Squamous cell lung cancer or metastatic skin cancer?

[MarieE]

I saw an article yesterday about biomarker testing and this caught my eye:

Naiyer Rizvi, MD: "OK. Jacob, any other biomarkers you feel are important up front? We've got the DNA-based test. We've got the RNA-based test. We have PD-L1 testing. Anything else that you use to inform treatment decisions?"

Jacob Sands, MD: "I think those are, obviously, the most important ones. And one thing I'll add to that is, even in people who have squamous cell carcinoma who are never smokers, or light with a distant history of smoking, we do test those as well. Then we had a recent publication in Lung Cancer looking at our squamous cell population and going back and looking at NGS testing from those. And interestingly, there are some where it looks like it's probably more of a metastatic skin cancer or something else like that, particularly in these non-smokers, and so just to consider that there can be other possible sources of that, particularly in that population. And we saw a UV signature on the NGS panel within that, and then looking back, they actually have a history of a squamous skin cancer that had been resected. So sometimes the picture isn't quite as clear, and it takes a little bit of digging as well. But we as well do NGS panel and a PD-L1 expression testing."

https://www.onclive.com/view/advanced-lung-cancer-a-year-in-review?utm_content=6-22-20_OncLiveSS_Peer Exchange Lung eNL_Infimzi AstraZeneca CID_ed911ebda20bce9db65a2f33a6eb3ab6&utm_term=Workup and Management of Nondriver Metastatic Lung Cancer&utm_medium=email&utm_source=CM ONCLIVE&utm_campaign=6-22-20_OncLiveSS_Peer Exchange Lung eNL_Infimzi AstraZeneca

My husband has had a number of instances of squamous cell skin cancer and has had Mohs surgery several times to treat it. The quotes above make me wonder whether it truly is lung cancer or cancer than originated in the skin and spread - especially since he falls in the 'never smoker' category. Not sure whether it makes a difference either way in his treatment, but it's on my list of questions for the next oncology visit.

[LUNGevityKristin]

Wow, this is very interesting.  Please let us know what the oncologist says after you speak with them!

[MarieE]

I had asked early on, when I first heard that the biopsy of the original tumor was squamous cell, but I was told it was highly unlikely since squamous skin cancer rarely spread. But this makes me wonder again ...

[MarieE]

We finally asked about this and were told that squamous cell cancer from the skin rarely metastasizes distantly (e.g., lung). Usually, if metastasis occurs it will be regional metastasis. On the other hand squamous cell cancer from the lung could be metastatic to the skin or anywhere in your body. So, while it could theoretically happen, it appears unlikely.