With a median follow-up of 56 months, patients with p16 (+) oropharyngeal squamous cell carcinoma exhibited a significantly better 5-year disease-free survival (80.7% vs. 57.6%, P < 0.001) and overall survival (84.9% vs. 59.1%, P < 0.001) than those with p16 (-) tumors.
While similar p16 and Rb expression patterns were observed in these HPV-negative tumors, a different expression pattern for p53 was noted where strong nuclear staining was seen in 8 cases (47%; P = 0.0004 compared with cervical tumors).
While loss of RB function was a rare event in human lymphomagenesis, p16 was absent in some 25% of high-grade non-Hodgkin's lymphomas; diffuse large cell lymphomas were the primary target of tumor suppressor gene inactivation.
While p16 is a relatively accurate marker for HPV within the oropharynx, recent reports suggest it may be unsuitable for use in other HNSCC subsites, where a smaller proportion of tumors are HPV-driven.
When H&E staining does not show carcinoma in cases of MCCUP, p16 IHC should be considered given the high prevalence of HPV-positive MCCUP and the potential for identification of a small primary tumor that might otherwise be missed with H&E staining.
When dichotomizing PD-L1 at 1%, the p16 and Ki-67 staining percentages were two predictors for PD-L1 expression with ORs of 11.41 (p = 0.035) and 757.77 (p = 0.045). p16 and Ki-67 staining percentages and several PET/CT-derived textural features can provide supplemental information to determine tumor PD-L1 expression in HNCs.
When compared to a reference of tumor tissue p16 IHC in 783 OPSCC patients, the clinic-HPV<sub>sero</sub> model incorporating a composite of 20 HPV serological antibodies (HPV<sub>sero</sub> ) and 4 clinical factors (c-index: 0.96) performed better than using HPV<sub>sero</sub> (c-index: 0.92) or HPV<sub>mi</sub> (c-index: 0.76) alone.
We were also interested in determining the mutational status of p16 in these tumors, in order to determine whether the combination of overexpression and gene alteration may predict a different clinical outcome from overexpression alone.
We used quantitative real-time PCR (RTQ-PCR) to determine copy number of p15, of p14(ARF) exon 1beta, and p16 exon 2 in 22 tumor cell lines and 83 bladder tumors, some of which had been assessed previously by duplex PCR.
We then considered 3 cutoffs (10%, 50% and 70% positive cells) to evaluate the outcome of OTs/non-OTs with similar p16 expression and p16-positive versus p16-negative tumors stratified by patient age.
We synthesized antitumor peptides by fusing CPP2 to the minimal inhibitory sequence of p16 (p16MIS), which had the ability to restore the function of lost p16, the expression of which was absent in tumor cell lines of various origins.
We studied growth factor receptors, p16 and Ki67 expression, by in situ hybridization, fluorescent in situ hybridization (FISH) and chromogen in situ hybridization (CISH), immunocytochemistry, and morphological quantification in 226 lesions, either infected by HPV6 and 11 (31 condylomas acuminata) or infected with oncogenic HPVs (48 invasive cancers, 147 anal intraepithelial neoplasias).No HER2/neu was detected.
We studied 11 head and neck squamous carcinoma (HNSC) cell lines and 46 primary tumors for p16 gene status by protein, mRNA, and DNA genetic/epigenetic analyses to determine the incidence, the mechanism(s), and the potential biological significance of its inactivation.
We retrospectively examined survival of 107 patients with locally advanced OPSCC after radiotherapy alone (n = 43) or chemoradiotherapy (n = 64) with respect to tumorp16 and HPV DNA status, using Cox's proportional hazard model.
We previously found p16 promoter methylation in DNA in the sera of 13 colorectal cancer patients out of 44 (30%) whose tumor DNA exhibited the methylation, using methylation-specific PCR (MSP).
We investigated whether HPV and p16 expression in MCNs can help identify oropharyngeal primaries in patients with cervical lymph node metastases from an unknown primary tumor (CUP) and predict their survival outcomes.
We identified 326 DNA HPV-positive VSCC with at least 1 cm of skin adjacent to the invasive tumor and analyzed HPV typing, HPV E6*I mRNA, and p16 immunohistochemistry in all cases.
We highlight the difficulty in distinguishing tumour cell necrosis from infarct-type necrosis and the limited utility of p16 immunohistochemical expression in the diagnosis of leiomyosarcoma.