Trying to understand CA125: Hello, Im trying to... - My Ovacome

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Trying to understand CA125

Horsesrock profile image

Hello, Im trying to find some clear guidance on the CA125 test. I was diagnosed in March with HGSOC stage 4. My CA125 was about 5,000. I had 4 chemos and it came down to about 800. I then had a successful debulk. 6 weeks later (last Tuesday) my 5th chemo and CA125 was back up around 1,200. I know the onc staff are keen we don't take too much notice but it would be comforting to understand more. I'd be so grateful if someone can direct me to a good site/article that explains the relationship between CA125 and OC. I'd also love to hear other peoples experience and whether they were similar to me. Is it possible to survive with high CA125 long term or can I expect my CA125 to suddenly drop to a normal level? With only one treatment left Im wondering if I'll ever get down below 35.

Many thanks!


12 Replies

Hope this publication can provide some general information (see link below). My CA125 was only 138 when I was diagnosed with stage 4 OC, just to show CA125 can be very different for all of us.

Wish you the best,


Horsesrock profile image
Horsesrock in reply to Liz9526

Brilliant. thanks Liz.

Hi Charlotte,

As I understand it, CA125 is only ever a part of the picture for your overall cancer status.

As you know, the normal upper limit is 35. Mine was 984 on diagnosis, but I know of women who had only a very mildly elevated figure (around 55-60) and others like you, who were in the several 1000s.

CA125 levels are typically measured not more than once a month as they can vary quite considerably during treatment. Things like having a cold, being very tired, having a flu vax, having chemo! etc can all also, affect your levels so it's important to see it in the wider context and not rely on that solely for your health status if that makes sense.

MY CA125 dropped from just under 1000 to 55 over the period of 4 chemo treatments, then went up again to 100, then down to 40-something. The general trend is downwards however (not upwards), so that's what we're focusing on. That's also pretty normal, as far as I can tell. If mine were to go up and up and up over the course of several weeks, it's likely the Onco would order a CT scan and use the two sets of results together to inform his decision on what I need next.

There are a lot of scientific, peer-reviewed, articles on Google which examine the relationship between CA125 serum levels and overall prognoses. However, there also seems to be some disagreement about if/how a prognosis can be affected by the CA125 levels, as measured at different stages of treatment, so if you read anything, please keep an open mind.

No-one can give those of us at Stage 3 or 4 a definitive answer about how long we might have left. There's no formula or algorithm to help them calculate, sorry. We just need to appreciate what we have right now xx

I found these articles below, using the google search phrase 'How do CA124 levels affect outcomes in ovarian cancer?'

ovarianresearch.biomedcentr... (Note that this article is 11 yrs old) (published 2020)

Hope this is helpful, take care

Annie xx

Thanks v much for your reply Annie. I’ll take a look. I know I shouldn’t get hung up on CA125 but it would be reassuring to hear from folk like me ie super high CA125 who are much further down the road.

We have many similarities such as ascites/ diagnosis/ and high CA125… as well as substantial drops in this level while doing chemo. I know is easier said than done, but we have to be patient and let the course of treatment take effect. I was advised by my surgeon that often CA125 increases after surgery as we all heal at different rates, etc. We have swelling and inflammation post surgery that we may not even realize is still there….and our CA125 May increase due to inflammation.

Being that you are only 6 weeks post surgery, this may be why it’s gone up. If it was dropping throughout your initial chemo cycles, that is a good indication that the chemo is working👍.

If it’s any comfort….my CA125 at initial diagnosis was 13,061😳. I did not show response to my first 3 cycles of chemo (still had 5 litres of ascites drained every 4 weeks)…. Then, I had a complete response after cycles 4-6 were completed😁. My CA125 is down to 28 as of a week ago…. That being said, my last chemo was May 20/21 and debulking surgery was June 22/21 so I am 12 weeks post surgery now.

There also has been indications that the Covid 19 vaccination and/or any cold or flu bug we may pick up (whether we have symptoms or not) may increase our CA125 marker.

I understand how hard it is, but try to be patient and not let the CA125 number get the best of you.

You are doing amazing!!


Surgery day - June 2021

Thanks Trish! That is what I needed to hear x

Hello, I was diagnosed in November 2017 and by the time I received Carbol/Taxol my CA125 was over 16000. After Chemo and debulking my Ca125 dropped to 9. It was July 2019 CA125 was 4500 after 18 weekily chemo Caro/taxol

Hello, I was diagnosed in November 2017 with stage 3C and by the time I received Carbol/Taxol my CA125 was over 16000. After Chemo and debulking my Ca125 dropped to 9. In July 2019 CA125 was 4500 after 18 weekly chemo Carbo/taxol CA125 was 4. August 2021 I’m at it again Ca125 was 1600 and after 4 chemos of Gemcitaban/carbo it’s going down and currently 122. My understanding is that normal CA125 is 0-40 so your 35 is within normal range. I didn’t expect to last 6 months but I’m still here 4 years later. I too set a lot of stall by my CA125. You’re not alone and the lovely ladies of this forum will support you. Dealing with this condition is tough but we’re resilient and somehow we cope with the treatment and move forward until the next time. Positive thoughts and best wishes to you.

Hi Charlotte,I understand your worries…it’s such a scary time when you get news like that,

I can recommend you look on Youtube and search for ‘Dr Hani Gabra’. He was my initial Dr and he has really helpful short videos on ca125 markers and what they mean.

If it helps, my ca125 was over 6000 and when I recurred I felt hopeless and frightened.

I had more surgery, then chemo and then Niraparib. I was told I was stage 4 in 2017 and I’m still here and doing well. Please stay hopeful. We see all different.

Please do pm me if you need or want to chat.

Much love, Nicky xx

Thanks Nicky , so pleased you are still clear. Do you mind telling when your CA125 became normal after surgery/chemo. Also what Niraparib dose you are on? Did it take a while for side effects to stabilise? I’m about 8 1/2 stone and really want the lease dose possible. Thank you X

Well...I have at least 2 tumors and without fail my CA125 is never more than 9 so contrary to your high numbers mine are always low. Oncs and I agree that the marker is obviously blocked so we don't include it anymore but rely on CT and PET scans. Hugs from paris

Oh lucky you to be in Paris! thanks for your reply... I think I need to chill on the CA125!

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