Hi. This is my first post. Diagnosed with IDC ER+ (male) breast cancer September 2022 and underwent left side mastectomy the same month. My oncology surgeon orders recurring Signatera blood tests for me and the three I’ve had so far have been negative.

My medical oncologist thinks the tests are worthless because if the test detects something suspicious, there’s no way to tell what organ or body part is being affected. My surgeon answers that by saying it doesn’t matter; if a test comes back positive, start chemotherapy. I told him I thought chemotherapy is targeted to the specific body part and the chemo, dosage, etc. could vary accordingly. He said that’s not correct.

I’d like to hear about other people’s experience with Signatera or comments about my two oncologists’ opinions about Signatera. Thanks.


Welcome to the forum , how confusing for you . You could maybe ask our nurses about this in the Ask the Nurses section see what they think ? I’d be more swayed towards the oncologists view of it was me as they are more involved with advising people re chemotherapy decisions .I think this is a very new test so maybe not many people have been through this process .

Ask our Nurses your questions

Hi @liverpoolwalrus, I hope you find the forum a useful place.

We have a board for men living with breast cancer which you can find here: Breast cancer in men - Breast Cancer Now forum

If at any point you feel like chatting to one of our team of breast care nurses, you can always call us on freephone 0808 800 6000 (Mon-Fri 9am-4pm; Sat 9am-1pm).

Sending our warmest wishes

Thank you very much.

We’ve had a lot of discussions in the US in regards to Signatera so I’ll tell you what the results of them have been. Yes, it’s useless. The reason is exactly what you state. A positive signatera test tells us nothing besides you have free floating cancer cells. But if a metastasis isn’t seen then what do you treat? Chemo isn’t always useful especially if the cancer cells aren’t dividing quickly. You don’t want to go into that unless you are sure it will be helpful. Plus just because you have free floating cancer cells doesn’t always mean a a truly positive test. There’s a woman on-line who started a whole discussion on reddit in regards to her experience with signatera. It was a trial when she had a positive test because it was just slightly positive and no one knew what to do about it. Eventually months later signatera came back and declared her test negative due to new data coming in. So that’s the point. It’s so new that no one knows what to do with the results and just because you have free floating cells doesn’t always mean apparently that a metastasis is imminent. Anyway just some info from over the seas :slight_smile: And also, your surgeon is a surgeon. Not an oncologist. He shouldn’t be weighing into your treatment decisions at all. He operates and that’s all.

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Thanks for that information. By the way, I’m in Florida, a lifelong Yankee.

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