Limited clinical benefit from trastuzumab in recurrent endometrial cancer: two case reports.

BACKGROUND

It is hypothesized that the HER-2/neu receptor could be used for targeted therapy in recurrent endometrial cancer.

CASES: A patient with type II endometrial cancer (serous), showing strong HER-2/neu overexpression and gene amplification in both primary and recurrent tumor, received single-agent trastuzumab (3x weekly, 8 mg/kg loading, 6 mg/kg maintenance dose). Because of progression after 4 cycles, weekly paclitaxel-trastuzumab (80 mg/m(2) paclitaxel; trastuzumab 4 mg/kg loading, 2 mg/kg maintenance dose) was initiated. However, progressive disease was also noted after 11 weeks of combined treatment. A second patient, with recurrent type II endometrial cancer (grade III endometrioid), had HER-2/neu gene amplification in the primary tumor. However, biopsy from a lung metastasis 3 years later appeared to be HER-2/neu-negative.

CONCLUSION

Based on lack of response and changes in tumor biology, trastuzumab was of little clinical value in 2 cases of recurrent type II endometrial cancer. This report underscores the importance of reassessment of a recurrent tumor before initiating targeted treatment.