Pathologic Changes in Breast Cancer After Anti-Estrogen Therapy

Samarnthai N et al. – These findings indicate increased differentiation of the tumor cells in response to anti–estrogen therapy and that may correlate with clinical response.

Methods

• Authors reviewed a cohort of patients who received preoperative anti–estrogen therapy after baseline biopsy and then had a repeat biopsy after several weeks on treatment.
• Patients with estrogen receptor positive tumors received anastrozole and fulvestrant in combination with gefitinib.
• Core needle biopsies were performed at day 1 and 21, and tumors were completely excised if operable at day 112.
• All patients were postmenopausal.

Results

• Following treatment, tumors had degenerative changes including smudged nuclei, decreased nuclear size, intranuclear vacuoles, vacuolated cytoplasm, and increased cellular discohesion.
• In addition, increased tubule formation and intracytoplasmic lumina were seen in 6/9 cases (66.7%) and decreased mitotic rate was demonstrated in 7/9 cases (77.8%).

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