Figure 1

Study flow chart. Overall flow chart showing the grouping of L-SCC in relation to HPV DNA, viral load, E6*I mRNA expression and immunohistochemical (IHC) protein pattern defining HPV involvement as extrapolated from CxCa and OP-SCC. HPV16_high—high, HPV16_low—low HPV16 viral load as determined by HPV16 qPCR. ^aFor two samples, HPV16 viral load could not be quantified because of β-globin negativity in qPCR. ^bFor two samples RNA was not analysable, that is, both HPV RNA and ubiquitin C RNA were negative. ^cFor 13 patient cases defined as HPV DNA−, ^done RNA− and ^eone RNA+ were of insufficient quality/quantity for IHC analysis. Combination of p16_high/pRb_low expression was found in 3 HPV DNA+/RNA+ tumours, but in none of the 23 HPV DNA+/RNA− or 47 HPV− tumours. This difference was statistically significant (χ²-test, P=0.002 and P<.0001). These three tumours were defined as HPV-driven L-SCC.