Interesting, page-1015

That’s a good question and something I think is often misunderstood.

A positive magsense scan requires the cancer to express the particular receptor/antigen that will be recognised by the antibody. But not all cancers are the same. In fact, there is significant heterogeneity between cancers- even the same type of cancer. Let’s take invasive ductal carcinoma (a type of common breast cancer) as an example. You can have oestrogen, progesterone and HER2 positive ductal carcinoma, or you can have oestrogen and progesterone negative and HER2 positive ductal carcinoma, or ER/PR positive and HER2 negative or triple negative ductal carcinoma. If you are just using a single antibody against HER2 this will allow you to pick up the first two groups, but not the last two groups. So a negative result is not necessarily reassuring in this case. Triple negative breast cancer is also associated with a far worse prognosis.

I mean we would really have to wait until comparative trials are performed to see how magsense stacks up in terms of its positive and negative predictive values. But my point is, a negative magsense result is not necessarily the same as there being no cancer.

What if there was a squamous cell carcinoma or some type of sarcoma or melanoma or lymphoma in the breast? These would all be negative with the Magsense HER2 scan but are all cancers that can occur in the breast.

I hope that makes sense? Happy to clarify anything further.