Influence of practice on the biochemical analysis of steroid receptors in human breast cancer.

The value of experience and practice in the routine biochemical analysis of steroid receptors was studied in 2576 different primary breast cancer specimens over five consecutive years. The positivity rate (beyond 3 fm/protein) and the measured concentrations of the steroid receptors increase. The positivity rate and average steroid receptor concentration of the samples immediately frozen is significantly higher compared to the overall sample population. It is concluded that the handling of the specimen before freezing and the experience of the technician play an important role in the routine biochemical analysis of steroid receptors.