Our natural hormones are delightful, double-edged swords. At puberty, they encourage our bodies to develop into beautiful young women, but they also give us acne and mood swings. In the middle of our reproductive life, they allow us to have children if we desire, but they also bring PMS and periods. Later in life, our natural hormone levels decrease with menopause and periods stop, but we start having hot flashes which are a whole new roller coaster. These conditions may be improved with external hormones, but that could increase the risk of breast cancer. That’s why, this Breast Cancer Awareness Month, we’re going to look at the relationship between hormones and breast cancer.
Estrogen and progesterone are two hormones that are higher in women and are intimately wrapped up in breast cancer risk. Estrogen stimulates the growth of milk ducts while progesterone matures the milk glands. When estrogen and progesterone ebb and flow throughout an ovulation cycle, they stimulate breast tissue to prepare for lactation and a possible pregnancy. Hormonal medications, such as hormonal contraception and Hormone Replacement Therapy can suppress and/or stimulate this process.
This in itself does not cause cancer. Cancer is caused by unregulated growth of damaged cells. Damaged cells can be caused by carcinogens in our food, environment, lifestyle choices, time, etc. If our body cannot get rid of the damaged cells, they can grow into cancer. Recent research shows that certain types of hormones can be more carcinogenic than others. It also matters what age a person is when exposed to hormones and for how long they are exposed.
Other Risk Factors
Some risk factors for breast cancer are modifiable and others are not. Genetics play a role in the risk calculator. If your family has a long history of breast, ovarian, uterine and colon cancer, talk to your doctor about whether genetic testing might be a good option for you to be aware of your risks.
Age is a big non-modifiable risk factor for breast cancer. Timing of pregnancy is a less modifiable risk factor. Breasts are not fully mature until pregnancy and lactation. Many studies have shown pregnancy earlier in life and breastfeeding is protective against breast cancer. These major life choices are a large commitment that are limitedly modifiable and sometimes completely out of our control, such as with infertility and lactation problems.
Long-term exposure to hormonal methods of birth control can increase risk of breast cancer. This difference becomes measurable after about a decade of use. However, it decreases back to baseline risk a few years after stopping birth control. Pregnancy is always riskier than any method of birth control for the average person. That’s why this is a complex discussion that an individual should have with their doctor so that they can make an informed decision based on their individualized risks. Pregnancy raises risks of blood clots, heart failure, stroke and death. Fortunately, all risks have small likelihoods. In fact, we’re more likely to die in a motor vehicle collision.
There are other modifiable risk factors that have been associated with an increased breast cancer risk besides hormones. Living an inactive lifestyle, regardless of a person’s weight, has been associated with breast cancer. Drinking alcohol, obesity and wearing an underwire bra have also been found to increase risk.
Hormone Replacement Therapy as Treatment
Hormones Replacement Therapy (HRT) has been associated with an increased risk of breast cancer. The same hormones in birth control at a different time in life seem to have a higher chance of leading to breast cancer. Length of exposure to hormones is still important and again, the risk goes down after stopping hormones. HRT has its benefits; it improves quality of life by minimizing hot flashes, mood swings and sexual side effects. HRT also keeps women’s bones thicker and healthier for longer, fighting off osteoporosis. Many women who have been through the symptoms that come with menopause will tell you that taking hormones is worth the risk, while most women who have had breast cancer will say it’s not.
HRT has been more thoroughly studied in the last 10 to 20 years than in decades preceding. New evidence has found that different types of progesterone, such as micronized progesterone, have lower risks of breast cancer than others. It has also been discovered that most of HRT breast cancer risk is related to progesterone rather than estrogen. Blood clot risks can be minimized by taking estrogen through a transdermal form rather than a pill. There are some new promising alternatives on the horizon, but for now, HRT remains the most effective short-term option for most.
If you’re still confused about what your risks are, you’re not alone. Each person’s breast cancer risks vary throughout their life and have to be weighed in balance with other risks and quality of life choices that are made every day. Hopefully we’ve learned through this pandemic that science is continuously developing and there’s new information to learn every day.
If you want to learn more about your individual risks of breast cancer, breast cancer screening, hormones, or birth control, we’re here to answer your questions. Call 972-542-8884 or complete this form to schedule an appointment.