CA15-3 blood result higher than normal


I’m new to this site and need some advise. I was diagnosed with breast cancer in 2022. I had a lumpectomy and radiotherapy and I now take Anastrazole. I’ve been suffering with chronic joint pain for months. After being fobbed off by my GP with physio referrals I was then fobbed off to an ‘out of hours doctors surgery’ The GP there said I need blood tests. My tests came back with CA15-3 at 35 and my Erythrocyte at 26. I had an MRI scan to check for secondary bone cancer which came back clear. My GP will not follow up why my CA15-3 blood result is high. I’ve been told it’s high because I had breast cancer and to mention it at my next mammogram appointment.

Is this something that I should be concerned about? My GP doesn’t seem concerned.


Hi I had breast cancer in 2000 and a bi lateral mastectomy.
I have had pain in my chest and been struggling to sleep on my right side .
I have been back under a consultant who ran bloods last July my result was 38 had scan mri couldn’t find anything .Has done blood test every 4 months ,level has dropped to 35 .
I asked where we go from here ,he said as it’s dropped I’m not worried as we didn’t find anything.
Back to him around April when he said he will repeat the bloods again .
He has got my gp to refer me to the pain clinic for chest pain .
The bloods are just watching.

Thanks for your reply lyndy61. I have asked my GP if I can have another blood test in a few months time to see if the levels change, and they said “what for”. Breast cancer runs in my family. 2 aunts both got secondary cancer, 1 died. Another aunt had a double mastectomy, but my GP refuses regular blood tests for myself, even though my C15-3 results are high.

My mum died of breast cancer ,I had a cousin die .
Now my 40 yr old niece has it .
Ask to be referred back to your consultant, mine has been very good speaking with other consultants.

My GP isn’t interested. I’m now looking at changing surgeries. My GP was struck off for 18 months, a few years ago, because he misdiagnosed a patient, they died and he amended their medical notes to cover his errors. I have tried to contact my cancer care nurse, but she doesn’t return any calls. I feel totally alone and really worried.

Hope you manage to see or speak to someone.

If I was you I’d bypass the gp & go straight to either the breast care team or if you have it oncologist.
I was told any concerns after BC to just go straight to BC team

You could try asking the hospital switchboard for a number / email address for your Consultant’s secretary . Sometimes these can also be found on the hospital website . Then you could phone them or better still email your Consultant via the secretary .

Welcome to the forum @Marhys

I’m so sorry to hear what you’re going through with your GP and that you’re not able to contact your cancer care nurse. The forum is full of kind people like those who have already replied here, I hope you find the support you are looking for.

Please know that our breast care nurses are here to talk any of your concerns through, here on the forum on the Ask our Nurses your questions or over the phone 0808 800 6000.

We’re thinking of you,