 10 fmol/mg protein or receptor positive by immunocytochemical assay (for patients not previously enrolled on clinical trial CAN-NCIC-MA17)
- ER+ and/or PR+ primary tumor OR hormone receptor status of primary tumor unknown (for patients previously enrolled on clinical trial CAN-NCIC-MA17)
PATIENT CHARACTERISTICS:
- Menopausal status not specified
- ECOG performance status 0-2
- Life expectancy ≥ 5 years
- WBC > 3.0 x 10^9/L OR granulocyte count (polymorphs + bands) ≥ 1.5 times 10^9/L
- Platelet count > 100 x 10^9/L
- AST and/or ALT 5 years ago that is presumed cured NOTE: *Elevated levels allowed provided imaging examinations have ruled out metastatic disease
PRIOR CONCURRENT THERAPY:
- See Disease Characteristics
- No concurrent selective estrogen receptor modulator (e.g., raloxifene, idoxifene)
- No other concurrent anticancer therapy
Data sourced from ClinicalTrials.gov (NCT00754845) and the linked publication. Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.