Letters Section Editor: Robert M. Golub,
MD, Senior Editor.
To the Editor: The meta-analysis of studies
of hair dye use and cancer risk by Dr Takkouche and colleagues1 was
based on a comprehensive search of relevant studies of cancer risk associated
with ever use, permanent dye use, and “intensive exposure,” defined
as more than 200 lifetime applications of hair dye. However, the article did
not present data on risks related to hair dye color, duration of use (although
duration was used to impute frequency when frequency was unavailable), or
year of use. Since these data were not always available in individual studies,
the meta-analysis presented only the variables that were provided by all studies.
By limiting the review to the “lowest common denominator,” valuable
information was lost.
Zahm SH, Fraumeni JF. Hair Dye Use and Non-Hodgkin Lymphoma. JAMA. 2005;294(10):1205. doi:10.1001/jama.294.10.1205-a