Oropharyngeal squamous cell carcinoma: p16/p53 immunohistochemistry as a strong predictor of HPV tumour status

Abstract

Aims Oropharyngeal squamous cell carcinomas (OPSCC) related to human papillomavirus (HPV) infection have a better prognosis than those without HPV infection. Although p16INK4a overexpression is used as a surrogate marker for HPV infection, 5–20% of p16‐positive OPSCC are described as being unrelated to HPV infection, with worse overall survival compared to OPSCC‐related HPV. There is therefore a risk of undertreating a proportion of OPSCC patients falsely considered to be HPV‐driven because of p16 positivity. TP53 mutations are highly prevalent in OPSCC driven by mutagens in tobacco and alcohol. We describe herein a combined p16/p53 algorithm to predict HPV tumour status in OPSCC. Methods and results A total of 110 OPSCC were identified in the database of the pathology department and were studied using p16 and p53 immunohistochemistry. For p16‐positive or p16‐negative/wild‐type patterns‐p53 (WT‐p53) cases (n = 63), DNA in‐situ hybridisation for high‐risk HPV was performed, and if negative the HPV status was controlled by HPV DNA polymerase chain reaction (PCR) (n = 19). A significant association between TP53 mutation and pattern of p53 expression was found (WT‐p53, seven of 16, P < 0.001). The p16‐positive/WT‐p53 was significantly associated with HPV+ tumour status (p16‐positive/WT‐p53, 50 of 110, P < 0.001). Interestingly, a subset of p16‐positive OPSCC was unrelated to HPV (13.5%, eight of 59), and showed mutant‐type staining of p53 expression. Conclusions The p16 protein immunopositivity in conjunction with the mutant‐type pattern of p53 staining helped to reclassify a subset of p16‐positive OPSCC as OPSCC‐unrelated HPV. This approach could be routinely applied by pathologists involved in the management of OPSCC, because of their potential therapeutic implications.

Low Prevalence of HPV Related Oropharyngeal Carcinogenesis in Northern Sardinia

“…Notably, if the HPV-related OPSCC rate is extremely variable, in the series where p16 IHC and nucleic acid detection are both performed, the false positive rate (FPR) of p16 IHC among HPV-negative cases is between 5 and 20% [ 11 , 18 , 35 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ], and is pretty constant for a given assay even in different populations (such as Dutch and Sardinians) (ISH, DNA detection without amplification, PCR) (some examples are shown in Table 2 ). When the current standard for the diagnosis of HPV-driven carcinogenesis is used (mRNA detection or sequential p16IHC and HPV-DNA PCR), the rate of HPV-negative OPSCC expressing p16 is notably always about 5.5% [ 11 , 44 , 45 , 46 ].…”

Relevance of Human Papillomaviruses in Head and Neck Cancer—What Remains in 2021 from a Clinician’s Point of View?

“…TP53 mutations are highly prevalent in OPSCC, unrelated to HPV infection but driven by mutagenic substances present in tobacco and alcohol [ 46 ]. Accordingly, it is well established that tobacco/alcohol-associated carcinogenesis is correlated to p53 mutations whereas in HPV-driven HNSCCs in the majority of cases, wild-type (wt) p53 can be detected [ 47 ]. Therefore, in smoking HNSCC patients, which seem to be more common in Germany than in the USA (see Section 4 ), for instance, it might be helpful to distinguish via p53 analysis between tumors that rather are HPV-driven (wt-p53) or indeed associated with tobacco-associated carcinogenesis (mutant p53) [ 48 , 49 ].…”

“…Therefore, in smoking HNSCC patients, which seem to be more common in Germany than in the USA (see Section 4 ), for instance, it might be helpful to distinguish via p53 analysis between tumors that rather are HPV-driven (wt-p53) or indeed associated with tobacco-associated carcinogenesis (mutant p53) [ 48 , 49 ]. Hence, and to overcome the aforementioned problem correlated to p16 INK4A IHC for HPV detection as described in 3.1, Benzerdjeb and colleagues [ 47 ] conducted a study on 110 OPSCC combining p16 INK4A IHC and p53 analysis in terms of detection of wt-p53 versus mutant p53. For p16 INK4A -positive or p16 INK4A -negative/wt-p53 cases (n = 63), DNA in situ hybridisation for high-risk HPV was performed, and if negative, the HPV status was controlled by HPV DNA PCR (n = 19).…”

“…As indicated in Section 3 , a precise HPV detection method should be able to reliably distinguish between HPV infection either with or without activity, since only active HPV infections are carcinogenic and are responsible for the biological behavior of tumors. As also outlined in Section 3 , we believe that the use of a combination of different detection methods, such as HPV DNA and RNA PCR combined with p16 INK4A and perhaps p53 IHC, may be best suited to fulfill this requirement [ 47 ]. Indeed, it is of crucial importance to identify the biologically active, i.e., causative HPV infections since sole detection of HPV DNA “presence” does not justify the claim that the tested (malignant) lesion is HPV-driven.…”

Understanding the Pattern of Oropharyngeal Cancers from North-East Romanian Patients

“…The authors suggest that these factors could be used for a better stratification and management of this category of patients [35]. A research team from Lyon used p16/p53 algorithm to predict HPV tumor status in OPSCC, and authors from Germany concluded that tobacco, alcohol abuse, age, and gender should be added to the current UICC (The Union for International Cancer Control) staging system to improve the risk stratification in HPV+ OPSCC [13,36]. Korsten LHA et al from Amsterdam evaluated the health-related quality of life for HPV-positive OPSCC patients.…”