CA-125 Results Went Up: Should I be concerned?

My doctor and I ignore the CA 125 test results. I'm in a clinical trial, so they test for it monthly. It doesn't seem to be meaningful for me.

Do you mind if I ask what clinical trial you're in? How did you pick that one?

I was given 4 options after the 1st Clinical Trial failed. That one was Keytruda and miraculous until it went overboard on my immune system.
The 2nd and current trial includes Verzenio (Abemaciclib) & Letrozole because the tumor is estrogen based. These are breast cancer drugs, so the "trial" part is to see about Uterine cancer.
The same trial was performed at Dana Farber, Boston with a small group with good results.
The trial is 18-301 on their website. My trial is at UCLA, the Dana Farber study is closed.
I was given 3 other options. More chemo was an easy NO!
I have info on the 2 other options, but not handy.
The goal is SD as in Stable Disease as determined by CT scans.
I hope this helps.

I was diagnosed with Stage III-C ovarian cancer in February 2022. I had complete hysterectomy, appendix removal, and partial stomach lining (omentum) removal in May 2022. Still in chemo (on my third combination of drugs - Avastin, Keytruda, and Cytoxan). This has been working well for me overall. I feel fine, and my PET scans show no activity or new implants. But, my CA-125 has been steadily rising since last October 2023. At that time I was diagnosed with three melanomas on my left leg. In December 2023, I was diagnosed with two melanomas and one borderline melanoma on upper body. Last month, I was diagnosed with two melanomas, one on back and one on arm. My CA-125 was in normal range until the melanomas started popping up. It has steadily increased since October and is now at 295 as of this week. My most recent PET scan, last week, indicated no activity or implants visible. My oncologist is monitoring the CA-125, but says they rely on imaging more than the blood test. It still worries me that CA-125 keeps rising. There doesn't seem to be any connection between melanomas and increasing CA-125. Does anyone have any thoughts on this? As I indicated, I feel fine, no pain, do normal activities; just some fatigue. Thanks for any input.

I don’t know if this is any help at all. I have Ovarian cancer too, Stage 4. Here’s my experience with the CA125 test.
- I started off over 1700 but after hysterectomy, cancer debulking, and chemo, it went down to the low 20’s and has stayed there for over a year now.

- After the cancer debulking, the surgeon told me that he had had to leave several of the tumors because of their location but he felt chemo would take care of them.

- I started just Avastin after chemo and had been told I would be given that for 2 years. But after a much shorter time, my oncologist used the months of a low CA 125 to declare me cancer free and was going to stop treatment.

- I asked for a PET scan first and discovered that chemo hadn’t been successful and I still have several tumors in my abdominal area and one in the lining of my lungs. My cancer surgeon said that for me, the CA125 isn’t an accurate measure of my cancer.

- I’m still on Avastin 6 months later, it’s kept the tumors from growing, and my CA125 is still in the low 20’s even though I have cancer tumors.

After being diagnosed and learning about the CA125, I had talked to my GP and asked why they don’t give it with our yearly physicals and blood tests. She said because it’s too unreliable. You’ve probably read that. For me, I can’t depend on the CA125 and I needed to get imaging tests. BUT, I can totally understand why having it rise is really concerning you. I hope someone has a more helpful response that’s more directly related to what you’re encountering with melanomas. Keep asking questions. Keep advocating for yourself to make sure you’re getting the best medical care you can get. Since I was diagnosed, I’ve talked to too many women who had oncologists who made pretty major mistakes. I hope you’ve got a good one. 🙏🏽

The reason CA-125 is not a good screening test for all women is because so many other things can cause it to rise, and ovarian cancer is relatively rare. (See list.)
CA-125 is used to assess women who already have ovarian cancer. That’s because if you have a history of cancer, it’s more likely that a high CA-125 is due to the cancer, and not something else. But if you don’t have a history of cancer, one of the more common things on the list is much more likely to be the cause.
For a woman with OC and a rising CA-125, the next step would be a CT or a PET scan. You had one recently and it was clear. This is very reassuring.
If there were only a few causes, and if OC were more common, CA-125 would probably be a good screening test for all women.
This is why mammograms are a good screening test—breast cancer is common and the list of things that can cause an abnormal mammogram is short.
I don’t see melanoma in this list. But ask your oncologist and your dermatologist if melanoma sometimes causes CA-125 to rise.

@jo72 :
This is very helpful information. It is consistent with what I have learned. The CA125 is not a definitive indicator of ovarian cancer as it is less/more sensitive in picking up cancer signals in some women than in others. As well one’s baseline pre-cancer can also differ. If your results are consistent over time but suddenly change it would signal cause for further investigation. I also agree that you are much more likely to get appropriate care in a major cancer clinic that is a teaching center than you would in a general hospital.
@jaymuss55: I would suggest getting an expert opinion as the original opinion that chemo can take care of the remaining tumours was incorrect in the first place. Btw, is there a theory about how or why your melanomas have sprung up?
It is really important to ask good questions and if the answers leave you wondering, don’t wait. See someone whose answers make sense. I wish you well and hope that you can get what you need.

Thank you for responding. I have asked my dermatologist and oncologist if the melanomas and rising CA-125 could be connected. Answer is pretty much, not really. I think the main reason I'm getting the melanomas is because of my weakened immune system. As a youngster, I got bad sunburns (burn, blister, peel), so I am sure that didn't help any. My oncologist is monitoring the CA-125, but relies more on imaging. I used to get CT scans after three cycles of treatments, but now they do PET scans after three cycles. My PET scans have all come back with no "activity", and no new implants found. Previous CT scans showed I had 4 or 5 tiny implants (pea size), but they are either gone now or are so small they are not showing up on PET scan. I am still searching for a cause of rising CA-125, but in meantime, am pleased with good PET scans. I still do chemo every 3 weeks, and thankfully, I have not had problems with it. The only one I had trouble with was when I was on Doxil, which they had to reduce the dosage on twice to the minimum, as it basically made the palms of my hands look and feel sunburned, the skin peeled, and I could barely bend my fingers. Was glad to get off that when they started me on my current "cocktail" of Avastin, Keytruda, and Cytoxan (Cyclophosomide (?)). Had to come off Avastin from October until early February, while have melanoma surgeries, one in November and the other in January. Will probably have to come off again when they remove ones just found.

Thank you for responding. I have been on Avastin for little over a year now, along with Keytruda, and Cytoxan. Once I started on this "cocktail", my CA-125 was in normal range until October last year, when the melanomas popped up, and it is continuing to rise. I get PET scans after three chemo cycles, and they check the CA-125 every cycle. I try not to worry too much about the rising CA-125, although it has gone up considerably, but try to focus on the PET scans being good - no activity or new implants. I had the debulking done in May 2022. Things looked good for a few cycles, but by August 2022, the CA-125 started going up so my oncologist started me on my second "cocktail" of chemo drugs. That worked for a while, but in March 2023, on my birthday of all things, CT scan was done and it showed small growth in size of a few remaining implants that were still there. That is when I was switched to my current regime of Avastin, Keytruda, and Cytoxan, which has worked well for me. I have been blessed not to have suffered any serious issues with chemo drugs, other than when I was on Doxil, which made my hands like they were sunburned, and the skin peeled and I was unable to bend fingers much. Other than fatigue, I feel okay most of the time. Sometimes it's hard for me to even realize I have this horrible disease going on inside of me. I try to remain positive, as there is so much negative stuff out there on length of life after diagnosis (which is why I try not to read much of it), but I remain positive, as I have a friend, who has a friend that was diagnosed with Stage IV OC, and she is still going at roughly 14 years post her diagnosis, so I do not give up hope. I admit, when diagnosed, I thought my life was over and I was devastated. I had worked with a woman who was diagnosed with OC back in 1998 and she died in 1999. I did not realize how far they had come with treatments. My first visit with the oncologist after diagnosis made me feel so much better, when I was told it is treatable. I give credit to God for giving the doctors the knowledge to know the best treatment for me, and prayers of family and friends. I know it is in His hands so I try not to dwell on it. But, I still seek an answer for rising CA-125...

I’m with you on the remaining positive part. When you don’t know how much time you might have left, you definitely don’t want to spend that time feeling down and lost. I think one of the morals of your story is that when you have something like Cancer, never let them set a medical test on your birthday, or any other special day.

Avastin only has kept my tumors from growing for much longer than it usually does. My oncologist has pointed that out. Thanks pal. I’m going back to see all my cousins in Minnesota at the end of July. I’m having a CT scan to check the tumors shortly before going. I have to admit that I hope I don’t find out that the tumors have quit responding to the Avastin before I go.

Thank you for the information on the repeat chemos. I have basically been told that when the tumors start growing again that there are a few other chemo drugs they can try but that my chances of surviving much more than another year or so are pretty slim. I’m working on preparing for the worst while hoping for the best and not giving in to that prognosis. I’m doing by best to stay positive as well and to maintain the belief that there is more hope out there than that. 🙏🏽