Abstract: Objective To study the effect of human serum insulin-like growth factor-1(IGF-1) on the endometrial thickening in women with breast cancer who accepted tamoxifen treatment. Methods Thirty-nine women with breast cancer treated with tamoxifen were enrolled and screened for the endometrial thickness by ultrasound every 3 months till 24 months after tamoxifen treatment. Spontaneously their blood serum was prepared for IGF-1 detection. When the endometrial thickness of patients was 0.5 cm or thicker by ultrasound, the research stopped. There were 26 cases who had the thickness less than 0.5 cm as A1 group. A2 group was comprised of the left 13 cases whose endometrial thickness was 0.5 cm or thicker.Human serum IGF-1 was detected by immunoradiometric assay(IRMA). Results The rate of endometrial incrassation was about 33.33% (13/39). The average age of A2 group was younger than that of A1 group significantly (P<0.05). The level of serum IGF-1 in all the patients decreased gradually as tamoxifen treatment extended. Compared with A2 group,the variation of serum IGF-1 level in A1 group was significantly greater in the sixth month after tamoxifen treatment (P<0.05). In the twenty-first month, the difference between two groups still existed but was not significant (P>0.05).Conclusion Tamoxifen treatment could decrease the serum IGF-1 level of women with breast cancer. The endometrial incrassation caused by tamoxifen treatment might be associated with the slower decrease of serum IGF-1 level.

Key words: insulin-like growth factor-1, breast cancer, endometrium, menopause