(flickr, starbooze)

There’s been a small, steady and troubling increase in breast cancer rates among a specific demographic of women for the last 37 years. A study published in the Journal of the American Medical Association uncovered, to the surprise of many breast cancer experts, that the number of young women – women between 25 and 39 years old – developing advanced breast cancer has increased by 2 percent every year since 1976.

That increase translates to about 1.4 additional breast cancer cases per 100,000 people every year for 34 years. They are small numbers at first glance, but over time they add up. Plus, the steady rise in cases shows no sign of ending, meaning more young women will be at risk every year.

The trouble with young women

Any increase in cancer cases is disturbing, but what’s especially troubling about these cases is the age at which they strike.

Young women are not regularly screened for breast cancer the way older women are. So, if cancer does develop in a young woman, it is far more likely to have spread to other areas of the body (metastasized) before it is discovered. This leaves women with fewer treatment options and less time to treat the cancer. Consequently, the prognosis for most young women who are diagnosed with breast cancer is only about five years.

Why this age?

That is the question that seems to puzzle most of the researchers. Why the steady increase in advanced breast cancer among this particular subset of women, but no corresponding increase in any other demographic?

Several theories have emerged, but it is helpful first to understand the connection between breast cancer risk and hormone exposure.

More hormones, more cancer risk

Several studies indicate that a woman’s risk of developing breast cancer at some point during her life is related to her exposure to certain hormones produced by her ovaries.

These hormones – estrogen and progesterone – stimulate cell growth in the body, even for cells that you don’t want in your body, such as cancerous cells.

So, anything that increases and sustains the presence of these hormones can increase her risk of developing breast cancer, which is likely to be particularly aggressive. 

According to the National Cancer Institute, some of the reproductive factors that prolong hormone exposure include:

• Early onset of menstruation
• Late onset of menopause
• Later age of first pregnancy
• Never giving birth

Delayed childbirth

With the connection between hormone exposure and cancer risk in mind, let’s turn to a 2009 Centers for Disease Control and Prevention (CDC) report on the later age of a woman’s first pregnancy. According to the study, between 1970 and 2006, the average age of first-time mothers increased from 21.4 to 25 years old. The increase was seen in varying degrees across all states and all demographics.