Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Clinical relevance of "withdrawal therapy" as a form of hormonal manipulation for breast cancer | Agrawal et al. World Journal of Surgical Oncology 2011 9 101 http content 9 1 101 5 t WORLD JOURNAL OF SURGICAL ONCOLOGY RESEARCH Open Access Clinical relevance of withdrawal therapy as a form of hormonal manipulation for breast cancer Amit Agrawal John FR Robertson and KL Cheung Abstract Background It has been shown in in-vitro experiments that withdrawal of tamoxifen inhibits growth of tumor cells. However evidence is scarce when this is extrapolated into clinical context. We report our experience to verify the clinical relevance of withdrawal therapy . Methods Breast cancer patients since 1998 who fulfilled the following criteria were selected from the departmental database and the case-notes were retrospectively reviewed 1 estrogen receptor positive operable primary breast cancer in elderly age 70 years locally advanced or metastatic breast cancer 2 disease deemed suitable for treatment by hormonal manipulation 3 disease assessable by UICC criteria 4 received withdrawal from a prior endocrine agent as a form of therapy 5 on withdrawal therapy for 6 months unless they progressed prior. Results Seventeen patients with median age of had withdrawal therapy as second to tenth line of treatment following prior endocrine therapy using tamoxifen n 10 an aromatase inhibitor n 5 megestrol acetate n 1 or fulvestrant n 1 . Ten patients had clinical benefit CB complete response partial response stable disease 6 months with a median duration of Clinical Benefit DoCB of 10 7-27 months. Two patients remain on withdrawal therapy at the time of analysis. Conclusion Withdrawal therapy appears to produce sustained CB in a significant proportion of patients. This applies not only to withdrawal from tamoxifen but also from other categories of endocrine agents. Withdrawal from endocrine therapy is therefore a viable intercalating option between endocrine agents to minimise resistance and provide additional line of therapy. It should be considered as .