The US Food and Drug Administration (FDA) is now warning that breast implants filled with either silicone or saline may, on rare occasions, give rise to cancer in the scar tissue around breast implants.

The safety notice was published this month and is based on an extensive review of the emerging literature on breast implants. The results, while limited, reveal a small number of squamous cell carcinoma (SCC) and lymphoma cases among individuals with breast prosthetics.

SCC is the second most common form of skin cancer. Other types of cancer previously associated with breast implants include T-cell lymphoma, which involves the immune cells that directly destroy pathogens in our bodies, and B-cell lymphoma, which involves the cells that produce antibodies against disease.

Both of these cancers seem to involve the immune system, and while they are not breast cancers as such, emerging evidence suggests they can affect tissue around the breast when an implant is present.

Unlike T-cell lymphomas, however, B-cell lymphomas and SCC do not show up on mammograms, which means they have evaded our screening methods for much longer.

To date, no case of breast implant-associated SCC has been reported in the United Kingdom, but in the US, more cases are being noticed. Researchers at the FDA have now identified close to 20 cases of SCC in the scar tissue around breast implants, as well as under 30 cases of various lymphomas.

The actual incidence rate remains unclear, but it is probably quite rare. Reported signs from patients include swelling, pain, lumps, or skin changes.

Unless you have any of these symptoms, experts say there is no need to rush to get your implants checked or removed. The risk of cancer remains very low, but that doesn't mean it's not worth keeping your eye on.

In 2018, a review initially identified 5 cases of SCC associated with breast implants, and, on average, these cases were diagnosed about 23 years after the prosthetics were first implanted. Two of these cases ultimately proved fatal.

At the time, researchers suspected chronic inflammation was to blame, and the new review backs up the immune system connection.

"In all of the documented cases of B-cell lymphomas, we have seen the presence of the Epstein-Barr virus, so it would seem that there is a viral mediator contributing to the pathogenesis," oncologist Mark Clemens told The Lancet.

Chronic inflammation is known to trigger SCC, but as of right now, experts say we don't have enough information on whether breast implants directly cause the inflammation or the associated cancers.

The current review can only point to a correlation, but given the possible risks, the FDA director for surgical and infection control devices, Binita Ashar, says the committee "wanted to provide clear and understandable information to the public as quickly as possible."

From now on, any reports of cancer developing in the scar tissue around breast implants should be reported to the FDA officials say, so they can figure out who is most at risk, and why.

(Those from outside the US should report to the governing body in their own country.)

Nigel Mercer, a regulator of healthcare products in the United Kingdom, told The Lancet he is not surprised to hear of another type of cancer associated with breast implants coming to light.

For many years, those who opted for surgical breast augmentation were given barely any safety information at all. In fact, in the first three decades of breast implant surgery, no clinical trials were done. Even now, long-term research is limited.

Only in 2011 did the FDA identify a possible cancer associated with breast implants, called anaplastic large cell lymphoma (ALCL) – a cancer also triggered when the immune system goes awry.

By 2016, the World Health Organization had followed suit, designating breast implant-associated ALCL (BIA-ALCL) as a T-cell lymphoma that can sometimes develop following breast implants.

Apart from that, we know little else.

At the beginning of April 2022, the FDA had counted 1,130 global cases of BIA-ALCL, including 59 deaths. In the UK, the incidence rate of these cancers is thought to be 1 in 15,000.

Rare or not, patients have a right to know the possible risks associated with their breast prosthetics. In fact, in many ways, patient demands have spurred on breast implant research.

Over the years, patients have reported numerous side effects from their breast prosthetics, including brain fog, inflammation, and fatigue.

Collectively, these symptoms are known as breast implant illness (BII), a poorly understood and understudied collection of complaints from thousands of people around the world who have received breast implants, either for aesthetics, gender-affirming purposes, or breast cancer.

The FDA has warned for years now that breast implants are not lifelong prosthetics, but the message is not often heard by the public. Initial research suggests the longer a breast implant remains in the body, the more likely it is to cause complications, like infections, inflammation, rupture, or localized pain. In rare cases, cancer might also be a risk factor.

The FDA currently recommends that people with breast implants undergo regular screening five or six years after initial implantation and then again every two or three years after that to ensure their prosthetics are in working order. But to date, research suggests less than 6 percent of patients actually do this.

To fix this, in 2020, the FDA recommended that manufacturers use a boxed warning to let patients know that breast implants are not supposed to be life-long devices. This suggestion, however, is not legally binding, and it's unclear how effective it's been.

As we wait for more evidence, officials at the FDA say they will continue working with the American Society of Plastic Surgeons to collect more detailed information on specific implant cases where cancer has been reported.