Decline in Hormone Replacement Prescription and Fall in Breast Cancer Incidence – An Epidemiologic Discussion: In Reply

by Prof. Dr. med. Andreas Stang in volume 16/2008

I agree with Neumann's view that a more comprehensive study of the factors influencing breast cancer incidence is desirable. However, he is asking for something that currently does not exist worldwide: cancer registration that captures not only the few cancer-characterizing variables but also the named risk factors. Even such a collection of data would not be sufficient. To assess the importance of such factors over time, a regular collection of these factors would also be required in women without breast cancer. This just seems altogether unaffordable.

With respect to the issue about transferability of US data to other populations, my article mentions that initial German analyses (Schleswig-Holstein) have shown a comparable decrease in incidence rates as well as in HRT prescriptions.

Epidemiologically, such notable and sudden decreases have not been observed in the incidence of breast cancer. The factors that Neumann lists (weight, age at menarche, number of children, duration of breast feeding, age at menopause) have changed over time. However, these factors do not change suddenly or drastically, so the sudden drop in incidence cannot be explained that way. The most important alternative explanation is the registration artifact of cancer registries, which was discussed extensively in the article.

Neumann criticizes that the usual substances prescribed as HRT in Germany differ from those prescribed in the United States. I do not understand this criticism as this is clearly addressed in my article. Why are epidemiologists so impressed by the sudden drop in incidence? Because over the past 30 years, the incidence of breast cancer has been increasing steadily and in a seemingly unstoppable manner, and no preventive measures have been able to stop this rise. DOI: 10.3238/arztebl.2008.808b


Prof. Dr. med. Andreas Stang, MPH
Sektion Klinische Epidemiologie
Institut für Med. Epidemiologie, Biometrie u. Informatik
Medizinische Fakultät
Martin-Luther-Universität Halle-Wittenberg
Magdeburger Str. 8
06097 Halle, Germany


Conflict of interest statement
The authors of both the letter and the reply declare that no conflict of interest exists according to the Guidelines of the International Committee of Medical Journal Editors.

References

1. Katalinic A, Rawal R: Decline in breast cancer incidence after decrease in utilisation of hormone replacement therapy. Breast Cancer Res Treat 2008; 107: 427–30.