Castle Biosciences GEP Skin

[xrt123]

I am wondering how people are using the information from Gene Expression Profiles (GEPs) in skin. One of our MOHs surgeon has started ordering fairly frequently and these predict for distant failure but not local recurrence. It was not designed to help make decisions about the benefit of adjuvant therapy, but now we are being sent patients to treat based on the findings. With the class 2A and class 2B are you doing ordering work up imaging differently? Are you ordering a CT primary site and CT Chest? PET? To me it seems reasonable that if you have a 20% chance of distant mets to start with some more extensive imaging up front.

The other question is with Class 2A/B are you covering regional nodes automatically? Based on the approach with head and neck for elective nodal coverage this also seems reasonable.

The ASTRO meetings I don't think have really touched on this topic from what I saw. The ASTRO guidelines are also nebulous about nodal coverage and do not discuss this. It will probably be years before we have prospective data so I was hoping to hear peoples thoughts. As of now I am pushing for baseline CT imaging and trying to talk patients in to covering regional nodes, but I am not so sure when its a lesion on the eyebrow or where I will have to treat parotid.

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[TheWallnerus]

I am wondering how people are using the information from Gene Expression Profiles (GEPs) in skin. One of our MOHs surgeon has started ordering fairly frequently and these predict for distant failure but not local recurrence. It was not designed to help make decisions about the benefit of adjuvant therapy, but now we are being sent patients to treat based on the findings. With the class 2A and class 2B are you doing ordering work up imaging differently? Are you ordering a CT primary site and CT Chest? PET? To me it seems reasonable that if you have a 20% chance of distant mets to start with some more extensive imaging up front.

The other question is with Class 2A/B are you covering regional nodes automatically? Based on the approach with head and neck for elective nodal coverage this also seems reasonable.

The ASTRO meetings I don't think have really touched on this topic from what I saw. The ASTRO guidelines are also nebulous about nodal coverage and do not discuss this. It will probably be years before we have prospective data so I was hoping to hear peoples thoughts. As of now I am pushing for baseline CT imaging and trying to talk patients in to covering regional nodes, but I am not so sure when its a lesion on the eyebrow or where I will have to treat parotid.

This sounds like a really bad idea to start irradiating people we otherwise wouldn’t until there is clear data saying to do so. Even if it means drawing ire of another doctor sending people to be irradiated.

 

[xrt123]

These are people generally who met criteria of being BWH Stage T2b/T3 that would meet criteria treatment for prevention of local recurrence at baseline. These are not people with well differentiated tumors and clear margins with no other high risk features.

 

[mheat3]

I tend to always get at least local imaging in these folks and consider PET pending tumor and patient risks. Haven't used GEP to specifically decide on PET or not but I don't think it would be unreasonable to do so.

The nodal question I always struggle with and I see A LOT of skin. We are all biased by the rare failures we see etc. I am always open to objective data or approach to that question if anyone has a good framework.