Role of cyclins A and E in endometrial carcinogenesis in breast cancer patients under tamoxifen treatment

PurposeThe objective of our study was to determine the relevance of cyclins A and E overexpression in endometrial carcinogenesis in hormone receptor-positive breast cancer patients under tamoxifen therapy.Experimental designWe assessed expression of cyclins A and E in Endometrial cytology samples collected from 36 ER and PR positive breast cancer patients; under tamoxifen treatment by using the Tao-brush non-invasive brushing cytology technique. Cyclins were detected in the collected samples by means of immuno-cytochemistry.The patients included in this study are a cohort of 36 breast cancer patients who were operated upon at the National Cancer Institute – Cairo University in the period from February 2006 to May 2008 and received tamoxifen (TAM) as part of their adjuvant treatment.ResultsCyclins A and E were expressed in 17 and 15 of the 36 collected endometrial cytology samples (47.2% and 41.6% respectively).Expression of cyclins A and E was highly correlated to Tamoxifen exposure duration (32 and 43 months respectively) p < 0.001. Tamoxifen median exposure duration was shortened to 21 months in cases showing positivity for either markers, while in cases showing positivity for both cyclins, the median exposure duration was longer (44.5 months) (p < 0.001). Neither cyclin A nor E was detected before median tamoxifen exposure duration of 11 months. Endometrial carcinoma cases had the longest Tamoxifen exposure duration (60 months).ConclusionCyclins A and E expression is involved in the carcinogenesis of endometrium in women with breast cancer and under tamoxifen-treatment. Follow up of the patients using these 2 markers is highly recommended starting from the 12th month.