[Effective reduction of elevated tumor markers by exemestane--a 12-year follow-up of a case of bone metastatic breast cancer].

A 75-year-old woman with low back pain had attended a local orthopedic clinic since around December 1990, but no remission had been achieved. The patient also had a gait disturbance, and visited our hospital for detailed examinations in May 1992. Bone scintigraphy revealed metastatic tumors of L 1 and L 2. Histopathological findings and tumor marker measurements led to a diagnosis of primary breast cancer. The patient was treated with TAM (20 mg/day) and 5-FU (150 mg/day). The tumor marker levels showed repeated cycles of slight increases and decreases. Acute elevations of the tumor markers occurring on January 24, 1997, and January 5, 2001, were successfully treated with MPA (800 mg/day) and 5'-DFUR (600 mg/day), but continuous administration of these drugs was difficult because of their adverse effects. A significant increase in the tumor marker levels (CA15-3 600 U/ml, CEA 197 ng/ml) was again observed on December 2, 2003. The patient showed no favorable response to the combination of MPA and 5'-DFUR but had persistent back pain. Exemestane given at 25 mg/day markedly improved both clinical symptoms and tumor marker levels. The results indicate that exemestane would be an effective hormone therapy for metastatic breast cancer.