By: Vickie Richter

Breast cancer! The words tend to strike fear in the hearts of most women. They are, in short, frightening, even when spoken in general conversation or overheard on the news. The most recent news, courtesy of Norwegian researchers, is that the rate that breast cancer grows varies and tends to have a faster growth rate among younger women, which provides little comfort.

The scientists used a new mathematical model that enabled them to estimate the numbers of breast cancers that were detectable by mammography. The lead researcher Harald Weedon-Fekjr, of the Department of Etiological Research, Cancer Registry of Norway, said, "We found that mammography screen test sensitivity increases sharply with increased tumor size, as one might expect. Detection rates are just 26 percent for a 5 millimeter tumor but increase to 91 percent once a tumor is 10 millimeter in size."

The researchers model was tested using mammography results from the ages 50 to 69 in a study of 395,188 women. A complex formula was used in determining what size tumors were when they were detected; surgically removed tumors were measured; and other data was compiled in the study. The researchers say these findings may aid in evaluating and planning screening programs, along with other studies and clinical trials. "There are enormous implications for the sensitivity of breast cancer screening programs," Weedon-Fekjr added.

The growth rate of tumors showed a significant difference between patients. Approximately one in 20 tumors doubled in size—10 to 20 millimeters—in just over a month, yet in other cases a similar number of tumors took over six years to double in size. The research team estimates it takes an average of 1.7 years for tumors to double in size based on their findings. And tumor growth appeared to be faster in younger women and slowed as women aged. The research team's report reads, "Tumor growth seems to vary greatly between tumors, with higher growth rates among younger women."

How often should a woman get a mammogram? Studies have shown conflicting evidence supporting mammography and whether or not it saves lives. All experts agree that if breast cancer is detected early, it is much easier to treat.

According to the American Cancer Society, breast cancer is the leading cause of cancer deaths among women worldwide. Globally, in 2007, it is estimated that 465,000 women died from breast cancer and 1.3 million new cases were diagnosed.

Debbie Saslow, director of breast and gynecologic cancer at the American Cancer Society, said, "This study continues to prove why we need to screen women every year, starting at age 40." And this is a good reminder to do a breast check monthly. For information on how to perform a breast self exam, the Susan G. Komen Race for the Cure website has a visual instructional tool for you to watch. Mark your calendar and develop a routine for this simple procedure; it could save your life.