Science is really cool… and a new research study from the team at the Perelman School of Medicine at the University of Pennsylvania (an Ivy League school, BTW) thinks it may have the answer on why women with a history of a previous pregnancy statistically end up with better outcomes after a melanoma diagnosis. I’m going to quote a passage on the webpage in its entirety because they summarize it better than I can:
The mechanism is related to a cellular protein called the G protein-coupled estrogen receptor (GPER). When GPER was activated and combined with anti PD-1inhibitor drugs in mouse cancer models, the therapy dramatically extended survival in all animals and completely eliminated the tumor in 50 percent of the mice.
Obviously, the research was conducted on mice, not humans; so let’s get that out of the way first. GPER is found in all female mammals, including mice, humans, and pretty much any other animal with breasts. Scientists suspect that GPER plays a role in the progression of breast cancer. But that’s a topic for a different blog. So what does that have to do with melanoma?
Melanocytes, the pigment-producing cells in the skin, has this GPER receptor. This receptor is normally activated by estrogen, which is higher in females and is at much higher levels in a female’s body during pregnancy. In fact, melasma or the darker patches of skin that sometimes occurs in pregnant women or women on birth control pills is thought to be due to the activation of GPER. Ok, still what does this have to do with melanoma?
Let’s say you’re a woman who has had a pregnancy. That means that GPER has been activated in your body. And then let’s say you develop melanoma at some point after that pregnancy. Once GPER is activated, the melanoma cancer cell becomes more differentiated. What does that mean? According to the article, “this means it divides less frequently, makes more pigment, and becomes more visible and vulnerable to the natural immune system. This makes it harder for the cancer to become resistant to immunotherapies.”
The next part of the study is really the show-stopper. The scientists stimulated GPER in the mice with melanoma and then used anti-PD-1 inhibitors to treat their tumors. These inhibitor drugs help boost the body’s immune response to cancer cells; but they’re not known for eliminating tumors completely and don’t provide long-term survival. But when GPER was activated and they used anti-PD-1 inhibitors, the researchers were able to eliminate tumors in half of the mice…
Half of the mice were basically cured using this approach. Let that sink in… That’s a pretty awesome stat (especially if you’re one of the half that it worked completely on). Ok, the other interesting thing about this study is that the scientists activated something found normally in the body rather than inhibiting something. The cool thing to think about that is that they activated something that is activated during the normal reproductive processes for females. GPER is not a toxic compound or none of us would be here to read this blog. So it could be an avenue of treatment unlike what researchers have traditionally pursued (activating rather than inhibiting) and could end up making melanoma treatments less toxic for the rest of the body.
So not only might they have figured out why women with previous pregnancies what better response rates to melanoma, they may have figured out how to extend that benefit to those of us women that have never had a pregnancy. And men, GPER is actually found in other organs too so you’re not cut out of the party, although there may be some interesting side effects for you…