Breast cancer could another lump appear?

  • 1 reply
  • 43 subscribers
  • 437 views

I’m still having chemotherapy for TNBC (I more lots of EC to have). I have noticed a small lump pop up in my armpit. My cancer hasn’t spread to my lymph’s (I have had 2 MRI’s which also confirmed this). I have had an infection in my mouth which required IV antibiotics last Saturday and oral antibiotics which I’m still taking. 

My question is, given I’m still having treatment, can a new tumour appear? I have spoken to my breast nurse who will let the oncologist know, and I’m back with him anyway next week so he will examine me. She didn’t seem particularly concerned and said infection can cause swollen lymps etc. 

  • Dear WhatNext

    Thank you for writing in with your question to us at ask a nurse. My name is Gemma, and I’m one of the Cancer Information Nurse Specialists here at the Macmillan support line.

    I see you have already joined a couple of our forums here at the online community; I hope you are finding it a supportive place to visit.

    It’s only natural you should worry that new lumps may be associated to your cancer diagnosis.  The likelihood of it being cancer spread is best answered by a member of your health care team, as there are so many variables to consider, they have the necessary access to your health records.  We would not be able to take into account your individual circumstances, so would only answer in general terms. 

    From what you have said, you have spoken with your own breast nurse about it, and she didn’t seem particularly concerned.   It certainly sounds like your mouth infection was quite a nasty one, with it requiring IV antibiotics, as you breast nurse rightly says, this could be explained by a nasty infection. You’ve done the right thing in keeping your team informed with the change you noticed, hopefully when you see your oncologist he will be able to reassure you.  

    It is relevant that neither MRI had shown any issues with your lymph nodes.  I see from your bio that you started carboplatin ad paclitaxel on the 3rd February 2024; I have assumed at least one of your scans has been after you had some of the chemotherapy at least. If the chemotherapy has shown to be effective on the breast lumps themselves, then it would be expected to be equally effective on anywhere the breast cancer cells may be. 

    I hope this goes some way to reassure you while you wait to hear back further from your hospital team. 

    If you have any further questions, please get in touch by email, webchat, or phone.

    You can also speak with the Macmillan Support Line team of experts. Phone free on 0808 808 0000 (7 days a week, 8am-8pm) or send us an email

    Ref/CF