Understanding CA125 - does anyone?

I had this test and it was normal. However, I'm being told that the mass I have on my left ovary is almost certainly cancer. My GP said that it's possible to have a normal test, but still have cancer. Does anyone understand the test? Does it mean anything that mine was negative? I know some early stage cancers test normal, but my mass is 7.5cm. I know as well that it's less reliable in younger women, but I'm 59 and had my menopause at 52. I've searched for some information, but I'm none the wiser.

34 Replies

  • Hi Katlan , I have ppc / fallopian tube cancer , it is stage 3 , I've had major surgery and I've just finished chemotherapy . When my cancer was found it was very advanced I had four CA125 tests in two years they were never above the normal range . My surgeon a women's cancer specialist explained to me in some women this test is not a good marker , as in my case .. I hope this is helpful to you by the way ime 50 .. Love Elaine

  • Thank you for your reply xx

  • Hi Katlan,

    A ca125 blood test isn't always an accurate test for Ovarian Cancer because some people can have a normal result and still have cancer, likewise if a ca125 count is high e.g. above 35 (35 or under being normal) it doesn't necessarily mean that it is cancer because it can be risen for other reasons (like an infection) this is why it isn't used for screening, it is just a guide to tell the doctor that something is wrong, In your case you have a mass and will only know if it is malignant or benign after you have had it removed (or a biopsy done) and it tested.

    I can understand your dilemma but there is no point in worrying... until you know for certain...(I know this is easier said than done) I am sorry you have this worry and send you my best wishes for a good result love x G x

  • Hi

    I had a full hysteretomy in november 2012. i had a mass on the left hand side of my body, i am beginning to get back to normal but i see my consultant in march for my first six month check-up, i had no follow -up from the consultant or the nurse's and because they had taken

    it all, they seemed to have thought i will be clear. But could the cancer come back and if so

    will it show as it did not until i had a scan ! would it make me feel better if i asked for a scan !

    any views !!!!

  • In that case you should know by now whether it was cancer or not, (they should have told you to put your mind at rest) and I can't understand why you haven't had a follow up, you should insist on having an appointment to have it explained to you. Sending best wishes love x G x

  • I would say not to get too concerned by the CA125 until after the cancer is confirmed. I watched a program on TV last year which showed a surgeon removing a large mass on a ladies ovary, he said it was almost certainly cancer and yet the tests showed it to be benign. The priority is to get the mass removed or tested then you can decide if the CA125 is a marker or not. Love Paul xx

  • Thanks everyone for the replies xx

  • Hi

    My CA125 was normal as I had a type of tumour that would not be revealed in this way.

    when it was removed I did not have to have any other treatment- just check ups. Hope you have a similar sort of diagnosis.



  • Thank you Anne, I have everything crossed.

  • Hi there...

    I have advanced disease and but my CA125 has always been mid to low normal. Strange isn't it? T xx

  • But then... some woman have a raised CA125 and they don't have the disease. The CA125 good as a marker for identification purposes. It's used to track the disease. I'd start worrying only if something is confirmed. Sending love to you.. T xx

  • What baffles me is that GPs do this test for you if you present with symptoms. If the test is negative you can have false reassurance.

  • I just think a ca125 test is better than no test at all xx

  • Katlan, the CA125 test isn't used alone to confirm diagnosis of OvCa but in conjunction with ultrasound, ct scan,biopsy etc . The blood test is not a good marker for some women and that's why it isn't used alone to diagnose OvCa. (However for the majority of us, it is a very good marker) I do understand your concerns that the test can give you a false reassurance if it's negative. GPs would obviously explain this to their patients. It baffles me that they say the mass is almost certainly cancer if you have not had surgery/biopsy and have the pathology results!

    All the best. Fingers and toes crossed for a good outcome.


  • The GP says the radiologist's report from my MRI scan says the mass definitely looks like cancer. She also said that they would only know for certain once the cells are examined. Thanks for your reply and kind words.

  • CA125 is a protein produced by some ovarian cancers that circulates in the blood. According to Cancer Research UK "the CA125 blood level is raised in about half the women who have early stage ovarian cancer. Around 9 out of 10 women (90%) with more advanced ovarian cancer have raised CA125 levels. "

    My CA125 doesn't go really high when my cancer is back but the significance for me is it trends upwards. In 2010 when my cancer came back on my spleen, my CA125 was 27 (within the normal range) but it had increased from 9 to 19 then to 27 in a matter of months. I had read if it doubles then I should be concerned so I then had a ct scan which then confirmed the cancer.

    best wishes


  • I agree, in Sandra,s case it is the trend that is important, throughout the last 4.5 yrs she has had her highest 143 and her lowest 8. On one occasion it rose to 20 from a low figure which triggered a scan and subsequent chemo (2nd line). She is currently 138 and rising. Xx

  • hi my sister ova. and ppc  ca 125 2400 1st cemo, down 1000.  idont know what im doing 1st email

  • Hi smcallis... So sorry to hear your sister's diagnosis. You'll find lots of information and support on this site. You've posted to an old thread though which can be difficult. Do please consider creating a new post, you'll see a green button at the top right hand side of this page and it's very straightforward. I know that whatever your concerns, there are many here who will have some information, wise words and empathy... Best wishes, Sx

  • For me the CA125 has always been a very reliable marker. I am stage 3, grade 3. I am Brca1 and been fighting this cancer for 5 years.

  • Thanks for all the really helpful replies. xx

  • For my wife the test was always a good indicator of positive or negative treatment response, every time it rose any scan would show increase in tumour size or quantity, when it reduced the scan would always show a reduction, so for us it was a great help. Which i guess just goes to show that everyone is different.

  • I have a CA125 blood test every 4mo. My understanding is that it is a good marker for my type of ovarian cancer. For over 3 yrs it has been normal, an I have been in remission for over 3yrs.

    I know several women who have ovarian cancer in my support group that have this test reg., and have been told that it is not a 100 percent perfect test, but it is what they have now.

    Is it possible for you to get a second opinion or to wait and be PET scanned.? It is a difficult decision to have surgery, and I would like to talk to more than one Dr. before I decided.

    Best luck


  • I have seen my consultant today. I have a 7.5cm tumour on my left ovary. He says the only way to know exactly what it is, is to have it removed. So, I'm to have a hysterectomy. They will call me on Friday with a date. I'm happy with this decision.

  • My CA 125 was also normal. Had 10 cm mass Lt ovary. Total abdominal hyst. done last month on the 8th. Stage 1. With the borderline ovarian cancer the CA 125 is usually normal. No chemo needed with stage 1. Please be sure your surgeon is a gym/oncologist. Hoping you have good results like I did!

  • Oh I meant to mention this--we're close in age. I'm 60. I'm starting my 5th week recovery and have done pretty well!

  • Thanks Optimistic, yes my surgeon is gynae/oncology. I'm just waiting for my operation now. It's the waiting that gets you! I'll just try and keep busy. I wish you all the very best for a continued good recovery xx

  • I'm having my surgery next Thursday. I feel really anxious and upset now. I just want it over.

  • All the best for Thursday x love and support x Sarah x

  • Thank you Sarah xx

  • Best of luck,prayers and hope for good news when you have yor surgery on Thursday xx


    Had op in Octob, mass exactly 7,5 right ovary, ca about 9. Also 59 yrs. Patogistology low grade 1a. Had few ca 125 after, it was never elevated, no before op neither after.

    In general, half of all 1 stage are without eleveted ca 125. In some cases it is sign cancer didnot spread all around.

    Wish you luck and sending hugs

  • Just a little tip as I see you're fairly new to the site....Welcome by the way!

    Before replying to a post, check when it was written.

    This one was 3 years ago.

    It's an unfortunate and sad fact of this forum that not all of our friends from 3 years ago are still with us.

    All the best.x

  • Yes, thanks a lot Mac27,,,it can be very easily seen when its written, just I'm very confused these days I suppose.

    And thanks for welcoming, really need a place to understand my own problem.

    How do you know she passed away. Maybe she just left the site. I hope so.

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