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.

I’m really hopeful about my appointment at the UC Davis Cancer Center down in Sacramento. I checked the center and it was given high ratings by different medical entities for whatever that’s worth. We have only 2 oncologists in my rural community. I tried both and I got different reasons, think both are awful. And I’m not a hard-to-please person at all. I have two disabled children and I have been really, really happy with numbers of different doctors they’ve had over time.

The oncologist surgeon involved in my treatment is about an hour away and I see him only every 6 months for a check-in. For this next check-in they assigned me to see his PA which I’m not happy about. I’ll wait and see how it goes.

I sincerely hope that at UC Davis I feel like I’m being seen by competent oncologists. I don’t know if they will offer me some hope. At this point, I’ve essentially been given none, so what do I have to lose?

Thank you so much for your input. Each time I hear from someone else dealing with this, I feel that I benefit. 🙏🏽

Regarding seeing a PA rather than the doctor, that seems to be the norm in my area (for any kind of doc, not just oncologist). When I was first diagnosed, through the debulking surgery, and for several chemo treatments after that, I saw my oncologist. After that, I always see the PA before treatments, and only see the oncologist after a scan has been done. I think if I insisted on an appointment with the doctor, I could get it though, but I'm okay seeing the PA as I know any concerns will be discussed with the doctor. My CA-125 has been rising steadily since Oct last year, and no explanation so far. They tell me they are monitoring it, whatever that means. My doctor says they rely more on imaging, and since my last three PET scans have shown no sign of activity or new implants, she does not feel we need to change the course of treatment. But after my last CA-125 test last week, where it has risen to 295, I am concerned. I haven't done it yet, as I want to formulate some questions, but I will be sending a message to her on MyChart. Since I'm dealing with OC as well as melanomas that keep popping up (8 since October), it's a double whammy. My dermatologist has no explanation for so many melanomas coming out, as I have seen her regularly every six months for years for upper and lower body checks. I am now seeing her every 3 months (going for biopsy of four moles next week while still waiting to see surgeon for two she found last month). My oncologist does not feel there is any connection between OC and rising CA-125. I've read enough to know that a weakened immune system can cause melanomas, and that is probably what is driving mine (been on chemo over two years, plus got bad sunburns in my youth). I am still looking for reason for my rising CA-125 and haven't found an answer yet.