(Ivanhoe Newswire) -- The growth rate for breast cancer tumors varies
considerably, but a new approach to estimate the growth speed based on screening
shows that they grow faster in younger women.
Harald Weedon-Fekj of the Department of Etiological Research Cancer Registry of
Norway reports this model of estimating tumor growth is based on breast
screening results from almost 400,000 women included in the Norwegian Breast
Cancer Screening Program.
The research shows one in 20 tumors double in size in just over a month from 10
to 20mm, while a similar number took more than six years to grow. The average
time it took for a tumor to grow from 10 to 20mm was 1.7 years.
Weeden-Fekj says he and his team found that, as expected, mammography screening
test sensitivity increases with larger tumors. He reports detection rates are 26
percent for a 5mm tumor and increase to 91 percent for one that is 10 mm.
Previous tumor growth rate models were based on small, selected samples. This
model, says Weeden-Fekj has “enormous implications for sensitivity of beast
cancer screening programs.” He also reports the team compared their model to the
previously used Markov model for tumor progression and found its predictive
power to be twice as accurate in addition to providing new estimates directly
linked to tumor size.
SOURCE: Breast Cancer Research, published online May 7, 2008
