Conditions: Estrogen Receptor Positive Male Breast Carcinoma Progesterone Receptor Positive Recurrent Breast Carcinoma Stage IIIB Breast Cancer Stage IIIC Breast Cancer Stage IV Breast Cancer
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 19
Healthy volunteers: no

Brief summary:
This phase II trial studies how well giving lapatinib ditosylate together with tamoxifen citrate works in treating patients with breast cancer that has spread from where it started to nearby tissue or lymph nodes or to other areas of the body and did not respond to previous treatment with tamoxifen citrate. Lapatinib ditosylate may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Estrogen can cause the growth of breast cancer cells. Hormone therapy using tamoxifen citrate may fight breast cancer by blocking the use of estrogen by the tumor cells. Sometimes when tamoxifen citrate is given, it does not stop the growth of tumor cells. The tumor is said to be resistant to tamoxifen citrate. Giving lapatinib ditosylate together with tamoxifen citrate may reduce drug resistance and allow the tumor cells to be killed.

Detailed description:
PRIMARY OBJECTIVES:

I. To determine the response rate (complete response and partial response) of tamoxifen (tamoxifen citrate) and GW572016 (lapatinib ditosylate) in women with hormone refractory, metastatic breast cancer.

II. To describe the changes in phosphorylation of epidermal growth factor receptor (EGFR), human EGFR 2 (her2), protein B kinase (AKT) kinase, mitogen activated protein kinase (MAPK), estrogen receptor (ER)-Serine (Ser) 118, and ER-Ser167 in tumor tissue after administration of tamoxifen and GW572016.

OUTLINE:

Patients receive lapatinib ditosylate orally (PO) daily and tamoxifen citrate PO daily. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at 1 month and then every 3 months thereafter.

Arms:
arm 1: Patients receive lapatinib ditosylate PO daily and tamoxifen citrate PO daily. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity.

Interventions: intervention 1: Laboratory Biomarker Analysis intervention 2: Lapatinib Ditosylate intervention 3: Tamoxifen Citrate
Intervention descriptions: intervention 1: Correlative studies intervention 2: Given PO intervention 3: Given PO

Protocol document: