Objective To described the tendency of Hormone Replacement Therapy (HTR) use in a 18-year follow-up retrospective cohort of women participating in the Valencian Community (VC), breast cancer screening program.

Methods Between 1992 and 2009, a retrospective cohort of participants in a population-based breast cancer-screening program in the VC was assessed. The study population was 683 739 women, 45–69 years. Trends in current HTR use, and new and leaving users, by educational level (EL) and age group were analysed. A regression analysis by the joint point (JP) for the tendency was calculated.

Results From 1992 to 2009, the 11.73% (N=71 827) of women was taken HRT, annual increases were found in the prevalence levels of HRT use to 2003 (13.5%) and remains in 2009 (12.5%). The peak by aged group was 20% in 2003 for the 55–59 group. The new users of HRT have increased until 1998, changing significantly, to decrease until 2009, as shows the JP regression analysis (p<0.005). The university (EL) new user's peak was in 1999 (12.3% vs 3.6%) in the no-studies group, in 2002 (8.2% vs 2.9%), in 2009 (2.7% vs 0.7%) (p<0.0001). The university leaving use peak was in 2004 (1.4% vs 1.05%) in the no-studies, in 2009 (0.4% vs 0.7%). There is a statistically significant difference in HTR users by EL, the regression analysis of the JP, shows that the trend is parallel increasing until the year 1998, and began a reduction until 2009.

Conclusions No too much impact had the WHI study in reduction of percentage of women taking HRT in our study.