Hiya.

Not sure about the false positive thing. But biopsies are generally accurate (I'm not saying they don't have a failure rate, i genuinely dunno). They usually fall within 3 categories, positive, negative and inconclusive. The inconclusive ones tend to be the most time-consuming ones because whilst not the positive or negative outcome doctors are looking for, it means they can still be highly suspect. This is common with biopsies that only take a small part of the tumour/lymph, rather than the entire thing. When they look at biopsies, they're looking at the cell structure. For example, my wife's breast cells came back as highly irregular, thus cancerous. Even amongst the irregular findings, there's varying degrees. I think that's how they decide how aggressive the cancer is. The more irregular, the more aggressive, if i recall correctly.  Not saying this is how it works in all cases, but it's how it was explained to us.

As for finding your primary, your body's lymph system usually drains in a certain way, so if one node is enlarged, and cells are found within, it points to a certain area being the culprit. But as you are finding out, it's not always a straight forward task.

Thanks for your reply

Another problem with cancer, it needs to be a certain size before it will get picked up with scans. So your primary might be very small, thus they can't locate it.

Sometimes the primary is never found. That is usually referred to as cancer/carcinoma of unknown primary [CUP]

Hi and thank you for your post,

I am sorry to learn of your situation, this must be a difficult time for both you and your wife.

I can understand that you are feeling overwhelmed and stressed by it all. Cancers of unknown primary (CUP) are rare and account for around  2% of all cancers. It is not always known why or how it happens if the primary cancer cannot be found.

The possible reasons for this might be, for example, the immune system may have successfully attacked the original primary cancer cells and it has disappeared while the secondary cancer has continued to grow or the primary cancer is very small and not causing symptoms or cannot be picked up on scans. You can read more about CUP on our website at this link.

Sometimes in rare situations like this, it can be helpful to ask for a second opinion, especially if you are concerned about the biopsy as this can help clarify things. This is something you could speak to your specialist or GP about. We have further information about getting a second opinion here.

Often when it is more complicated, the doctors themselves may ask for second opinions from colleagues, and they will also discuss your situation at an MDT (multidisciplinary team) meeting which involves a variety of health professionals including, doctors, nurses and colleagues involved in diagnosis such as pathologists and radiographers.

I don't know if this is the case, where you are being treated, but some hospitals may have a team of doctors and nurses who specialise in cancer of unknown primary. It might be worth checking this with your specialist.

When the doctors plan treatment they will always weigh up whether the benefits of treatment will be outweighed by possible side effects. I wondered if it's possible to ask to speak with someone who is involved in your care such as the specialist or nurse specialist (if you have one) about any concerns you may have about having treatment.

I hope this reply helps in some way. Living with this uncertainty is difficult, please get back to us if you need any more information or support.  You may find it helpful to talk things through with one of the nurses on our helpline.  The number to call is Freephone 0808 800 4040 and the lines are open from 9am till 5pm Monday to Friday.

Take care, all the best

Jemma

Thanks for your reply Jemma. I didn't realise it was so rare, maybe I should play the lottery. 

The consultant mentioned same points as you. I gather there is a whole team looking at this and they have concluded that they need to treat this secondary area as there is a risk of cancer spreading from there at some point in the future. 

Thanks for the 'second opinion' link. I feel like I'm so far along the treatment route now that asking for a second opinion would be pointless. I'm having a PEG fitted tomorrow and my chemoradio will start in two weeks. It's all a bit crazy. 

Thanks again for your input, much appreciated.