p53 gene status as a predictor of tumor response to induction chemotherapy of patients with locoregionally advanced squamous cell carcinomas of the head and neck

Differential biomarker expression in head and neck cancer correlates with anatomical localization

We tested the expression of known (p16(ink4), Ki67, p53, EGFR) and a new immunohistochemical (collagen XVII/BP180) biomarker in head and neck squamous cell carcinomas (SCC) of diverse anatomical localization. Tissue microarrays (TMA) of 124 SCC were created, immunostained, and analyzed following whole slide digitalization using the Pannoramic Scan and the TMA Module software (3DHISTECH Kft, Budapest, Hungary). Statistical analysis of scoring results was carried out using Pearson's chi-square test. We observed the significant elevation of p16(ink4) and Ki67 expression in supraglottic, tonsillar and tonsillo-lingual SCCs compared to those affecting the oral cavity, oropharynx without tonsils, larynx without supraglottis and the hypopharynx. This differential antigen expression may reflect the diverse route of embryologic differentiation followed by the affected regions except those of the tonsils and the supraglottis which show similar antigenic pattern but diverse developmental path. All the other biomarkers tested including p53, collagen XVII and EGFR were detected in the majority of cancers including high grade cases, but did not reveal any significant regional difference. Based on our results oropharyngeal squamous cell carcinomas may not be regarded as one entity. Concerning the oral cavity and the oropharynx, cancers affecting the tonsils (palatine and lingual) show significantly elevated p16(ink4) and Ki67 expression; so as the cancers of the supraglottis compared to the rest of larynx. Consequently, tonsillar and supraglottic cancers show similar biomarker profiles. Correlation of differential biomarker expression with diverse biological behavior in head and neck cancers need further investigations.

Clinical outcomes and correlates of TP53 mutations and cancer

The initial observation that p53 accumulation might serve as a surrogate biomarker for TP53 mutation has been the cornerstone for vast translational efforts aimed at validating its clinical use for the diagnosis, prognosis, and treatment of cancer. Early on, it was realized that accurate evaluation of p53 status and function could not be achieved through protein-expression analysis only. As our understanding of the p53 pathway has evolved and more sophisticated methods for assessment of p53 functional integrity have become available, the clinical and molecular epidemiological implications of p53 abnormalities in cancers are being revealed. They include diagnostic testing for germline p53 mutations, and the assessment of selected p53 mutations as biomarkers of carcinogen exposure and cancer risk and prognosis. Here, we describe the strengths and limitations of the most frequently used techniques for determination of p53 status in tumors, as well as the most remarkable latest findings relating to its clinical and epidemiological value.

Update of prognostic and predictive biomarkers in oropharyngeal squamous cell carcinoma: a review

Oropharyngeal squamous cell carcinomas (OSCC) constitute about 5% of all cancers in the western world and the incidence and mortality rates of this tumor have shown little improvement over the last 30 years. Molecular targeted therapy, a promising strategy for the treatment of OSCC and other cancers, requires the understanding of specific molecular events of carcinogenesis and the different pathological, partly interrelated pathways. Extended knowledge of the prognostic or predictive value of molecular biomarkers in oropharyngeal cancer is necessary to allow a better characterization and classification of the tumor, improve the appraisal of clinical outcome and help to specify individual multimodal therapy with increased efficiency. This work affords an updated summary regarding recent data about tissue biomarkers in patients with OSCC, based on the six essential hallmarks of cancer described by Hanahan and Weinberg (Cell 100(1):57-70, 2000) providing the characterization of a malignant cell.

Pleural metastases as a unique entity with dismal outcome of head and neck squamous cell carcinoma

Once distant metastasis occurs, head and neck squamous cell carcinoma (HNSCC) patients generally have a poor prognosis with limited treatment options. A subgroup of patients who developed pleural metastases after curative treatment of localized HNSCC appeared to have worse outcomes. All patients from National Taiwan University Hospital who were diagnosed with localized HNSCC from January 1, 2000 to December 31, 2007 and developed distant metastases were included in this analysis. Medical records were reviewed. Patients with pleura as the first metastatic sites were compared to those with other first metastases for differences in basic demographics, time to distant metastasis (TTM) and overall survival (OS). A total of 198 patients were included, and 52 (26%) had pleural involvement at first diagnosis of distant metastases. Younger age at diagnosis (P=0.002) and buccal mucosa origin (P=0.006) were risk factors for developing pleural metastases. Patients with pleura as the first metastatic sites, compared to those with other first metastases, had significantly shorter TTM (median 7.5 vs. 11.1 months, P<0.001) and OS (median 9.6 vs. 16.5 months, P<0.001). By multivariate analysis, pleural metastases remained an independent predictor for shorter OS. In conclusion, patients with pleural metastases comprise a unique subgroup of HNSCC which rapidly develop distant metastases with poor prognosis.

Nutlin-3, the small-molecule inhibitor of MDM2, promotes senescence and radiosensitises laryngeal carcinoma cells harbouring wild-type p53

BACKGROUND

Primary radiotherapy (RT) is a mainstay of treatment for laryngeal squamous cell carcinoma (LSCC). Although the cure rates for early (T1) vocal cord tumours are high, RT proves ineffective in up to a third of T3 carcinomas. Moreover, RT is associated with debilitating early- and late-treatment-related toxicity, thus finding means to de-escalate therapy, while retaining/augmenting therapeutic effectiveness, is highly desirable. p53 is a key mediator of radiation responses; we therefore investigated whether Nutlin-3, a small-molecule inhibitor of MDM2 (mouse double minute 2; an essential negative regulator of p53), might radiosensitise LSCC cells.

METHODS

We performed clonogenic assays to measure radiosensitivity in a panel of LSCC cell lines (for which we determined p53 mutational status) in the presence and absence of Nutlin-3.

RESULTS

LSCC cells harbouring wild-type p53 were significantly radiosensitised by Nutlin-3 (P<0.0001; log-rank scale), and displayed increased cell cycle arrest and significantly increased senescence (P<0.001) in the absence of increased apoptosis; thus, our data suggest that senescence may mediate this increased radiosensitivity.

CONCLUSION

This is the first study showing Nutlin-3 as an effective radiosensitiser in LSCC cells that retain wild-type p53. The clinical application of Nutlin-3 might improve local recurrence rates or allow treatment de-escalation in these patients.

TP53 Mutations and Pathologic Complete Response to Neoadjuvant Cisplatin and Fluorouracil Chemotherapy in Resected Oral Cavity Squamous Cell Carcinoma

Purpose

To find out if TP53 functional status predicts response to neoadjuvant chemotherapy and thus may be helpful during treatment decision making of oral cavity squamous cell carcinoma (SCC) patients.

Patients and Methods

We analyzed the predictive value of TP53 mutations and their functional status on the basis of the transactivation activity of p53 mutant proteins in 53 pretreatment biopsies of oral cavity SCC patients receiving primary cisplatin and fluorouracil chemotherapy followed by surgery.

Results

The surgical specimens showed that 15 patients (28%) achieved a pathologic complete remission (pCR) at both T and N sites, and 38 patients had residual tumor cells. Among the 53 pretreatment biopsies, 24 (45%) displayed TP53 mutations: 22 single-nucleotide substitutions and two deletions. According to functional status that could be determined only for the 22 substitutions, 21 mutations were nonfunctional and one was partially functional. TP53 mutation was found in four (27%) of 15 patients who achieved a pCR and in 20 (53%) of 38 nonresponder patients; the difference was not statistically significant (P = .12). In contrast, two (14%) of 14 cases with pCR carried a nonfunctional TP53 mutation, a frequency significantly less than that found in the nonresponders (19 [51%] of 37; P = .02). TP53 mutation predicted pCR in four (17%) of 24 patients and a nonfunctional mutation in only two (9%) of 22 patients.

Conclusion

The results indicate that the loss of function (transactivation activities) of p53 mutant proteins may predict a significant low pCR rate and suboptimal response to cisplatin-based neoadjuvant chemotherapy in patients with oral cavity SCC.

p53 genotype predicts response to chemotherapy in patients with squamous cell carcinoma of the esophagus

BACKGROUND

Response to chemotherapy and anatomical spread are significant prognostic factors in patients with esophageal squamous cell carcinoma (ESCC) treated by chemotherapy then surgery. Predicting the response to chemotherapy would allow significant optimization of cancer treatment.

METHODS

Genomic mutation and protein expression of p53 were investigated retrospectively by polymerase chain reaction (PCR) single-strand conformation polymorphism (SSCP) and immunohistochemistry (IHC) using biopsy specimens from 77 ESCC patients before chemotherapy with 5-fluorouracil, adriamycin, and cisplatin. p53 status was correlated with various clinicopathological factors. Thereafter, we performed a prospective study of 20 consecutive patients to test our prediction model.

RESULTS

The retrospective study showed mutant p53 genotype and positive p53 IHC staining in 46.8 and 55.8% of patients, respectively, which was not associated with patient's clinicopathological findings including initial tumor stage. Objective response to chemotherapy was observed in 65.9% of patients with wild genotype, but in only 16.7% of patients with mutant genotype. Patients with mutations in p53 therefore showed significantly poorer prognosis than those without mutant p53. In contrast, p53 IHC staining did not correlate with response to chemotherapy, curative resection rate or prognosis. In the prospective study, p53 mutation was seen in 50% (10/20) of patients and was again consistently associated with poorer response to chemotherapy and poorer prognosis.

CONCLUSIONS

p53 genotype of pretreatment biopsy is a potentially useful predictor of response to chemotherapy and prognosis in ESCC patients. This information might be valuable to clinicians in deciding on the optimal clinical strategy in patients with ESCC.

Molecular markers predict outcome in squamous cell carcinoma of the head and neck after concomitant cisplatin-based chemoradiation

Not all patients with squamous cell carcinomas of the head and neck (HNSCC) benefit from concurrent cisplatin-based chemoradiation, but reliable predictive markers for outcome after chemoradiation are scarce. We have investigated potential prognostic biomarkers for outcome in a large group of patients. Ninety-one tumor biopsies taken from consecutive HNSCC patients were evaluated for protein expression on a tissue microarray. Using immunohistochemistry, 18 biomarkers, involved in various cellular pathways were investigated. Univariable and multivariable proportional hazard analyses were performed to investigate associations between each individual marker and outcome. In addition, the global test was used to test all variables simultaneously and selected combinations of markers for an overall association with local control. Univariable analysis showed statistically significant increased relative risks of RB, P16 and MRP2 for local control and MDR1 and HIF-1alpha for overall survival. MRP2, MDR1 and P16 levels were positively associated with outcome whereas RB and HIF-1alpha had a negative relationship. Using Goeman's global testing no combination of markers was identified that was associated with local control. Grouping the markers according to their function revealed an association between a combination of 3 markers (P16, P21 and P27) and outcome (p = 0.05) was found. In the multivariable analysis, MRP2 and RB remained significant independent predictive markers for local control. This study describes the prognostic value of biomarkers for the outcome in patients uniformly treated with concurrent chemoradiation. MRP2 and RB were found to be associated with outcome in patients treated with concurrent chemoradiation.

Identification of SULF2 as a novel transcriptional target of p53 by use of integrated genomic analyses

Microarray analysis has been useful for identifying the targets of many transcription factors. However, gene expression changes in response to transcription factor perturbation reveal both direct transcriptional targets and secondary gene regulation. By integrating RNA interference, gene expression profiling, and chromatin immunoprecipitation technologies, we identified a set of 32 direct transcriptional targets of the tumor suppressor p53. Of these 32 genes, 11 are not currently associated with the core p53 pathway. From among these novel pathway members, we focused on understanding the connection between p53 and SULF2, which encodes an extracellular heparan sulfate 6-O-endosulfatase that modulates the binding of growth factors to their cognate receptors and that has been shown to function as a tumor suppressor. Genetic and pharmacologic perturbation of p53 directly influences SULF2 expression, and similar to silencing of TP53, RNA interference-mediated suppression of SULF2 results in an impaired senescence response of cells to genotoxic stress. Thus, our integrated genomic approach has led to the identification of a novel mediator of p53 network biology.

Molecular techniques and genetic alterations in head and neck cancer

It is well known that cellular DNA alterations can lead to the formation of cancer, and there has been much discovery in the pathways involved in the development of head and neck squamous cell carcinoma (HNSCC). With novel genome-wide molecular assays, our ability to detect these abnormalities has increased. We now have a better understanding of the molecular complexity of HNSCC, but there is still much research to be done. In this review, we discuss the well described genetic alterations and touch on the newer findings, as well as some of the future directions of head and neck cancer research.

Structural profiles of TP53 gene mutations predict clinical outcome in diffuse large B-cell lymphoma: an international collaborative study

The purpose of this study is to correlate the presence of TP53 gene mutations with the clinical outcome of a cohort of patients with diffuse large B-cell lymphoma (DLBCL) assembled from 12 medical centers. TP53 mutations were identified in 102 of 477 patients, and the overall survival (OS) of patients with TP53 mutations was significantly worse than those with wild-type TP53 (P < .001). However, subsets of TP53 mutations were found to have different effects on OS. Mutations in the TP53 DNA-binding domains were the strongest predictors of poor OS (P < .001). Mutations in the Loop-Sheet-Helix and Loop-L3 were associated with significantly decreased OS (P = .002), but OS was not significantly affected by mutations in Loop-L2. A subset of missense mutations (His158, His175, Ser245, Gln248, His273, Arg280, and Arg282) in the DNA-binding domains had the worst prognosis. Multivariate analysis confirmed that the International Prognostic Index and mutations in the DNA-binding domains were independent predictors of OS. TP53 mutations also stratified patients with germinal center B cell-like DLBCL, but not nongerminal center B cell-like DLBCL, into molecularly distinct subsets with different survivals. This study shows the prognostic importance of mutations in the TP53 DNA-binding domains in patients with DLBCL.

Expression of p53 and Bcl-xL as predictive markers for larynx preservation in advanced laryngeal cancer

OBJECTIVE

To assess tumor markers in advanced laryngeal cancer.

DESIGN

Marker expression and clinical outcome.

PATIENTS

Pretreatment tumor biopsy specimens were analyzed from patients enrolled in the Department of Veterans Affairs Laryngeal Cancer Study.

MAIN OUTCOME MEASURES

Expression of p53 (OMIM TP53) and Bcl-xL (OMIM 600039) in pretreatment biopsy specimens was assessed for correlation with chemotherapy response, laryngeal preservation, and survival.

RESULTS

Higher rates of larynx preservation were observed in patients whose tumors expressed p53 vs those that did not (80% [36 of 45 patients] vs 59% [24 of 41 patients], P =.03). Higher rates of larynx preservation were also observed in patients whose tumors expressed low levels of Bcl-xL vs high levels of Bcl-xL (90% [18 of 20 patients] vs 60% [30 of 50 patients], P =.02). Patients were categorized into 3 risk groups (low, intermediate, and high) based on their tumor p53 and Bcl-xL expression status. Patients whose tumors had the high-risk biomarker profile (low p53 expression and high Bcl-xL expression) were less likely to preserve their larynx than patients whose tumors had the intermediate-risk biomarker profile (high p53 expression and low or high Bcl-xL expression) or the low-risk biomarker profile (low p53 expression and low Bcl-xL expression). The larynx preservation rates were 100% (10 of 10 patients), 77% (26 of 34 patients), and 54% (7 of 13 patients) for the low-risk, intermediate-risk, and high-risk groups, respectively (P =.04, Fisher exact test).

CONCLUSION

Tumor expression of p53 and Bcl-xL is a strong predictor of successful larynx preservation in patients treated with induction chemotherapy and followed by radiation therapy in responding tumors.

p53 expression in concurrent chemoradiotherapy with docetaxel for head and neck squamous cell carcinoma

BACKGROUND

The current study aimed to evaluate the significance of an immunohistochemical assessment of tumor suppressor p53 as a prognostic marker in head and neck squamous cell carcinoma (HNSCC) patients treated with docetaxel and radiotherapy.

METHODS

The expression of tumor suppressor p53 and its phosphorylated form at the Ser392 residue was retrospectively evaluated by immunohistochemistry in 51 Stage T1-3N0-2M0 (except T1N0 glottis) HNSCC patients who were treated with 10mg/m(2)/week docetaxel four to six times and received concurrent chemoradiotherapy.

RESULTS

Kaplan-Meier univariate analysis revealed that no difference in rates for overall and disease-free survival (DFS) between patients with p53-positive and -negative tumors (p=0.786 and p=0.924, respectively). The prognostic significance of phosphorylated p53 at the Ser392 residue was neither observed.

CONCLUSIONS

An immunohistochemical assessment of the expression of p53 and its phosphorylated form might not be of clinical use in defining subgroups of patients with poor prognosis.

Molecular pathogenesis of oral squamous cell carcinoma: implications for therapy

The development of oral squamous cell carcinoma (OSCC) is a multistep process requiring the accumulation of multiple genetic alterations, influenced by a patient's genetic predisposition as well as by environmental influences, including tobacco, alcohol, chronic inflammation, and viral infection. Tumorigenic genetic alterations consist of two major types: tumor suppressor genes, which promote tumor development when inactivated; and oncogenes, which promote tumor development when activated. Tumor suppressor genes can be inactivated through genetic events such as mutation, loss of heterozygosity, or deletion, or by epigenetic modifications such as DNA methylation or chromatin remodeling. Oncogenes can be activated through overexpression due to gene amplification, increased transcription, or changes in structure due to mutations that lead to increased transforming activity. This review focuses on the molecular mechanisms of oral carcinogenesis and the use of biologic therapy to specifically target molecules altered in OSCC. The rapid progress that has been made in our understanding of the molecular alterations contributing to the development of OSCC is leading to improvements in the early diagnosis of tumors and the refinement of biologic treatments individualized to the specific characteristics of a patient's tumor.

p53 status correlates with histopathological response in patients with soft tissue sarcomas treated using isolated limb perfusion with TNF-alpha and melphalan

BACKGROUND

Recombinant tumor necrosis factor-alpha (TNF-alpha) combined to melphalan is clinically administered through isolated limb perfusion (ILP) for regionally advanced soft tissue sarcomas of the limbs. In preclinical studies, wild-type p53 gene is involved in the regulation of cytotoxic action of TNF-alpha and loss of p53 function contributes to the resistance of tumour cells to TNF-alpha. The relationship between p53 status and response to TNF-alpha and melphalan in patients undergoing ILP is unknown.

PATIENTS AND METHODS

We studied 110 cases of unresectable limbs sarcomas treated by ILP. Immunohistochemistry was carried out using DO7mAb, which reacts with an antigenic determinant from the N-terminal region of both the wild-type and mutant forms of the p53 protein, and PAb1620mAb, which reacts with the 1620 epitope characteristic of the wild-type native conformation of the p53 protein. The immunohistochemistry data were then correlated with various clinical parameters.

RESULTS

P53DO7 was found expressed at high levels in 28 patients, whereas PAb1620 was negative in 20. The tumours with poor histological response to ILP with TNF-alpha and melphalan showed significantly higher levels of p53-mutated protein.

CONCLUSIONS

Our results might be a clue to a role of p53 protein status in TNF-alpha and melphalan response in clinical use.

Cell cycle dysregulation in oral cancer

The dysregulation of the molecular events governing cell cycle control is emerging as a central theme of oral carcinogenesis. Regulatory pathways responding to extracellular signaling or intracellular stress and DNA damage converge on the cell cycle apparatus. Abrogation of mitogenic and anti-mitogenic response regulatory proteins, such as the retinoblastoma tumor suppressor protein (pRB), cyclin D1, cyclin-dependent kinase (CDK) 6, and CDK inhibitors (p21(WAF1/CIP1), p27(KIP1), and p16(INK4a)), occur frequently in human oral cancers. Cellular responses to metabolic stress or genomic damage through p53 and related pathways that block cell cycle progression are also altered during oral carcinogenesis. In addition, new pathways and cell cycle regulatory proteins, such as p12(DOC-1), are being discovered. The multistep process of oral carcinogenesis likely involves functional alteration of cell cycle regulatory members combined with escape from cellular senescence and apoptotic signaling pathways. Detailing the molecular alterations and understanding the functional consequences of the dysregulation of the cell cycle apparatus in the malignant oral keratinocyte will uncover novel diagnostic and therapeutic approaches.

Excision Repair Cross Complementation Group 1 Immunohistochemical Expression Predicts Objective Response and Cancer-Specific Survival in Patients Treated by Cisplatin-Based Induction Chemotherapy for Locally Advanced Head and Neck Squamous Cell Carcinoma

PURPOSE

To assess the correlation of excision repair cross complementation group 1 (ERCC1) immunohistochemical expression with objective tumor response and cancer-specific survival in patients with locally advanced head and neck squamous cell carcinoma treated with cisplatin-based induction chemotherapy.

EXPERIMENTAL DESIGN

The initial cohort was composed of 107 patients who were treated from 1992 to 1996 by an induction chemotherapy regimen for locally advanced head and neck squamous cell carcinoma. p53 mutations had previously been studied. Pretherapeutic biopsy samples from 96 patients with a known tumor response were available. Two independent observers blinded to clinical annotations evaluated ERCC1 immunohistochemical expression.

RESULTS

Of 96 patients, 68 (71%; 95% confidence interval, 61-79%) had tumors that expressed ERCC1 intensively and diffusely. Using the logistic regression method, the 28 (29%) patients with tumors expressing ERCC1 at lower levels had a 4-fold greater odds of benefiting from an objective response to chemotherapy (odds ratio, 4.3; 95% confidence interval, 1.4-13.4; P = 0.01) compared with the group of 68 patients with high ERCC1 expression. ERCC1 and p53 status, but not their interaction, were independent predictors of tumor response. In a Cox proportional hazard model adjusted on age, TNM stage, tumor differentiation, and tumor localization, ERCC1 low expression was associated with a lower risk of cancer death (risk ratio, 0.42; 95% confidence interval, 0.20-0.90; P = 0.04) whereas p53 status had no prognostic value.

CONCLUSION

Our results suggest that those patients characterized by low ERCC1 expression are more likely to benefit from cisplatin induction chemotherapy compared with patients with high ERCC1 expression.

Mutant p53 proteins: between loss and gain of function

Cancer might result from both the aberrant activation of genes, whose physiological tuning is essential for the life of a normal cell, and the inactivation of tumor suppressor genes, whose main job is to preserve the integrity of cell genome. Among the latter, p53 is considered a key tumor suppressor gene that is inactivated mainly by missense mutations in half of human cancers. It is becoming increasingly clear that the resulting mutant p53 proteins gain oncogenic properties favoring the insurgence, the maintenance, and the spreading of malignant tumors. In this review, we mainly discuss the molecular mechanisms underlying gain of function of human tumor-derived p53 mutants, their impact on the chemoresistance and the prognosis of human tumors, with a special focus on head and neck cancers, and the perspectives of treating tumors through the manipulation of mutant p53 proteins.

Molecular and cytogenetic subgroups of oropharyngeal squamous cell carcinoma

PURPOSE

The aim of this study was to acquire further insights into the pathogenetic pathways of head and neck squamous cell carcinomas (HNSCC) that may be useful for identifying new biomarkers instrumental in developing more specific treatment approaches.

EXPERIMENTAL DESIGN

Cell cycle regulators and epidermal growth factor receptor (EGFR) and BRAF genes were analyzed in a series of 90 oropharyngeal SCCs of a cohort of surgically treated patients from a single institution, and the results were matched with the presence of high-risk human papillomavirus (HR-HPV) DNA and the TP53 status.

RESULTS

At least four distinct groups of tumors were identified sharing a common histology but displaying different molecular/cytogenetic patterns: (a) 19% were HPV-positive SCCs whose lack of alterations of the investigated genes could explain their particular natural history, which requires less aggressive treatment; (b) 37% were HPV-negative SCCs carrying TP53 mutations, which may be more effectively treated by drugs acting through p53-independent apoptosis; (c) 34% were HPV-negative SCCs carrying wild-type TP53 and loss of 9p21 (p16INK4a and p15INK4b) and/or cyclin D1 overexpression that justify treatment with DNA-damaging drugs followed by cell cycle inhibitors; and (d) 10% were HPV-negative lacking tumor suppressor genes and cell cycle alterations. The second, third, and fourth groups also showed an increased copy number of EGFR and chromosome 7 (43%) that might justify the additional or alternative use of EGFR inhibitors.

CONCLUSIONS

Our findings suggest that assessing HPV, TP53, 9p21, and EGFR status may be crucial to finding more tailored and beneficial treatments for oropharyngeal SCCs.

High-Risk Human Papillomavirus Affects Prognosis in Patients With Surgically Treated Oropharyngeal Squamous Cell Carcinoma

Purpose

Human papillomavirus (HPV) DNA tumors actively integrating the E6 and E7 oncogenes have a distinct biologic behavior resulting in a more favorable prognosis. To which extent the viral integration by itself, and/or the associated wild-type (wt) TP53 status, and/or a functional p16 contribute to prognosis is unclear.

Patients and Methods

To clarify how the presence of high-risk (HR) -HPV, TP53, and p16INK4a status interact with clinical outcome, we considered a retrospective series of 90 consecutive oropharyngeal cancer patients treated primarily with surgery.

Results

Seventeen (19%) patients showed integrated HPV 16 DNA (HPV positive), wt TP53 in all but two patients, normal p16INK4a in 15 assessable patients, and p16 expression in all 17 patients. Thirty-five patients (39%), two of whom were HPV positive, harbored TP53 mutations. p16INK4a deletion and p16 null immunophenotype occurred in 28 and 58 patients, respectively, and was similarly distributed in both patients with mutated TP53 (48% and 82%, respectively) and in patients with wt TP53 (46% and 77%, respectively). Statistical analysis showed that HPV-positive status significantly affects all investigated end points: overall survival (P = .0018), incidence of tumor relapse (P = .0371), and second tumor (P = .0152), whereas TP53 and p16INK4a status and p16 expression were not prognostic by themselves.

Conclusion

Our molecular and clinical results are in agreement with previous findings but provide additional information into the biologic mechanisms involved in HR-HPV oropharyngeal cancer in comparison to HPV-negative tumors. According to the reduced risk of relapse and second tumors associated with HR-HPV positivity of oropharyngeal cancer, the therapeutic strategy and follow-up procedures should be reviewed.

Reassessment of the role of induction chemotherapy for head and neck cancer

Head and neck cancers are a complex group of diseases defined by variations in histological features, anatomical location, and cause. Once the realm of surgeons and radiation oncologists, the treatment of locally advanced disease now involves medical oncologists. Major developments include primary chemoradiotherapy for unresectable disease and organ preservation, the addition of chemotherapy to adjuvant radiotherapy, improvement in surgical and radiation techniques, and biological therapies. Concomitant chemoradiotherapy consistently improves locoregional control. However, control of distant metastases is poor, resulting in an increasing proportion of deaths from systemic recurrence. Given this shift in site of recurrence, therapeutic strategies to suppress distant metastases may be the next goal for further improvement of survival. One approach that merits reassessment is the use of induction chemotherapy in the setting of locally advanced disease--both resectable and unresectable. In this review we summarise data for the use of induction chemotherapy to define better which patients will likely benefit from this approach now and which questions are important in the design of future clinical trials.

Molecular markers of head and neck squamous cell carcinoma: promising signs in need of prospective evaluation

BACKGROUND

The aim of this article is to review recent developments in the biological understanding of head and neck squamous cell carcinomas.

METHODS AND RESULTS

We describe the markers according to their function and their prognostic or predictive roles. Some associations can be found between molecular markers and invasiveness, aggressiveness, degree of differentiation, and tumor stage, but only a few clinical studies have shown an impact on prognosis. In addition, despite an increasing number of articles relating to this topic, the small number of patients included in the studies reported reduces the clinical implications of these results. Few studies applied a more comprehensive molecular analysis approach, such as DNA microarrays or differential expression profiling by polymerase chain reaction, to identify a combination of markers that could be more informative than a single molecular marker.

CONCLUSION

Some progress has been made with respect to molecular markers and head and neck cancers. Translational and prospective, hypothesis-driven research must proceed with sufficient rigor to facilitate the clinical applicability of such results.

Genetic factors influencing pyrimidine-antagonist chemotherapy

Pyrimidine antagonists, for example, 5-fluorouracil (5-FU), cytarabine (ara-C) and gemcitabine (dFdC), are widely used in chemotherapy regimes for colorectal, breast, head and neck, non-small-cell lung cancer, pancreatic cancer and leukaemias. Extensive metabolism is a prerequisite for conversion of these pyrimidine prodrugs into active compounds. Interindividual variation in the activity of metabolising enzymes can affect the extent of prodrug activation and, as a result, act on the efficacy of chemotherapy treatment. Genetic factors at least partly explain interindividual variation in antitumour efficacy and toxicity of pyrimidine antagonists. In this review, proteins relevant for the efficacy and toxicity of pyrimidine antagonists will be summarised. In addition, the role of germline polymorphisms, tumour-specific somatic mutations and protein expression levels in the metabolic pathways and clinical pharmacology of these drugs are described. Germline polymorphisms of uridine monophosphate kinase (UMPK), orotate phosphoribosyl transferase (OPRT), thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and methylene tetrahydrofolate reductase (MTHFR) and gene expression levels of OPRT, UMPK, TS, DPD, uridine phosphorylase, uridine kinase, thymidine phosphorylase, thymidine kinase, deoxyuridine triphosphate nucleotide hydrolase are discussed in relation to 5-FU efficacy. Cytidine deaminase (CDD) and 5'-nucleotidase (5NT) gene polymorphisms and CDD, 5NT, deoxycytidine kinase and MRP5 gene expression levels and their potential relation to dFdC and ara-C cytotoxicity are reviewed.

Genetic and expression profiles of squamous cell carcinoma of the head and neck correlate with cisplatin sensitivity and resistance in cell lines and patients

PURPOSE

The choice of treatment for squamous cell carcinoma of the head and neck (SCCHN) is still primarily based on the tumor-node-metastasis classification. However, it is reasonable to believe that biological profiles of SCCHN may be independently associated with response to therapy. The aim of the present study was to examine genetic changes and gene expression profiles that might correlate with sensitivity to cisplatin [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay] in 10 SCCHN cell lines.

EXPERIMENTAL DESIGN

Five cisplatin-sensitive and five cisplatin-resistant cell lines [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay] were studied by comparative genomic hybridization, spectral karyotyping, and cDNA microarray analysis (21,632 sequence-validated human cDNA; confirmation by reverse transcriptase-PCR for selected genes). For the MET proto-oncogene, which showed low expression in the chemosensitive cell lines, we did immunohistochemical staining on SCCHN of 29 patients who received induction chemotherapy.

RESULTS

The five cisplatin-resistant cell lines showed significantly more genetic imbalances (regions of loss and amplification) and chromosomal abnormalities by comparative genomic hybridization and spectral karyotyping, respectively, than did the five cisplatin-sensitive cell lines. Microarray studies identified approximately 60 genes that clearly distinguish between the two groups of cell lines. Some of these genes are known to be involved in tumor progression, metastasis, and drug resistance. We identified low expression of c-met (immunohistochemistry) as a predictive factor for complete response in nondiploid tumors (P = 0.026).

CONCLUSIONS

We conclude that cisplatin sensitivity and resistance are related to distinctive differences in the genetic and expression profiles in individual SCCHN tumor cell lines and in SCCHN patients. The genes we have identified may serve as potential targets for novel treatment strategies.

Prognostic impact of the epidermal growth factor receptor levels for patients with larynx and hypopharynx cancer

The aim of this study was to analyse prognostic factors for disease free interval (DFI) and overall survival (OS) among patients with larynx and hypopharynx cancer requiring a total laryngectomy. Three groups of patients were studied according to the type of treatment they received. Fifty-eight patients had total laryngectomy, 71 patients had organ preservation treatment including induction chemotherapy followed by exclusive radiotherapy, 26 patients received induction chemotherapy followed by salvage total laryngectomy. The studied potential prognostic factors were age, gender, performans status, primary tumor localization, T status, N status, tumor volume and tumoral EGFR level (fmol/mg protein). The multivariate analysis showed that both N status and tumor volume were significant for DFI and OS. EGFR level was significant only for patients treated by induction chemotherapy and exclusive radiotherapy (p = 0.05 and 0.05 for DFI and OS length, respectively). Among this group, patients with tumor EGFR levels lower and higher than 100 fmol/mg protein had 53% versus 22% and 51% versus 18% 5-year of DFI and OS rates, respectively (Log rank test: p = 0.001 and 0.0001). EGFR determination appears to be a powerful prognostic parameter for patients treated by induction chemotherapy followed by exclusive radiotherapy. Laryngectomy seems to erase the prognostic impact of EGFR expression. These results profile the use of EGFR targeting therapy for this category of patients.

Chromosomal instability in oral cancer cells

Chromosomal instability is a common feature of human tumors, including oral cancer. Although a tumor karyotype may remain quite stable over time, chromosomal instability can lead to 'variations on a theme' of a clonal cell population, often with each cell within a tumor possessing a different karyotype. Thus, chromosomal instability appears to be an important acquired feature of tumor cells, since propagation of such a diverse cell population may facilitate evasion of standard therapies. There are several sources of chromosomal instability, although the primary causes appear to be defects in chromosomal segregation, telomere stability, cell-cycle checkpoint regulation, and the repair of DNA damage. Our understanding of the biological basis of chromosomal instability in cancer cells is increasing rapidly, and we are finding that the seemingly unrelated origins of this phenomenon may actually be related through the complex network of cellular signaling pathways. Here, we review the general causes of chromosomal instability in human tumors. Specifically, we address the state of our knowledge regarding chromosomal instability in oral cancer, and discuss various mechanisms that enhance the ability of cancer cells within a tumor to express heterogeneous karyotypes. In addition, we discuss the clinical relevance of factors associated with chromosomal instability as they relate to tumor prognosis and therapy.

Concomitant boost radiation and concurrent cisplatin for advanced head and neck carcinomas. Preliminary results of a phase II, single-institutional trial

INTRODUCTION

This study aims to asses the effectiveness and toxicity of boost radiotherapy concomitant and concurrent cisplatin for patients with locally advanced head and neck cancer (LAHNC).

MATERIAL AND METHODS

There were 30 patients included in a prospective, phase II single-institution trial and of whom, 29 were at AJCC stage IV and 1 at stage III. Treatment consisted of radiotherapy acceleration fractionation with concomitant boost, 72 Gy, and 2 cycles of concomitant cisplatin (20 mg/m2/day continuous infusion; days 1-5 and 29-33). Amifostine, (i.v. 200 mg/m2) was administered to 26 prior to the first fraction of radiotherapy. Endpoints of the study were quality-of-life (QL), overall survival, and local control of disease.

RESULTS

Complete response (CR) was achieved in 23 patients (77%), 2 patients had partial response (PR) (7%), 4 had no response (13%), and 1 was not evaluated for response. The 2-year overall survival and loco-regional control were 60% and 56%, respectively. Main toxicity was grade 3 or 4 mucositis in 93% of the patients. QL scores (questionnaire QLQC30; version 3.0) and the HN cancer module QLQ-HN35) showed a worsening in areas related to the treatment e.g. dry mouth, problems stretching the mouth, and sticky saliva.

CONCLUSIONS

this combination modality is active, but toxic, in the treatment for LAHNC. Concomitant boost radiotherapy is probably, not the best radiotherapy schema for combining with chemotherapy in LAHNC.

Prediction of TP53 status for primary cisplatin, fluorouracil, and leucovorin chemotherapy in ethmoid sinus intestinal-type adenocarcinoma

PURPOSE

To assess the role of TP53 status in predicting pathologic complete remission after primary chemotherapy in patients with ethmoidal intestinal-type adenocarcinoma (ITAC).

PATIENTS AND METHODS

Thirty patients with ethmoidal ITAC enrolled onto a phase II study received chemotherapy with cisplatin, fluorouracil, and leucovorin (PFL) followed by surgery and radiation. On surgical specimens, absence of viable tumor cells was defined as pathologic complete remission (pCR). TP53 status/p53 function, analyzed on pretreatment biopsies, were retrospectively correlated with pathologic results and patient outcome.

RESULTS

Twelve patients achieved a pCR; 18 patients did not (overall response rate, 40%). In patients with wild-type (wt) TP53 or functional p53 protein, the pCRs were 83% and 80%, respectively; in patients with mutated TP53 or impaired p53 protein, pCRs were 11% and 0%, respectively (P < or = .0001). At a median 55-month follow-up, all pCR patients were disease-free; 44% of nonresponding patients experienced relapse (P = .0061).

CONCLUSION

The results indicate the existence of two genetic ITAC subgroups, defined by differences in TP53 mutational status or protein functionality, that strongly influence pathologic response to primary chemotherapy and, ultimately, prognosis. PFL seems to be highly effective in terms of pCR and disease-free survival in the presence of a wt or a still-efficient p53 protein, even when encoded by a mutated TP53 gene (eg, early-stop codon mutation), but ineffective in ITACs carrying a disabled p53 protein. Whether this model is extensible to other head and neck cancers needs appropriate investigation.

Towards fast and inexpensive molecular diagnostic: the case of TP53

BACKGROUND

Much research suggests that TP53 mutations have prognostic importance and sometimes are a significant factor in clinical oncology. A considerable effort has been made to develop fast and inexpensive methods for TP53 mutations detection.

METHODS

On the basis of describing the role of TP53 as tumor suppressor gene and TP53 mutation spectrum, the authors discuss conventional methods and new technologies for TP53 mutations detection. This discussion is supported by more recent publications in the field of both molecular genetics and analysis technologies.

RESULTS

Biosensors and gene chips are of considerable recent interest, due to their tremendous promise for obtaining sequence-specific information in a faster, simpler and cheaper manner compared to traditional methods.

CONCLUSIONS

New methods such as biosensors and gene chips appear promising as analytical methods of detecting mutations.

Matrix Metalloproteinase 3 Polymorphism

PURPOSE

Treatment of head and neck cancer often associates different therapeutic modalities, including surgery, radiotherapy, and chemotherapy. In an attempt to optimize therapeutics, the identification of molecular markers linked to response to chemotherapy remains important. Recently, the involvement of metalloproteinases in resistance to chemotherapy was suggested through their interaction with the Fas/Fas ligand pathway. Indeed metalloproteinases enhance Fas ligand shedding modulating chemotherapy efficiency. On the basis of these findings, we tested the existence of a correlation between response to chemotherapy and four metalloproteinase polymorphisms in a prospective series of 148 head and neck cancer patients.

EXPERIMENTAL DESIGN

Patients were genotyped using automated fragment analysis and 5'-nuclease allelic discrimination assay. Response to chemotherapy was clinically assessed without knowledge of the genotype status.

RESULTS

A significant relation between the metalloproteinase type 3 (MMP3) -1612insA polymorphism and response to chemotherapy was identified. Indeed, patients with the 6A/6A genotype responded more frequently (86%) to treatment as compared with patients with the 5A/6A (65%) or 5A/5A (55%) genotypes (P = 0.04). A multivariate analysis, including tumor stage, gender, TP53 mutations, and MMP3 polymorphism, showed that the 6A/6A genotype was an independent factor of response to 5-fluorouracil-cisplatin chemotherapy in head and neck cancer patients with an odds ratio of 6.7 as compared with the 5A/5A genotype.

CONCLUSIONS

This work showed that genotyping the MMP3 gene enhancer polymorphism -1612insA could help predict chemosensitivity in head and neck cancer patients.

Hyperfractionated Radiotherapy and Concomitant Cisplatin for Locally Advanced Laryngeal and Hypopharyngeal Carcinomas

SUMMARY

ABSTRACT The purpose of this study was to achieve locoregional control of locally advanced laryngeal carcinoma, survival, and organ preservation using split hyperfractionated accelerated radiation therapy and cisplatin concomitantly. This study was a phase II trial of chemoradiotherapy with split hyperfractionated accelerated radiation therapy, 1.6 Gy per fraction given twice per day to a total dose of 64 to 67.2 Gy for a total of 6 weeks with a 2-week gap, and cisplatin 20 mg/m2, days 1 to 5, in continuous perfusion, concomitantly. Seventy-three patients were treated (stage IV, 64%). At a median follow-up of 55 months for living patients, median survival was 44 months, and 5-year overall survival and disease-free survival were 42% and 39%, respectively. Toxicities included mucositis (grade III, 40%; grade IV, 28%), epithelitis (grade III, 28%). Of the 73 patients, 32 (44%) have continued with their larynx free of disease. Split hyperfractionated accelerated radiation therapy and concomitant cisplatin has been demonstrated to be an active treatment for locally advanced laryngeal carcinomas, but more active combinations of chemotherapy and radiotherapy, without increase of toxicity, are necessary to increase the rate of locoregional control, organ preservation, and survival.

p53 family members and chemoresistance in cancer: what we know and what we need to know

Resistance to chemotherapy remains a major obstacle to the successful management of many human cancers. Numerous genetic and epigenetic changes in the cancer cell may contribute to drug resistance. However, with the recognition of important roles for both p53 and its more recently described paralog p73 in mediating the activity of anti-cancer drugs, there has been increasing recognition that cellular resistance to such agents can and does arise through failure of p53 family member signalling. Abrogation of function in p53 occurs through point mutations which abolish DNA binding or by dominant negative inhibition by variants of p73 lacking the N-terminal transactivation domain. Conversely, the function of full-length transactivation-competent (TA)p73 variants expressing the transactivation domain is itself subject to trans-dominant inhibition by certain p53 mutants and, in some cancers, by transcriptional silencing. The specificity of target gene activation by p53 and TAp73 is modulated by transcriptional co-activators which thereby act as response modifiers. Changes in the activity/expression of co-activators may therefore cause an altered cellular response to p53/p73 activation. Despite these advances in understanding how cells respond to DNA damage in vitro, and how this is affected by molecular genetic changes which affect p53 family member signalling, the contribution of these to in vivo drug resistance has not been definitively established. Our major task now is to determine how these changes operate individually and collectively in vivo to produce the phenotype of clinical drug resistance, and how we can translate this knowledge into clinically useful strategies to improve the outcome of chemotherapy.

Cytology vs molecular analysis for the detection of head and neck squamous cell carcinoma in oesopharyngeal brush samples: a prospective study in 56 patients

Oesopharyngeal brush (OPB) sampling with cytological analysis can yield exfoliated cells from asymptomatic tumours of the upper aero-digestive tract and the oesophagus. In this study, we compared cytological evaluation and molecular analysis for the detection of exfoliated cancer cells sampled with an OPB. A total of 56 patients with a known unique head and neck squamous cell carcinoma (HNSCC) and five healthy controls were enrolled prospectively. Exfoliated cells from these 61 patients were collected with an OPB before initial endoscopy. p53 mutations and UT 5085 microsatellite instability (MI) were analysed in the HNSCC tumour, lymphocytes and the corresponding OPB DNA samples. p53 mutations and UT5085 MI were detected in 31 out of 56 and 14 out of 56 HNSCC, respectively, but not in any of the five controls. Direct sequencing of p53 was able to detect mutations in OPB DNA in only two out of 29 patients harbouring a p53-mutated primary tumour. Microsatellite instability was detected in OPB DNA of 11 out of 13 informative (bandshift detected in tumour) patients, whereas cytological analysis detected abnormal cells in only six of the same 13 patients (P=0.03). In informative patients, all positive OPB samples at cytological analysis were also positive at molecular analysis of UT5085, and both analyses confirmed the two negative samples. Molecular analysis of OPB from eight uninformative patients and from five healthy controls were all negative. OPB sampling with MI-based molecular analysis could be efficient for early detection of recurrent HNSCC. This result prompts us to use other microsatellite markers in order to maximise the percentage of informative patients.

The p53 network in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and, despite advances in treatment, still represents a clinical challenge. Inactivation of one or more components of the p53 network is an extremely common event in human neoplasia. In HNSCC, disabling of p53 occurs in a high proportion of cases by mutation in the p53 gene, but other mechanisms of inactivation, such as the presence of human papillomavirus (HPV) and molecular abnormalities in other components of the pathway, are also recognised. The frequent changes occurring in the p53 pathway in HNSCC imply that molecular genetic and immunocytochemical analysis of this critical tumour suppressor network may be of diagnostic and prognostic utility in the clinical management of HNSCC. Further, these changes also provide targets for the development of novel therapeutic approaches to this increasingly common cancer, in which clinical cure for advanced disease remains an elusive goal.

TP53 and head and neck neoplasms

Head and neck cancer is an important health problem around the world, accounting for approximately 500,000 new cases each year of head and neck squamous cell carcinoma (HNSCC). Carcinogenesis of head and neck results from a dysregulation of cellular proliferation, differentiation, and cell death. The major etiologic agents are tobacco and alcohol consumption and for some cases, human papilloma virus (HPV) infection. All three factors are associated with the disruption of a cellular pathway essential for the maintenance of cellular integrity, the p53 pathway. The objective of this review is to point out the specificity of p53 gene (TP53) alterations in head and neck cancer in relation with chemocarcinogenesis and to discuss whether or not the determination of p53 alterations will be of clinical relevance in the management of head and neck cancer in terms of prognosis and response to treatments.

p53 and cyclin D1 as prognostic factors in squamous cell carcinoma of the larynx

OBJECTIVES/HYPOTHESIS

Proteins p53 and cyclin D1 play a crucial role in cell cycle control. Protein p53 mutations are one of the most common genetic alterations in human cancer, and cyclin D1 gene amplification has been found to be associated with poor prognosis in different types of tumors. Functional alterations of these proteins may play an important role both in the carcinogenesis of squamous carcinomas of the head and neck and in the clinical evolution of these tumors. The objective of the present study was to evaluate whether the presence of p53 and/or cyclin D1 proteins (detected by immunohistochemical analysis) could serve as relevant variables for the assessment of the prognosis of laryngeal squamous cell carcinoma.

STUDY DESIGN

Retrospective multicentric study.

METHODS

Paraffin-embedded biopsy specimens from 62 human epidermoid laryngeal carcinomas were randomly selected. The expression of p53 and cyclin D1 was examined by means of immunohistochemical analysis with a view to evaluating whether there is a correlation between the aberrant expression of these proteins and disease prognosis.

RESULTS

In the sample, the presence of immunohistochemically detectable p53 is associated with shorter survival and disease-free intervals, as shown in Kaplan-Meier survival curve analysis. Indeed, multivariate statistical analysis revealed that the accumulation of p53 is an independent prognostic factor, which is associated with shorter survival. This association was not evident in the case of cyclin D1.

CONCLUSION

A more precise prognosis of patients with laryngeal epidermoid carcinomas could be achieved by taking into account the presence of p53 (as assayed by immunohistochemical analysis) in biopsy tissue

Tumour stage, node stage, p53 gene status, and bcl-2 protein expression as predictors of tumour response to platin-fluorouracil chemotherapy in patients with squamous-cell carcinoma of the head and neck

The purpose of this study was to establish the relative contribution of tumour stage, node stage, p53 gene status, p53 expression, and bcl-2 protein expression to tumour response to platin-fluorouracil chemotherapy in 141 patients with squamous-cell carcinomas of the head and neck. Tumour response was measured at the primary site after three cycles of chemotherapy. Exons 2-10 and the coding part of exon 11 were sequenced on both strands. Bcl-2 or p53 expression was detected by immunohistochemistry. Predictor variables of objective response (reduction of at least 50% of tumour size) were tested in univariate and multivariate analyses. P53 mutations were found in 52 patients (37%). Tumour cells expressed p53 in 84 cases (59%) and bcl-2 in 25 cases (18%). T1 or T2 stage (adjusted odds ratio, 3.3; 95% confidence interval 1.3-8.7; P=0.01), N0 node stage (adjusted odds ratio, 2.7; 95% confidence interval 1.1-6.4; P=0.03), p53 wild-type gene (adjusted odds ratio, 4.0; 95% confidence interval 1.7-9.5; P=0.002), and bcl-2 protein expression (adjusted odds ratio, 20; 95% confidence interval 2.3-170; P=0.006), were positively associated with tumour response. P53 protein expression was not predictive of response. In conclusion, tumour stage, node stage, p53 gene status, and bcl-2 expression are independent predictors of tumour response to platin-fluorouracil in patients with squamous-cell carcinomas of the head and neck.

Clinical relevance of molecular markers in lung cancer

The last two decades have seen an exponential growth of our knowledge on the molecular biology of cellular processes and neoplastic transformation. There is high expectation that these advances will be translated into further improvement in the care of cancer patients, especially in the areas of prevention, diagnosis and treatment. Realizing that the histopathological classification of lung cancer has reached its limit in providing additional critical information to further improve treatment strategy, numerous molecular aberrations occurring in lung cancers have been explored as potential new diagnostic markers and markers for molecular sub-staging. Despite extensive studies, most results remain largely controversial. This manuscript will briefly review molecular/genetic changes that have been investigated as candidate diagnostic, prognostic and predictive markers and as biomarkers for early detection in lung cancer. A more concerted and global approach to study the clinical relevance of molecular changes in lung cancers is required in the future.

End points for new agents in induction chemotherapy for locally advanced head and neck cancers

More than 60% of patients diagnosed with squamous cell carcinoma of the head and neck present at a locally advanced stage. Although multimodality therapy has improved locoregional control, the 5-year survival rate of this population rarely exceeds 30%. In this review, we analyzed the impact of chemotherapy in the management of locally advanced head and neck cancer and we underline the potential benefit of induction chemotherapy. The Meta-Analysis of Chemotherapy in Head and Neck Cancer collaborative group has suggested a survival advantage of 5% at 5 years for platin-5-fluorouracil induction chemotherapy. We have analyzed cofactors that may affect the survival of head and neck patients and propose new end points for assessment of the efficacy of induction chemotherapy. The detrimental effect of second primary tumors on long-term results is stressed and we have suggested the use of overall 2-year survival as a surrogate end point for induction chemotherapy efficacy. Finally, we have examined the impact of new cytotoxic agents and present the promising results of new taxane-based combinations.

Alteration of p53 pathway in squamous cell carcinoma of the head and neck: impact on treatment outcome in patients treated with larynx preservation intent

PURPOSE

To identify the role of p53 pathway alteration(s) as predictors of treatment outcome in patients with advanced, resectable, squamous cell carcinoma (SCC) of the larynx and pharynx treated with larynx preservation (LP) intent.

PATIENTS AND METHODS

Seventy-one patients treated on two consecutive LP protocols were studied based on availability of representative tissues. We analyzed the expression pattern of p53, its upstream regulator mdm2, and downstream transcriptional target p21/WAF1 by immunohistochemistry. Positive phenotype was defined as >or= 20% of tumor cells showing nuclear immunoreactivity. Results were correlated with treatment outcomes.

RESULTS

Positive phenotype was observed in 35 (49%) of 71 cases for p53, in 52 (74%) of 70 for mdm2, and in 37 (54%) of 68 for p21. There was no correlation between p53 phenotype and p21 nuclear accumulation. The mdm2-negative phenotype was most predictive of major response at the primary tumor site (P =.088). p53-positive phenotype was associated with worse local control with LP (LCLP; 49% v 23%, P =.053) and inferior overall survival (OS; 51% v 29%, P =.017) at 5 years. On Cox regression analysis, p53-positive phenotype predicted inferior OS (P =.033) and showed a trend for worse LCLP (P =.102). When analyzed in a multivariate model as continuous variables, p53 showed a stronger correlation with inferior OS (P <.01), and mdm2 was associated with worse OS (P <.01).

CONCLUSION

Among the three markers studied, our data support p53 phenotype as the most informative predictor of unfavorable outcomes in the LP setting, and suggest a role for mdm2 phenotype that requires further exploration. Our analysis does not support a p53-dependent mechanism for p21 expression. Prospective and larger studies are necessary before integration of these molecular markers as part of molecular staging and predictors for organ preservation or other outcomes.

P53 gene mutations: case study of a clinical marker for solid tumors

P53 is a tumor-suppressor gene that codes for a multifunctional DNA-binding protein involved in cell cycle arrest, DNA repair, differentiation, and apoptosis. The P53 gene is mutated in approximately 50% of human cancers and in germline DNA of families with inherited cancer syndromes. The role of P53 mutations in the program of carcinogenic genetic alterations differs among tumor sites ranging from the earliest mutations that can be detected in premalignant cells to mutations that trigger malignant transformation of a benign neoplasm. P53 mutations can cause expression of abnormal proteins or result in complete absence of P53 expression. For these reasons the role of P53 genetic disruption has different implications in different tumor types and may vary depending on the effect of the mutation on P53 protein function. Immunohistochemical detection of P53, commonly used as a surrogate for identification of a mutant gene, has imperfect sensitivity and specificity, further complicating correlations between P53 gene status and clinical outcomes. The presence of P53 mutations has been shown to affect prognosis of some cancers. The identity of P53 mutations can be used to determine tumor clonality. The detection of P53 mutations suggests the severity of premalignant lesions. Evolving technology for more accurate identification of P53 mutations, better understanding of the function of mutant P53 protein, and more detailed analysis of individual tumor types may expand the relevance of P53 gene analysis for clinical outcomes and therapeutic response.

Influence of epidermal growth factor receptor (EGFR), p53 and intrinsic MAP kinase pathway status of tumour cells on the antiproliferative effect of ZD1839 ("Iressa")

of ZD1839 ("Iressa") is an orally active, selective epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), which blocks signal transduction pathways implicated in proliferation and survival of cancer cells, and other host-dependent processes promoting cancer growth. Permanent downstream activation of the mitogen-activated protein kinase pathway can theoretically bypass the upstream block of epidermal growth factor receptor-dependent mitogen-activated protein kinase activation at the epidermal growth factor receptor level. We investigated the impact of epidermal growth factor receptor content, p53 status and mitogen-activated protein kinase signalling status on ZD1839 sensitivity in a panel of human tumour cell lines: seven head and neck cancer cell lines and two colon cancer cell lines (LoVo, HT29) with derivatives differing only by a specific modification in p53 status (LoVo p53 wt + p53 mut cells, HT29 p53 mut + p53 wt rescued cells). The antiproliferative activity of ZD1839 was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide test. ZD1839 concentrations ranged from 0.2-200 microM (48 h exposure). Epidermal growth factor receptor expression, p53 status and p42/p44 (for testing a constitutively active mitogen-activated protein kinase pathway status) were determined by competition analysis (Scatchard plots), denaturing gradient cell electrophoresis and Western blot, respectively. Epidermal growth factor receptor levels ranged from 388 to 33794 fmol mg(-1) protein, a range that is similar to that found in head and neck tumours. The IC(50) values for cell sensitivity to ZD1839 ranged from 6 to 31 microM and a significant inverse correlation (P=0.022, r=0.82) between IC(50) values and epidermal growth factor receptor levels was observed. There was no influence of p53 status on the sensitivity to ZD1839. In two head and neck cancer cell lines with comparably elevated epidermal growth factor receptor expression, a two-fold higher ZD1839 IC(50) value was found for the one with a constitutively active mitogen-activated protein kinase. In conclusion, ZD1839 was active against cells with a range of epidermal growth factor receptor levels, although more so in cells with higher epidermal growth factor receptor expression. Activity was unaffected by p53 status, but was reduced in cells strongly dependent on epidermal growth factor receptor signalling in the presence of an intrinsically activated mitogen-activated protein kinase pathway.

Cancer of the oropharynx

Oropharyngeal cancer is a rare tumour. Tobacco use and alcohol consumption are recognised as major risk factors. Several carcinogens, occupational exposures and vitamin deficiencies represent the most significant predisposing factors. A varying host susceptibility to carcinogens can be inferred. Carcinoma of the oropharynx has to be suspected whenever sore throat, odynophagia, and ear-ache are described by the patient. Biopsy is mandatory for the definitive diagnosis. TNM classification is crucial for treatment decision-making, while stage grouping is less important. Prognostic factors are treatment-related. Standard treatment of T1-T2 tumours is radiation therapy, for T3 and T4 tumour treatment options are controversial. More advanced tumours can be treated either with surgery followed by conventional radiotherapy or by combined chemo-radiation. Non-conventional fractionation radiotherapy in combination with chemotherapy may represent a third option. Acute toxicity needs to be managed promptly. Late sequelae are less known. Treatment of such tumours requires a multidisciplinary approach within experienced centres.