Prognostic value of the expression of p53 and bcl-2 in patients with laryngeal carcinoma

Biomarkers of laryngeal squamous cell carcinoma: a review

Laryngeal carcinoma is the second common malignancy of the upper aerodigestive tract after lung cancer; in most cases is a squamous cell carcinoma, whose risk factors include tobacco smoking and alcohol consumption. Despite therapeutic progress, the five-year overall survival rate for this malignancy has remained nearly 50% and many patients already present metastasis at the time of diagnosis. To date, there are no tools that predict the evolution of laryngeal carcinoma: in this light, during the last years, many studies were planned with the aim to investigate the role played by different biomarkers expressed by larynx cancer, which can help make an early diagnosis, predict disease evolution and direct therapeutic choice. This review aims to summarize these markers and correlating them with disease evolution.

Prognostic value of Bcl-2 expression in squamous cell carcinoma of the larynx: a systematic review

The aim of this systematic review was to determine the prognostic value of Bcl-2 immunostaining in patients affected by laryngeal squamous cell carcinoma. An appropriate search was conducted on PubMed to retrieve articles dealing with this topic. A double cross-check was performed on citations and full-text articles by 2 investigators independently to review all manuscripts and perform a comprehensive quality assessment. Of 115 abstracts identified, 15 articles were included. These studies reported on 1,150 patients with histologically confirmed diagnosis of laryngeal squamous cell carcinoma. Only a few studies showed a statistical correlation between Bcl-2 immunohistochemical expression and at least 1 of the clinical and histopathological parameters considered by the authors. Moreover, these findings were also discordant between them. Overall the studies analyzed suggested that Bcl-2 expression was statistically connected with N stage (2/14), grading (2/14), disease-free survival (3/14) and overall survival (5/14). Interestingly, all of the 3 studies investigating the relation between Bcl-2 and radioresistance showed significant results in terms of recurrence-free survival and overall survival. Our review strongly suggests that the immunohistochemical staining of Bcl-2 does not correlate with tumoral aggressiveness and prognosis of patients affected by laryngeal squamous cell carcinoma and treated with primary surgery. However, an interesting connection of this protein could be demonstrated with tumoral radioresistance. Further, high-quality prospective studies should be carried out to confirm this hypothesis.

Possible implication of Mdm2 as a prognostic marker in invasive laryngeal carcinoma

Laryngeal squamous cell carcinoma is one of the most common malignant neoplasms of the head and neck. In Brazil, laryngeal tumors represent 2% of all cancers and are associated with approximately 3,000 deaths annually. Human papillomavirus (HPV) has been reported to play an important role in the etiology of laryngeal cancer. The aim of the present study was to evaluate the expression of p53, p27, and Mdm2 in laryngeal carcinomas. Sixty-three larynx biopsies were selected for the study, including 9 in situ laryngeal carcinomas, 27 laryngeal carcinomas without metastasis and 27 laryngeal carcinomas with metastasis. Twenty-seven cervical lymph nodes from patients with metastatic lesions were also evaluated. The expression levels of p53, p27, and Mdm2 were assessed by immunohistochemistry using a computer-assisted system. HPV detection and typing were performed using PCR, and the HPV types that were evaluated included HPV 6, 11, 16, 18, 31 and 33. Out of 63 patients, 53 (84.1%) were positive for β-globin (internal control), and 10 (15.9%) were β-globin negative and therefore excluded from the evaluation. Thus, 7 (13.2%) out of 53 patients were HPV positive, and 46 (86.8%) out of 53 patients were HPV negative. Statistically significant differences (p < 0.05) in Mdm2 expression levels were observed in the in situ laryngeal carcinoma samples compared with the laryngeal carcinoma samples with metastasis. No statistically significant differences (p > 0.05) in either p53 or p27 expression levels were detected. These findings suggest that Mdm2 may be associated with the invasiveness and aggressiveness of laryngeal carcinomas.

Bcl-2 blocks cisplatin-induced apoptosis and predicts poor outcome following chemoradiation treatment in advanced oropharyngeal squamous cell carcinoma

PURPOSE

This study aimed to test the hypothesis that elevated expression of antiapoptotic Bcl-2 family proteins predicts a poor therapeutic response of oropharyngeal squamous cell carcinoma (OPSCC) to concurrent platinum-based chemoradiation therapy.

EXPERIMENTAL DESIGN

Levels of Bcl-2, Bcl-XL, and Bcl-w were determined and correlated with resistance to cisplatin in a large panel of cell lines derived from squamous cell carcinoma of the head and neck (HNSCC). Univariate and multivariate analyses were used to evaluate the relationship between Bcl-2 and Bcl-XL expression and disease-free survival following chemoradiation therapy in a uniformly treated cohort of patients with OPSCC.

RESULTS

In HNSCC cell lines, high endogenous Bcl-2 expression was associated with increased cisplatin resistance, and experimental overexpression of Bcl-2 promoted cisplatin resistance. In patients, tumors positive for Bcl-2 before treatment had greater risk of treatment failure (hazard ratio, 5.99; 95% confidence interval, 1.73-20.8; P=0.0014). In contrast, endogenous Bcl-XL showed no correlation either with cisplatin sensitivity in the cell line panel in vitro, or with risk of recurrence in vivo (hazard ratio, 1.28; 95% confidence interval, 0.39-4.19; P=0.68). Associations between Bcl-2 expression and other clinical characteristics did not account for the predictive value of Bcl-2.

CONCLUSIONS

Immunohistochemical assessment of Bcl-2 in pretreatment biopsy specimens can predict response of advanced OPSCC to concurrent platinum-based chemoradiation. As treatments targeting Bcl-2 and its family members become available, this immunohistochemical assessment could help personalize therapy by identifying a subpopulation of patients with a poor prognosis who might benefit from such treatments.

Expression of cell cycle and apoptosis regulatory proteins in keratoacanthoma and squamous cell carcinoma

Some authors view keratoacanthoma (KA) as a variant of squamous cell carcinoma (SCC), while others consider it a separate entity that must be distinguished from SCC. Involution displayed by KA is an important difference between these two entities. It has been suggested that apoptosis plays a role in the involution process of KA, although the exact trigger for it remains unclear. A hundred and fifty specimens were included in this study, 30 cases for each of the following groups: normal skin (NS), proliferative keratoacanthoma (pKA), regressing keratoacanthoma (rKA), well-differentiated squamous cell carcinoma (wdSCC), and poorly differentiated squamous cell carcinoma (pdSCC). They were immunohistochemically examined for the expression of p53, Ki-67, bak, and bcl-2. Significantly higher p53 and Ki-67 expressions were observed in all tumor lesions examined as compared with NS. There was higher bak expression in KAs compared to NS and a significant reduction of bak expression in pdSCC together with a significant reduction of bak expression in SCCs compared to pKA. Bcl-2 expression was similar in NS and SCCs, but was lower in rKA. We found a significant positive correlation between p53 and Ki-67, p53 and Bak in NS and examined skin tumors. Lower bcl-2 expression in conjunction with higher bak expression in rKA suggests a possible role of these apoptosis-regulating proteins in tumor regression. In contrast to this finding, a steady level of bcl-2 expression in pdSCC combined with lower bak expression levels and a high proliferation rate could contribute to progression and aggressiveness in these tumors. Bak and p53 expression is a sun-related and age-dependent process in NS and skin tumors.

Evaluation of Apoptosis Markers in Conjunctival and Eyelid Benign and Malignant Tumors

The balance between cell proliferation and programmed cell death plays a crucial role in malignant development. Bcl-2 family proteins, including proapoptosis protein Bak and antiapoptosis protein Bcl-2, regulate the apoptotic process. Mutation of the p53 gene, which results in P53 protein accumulation, was observed in many types of human cancer. The aim of our study was to evaluate immunohistochemical Bcl-2, Bak, and P53 protein expression and the relation between these proteins in conjunctival and eyelid benign and malignant tumors. We examined a series of 42 papillomas (CEP), 12 squamous cell cancers (SCC), and 19 cases of basal cell cancer (BCC). The age in the CEP group ranged from 18-94 years, and in the SCC and BCC groups from 42-87 years. Staining patterns were correlated with sex, age, and tumor localization. P53 protein-positive immunostaining was observed in 71% of cases, Bcl-2 in 83.9%, and Bak in 74.2 cases in the SCC and BCC groups. In the CEP group, P53 overexpression was observed in 90.5% of cases, Bcl-2 in 71.4%, and Bak in 76.2%. No statistically significant correlation was found between examined protein expression and sex, age, and tumor localization. An inverse correlation was observed between P53 and Bak protein expression in the CEP group. No statistically significance correlation was noted between Bcl-2 and P53 and Bcl-2 and Bak protein expression in both examined groups. The obtained data suggests that P53 and Bcl-2 protein expression coupled with decreasing Bak expression are associated with apoptosis and proliferation as well as malignant progression in conjunctival and eyelid tumors.

p53, Ki67 and cyclin D1 as prognosticators of lymph node metastases in laryngeal carcinoma

The prognosis in patients suffering from head and neck squamous cell carcinomas depends on many factors. However, regional lymph node metastases are the most important parameter in determining the cure and survival of patients with head and neck cancers. The evaluation of cancer cell biology enables differentiation of their proliferation and tendency of metastases. Immunohistochemical examinations complement the well-established routine histological examination. The aim of this study was to evaluate the prognostic importance of the level of immunoproliferating proteins such as cyclin D1, nuclear antigen Ki67 and suppressor gene p53 for regional lymph node metastases in laryngeal carcinoma. The research was carried out on 73 patients treated for squamous cancer of the larynx in the Department of Otolaryngology University School of Medical Sciences in Poznan in the years 1994-1999. The group was comprised of 4 female and 69 male patients. Their ages ranged from 37 to 79 years, with a mean of 59 years. Clinical data included sex, age, localization and local and regional extent of the tumor, presence or lack of distant metastases, treatment, histological examination as well as immunohistochemical evaluation of suppressor gene p53, proliferative proteins Ki67 and cyclin D1. No statistically significant correlation was found between staining intensity of suppressor gene p53, cyclin D1 and the degree of local advancement (T). There was no correlation between the level of immunoproliferative markers and regional lymph node metastases. Statistically significant correlation was found between T stage and staining for Ki67 (P=0.017) as well as between cyclin D1 level and Ki67 (P<0.05). In conclusion, (1) no significant correlation was found between Ki67 and cyclin D1, p53 and TNM classification; (2) lack of correlation was confirmed between N+, p53, Ki67, cyclin D1 and Jacobsson classification; (3) the degree of histological grading correlated, however, with Jacobsson classification and cyclin D1 expression.