p53 expression in locally advanced pharyngeal squamous cell carcinoma

p16, p53 and EGFR expression in head and neck squamous cell carcinoma and their correlation with clinicopathological parameters

INTRODUCTION

Oral squamous cell carcinoma is a major cause of death throughout the developed world. Human papillomavirus (HPV) type 16 has also been suggested to play a role in etiology of head and neck squamous cell carcinoma (HNSCC). p16 expression is now being used as a surrogate marker of HPV infection in squamous cell carcinoma. Dysfunction in the p53 tumor suppressor gene is implicated in many cancers, including head and neck cancer. Overexpression or mutation of EGFR is found in 80%-100% of the patients with HNSCC, and is associated with poor prognosis and decreased survival.

MATERIALS AND METHODS

In this cross-sectional observation study, total of 100 cases of HNSCC were taken. p16, p53, and EGFR expression was determined by immunohistochemical staining and correlated with clinicopathological parameters. p16 expression was also correlated with expression of p53 and EGFR. The obtained results were analyzed and evaluated using Chi-square test, value of P < 0.05 was taken significant.

RESULTS

p16, p53, and EGFR were positive in 60%, 44%, and 58% cases, respectively. A statistically significant association was observed between p16 with age, site of the tumor, abnormal sexual habits and lymph node involvement. Significant expression also seen between p53 with age and abnormal sexual habits and immunohistochemical expression of p16 with p53 and EGFR.

CONCLUSION

Immunohistochemical expression of p16 can be used as a surrogate marker of HPV. Study of p16, p53, and EGFR expression may provide clinicians with more exact information in order to evaluate tumor aggressiveness and treatment modalities.

Expression of cell cycle-related proteins in oropharyngeal squamous cell carcinoma based on human papilloma virus status

The molecular association between human papilloma virus (HPV) and cell cycle-related (CCR) proteins is not fully understood in oropharyngeal squamous cell carcinoma (OPSCC). Herein, we examined the expression levels of CCRs in OPSCCs based on HPV status. In situ hybridization (ISH)- and polymerase chain reaction (PCR)-based assays were used to detect HPV status in 98 OPSCCs, and CCRs were detected by immunostaining. Of 98 tumors, 47 had HPV-positive tumors by either ISH- or PCR-based assays. Concordance analysis between ISH- and PCR-based tests showed a good agreement in OPSCC. Expression of p16 was moderate, consistent with HPV positivity as determined by ISH-based analysis. High p53-, phospho (p)-Rb-, SKP2-, cyclin D1-, and p-c-myc-positive rates were correlated with HPV-negative tumors, whereas high p16- and p27-positive rates were associated with HPV-positive tumors. The positive rates for p21 and cyclin A did not differ between HPV-positive and HPV-negative tumors. Finally, Ki-67 positivity was commonly observed for both types of OPSCCs. Although expression of p16 is thought to be a marker of HPV infection, ISH- or PCR-based tests should be used for HPV detection. In addition, our results regarding CCRs may be helpful for understanding the carcinogenesis of OPSCC.

Prognostic value of the epidermal growth factor receptor (EGRF) and p53 in advanced head and neck squamous cell carcinoma patients treated with induction chemotherapy

We measured the expression of the p53 nuclear protein and epidermal growth factor receptor (EGFR) in 46 biopsy samples from patients with advanced head and neck cancer treated with induction combination chemotherapy of 5-fluorouracil, cisplatin, and paclitaxel. Tumour expression of p53 protein was analysed with the monoclonal D07 antibody and EGFR with monoclonal H11 antibody. The overall response, defined as complete (CR) and partial response (PR) rates to treatment, was 88%. p53 positive staining was significantly more frequent in patients who did not respond to the induction treatment. EGFR expression failed to show any correlation with the response rate. Multivariate analysis indicated that a tumour location in the oral cavity together with p53 expression combined with moderate-to-high EGFR staining were independent prognostic factors of a shorter disease-free survival (DFS). Location of the tumour in the oral cavity and EGFR expression had independent prognostic value for overall survival (OS). We conclude that the EGFR status and an oral cavity location of the tumour have independent prognostic value in patients with advanced head and neck carcinoma treated with induction chemotherapy. The p53 status appears to be a determinant of the tumour chemo-sensitivity in advanced head and neck squamous cell carcinoma (HNSCC). The presence in the tumour of a p53-positive stain and moderate-to-high staining of EGFR is associated with a shorter DFS and time to treatment failure (TTF) probably reflecting a more aggressive tumour phenotype.

Nuclear and cytoplasmic p53 expression in pharyngeal squamous cell carcinoma: prognostic implications

BACKGROUND

The role of p53 expression in human neoplasms is still controversial, and it has been associated with both favorable and unfavorable outcome of the patients. Also cytoplasmic expression of p53 protein has been reported to affect survival in some cancers. Furthermore, an association between p53 and beta-catenin expression has been demonstrated. We studied the expression of p53 in a large group of oropharyngeal and hypopharyngeal squamous cell carcinomas and its relation to catenin expression, histologic differentiation, clinical data, and prognosis.

METHODS

Primary tumors for analyses were obtained from 123 patients diagnosed with squamous cell carcinoma of the oropharynx or hypopharynx between 1975 and 1998 in Eastern Finland. Immunohistochemistry was used to evaluate the expression of p53 as well as alpha-, beta-, and gamma-catenins.

RESULTS

In the primary tumors (n = 123), the nuclear p53 expression index was low in 42 (34%), intermediate in 38 (31%), and high in 43 (35%) cases. Cytoplasmic p53 expression was present in 56 (46%) and absent in 67 (54%) tumors. In univariate analyses (Kaplan-Meier), hypopharyngeal primary site (p =.02), high T class (p <.0005), presence of distant metastases (p =.02), low Karnofsky performance index (p <.0005), high nuclear p53 expression index (p =.01), and positive cytoplasmic p53 expression (p =.04) predicted poorer overall survival (OS). In Cox proportional hazards model, only T class (p =.0005), Karnofsky performance index (p =.005), and nuclear beta-catenin expression (p =.038) predicted poorer OS.

CONCLUSION

Positive cytoplasmic p53 expression and nuclear p53 overexpression seem to relate to more aggressive features and unfavorable outcome in pharyngeal squamous cell carcinoma (PSCC). However, unlike more traditional variables, p53 expression is not an independent predictor of disease outcome in PSCC.