Many everyday things in our lives are linked to increased cancer risk, like birth control and hormone therapy, two common treatments meant to help us. And the headlines about those risks can be confusing and scary.
Before making big decisions about your treatment options, it’s important to learn how significant those risks really are, and what those numbers could mean for you as an individual.
Individual Cancer Risks Vary
Dr. Kevin Hall, a gynecological oncologist with University Health and UT Health professor and division chief of gynecologic oncology and urogynecology, said the risks and the benefits of each of these medications vary for each person.
Risk factors like smoking, a healthy weight, diabetes or a family history of certain cancers all contribute to your individual risk level.
“The individual patient is not going to be at the same risk as the general population,” Hall said.
People often don’t tend to see their own risk factors as risk factors, Hall said, which is why it’s important to discuss behaviors and family history with a doctor.
“These are personalized discussions that have to go on between you and your prescribing physician,” Hall said. “It’s your physician’s job to try to sort through those risks with you to try to help you make those informed decisions.”
Oral Contraception, or “The Pill”
Oral contraception has been tied to a slight increase in cervical cancer risk, but Hall noted that the “why” of that is not fully understood, and points out that there is another, much likelier culprit.
“Ninety-nine percent of people that have cervical cancer have a high-risk HPV infection,” he said. “However, people who take birth control pills also don’t routinely use condoms because they are already protected from pregnancy, so they may have a higher risk of transmission of HPV.”
(A vaccine is now available to prevent many strains of HPV, preventing several types of cancer, but as of 2019 only a little more than half of U.S. teens had received it.)
There are other possible effects of taking oral contraception besides avoiding an unintended pregnancy.
“Birth control increases risk of breast and cervical cancer,” Hall said. “It reduces risk of endometrial, ovarian and colorectal cancer.”
“With oral contraceptives, the dose is so much higher and in a younger population, so there are very different risks than for the hormone replacement given to older patients. The dose for oral contraceptives is designed to override the normal ovulation, whereas the dose for hormone replacement therapy replaces what is lost by menopause,” he said. “The oral contraceptive dose is roughly 10 times more potent than hormone replacement therapy.”
Family History as a Factor
Family history is an important element to factor into a decision here, he said. People with a BRCA mutation may be at a higher risk for cancer if they take oral contraceptives.
We actually give oral contraceptive pills to young patients with BRCA mutations as a protective measure for the prevention of ovarian cancer until they have completed childbirth. Her breast cancer risk, however, may be elevated by this – but there is better screening for breast cancer and no proven beneficial screening for ovarian cancer.
Hormone Replacement Therapy (HRT)
Hormone replacement therapy has also drawn a lot of attention.
An examination of many studies published in The Lancet showed that women who took hormone therapy for relief of menopausal symptoms face an increased risk of breast cancer. For women who took hormone therapy for five years, their risk of breast cancer increased by a range of 0.5% to 2%.
And that’s for the group, made up of many thousands of women, as a whole.
Hall said that overall slight increase should be weighed against the amount of relief from the symptoms of perimenopause, which can include:
- Hot flashes
- Sleep problems
- Weight gain
- Vaginal and bladder problems
- Changes in sexual function
Women may experience some, none or all of these symptoms in varying degrees.
Two in 10,000
Plus, there’s the amount of risk involved. “Hormone replacement therapy increased the risk of breast cancer, heart attacks, strokes, clots – those risks are in the one or two people out of 10,000 over the general population,” Hall said. “But HRT is protective against osteopenia and colon cancer at about the same risk, so there’s pro and cons.”
“Currently, we recommend it for severe symptoms until the time a woman would naturally go through menopause, then wean her off it with monitoring.” Many women, however, have a hard time managing the symptoms without the therapy, so Hall keeps them on the therapy while continuing to monitor.
“It comes down to informed consent. My job as provider is to say okay these are the risks … if you understand the risks, we will keep you on this therapy.”
It’s important to have these conversations – and to be frank about them, he said. “Don’t be afraid,” Hall said. “Be informed.”
Cancer Care at University Health
Learn more about cancer care services at University Health in San Antonio.