Hi Gracie

there has been some work on using surrogate markers to predict the presence of HPV. What this means is that researchers are trying to find ways of determining if the thing they can detect which is not the actual disease or outcome has some sort of link to the disease or outcome. An obvious example of this is blood pressure. We all know that high blood pressure is not good. We also know that the reason blood pressure is not good is because it is a "marker" of cardiovascular disease which will eventually kill you. The high blood pressure itself won't kill you - it is a marker for the thing that will (ie cardiovascular disease).

So,back to your question...your father's doctors are trying to determine if your Dad's tumour is HPV +ve. Now the best way to do this is actually test for HPV which I believe is either expensive or tricky and not available in all hospitals. The cheaper and technically easier method is to test for P16. Without going into the biological ins and outs of this (which I don't understand anyway), the researchers have found that there is good correlation between the overexpression of P16 and HPV +ve tumours.

Wittekindt C and colleagues published their findings in Current Research in Head and Neck Cancer. 2005,vol62,p72-80 which basically says, yes there is a correlation between P16 and the presence of HPV+ve tumours. What this means is that testing positive for P16 probably means that the tumour is HPV+ve and therefore, yes, your Dad probably has a better prognosis.

The quote below is from the trial that found this. There are a very few people with HPV+ve tumours who test negative for P16 and even fewer who test postitive for P16 when they have a -ve tumour so this is a reasonable though not infallible measure to test for HPV+ve oral tumours.

[quote] We found 53% of the tested tonsillar carcinomas to be HPV positive. 56% of all tumors tested were immunohistochemically positive for the p16 protein. In 16 of 18 of the HPV-positive carcinomas diffuse p16 expression was observed. In contrast, only 1 of the HPV-negative carcinomas showed focal p16 staining (p < 0.001). Clinical outcome analysis revealed a significant correlation of p16 expression with increased disease-free survival (p = 0.02). These data indicate that p16 is a technically simple immunohistological marker, applicable for routine pathological histology, and its prognostic value for survival is fully equivalent to HPV DNA detection.
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