Trastuzumab and Exemestane in Treating Postmenopausal Women With Metastatic or Locally Advanced Breast Cancer
Trastuzumab and Exemestane in Treating Postmenopausal Women With Metastatic or Locally Advanced Breast Cancer
RATIONALE: The monoclonal antibody trastuzumab can locate breast cancer cells that have HER2
 on their surface and either kill them or deliver tumor-killing substances to them without
 harming normal cells. Estrogen can stimulate the growth of breast cancer cells. Hormone
 therapy using exemestane may fight breast cancer by reducing the production of estrogen.
 Combining trastuzumab with exemestane may be an effective treatment for breast cancer with
 high amounts of HER2.

 PURPOSE: Phase II trial to study the effectiveness of combining trastuzumab with exemestane
 in treating postmenopausal women who have metastatic or locally advanced HER2-positive breast
 cancer.
OBJECTIVES:

 -  Determine the efficacy of exemestane and trastuzumab (Herceptin), in terms of response
 rate and time to progression, in postmenopausal women with metastatic or locally
 advanced hormone-responsive, HER2/neu positive breast cancer.

 -  Determine the toxicity of this regimen in these patients.

 OUTLINE: This is a multicenter study.

 Patients receive trastuzumab (Herceptin) IV over 30-90 minutes on day 1 and oral exemestane
 once daily. Treatment repeats every 3 weeks in the absence of disease progression or
 unacceptable toxicity.

 Patients are followed every 3 months.

 PROJECTED ACCRUAL: A total of 18-60 patients will be accrued for this study.
DISEASE CHARACTERISTICS:

 -  Histologically confirmed breast cancer

 -  Stage IV or locally advanced disease

 -  Staged by bone scan or CT scan of chest and/or abdomen within the past 6
 weeks

 -  HER2/neu positive by fluorescent in situ hybridization (if 2+ by immunohistochemistry)
 or 3+ by immunohistochemistry

 -  Measurable disease defined by 1 of the following criteria:

 -  At least 1 dimension at least 1 cm by CT scan or other imaging scan

 -  At least 1 diameter at least 1 cm by plain x-ray (excluding bone lesions)

 -  Palpable lesion with both diameters at least 1 cm with caliper OR

 -  Evaluable disease defined by 1 of the following criteria:

 -  Positive bone scan

 -  Palpable masses with diameter less than 1 cm, masses with margins not clearly
 defined on CT scan or x-ray, or with both diameters less than 1 cm

 -  Bone scan and CA 27.29 if bone scan only evaluable disease

 -  Hormone receptor status:

 -  Estrogen receptor and/or progesterone receptor positive

 PATIENT CHARACTERISTICS:

 Age

 -  18 and over

 Sex

 -  Female

 Menopausal status

 -  Postmenopausal by 1 of the following criteria:

 -  60 years of age and over

 -  45 years of age and over with amenorrhea more than 12 months and an intact uterus

 -  Follicle-stimulating hormone levels within postmenopausal range

 -  Undergone bilateral oophorectomy

 Performance status

 -  ECOG 0-2

 Life expectancy

 -  Not specified

 Hematopoietic

 -  Not specified

 Hepatic

 -  Bilirubin less than 1.5 times upper limit of normal

 Renal

 -  Creatinine less than 2 mg/dL

 Cardiovascular

 -  Ejection fraction greater than 50%

 Other

 -  Not pregnant or nursing

 PRIOR CONCURRENT THERAPY:

 Biologic therapy

 -  No prior trastuzumab (Herceptin)

 Chemotherapy

 -  Prior chemotherapy allowed

 Endocrine therapy

 -  No prior exemestane

 -  No other prior hormonal agent (except tamoxifen)

 Radiotherapy

 -  Not specified

 Surgery

 -  Not specified