Biological markers as indicators of pathological response to primary chemotherapy in oral-cavity cancers

Expression of p53, Bcl-2 and Bax in endometrial carcinoma, endometrial hyperplasia and normal endometrium: a histopathological study

Our objective was to examine the expression rates of p53, Bcl-2 and Bax in endometrial carcinoma, endometrial hyperplasia and normal endometrium. A total of 94 endometrial frozen sections (carcinoma 48, hyperplasia 21, normal tissue 25) were examined immunohistochemically in terms of the expression rates of p53, Bcl-2 and Bax. All of the specimens in the non-malignant groups were positive for Bax, whereas this rate was 85.4% in the group with malignant specimens (p = .03). Conversely, p53 was expressed only in the cancerous group (77.1%, p < .001). The Bcl-2 expression rate was 54.2% in the cancer group, 76.2% in the group with hyperplasia and 60% in the group containing normal tissue (p = .23). Comparing to the non-malignant specimens, the mean Bcl-2/Bax were significantly higher in the malignant group. In conclusion, Bax under-expression, p53 over-expression and a high Bcl-2 to Bax ratio might be associated with endometrial carcinoma. Bcl-2, however, plays no significant role in this regard. Impact statement What is already known on this subject? The p53, Bcl-2 and Bax are the three major genes that regulate apoptosis. Some studies have suggested that these genes may play a role in the pathogenesis of endometrial carcinoma. The available reports, however, are old and inconclusive. What do the results of this study add? Comparing immunohistochemically obtained p53, the Bcl-2 and Bax expression rates between normal endometrial tissue, endometrial specimens with endometrial hyperplasia and specimens with carcinoma showed that Bax under-expression, p53 over-expression and a high Bcl-2 to Bax ratio were associated with malignancy. Using an up-to-date technique to examine the three major regulators of apoptosis at the same time, in a rather large sample size of both normal and abnormal endometrial tissue specimens simultaneously, are the major advantages of the present work. What are the implications of these findings for clinical practice and/or further research? According to our findings, the status of p53, Bcl-2 and Bax expression in the endometrial tissue can be used for risk stratification of endometrial carcinoma for both screening and preventive purposes.

The evaluation of bcl-2 expression as a prognostic marker in early stage laryngeal cancer

Aims and background

To evaluate the effect of bcl-2 expression on the local control and overall survival of patients with early stage laryngeal cancer treated with radiotherapy alone.

Methods and study design

We included 53 patients with stage Tis, T1, and T2 laryngeal cancer who were irradiated in our department. Paraffin blocks of all biopsy specimens were subjected to immunohistochemical analysis with a bcl-2 oncoprotein mouse clone 124 Scytek kit.

Results

The mean follow-up time was 61 months (range, 7–166). Local-regional recurrence was observed in 10 (19%) patients. Forty-three patients (81%) had negative bcl-2 staining, 5 patients (9%) had + staining, 3 patients (6%) ++ staining, and 2 patients (4%) +++ staining. No relationship was detected between bcl-2 expression and local control or overall survival. The emergence of a recurrence and a younger age (<50 years) were significantly related to poor overall survival (P = 0.000 and P = 0.021, respectively). Patients with hemoglobin levels in the middle of radiotherapy and at the end of radiotherapy higher than 13 g/dl had improved overall survival in multivariate analyses (P = 0.002 and P = 0.001, respectively). Regarding local control, the following were poor prognostic factors: smoking more than 20 cigarettes a day (P = 0.001) and being younger than 50 years of age (P = 0.001).

Conclusions

No correlation was observed between bcl-2 expression and local control or overall survival. Whereas hemoglobin level, age and existence of a recurrence had a prognostic impact on overall survival, patient age and smoking status influenced local control rates.

Significance of apoptosis related proteins on malignant transformation of ovarian tumors: A comparison between Bcl-2/Bax ratio and p53 immunoreactivity

In this study, we compared the immunoreactivities of Bcl-2, Bax and p53 proteins in ovarian tumors and related the immunohistochemical findings to the histological type of the tumors. Formalin-fixed, paraffin wax-embedded tissue sections from 40 patients who had serous-mucinous borderline tumors and serous-mucinous adenocarcinoma of the ovary (n=10 each) were stained with hematoxylin-eosin (H&E). After histopathological examination, serial sections were stained immunohistochemically with primary antibodies to Bcl-2, Bax and p53 using an avidin-biotin-peroxidase method. A semi-quantitative grading system was used to compare the immunohistochemical staining intensities. The nuclear DNA fragmentation of apoptosis was determined using TUNEL method. As a result of immunohistochemical staining, increased immunoreactivity of Bcl-2 was observed in adenocarcinomas when compared to borderline tumors (P<0.001). Strong immunoreactivity of Bcl-2 and mild immunoreactivities of Bax and p53 were detected in ovarian adenocarcinomas. There were no significant statistical differences in the immunoreactivity of Bax among the histological type of ovarian tumors. Whereas a balance was observed between the immunoreactivities of Bcl-2 and Bax in the borderline cases, and this balance was strongly changed toward the anti-apoptotic Bcl-2 protein in patients with adenocarcinoma. TUNEL staining of sections indicated apoptotic cells in the serous borderline tumors were about 8-fold higher than in the serous adenocarcinoma. The results of this study on apoptosis-related factors might help to develop novel protective and therapeutic approaches, such as isoflavonoids and isothiocyanates, which were associated with decreased Bcl-2/Bax ratio, against the malignant epithelial ovarian tumors.

A systematic review of p53 as a prognostic factor of survival in squamous cell carcinoma of the four main anatomical subsites of the head and neck

OBJECTIVES

To summarize existing evidence about whether the presence of mutant or upregulated p53 is a prognostic factor for patients presenting with squamous cell carcinoma arising from the larynx, oropharynx, hypopharynx, or oral cavity.

METHOD

Relevant articles were identified using strict criteria for systematic searches. Associations between mutant or upregulated p53 versus wild-type or low/undetectable p53 in relation to overall survival and DFS were summarized by extracting or deriving hazard ratio (HR) estimates. Random-effects meta-analyses were used to account for between-study heterogeneity and to summarize the effect of p53 across studies.

RESULTS

The meta-analyses gave a statistically significant pooled HR for overall survival in oral cavity [pooled HR, 1.48; 95% confidence interval, (95% CI), 1.03-2.11], and for disease-free survival in oral cavity (pooled HR, 1.47; 95% CI, 1.12-1.93) and in oropharynx (pooled HR, 0.45; 95% CI, 0.27-0.73). Despite attempts to limit it, between-study heterogeneity was large in the majority of meta-analyses and the prognostic value of p53 was generally inconsistent and inconclusive across studies.

CONCLUSION

The meta-analysis results highlight that current evidence about the prognostic value of p53 in patients with squamous cell carcinoma of the head and neck is inconclusive. Large heterogeneity exists across studies in study-level and patient-level characteristics, making it difficult to ascertain a clear picture. Future studies are required in which p53 expression is investigated in a more standardized and biologically informative manner. In particular, prospectively planned individual patient data meta-analyses are needed to establish the prognostic importance of p53 for specific subgroups of patients undergoing specific treatments.

Expression of Bcl-2 but not Bax has a prognostic significance in tongue carcinoma

BACKGROUND

Among the molecular mechanisms involved in carcinogenesis, defects in the regulation of programmed cell death (apoptosis) make important contributions to the pathogenesis and progression of cancer. Apoptosis regulatory genes include the antiapoptotic bcl-2 gene and the proapoptotic bax gene. The aim of this study was to determine the spectrum of Bax and Bcl-2 expression, and to correlate these findings with clinicopathologic variables and prognosis.

METHODS

In this study we have evaluated the immunohistochemical expression of Bcl-2 and Bax proteins in a series of 35 squamous cell carcinomas of the tongue.

RESULTS

Immunoreactivity for Bax was detected in 37.1% and for Bcl-2 in 8.6% of cells, and for both proteins the staining was cytoplasmic and granular. Bcl-2 and Bax expression was mainly seen in peripheral cells of epithelial tumor islands with decreasing immunoreactivity toward the center of the neoplastic nests. Bax immunoexpression was significantly correlated with histologic grading (P=0.05), but not with the remaining clinicopathologic variables. Bcl-2 immunoreactivity was significantly correlated with N-stage (P=0.01) and survival. Patients with Bcl-2-negative tumors [mean survival: 73.97 months; 95% confidence interval (CI): 59-88] vs. Bcl-2-positive ones (mean survival: 17.67 months; 95% CI: 6-29) had a longer survival (P=0.01; odds ratio=6.9).

CONCLUSIONS

Bcl-2 is associated with aggressive disease, neck lymph node metastasis, and poor prognosis. Whereas Bax is related with histologic grade.

Mcl-1, vascular endothelial growth factor-R2, and 14-3-3sigma expression might predict primary response against radiotherapy and chemotherapy in patients with locally advanced squamous cell carcinomas of the head and neck

PURPOSE

This study was done to explore whether the expression of a selected set of proteins could predict primary response to radiotherapy or concomitant radiotherapy and chemotherapy in patients with advanced head and neck cancer.

EXPERIMENTAL DESIGN

Forty-three pretreatment tumor biopsies were taken during diagnostic panendoscopy and examined for Mcl-1, vascular endothelial growth factor (VEGF)-R2, CD9, and 14-3-3sigma expression by immunohistochemistry. Forty-three patients underwent primary radiotherapy, of which, 29 patients received concomitant chemotherapy (low dose daily cisplatin, mitomycin C bolus). The primary end-point was locoregional tumor control 6 months after completion of radiotherapy. Mcl-1, VEGF-R2, CD9, and 14-3-3sigma expression were correlated with patients' primary response to radiotherapy and chemotherapy and with established clinicopathologic variables.

RESULTS

Thirty complete and 13 partial responses were observed in our patient group. High expression levels of Mcl-1 (P=0.021), VEGF-R2 (P=0.032), and 14-3-3sigma (P=0.013), but not of CD9, in tumor biopsies was correlated with complete response. Overexpression of at least two of the three aforementioned proteins in pretreatment biopsies predicted-with a likelihood of 80%-whether a patient would achieve complete response to radiotherapy and chemotherapy. However, if only one of these proteins is overexpressed, there is a likelihood of 84.6% that this patient would not completely respond to therapy.

CONCLUSION

Determining the expression levels of Mcl-1, VEGF-R2, and 14-3-3sigma may be helpful in predicting the early clinical response in head and neck tumor patients receiving primary radiotherapy and chemotherapy and may further allow a pretherapeutic selection of patients.

Prognostic relevance of cell proliferation in head and neck tumors

Cell proliferative activity has been extensively investigated in head and neck tumors. Ki67/MIB-1 immunostaining, tritiated thymidine or bromodeoxyuridine labeling indices, DNA S-phase fraction, proliferating cell nuclear antigen expression, potential doubling time and analysis of the nucleolar organizer region associated proteins (AgNORs) have shown significant correlation with prognosis in 4806 cases of tumors of the oral cavity, salivary glands, pharynx and larynx. However, this was not observed in 2968 other reported cases. Discrepancies may depend on various factors: the heterogeneity of the series, which include tumors from various anatomic sites and patients treated with different therapy, and the lack of standardization of methods for assessing cell proliferation. Furthermore, none of the methods currently applied can by themselves define the actual proliferative activity, as it depends both on the proportion of cells committed to the cycle (growth fraction) and the speed of the cell cycle. Indeed, the actual proliferative activity of a tumor could well be measured by the equation [PA = Ki67 or MIB-1 scores x AgNORs], as we did in pharyngeal carcinoma. Provided that large and homogeneous series are evaluated by standardized methods, cell proliferative activity can still be regarded as an inexpensive and reliable prognostic factor in head and neck tumors.

The mechanism of action of docetaxel (Taxotere) in xenograft models is not limited to bcl-2 phosphorylation

Docetaxel is a new taxoid compound with a broad spectrum of antitumor activity. Previous studies have shown that in vitro treatment of specific human tumor lines with docetaxel is associated with the phosphorylation and inactivation of the bcl-2 protein and the occurrence of apoptosis. The goal of this study was to examine whether bcl-2 expression is truly required for in vivo responsiveness to docetaxel. The expression and state of phosphorylation of bcl-2 was examined in human MX-1 breast or DU-145 prostate tumors explanted from nu/nu mice treated with docetaxel. The MX-1 cells accumulated in the G2/M phase of the cell cycle and exhibited phosphorylation of bcl-2 after treatment with docetaxel. By Western blot analysis DU-145 prostate tumor cells did not express bcl-2 protein before or following in vivo treatment with docetaxel. However, docetaxel was highly active against the DU-145 tumor xenograft model. Thus, docetaxel induces apoptosis and cell death through a different, bcl-2-independent mechanism in the DU-145 human prostate tumor, indicating that bcl-2 may not have prognostic value for treatment with docetaxel.

Prognostic significance of p53 expression in oral squamous cell carcinoma without neck node metastases

BACKGROUND

Aberrations of the p53 gene and overexpression of its protein are widely recognized markers of malignancy including oral squamous cell carcinomas. This study was performed to evaluate the relationship of immunoexpression of p53 protein in series of 91 squamous cell carcinomas of the oral cavity with clinicopathologic parameters and to investigate whether p53 immunoexpression might influence the clinical outcome of the disease.

METHODS

From a group of 287 consecutive patients, 91 surgically treated ones were randomly selected. P53 protein expression was investigated by means of immunohistochemistry. Clinical and histopathologic data were gathered, and the patient survival was analyzed.

RESULTS

Of the oral carcinomas, 52.7% (n = 48) overexpressed p53, using a threshold of 10% stained cell nuclei. There was a negative correlation of p53 immunoexpression with a histologic grade of differentiation (r = -0.236, p =.06) but not with clinical variables. Overall survival rate was 59% at 5 years. In univariate analysis, tumor size, node status, and advanced clinical stage were significantly associated with shortened overall survival. In patients without neck node metastases, p53 showed a strong correlation with survival (p =.01). In multivariate analysis performed only on N0 patients, tumor extension and p53 immunoexpression were found to be the only independent prognostic parameters with relative risks of 1.9 and 4.3, respectively.

CONCLUSIONS

A strong relationship was observed between p53 immunoexpression and poor prognosis in patients with oral squamous cell carcinomas without neck node metastases.

Urinary thioether excretion and erythrocyte glutathione S-transferase activities in smokers and patients with squamous-cell laryngeal cancer

Various biomarkers exist for assessment of exposure to cigarette smoke. The aim of this study is to evaluate whether the urinary thioethers (UT) and erythrocyte glutathione S-transferase (GST) enzyme activities can be used as a biomarker or indicator of a higher risk of laryngeal cancer among smokers. In the present study, the concentration of UT and erythrocyte CST activities were measured in a sample of 84 subjects: controls, smokers, and smokers with squamous-cell carcinoma of the larynx (SLC). For this study, cases were restricted to men, since the number of women was not sufficient for statistical comparisons. Smoking significantly increased UT levels without a marked change in GST activity. However, in SLC smoking patients both UT levels and GST activity were significantly elevated. The use of nonspecific UT levels with GST activity determination seems to be a reliable indicator for the presence of laryngeal cancer in smokers.

Clinical implications of biomarkers in head and neck cancer

The term biomarker refers to a host of biologic factors found within a tumor or other clinical specimen that can be used to assess the tumor in some way. Biomarkers have many potential clinical applications. Before they are used in actual clinical settings, however, they must be carefully validated. The literature contains many reports of this ongoing work related to head and neck squamous cell carcinoma. Candidate biomarkers for this disease include the p53 gene and its protein; microsatellite regions throughout the genome; human papillomavirus; proteins involved in cellular proliferation, apoptosis, angiogenesis, and intracellular adhesion; epithelial growth factor receptor; and various measures of immune response to cancer. The best new evidence for the validity of each of these candidates is critiqued in this review.

Expression of apoptosis-related markers and clinical outcome in patients with advanced colorectal cancer

The clinical relevance of bax and bcl-2 protein expression has been investigated in 84 patients with recurrent or metastatic colorectal cancer submitted to a chemotherapy regimen including methotrexate and fluorouracil/leucovorin. Cytoplasmic immunostaining of bax and bcl-2 was present in 65.5% and 38%, respectively, of the tumours. No association was found between bax and bcl-2 or between p53 and bax or bcl-2 protein expression. Moreover, the biomarkers were unrelated to patient and tumour characteristics known to affect the clinical outcome of colorectal cancer patients. In general, the apoptosis-related markers did not appear indicative of short- and long-term clinical response nor of prognosis. Bcl-2-negative lesions were more frequent among patients who reached an objective clinical response, which is in agreement with previously reported data regarding other tumour types. When the interrelationship between p53 and bax expression was examined, a better response rate (40%) was found for patients whose tumours did not express p53 and bax, and a better prognosis (2-year probability of overall survival 75%) for patients with p53-positive and bax-negative tumours. In the present series of patients with advanced colorectal cancer submitted to systemic chemotherapy we did not find a clear association between expression of apoptosis-related markers and clinical outcome, even in the subset of patients in which the apoptotic index as determined by the TUNEL approach was investigated.

bcl-2 expression in head and neck cancer: an enigmatic prognostic marker

PURPOSE

The role of bcl-2 overexpression in cancer presents a paradox. In some tumor types, it is associated with favorable outcome, whereas in others the reverse is true. The purpose of this study was to explore the influence of bcl-2 in a large series of head and neck cancer patients treated in the CHART randomized trial.

METHODS AND MATERIALS

Histologic material was obtained from 400 patients; bcl-2 expression was assessed by immunohistochemistry as either positive or negative cytoplasmic staining.

RESULTS

Positivity of bcl-2 was recorded in 12.8% (9.5-16.5%, 95% confidence limits) of tumors. There were significant differences in positive tumors within different sites with nasopharynx showing the highest incidence (46.2%). A multivariate logistic regression analysis showed that bcl-2 was strongly associated with histologic dedifferentiation, as well as increasing N stage and female gender. In univariate analyses, bcl-2 positive patients had a lower locoregional relapse rate (RR 0.57, p = 0.02) and improved survival (RR 0.49, p = 0.004) compared to bcl-2 negative patients; this became more significant in multivariate analysis.

CONCLUSION

These data demonstrate that bcl-2 overexpression is a marker of what is considered to be more advanced and aggressive disease yet it is associated with a more favorable outcome irrespective of the treatment schedule.

Prognostic significance of p53/bcl-2 co-expression in patients with laryngeal squamous cell carcinoma

OBJECTIVE

The p53, bcl-2, and bax genes are known to be involved in control of cell cycle progression and regulation of apoptotic cell death. Although they are frequently altered in laryngeal squamous cell carcinoma, their clinical relevance is not yet fully understood. In the present study, individual and combined expressions of these genes were related with patient survival as well as with proliferative and apoptotic activity.

DESIGN

Retrospective study.

METHODS

Paraffin-embedded tissue sections of 88 laryngeal squamous cell carcinomas that were diagnosed and treated between 1986 and 1996 were investigated for p53, bcl-2, and bax protein expression by immunohistochemistry. Apoptotic cells were visualized using the nick end labeling method. To assess proliferative activity of tumors, mitotic indices were determined.

RESULTS

Age of patients, advanced disease (stages HI and IV), high mitotic activity, positive bcl-2 expression, high level of p53 expression, and p53/bcl-2 co-expression were significantly associated with shortened overall survival in univariate analysis. In multivariate analysis, only age and p53/bcl-2 co-expression had independent prognostic value. Other combinations of genes, i.e., bcl-2-to-bax and p53-to-bax ratios, were not associated with patient outcome. A significant positive correlation was found between apoptotic and mitotic activity. However, protein levels of p53, bcl-2, and bax were unrelated to proliferation and apoptosis of tumor cells.

CONCLUSIONS

The co-expression of p53/bcl-2 was an independent predictor of patient outcome and had a prognostic value superior to both parameters considered separately. The rate of apoptosis mainly counterbalanced proliferative activity but appeared not to be significantly influenced by p53, bcl-2, and bax.

Molecular markers predictive of response and prognosis in the patient with advanced squamous cell carcinoma of the head and neck: evolution of a model beyond TNM staging

Advanced head and neck cancer is a disease with poor prognosis. TNM staging is an inadequate prognostic indicator of individual response to evolving multimodal therapies. New markers have been studied in progressively more refined analyses. Even though their role in predicting response and prognosis of head and neck cancer is still under evolution, it is becoming clear that individual markers are inadequate in constructing a prognostically meaningful tumor profile for each patient. Rather the combined study of a number of well-characterized markers acting in unrelated cellular pathways may be much more successful in defining prognostic patient categories of greater utility than traditional TNM staging. Special attention should also be paid to the expression pattern and location of tumor markers within the biopsy specimen as these parameters also appear to influence prognostic significance.

Biomarkers and outcome after tamoxifen treatment in node-positive breast cancers from elderly women

The predictive role of tumour proliferative rate and expression of p53, bcl-2 and bax proteins, alone and in association with tumour size, nodal involvement and oestrogen receptors (ER), was analysed on 145 elderly patients (> or =70 years of age) with histologically assessed node-positive breast cancers treated with radical or conservative surgery plus radiotherapy followed by adjuvant tamoxifen for at least 1 year. The 7-year probability of relapse was significantly higher for patients with tumours rapidly proliferating (hazard ratio (HR) = 2.0, P = 0.01), overexpressing p53 (HR = 4.4, P = 0.0001), weakly or not exhibiting bcl-2 (HR = 1.9, P = 0.02), without ERs (HR = 3.4, P = 0.0001) or with > or = 4 positive lymph nodes (HR = 2.3, P = 0.003) than for patients with tumours expressing the opposite patho-biological profile. Conversely, tumour size and bax expression failed to influence relapse-free survival. Adjustment for the duration of tamoxifen treatment did not change these findings. Oestrogen receptors, cell proliferation, p53 accumulation and bcl-2 expression were also predictive for overall survival. Within ER-positive tumours, cell proliferation, p53 accumulation, bcl-2 expression and lymph node involvement provided significant and independent information for relapse and, in association, identified subgroups of patients with relapse probabilities of 20% (low-risk group, exhibiting only one unfavourable factor) to 90% (high-risk group, exhibiting three unfavourable factors). Such data could represent the initial framework for a biologically tailored therapy even for elderly patients and highlight the importance of a patho-biological characterization of their breast cancers.

Biological markers as indicators of response to primary and adjuvant chemotherapy in breast cancer

Interest in translational studies on breast cancer is presently devoted to identify biological predictors of treatment response. In patients with operable breast cancer, subjected to primary and adjuvant chemotherapy, we analyzed the predictivity on objective clinical response and relapse-free survival of biological markers related to different cellular aspects and functions. Tumour proliferative rate (evaluated as the (3)H-thymidine-labelling index, TLI), oestrogen and progesterone receptors (ER and PgR, evaluated by the dextran-coated-charcoal method), nuclear DNA ploidy and the immunocytochemical expression of p53, bcl-2 and bax proteins were determined before primary treatment, at the time of diagnosis, and after primary chemotherapy, at surgery. Objective clinical response was significantly related only to pre-treatment p53 expression or PgR status, with a higher rate for tumours not expressing than for those expressing p53 (94% vs. 72%), as well as for PgR-negative (PgR(-)) than for PgR-positive (PgR(+)) tumours (86% vs. 68%). In the overall series, 8-year clinical outcome was significantly related only to post-treatment steroid receptors. In particular, higher 8-year relapse-free survival rate was observed for patients with ER(-) or PgR(-) than for those with ER(+) (64% vs. 38%) or PgR(+) (53% vs. 37%) tumours. Such findings held true even within the sub-set of patients who received adjuvant post-operative chemotherapy, i.e., those with node-positive (N(+)) or ER(-)/node-negative (N(-)) tumours, among whom also rapid proliferation or the presence of apoptosis-favouring markers (bcl-2(-) or bax(+), singly and in association) on surgical specimens identified a sub-set of women who benefited from systemic treatment. The different biological markers were variously indicative of clinical outcome, with a predictivity on tumour shrinkage for p53 and PgR, detected before primary chemotherapy, and on long-term follow-up for ER, PgR and, to a lesser extent, TLI and apoptosis-modulating markers. Int. J. Cancer (Pred. Oncol.) 84:580-586, 1999.

Oral squamous cell carcinoma is associated with decreased bcl-2/bax expression ratio and increased apoptosis

Expression of bcl-2 and bax and apoptosis were studied in fresh frozen samples of normal oral epithelium (OE, n = 7) and oral squamous cell carcinomas (OSCC, n = 16) by immunohistochemistry and the TUNEL method. In OE, bcl-2 was expressed in both basal (96.6% +/- 2.3% [mean +/- SD]) and suprabasal (91.8% +/- 6.2%) compartments. In OSCC, compared with OE, there was a marked reduction of bcl-2-positive cells in the basal part, and in the central parts of well-differentiated (33.0% +/- 19.7%, P < .001) and moderately differentiated (6.1% +/- 4.6%, P < .001) and also in poorly differentiated (1.9% +/- 0.2%, P < .001) tumors. More cells expressed bax in the suprabasal layer of OE (65.6% +/- 9.9%) and central parts of OSCC than in the basal layer of OE (19.1% +/- 4.1%) and basal parts of OSCC. A higher proportion of cells expressed bax in the central part of well-differentiated OSCC (74.3% +/- 8.2%) than in poorly differentiated OSCC (24.9% +/- 9.7%, P < .001). Apoptotic cell death was more pronounced in OSCC (1.5% +/- 0.9%) than in OE (0.4% +/- 0.1%, P < .05). We conclude that, in OSCC, compared with OE, there is a decreased bcl-2 expression, a lowered bcl-2/bax ratio and increased apoptosis. The expression of bax correlates with histological tumor grading in oral squamous cell carcinoma.

Molecular markers as prognostic factors for local recurrence and radioresistance in head and neck squamous cell carcinoma

Squamous cell carcinoma of the head and neck affects more than 500,000 people worldwide each year. Local-regional recurrence of disease is a common and challenging oncological problem in patients affected by this disease. Identification of risk factors for local relapse after appropriate local therapy with surgery, radiation, or combination therapy remains an active area of clinical research. The recent development of novel molecular markers has resulted in numerous studies evaluating the prognostic significance and potential clinical utility of these markers in identifying patients at risk for local-regional relapse. This article reviews recent studies evaluating molecular markers, including p53, angiogenesis-related markers, cyclin D1, epidermal growth factor receptor, loss of heterozygosity, DNA ploidy, and cell kinetic markers. The potential clinical utility of these markers and future directions along this avenue of investigation are discussed.