In a patient with history of successfully treated locally advanced H&N cancer, how do you discern between a metachronous second primary locally advanced lung SCC vs. metastatic head and neck SCC?
What clinical or radiographic factors would lean you in either direction - ie. time since index diagnosis, distribution or appearance of lung and nodal disease, presence of lymphangitic carcinamatosis, etc?
Is there a role for p16 (even though it can be positive in lung primary)?
HPV testing (E6/7 ISH or DNA PCR)?
Any role for NavDx? Guardant360?
Answer from: Radiation Oncologist at Academic Institution
This is a difficult clinical situation and unfortunately, too common. If you look at VAMC data, the incidence of a metachronous or synchronous lung cancer in the setting of HN cancer is approximately 20%. This data was prior to the increase in HPV related malignancies so most patients were smokers.&...
Comments
Radiation Oncologist at RadiantCare
I agree if it was a single lung lesion, I would SB...
I agree if it was a single lung lesion, I would SB...
Answer from: Medical Oncologist at Academic Institution
This scenario does come across in clinical settings often. As such, there are no bio-markers between squamous cell lung vs squamous cell H&N which can help differentiate though the presence of p16 can help.
The radiological appearance of lung lesions can be helpful especially if prior CT scans ...
Answer from: Medical Oncologist at Community Practice
This is a challenging clinical scenario. Testing for p16 makes sense because if the results are discrepant between the primary H&N cancer and the metachronous lung and mediastinal tumors, the second is almost certainly a de nove squamous NSCLC. If the results are congruent, the question remains....
Answer from: Medical Oncologist at Community Practice
Agree with the above suggestions of looking for help from pathology and radiology colleagues.
Would also consider circulating tumor DNA from a tissue-informed assay like Signatera. If initial tissue of the h/n derived genomic alterations are present as cell free DNA, then would be more likely to co...
What (if any) is the role of immunotherapy in thes...