Correcting Influencers about Cancer Risk and The Pill

They are abusing statements by the WHO, because fear sells.

Recently, a large Instagram account shared a scary post along the lines of,

“The WHO calls birth control pills class 1 carcinogens.”

I understand how this could fill people with fear, and even lead some to stop their birth control pills. However, the headline is taken out of context explicitly to scare people to stop taking the pill and almost always to buy the product or service offered by the influencer.

This headline, or variations on it, predictably makes the rounds every year. As it’s in the steady rotation of disinformation, it’s worth knowing more. And like with most misinformation, the headline is simple and scary, while the full context is more complex and requires patience to read beyond the headlines to fully understand the actual level of risk.

For example, sunlight causes cancer. If this were a misinformation headline it would read, SUNLIGHT CAUSES CANCER!! But this fact does not lead us to head underground and decide to become mole people. Basically, context matters and context is not something you get from the type of influencers who profit from fear, because fear gets more traffic and page clicks than facts.

Let’s start with the facts, most birth control pills contain an estrogen, most often ethinyl estradiol, and a progestin, a progesterone-type drug. Some birth control pills just contain progestin. These hormones are semi-synthetic, meaning they are made in the lab from an organic chemical extracted from a substance found in nature, here it is found in yams or soybeans. I could easily rebrand any birth control pill as natural and organic, but hey, I have ethics.

For this post we will focus on estrogen containing birth control pills, because the data on the pills without estrogen really isn’t clear. However, if there is a risk it is likely as low or even lower than the risk with estrogen containing pills.

All estrogen can cause cancer, and not just estrogens made in a lab. This is a known property of the hormone, it’s just the WHO doesn’t classify hormones made by the body as carcinogens. This fact about estrogen causing cancer doesn’t mean that everyone with estrogen in their body or who takes pharmaceutical estrogen will get cancer, it means that with some cancers estrogen is a cofactor or cause. This information needs to be evaluated and used to weigh the benefits versus the risk or therapies that have these hormones. As the WHO supports the use of hormonal contraception, it’s pretty clear they don’t consider hormonal contraception cancer causing along the lines of cigarettes. In fact, the WHO has a big document on the medical eligibility of contraception that you can access here. This document spells out who is at low risk for complications from all the different methods of contraception and who is at higher risk and should avoid certain methods. If hormonal contraception were a great cancer evil, this document would most certainly explain that fact. It does not. The WHO is clearly not warning people against oral contraceptives as a class of drugs.

Damn these influencers are so disingenuous and willfully misinformed.

The two main cancers related to estrogen are endometrial cancer (cancer of the lining of the uterus) and breast cancer. This is one of the reasons a later onset of periods and an earlier menopause is associated with a lower risk of breast cancer, because with fewer menstrual cycles there is a lower cumulative estrogen exposure over the lifetime. And this is also likely part of the reason why obesity after menopause is associated with an increased risk of breast cancer, as fatty tissue makes estrogen, so there is a prolonged exposure to estrogen.

This is also a good time to point out that pregnancy is associated with breast cancer. I know that shocks everyone, but there is about a 5% increased risk and that risk stays elevated for at least 5 years. This is all estrogen-receptor positive cancer, so clearly this is hormone driven, as there is no bump in estrogen receptor negative cancer. Why don’t these influencers have headlines about pregnancy being a carcinogen? I mean, I know why. They are almost always selling you shit that depends on your hormones being broken. They don’t care if you get cancer, they just want to scare you about the pill so you buy their grift.

How does estrogen cause cancer? For some cells, estrogen is part of the signaling that tells cells to divide, for example it causes the lining of the uterus to grow and also stimulates breast tissue. When cells divide the DNA accumulates mutations, and sometimes those mutations can be cancerous. So more divisions, the greater the cancer risk. Estrogen can also cause cancer by release of certain molecules as it is metabolized or broken down by the body. You can read more about that here and how it is abused by people trying to scare you about dirty estrogen.

While estrogen is carcinogenic, it is also important to note that the body has checks and balances for this cancer-risk. You may have even heard of one, the BRCA 1 gene. This gene codes for a protein that fixes DNA, known as a tumor suppressor. People with a BRCA 1 mutation don’t have enough tumor suppressor protein and so they begin to accumulate mutations, leading to a very high rate of cancer.

So knowing that estrogen made naturally by the body can cause cancer makes that headline about the WHO that is presented with no context on Instagram even more disingenuous (apparently, I need a disingenuous scale). A more generous interpretation of this kind of heading is that the person posting is not educated enough to know that estrogen is itself carcinogenic.

Forget about that lazy or ignorant or malicious (or all three) influencer and let’s focus on what matters. What additional risks are imparted by birth control pills and, if so, what is that risk? How can we put that risk into perspective?

Several studies have looked at oral contraception and cancer risk, and overall the risk of breast cancer while taking the pill is elevated by 8-24%, depending on the study. That sounds scary, but given the baseline rate of breast cancer for most women of pill taking age is very low, the actual numbers are very low. For all women, it seems the highest risk is one in 7,690 women, meaning if 7,690 women take the pill for one year, an additional one will get invasive breast cancer. The risk is even lower if you just look at women younger than 35 years of age, for these women it means 1 additional case of invasive breast cancer for 50,000 women for each year on the pill. There appears to be no risk with one year of use. Studies are conflicting on whether the risk drops back to baseline within a year or persists for several years.

The birth control pill also prevents two cancers: endometrial (lining of the uterus) and ovarian. For women who take birth control pills for 20 or more years there is a 40% reduced risk of ovarian cancer and a 60% reduced risk of endometrial cancer. This protection continues for 30–35 years after stopping the birth control pill. As we have no screening test for ovarian cancer and many are diagnosed late, leading to a high mortality rate, reducing the risk of ovarian cancer is a real bonus.

How can estrogen cause endometrial cancer and yet the birth control pill prevent it? While estrogens cause this cancer, progestins prevent it. And the amount of progestin in the pill more than counteracts the effect of the estrogen.

In addition to being cancer preventing, the pill has other health benefits. Hormonal contraception reduces blood loss with menstruation preventing anemia, which can have serious health consequences. Controlling bleeding with the pill may even prevent some from needing a hysterectomy. The pill can treat menstrual cramps, improve endometriosis-related pain, reduce or prevent menstrual diarrhea, help with PMS (premenstrual syndrome), and treat acne just to name a few very-real benefits.

However, the people trying to scare you about the pill don’t want you to know about these benefits because they are often trying to sell you hormone balancing supplements and/or diets, period “coaching”, so-called natural remedies to prevent pregnancy, menstrual trackers, or ovulation prediction kits. Remedies that depend in large part on not taking the pill. The birth control pill is one of the most tested medications that we have, and yet if an influencer is selling supplements they are literally peddling the least tested therapy. They could be selling dirt from someone’s backyard or products adulterated with hormones–which is not uncommon–and you would never know until you became sick.

My advice is if any influencer promotes this cancer-scare tactic, block them. They are not interested in your health, they are interested in sowing fear for clicks and cash. Or they are too lazy to look up the facts. Or both.

Here are the facts:

• The WHO labeling hormonal contraception as a carcinogen doesn’t mean it is like cigarettes.

• The WHO has guidelines on who can safely use the pill.

• If you are under the age of 35, the risk of breast cancer from the estrogen-containing birth control pill is 1 in 50,000.

• Overall the risk is no higher than one in 7,690.

• Pregnancy also increases the risk of breast cancer.

• The pill dramatically reduces the risk of cancer of the ovary and cancer of the endometrium.

• The pill has many health benefits in addition to preventing pregnancy.

The accurate headlines are quite a bit different, eh?

References

1. WHO Medical eligibility criteria for contraceptive use

   Fourth edition. Department of Reproductive Health, World Health Organization.

2. Lina S. Mørch et al. Contemporary Hormonal Contraception and the Risk of Breast Cancer. N Engl J Med 2017; 377:2228-2239.

3. Nicholas HB et al. Breast Cancer Risk After Recent Childbirth

   A Pooled Analysis of 15 Prospective Studies. Annals of Internal Medicine. 2019;170:22-30.

4. ACOG Hormonal Contraception and Risk of Breast Cancer

   Practice Advisory. January 2018.

5. PubChem Ethinyl Estradiol https://pubchem.ncbi.nlm.nih.gov/compound/Ethinylestradiol

6. Carcinogenicity of combined hormonal contraceptives and combined

   menopausal treatment, 2005 statement WHO.