Exemestane or Anastrozole in Treating Postmenopausal Women Who Have Undergone Surgery for Primary Breast Cancer
Condition: Breast Cancer
MeSH terms: Breast Neoplasms
Intervention: anastrozole; exemestane
Intervention description: Given orally; Given orally
Intervention MeSH terms: Anastrozole; Exemestane
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 7576.0
Sex: Female
Minimum age: 18 Years
Maximum age: 120 Years
Healthy volunteers: No
Keywords: stage IIIA breast cancer; stage I breast cancer; stage II breast cancer

Summary:

      RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy, using
      exemestane or anastrozole, may fight breast cancer by reducing the production of estrogen. It
      is not yet known whether exemestane is more effective than anastrozole in preventing the
      recurrence of breast cancer.

      PURPOSE: This randomized phase III trial is studying exemestane to see how well it works
      compared to anastrozole in preventing cancer recurrence in postmenopausal women who have
      undergone surgery for primary breast cancer.
    

Eligibility criteria:

        DISEASE CHARACTERISTICS:

          -  Histologically confirmed invasive breast cancer

               -  pT1-3; pNX, pN0-2 or pN3*; M0

               -  Neoadjuvant patients are eligible no earlier than 3 weeks or later than 3 months
                  after excisional surgery, provided both the clinical-diagnostic staging of cancer
                  and postsurgical resection-pathologic staging of cancer meet the requirements for
                  primary tumor, regional lymph nodes, and distant metastasis classification NOTE:
                  *Only when the sole basis for this classification is the presence of 10 or more
                  involved axillary lymph nodes

          -  Completely resected disease

               -  Primary surgery performed at least 3 weeks but no more than 3 months before study
                  entry (if no chemotherapy was given)

                    -  Primary surgery is defined as the last surgery at which histologic evidence
                       of invasive or in situ disease was present in the pathology specimen

               -  Patients with positive sentinel lymph node biopsy are eligible provided they have
                  had a subsequent axillary lymph node dissection

          -  No metachronous breast cancer

          -  Bilateral mammogram within the past 12 months unless initial surgery was a total
             mastectomy, in which case only a mammogram of the remaining breast is required

          -  No metastases confirmed by 1 of the following methods:

               -  Bone scan* (required only if alkaline phosphatase is at least 2 times normal
                  and/or there are symptoms of metastatic disease)

               -  Abdominal ultrasound or CT scan (required only if AST/ALT or alkaline phosphatase
                  is at least 2 times normal, unless the elevation is in the bone fraction)

               -  Chest x-ray NOTE: *Confirmatory x-ray, CT scan, or MRI required if the bone scan
                  results are questionable

          -  No locally recurrent disease

          -  No prior or concurrent carcinoma in situ of the contralateral breast treated with
             partial mastectomy and/or hormonal therapy

               -  Patients with prior or concurrent carcinoma in situ of the ipsilateral breast are
                  eligible provided the tumor was completely excised AND they have not received
                  prior hormonal therapy

          -  Hormone receptor status:

               -  Estrogen receptor- and/or progesterone receptor-positive by immunohistochemistry
                  or tumor receptor content ≥ 10 fmol/mg protein

        PATIENT CHARACTERISTICS:

        Age

          -  Postmenopausal

        Sex

          -  Female

        Menopausal status

          -  Postmenopausal prior to chemotherapy, defined as 1 of the following:

               -  Over 60 years of age

               -  Age 45-59 with spontaneous cessation of menses for more than 1 year prior to
                  study entry

               -  Age 45-59 with menses ceasing (secondary to hysterectomy or spontaneously) within
                  the past year AND a follicle-stimulating hormone (FSH) level prior to study entry
                  in the postmenopausal range*

               -  Age 45-59, previously on hormone replacement therapy (HRT) and have discontinued
                  HRT upon diagnosis of this malignancy AND has an FSH level prior to study entry
                  in the postmenopausal range*

               -  Has undergone bilateral oophorectomy NOTE: *By institutional standards OR > 34.4
                  IU/L if institutional range is not available)

        Performance status

          -  ECOG 0-2

        Life expectancy

          -  At least 5 years

        Hematopoietic

          -  WBC at least 3,000/mm^3 OR

          -  Granulocyte count at least 1,500/mm^3 AND

          -  Platelet count at least 100,000/mm^3

        Hepatic

          -  See Disease Characteristics

          -  AST and/or ALT less than 2 times upper limit of normal (ULN)*

          -  Alkaline phosphatase less than 2 times ULN* NOTE: *Unless imaging examinations have
             ruled out metastatic disease

        Renal

          -  Not specified

        Other

          -  Able to swallow study medication and have adequate unassisted oral intake in order to
             maintain reasonable nutrition status

          -  No other non-breast malignancy within the past 5 years except adequately treated
             nonmelanoma skin cancer, curatively treated carcinoma in situ of the cervix, or other
             curatively treated solid tumors with no evidence of disease for at least 5 years

          -  No other concurrent medical or psychiatric condition that would preclude study
             participation and/or interfere with results

        PRIOR CONCURRENT THERAPY:

        Biologic therapy

          -  Prior and concurrent trastuzumab (Herceptin®) allowed

        Chemotherapy

          -  See Disease Characteristics

          -  At least 3 weeks but no more than 3 months since prior chemotherapy

          -  Prior adjuvant chemotherapy allowed

        Endocrine therapy

          -  See Disease Characteristics

          -  No prior aromatase inhibitor

          -  No prior tamoxifen or other selective estrogen receptor modulators (SERMs) except
             raloxifene

               -  At least 3 weeks since prior raloxifene

          -  At least 3 weeks since prior and no concurrent over-the-counter products or
             supplements considered to have an estrogenic effect, including any of the following:

               -  Ginseng

               -  Ginkgo biloba

               -  Black cohosh

               -  Dong quai

               -  Fortified soy supplements (e.g., phytoestrogen preparations)

          -  At least 3 weeks since other prior hormonal therapy or steroids considered to have an
             estrogenic effect

          -  No concurrent estrogens, progesterones, androgens, or SERMs

               -  Concurrent intermittent vaginal estrogens (e.g., vagifem, estrogen vaginal cream,
                  testosterone, estradiol vaginal gel, or Estring) allowed if other local measures
                  for intractable vaginal atrophy are insufficient

          -  No other concurrent therapy that would have an estrogenic effect, including endocrine
             therapy, hormonal therapy, or steroid therapy

        Radiotherapy

          -  See Disease Characteristics

          -  Prior adjuvant radiotherapy allowed

          -  Concurrent radiotherapy allowed

        Surgery

          -  See Disease Characteristics