Breast Cancer in Transgender People

Breast cancer is a vicious disease that is far more prevalent than we would like. One in eight women will receive a breast cancer diagnosis in their life, and one in one thousand men receive the same. However, more rarely discussed when mentioning these statistics is the risk of breast cancer for transgender people.

Transgender people–those who identify with a different gender than the one they were assigned at birth–may choose to receive treatments to align their bodies with the physical standard of their gender. This process, called transitioning, can include surgeries as well as gender-affirming hormone therapy. While some find these changes unnecessary, others rely on them to feel comfortable in their own bodies.

What gender is most likely to get breast cancer?

Most people could tell you that women are more likely to get breast cancer than men. And while this is correct, many don’t know the reasons why. Between the excess breast tissue and ‘female’ hormones, the female gender identity seems to come with risk. This includes both cisgender–those who are not transgender–and transgender women. However, everyone of any gender should invest in regular breast checks, looking for lumps or any other possible changes to their breasts.

Risk for Trans Women

An increased amount of estrogen and progesterone, commonly known as the female hormones, in the body for any reason will increase the breast cancer risk for anyone, regardless of gender. However, these two hormones can both be used in hormone treatment for trans women or non-binary people, giving their bodies access to more than they naturally produce. While this is perfect for helping transition (alter their physical characteristics to match their gender identity) it does introduce an increased risk where there wasn’t as high a risk before.

Risk for Trans Men

Transgender men, however, tend to lower breast cancer risk factors through both surgical means and cross-sex hormone treatment. Trans men and some non-binary people receive top surgery, a form of mastectomy that removes the breasts to give them flatter chests. While this procedure is different from a mastectomy performed to clear out breast cancer, a large amount of breast tissue is still removed. With less breast tissue, there is, simply put, less room to develop breast cancer. However, the lymph nodes and glandular tissue–two places breast cancer is likely to form–are usually still left in place. Also, consider that scars left behind can make breast imaging for breast cancer screening difficult.

Furthermore, breast cancer cases in trans men are relatively low because of their own hormone therapy. Trans men, and some non-binary people, go through testosterone therapy. Testosterone, commonly considered the male hormone, can bring trans men’s physical appearance closer to that of the general male population. And, while an unusually high amount of androgens–hormones relevant to sexual development, including testosterone–can lead to an increased breast cancer risk, testosterone treatment doesn’t tend to add enough of the hormone to the body to cause this kind of higher breast cancer risk.

Cisgender People

When discussing cisgender people, breast cancer development is far more likely to happen in women. However, even among cisgender women, some are more at risk than others, especially due to factors out of their control. For example, those who started menstruating early and became menopausal late have an increased risk. This increase is due to the excess amount of estrogen and progesterone these women were exposed to; as with trans women, the excessive amount increases the risk of breast cancer.

Cisgender men generally have the lowest risk of breast cancer. However, this does not mean they have no risk. Cis men absolutely should still be aware of the signs and symptoms of breast cancer, such as breast pain and nipple discharge, as well as the risk factors, such as family history and testicular surgery.

Is Trans hormone therapy dangerous?

As with any medical procedure or treatment, there are some risks to hormone treatment. Taking estrogen while smoking, for example, increases the risk of blood clots. One risk of taking testosterone is a high hematocrit count, or overly thick blood, leading to a possible stroke or heart attack. And while many trans men, trans women, and non-binary people may choose not to pursue hormone therapy due to these risks, one must also consider that those listed above are not the only people who utilize this treatment.

Many cisgender menopausal and postmenopausal women participate in hormone replacement therapy to treat their menopausal symptoms. The boost in estrogen that they no longer naturally produce minimizes their hot flashes and vaginal discomfort and has even been proved to reduce bone fracture and prevent bone loss.

Risks for this treatment are commonly listed as blood clots, stroke, heart disease, and, of course, breast cancer. So, while it is well known that hormone treatment alters the absolute risk of breast cancer, this is not strictly an issue for transgender people.

Who has the highest risk of breast cancer?

A Dutch study published online in 2019–”Breast cancer risk in transgender people receiving hormone treatment: nationwide cohort study in the Netherlands“–investigated the risk of breast cancer in transgender people receiving hormone treatment between 1972 and 2016 from a specialist clinic in Amsterdam (1). In this time, 2,260 trans women and 1,229 trans men were treated. In the population of transgender women–those assigned male at birth (amab) but identify with the female sex–15 cases of invasive breast cancer were diagnosed, approximately .7%. However, among cisgender women, the statistic is closer to 12.5% or one in eight women.

Of the transgender men–those who were assigned female at birth (afab) but have a male gender identity–examined in the study, only four cases of invasive breast cancer were diagnosed. This gives trans men a standard risk of approximately .3% if the study is trusted. Cisgender men receive breast cancer diagnoses in one in 1000 men, approximately .1%. However, the numbers and data pulled from the study are not the be all end all for transgender breast cancer risk statistics. More research needs to be done to have more confidence in the numbers.

However, using the data we have available from the study, those with the highest risk of breast cancer are the general female population, with cisgender women having the highest risk of all. Trans women follow after, then the general male population, with cisgender males having the lowest risk of breast cancer.

It is crucial for transgender people to understand the health risks that can come with transitioning. While many choose not to transition, many consider it of absolute importance to their health, both physical and mental. Further research needs to be done to better understand just what transitioning means to understand any potential side effects or health problems. Patients will need to know their new risks and new preventative measures to perform that they may not be familiar with, such as regular self-breast checks.

Dr. Gorman at the Texas Breast Center works to keep her patients informed of breast cancer risks, screening options, and treatment. Each patient she and her team see is treated with a personalized and targeted treatment plan.