Tamoxifen Citrate in Treating Patients With Metastatic or Recurrent Breast Cancer

Official Title

A Phase II Prospective Trial Correlating Progression Free Survival With CYP2D6 Activity in Patients With Metastatic Breast Cancer Treated With Single Agent Tamoxifen

Summary:

RATIONALE: Estrogen can cause the growth of breast cancer cells. Hormone therapy using tamoxifen citrate may fight cancer by blocking the use of estrogen by tumour cells. PURPOSE: This phase II trial is studying how well tamoxifen citrate works in patients with metastatic or recurrent breast cancer.

Trial Description

Primary Outcome:

• Correlation between CYP2D6 score (0 vs 1-2) and progression-free survival (PFS)

Secondary Outcome:

• Correlation of CYP2D6 score (0 vs 1 vs 2) with PFS
• Correlation of CYP2D6 score (0 vs 1-2) with PFS at 6 months
• Correlation of endoxifen concentration with response
• Correlation of CYP2D6 with response

OBJECTIVES:
Primary

• To correlate CYP2D6 score (0 vs 1-2) and progression-free survival (PFS) of patients with metastatic breast cancer treated with tamoxifen citrate. Secondary

• To correlate CYP2D6 score (0 vs 1 vs 2) and PFS of patients treated with this regimen.

• To correlate CYP2D6 score (0 vs 1 + 2) and the proportion of these patients who are PFS at 6 months.

• To correlate endoxifen concentration with response in patients treated with this regimen.

• To correlate CYP2D6 with response in patients treated with this regimen.

• To correlate the presence of candidate estrogen receptor (ESR) 1 and 2 variant alleles, UGT7, SULT1A1, and other candidate genes to PFS.

OUTLINE:

This is a multicentre study. Patients receive oral tamoxifen citrate once daily on days 1-28. Treatment repeats every 28 days in the absence of disease progression or unacceptable toxicities. Blood, plasma, and tissue samples are collected periodically for laboratory studies. After completion of study therapy, patients are followed up every 3-6 months for 5 years.

View this trial on ClinicalTrials.gov