<qa>  What is the duration of the course?- Phase I closed to accrual effective 10232003: Patients receive oral tipifarnib twice daily on days 1-21. Patients also receive oral tamoxifen daily on days 8-18 during course I only and on days 1-28 during all subsequent courses. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. 