Letrozole in Breast Cancer Who Have Received 5 Years of Aromatase Inhibitor Therapy
Condition: Breast Cancer
MeSH terms: Breast Neoplasms
Intervention: letrozole; placebo
Intervention description: Given orally; Given orally
Intervention MeSH terms: Letrozole
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Enrollment: 1918.0
Sex: Female
Minimum age: 0 Years
Maximum age: 120 Years
Healthy volunteers: No
Keywords: stage I breast cancer; stage II breast cancer; stage IIIA breast cancer; stage IIIB breast cancer; stage IIIC breast cancer

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.
    

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 < 2 times upper limit of normal (ULN)*

          -  Alkaline phosphatase < 2 times ULN*

          -  Able (i.e. sufficiently fluent) and willing to complete quality-of-life questionnaires
             in either English or French (NCIC CTG participating centers)

               -  Inability to complete questionnaires due to illiteracy in English or French, loss
                  of sight, or other equivalent reason allowed

          -  Accessible for treatment and follow-up

          -  No other prior or concurrent malignancy except adequately treated, superficial
             squamous cell or basal cell skin cancer, carcinoma in situ of the cervix, or other
             cancer treated > 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