The role of epidermal growth factor receptor and E-cadherin for the outcome of reduction in the overall treatment time of radiotherapy of supraglottic larynx squamous cell carcinoma

PTEN Is Associated With Worse Local Control in Early Stage Supraglottic Laryngeal Cancer Treated With Radiotherapy

Objectives

The aim of this study was to establish the prognostic value of the epidermal growth factor receptor (EGFR) and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression on local control in patients with early stage supraglottic laryngeal squamous cell carcinoma (LSCC) treated with radiotherapy only.

Study design

Retrospective cohort study.

Methods

Immunohistochemical staining for EGFR and PTEN was performed on pretreatment biopsies of a selected well-defined homogeneous group of 52 patients with T1-T2 supraglottic LSCC treated with radiotherapy between 1990 and 2008. Kaplan-Meier analysis and univariate and multivariate Cox Regression analyses were performed to correlate clinical data and expression levels of EGFR and PTEN with local control.

Results

Kaplan-Meier survival analysis and Cox Regression analysis showed a significant association between PTEN expression and local control (hazard ratio [HR] = 3.26, 95% confidence interval [CI] = 1.14-9.33, P = .027) and between lymph node status and local control (HR = 3.60, 95% CI = 1.26-10.31, P = .017). Both were independent prognostic factors in a multivariate analysis (HR = 3.28, 95% CI = 1.14-9.39, P = .027 and HR = 3.62, 95% CI = 1.26-10.37, P = .017, respectively). There was no significant association between EGFR expression and local control (HR = 1.32, 95% CI = 1.17-10.14, P = .79).

Conclusion

This study showed an association between both high PTEN expression and the presence of lymph node metastasis and deteriorated local control in early stage supraglottic LSCC treated with radiotherapy.

Level of Evidence

NA.

Genetics and management of locally advanced carcinomas of the head and neck: role of altered fractionation radiotherapy

Squamous cell carcinoma of the head and neck (SCCHN) accounts for 5-7% of all malignancies. About 60% of newly diagnosed SCCHN are detected as locally advanced disease. Chemoradiation is a standard option and response rate to it is variable. Recently, a genetic classification of SCCHN has been proposed by Chung et al., who categorized all SCCHN into four subtypes. The basal-like variant is characterized by high expression of EGFR. Literature data suggest higher efficacy of accelerated and/or hyperfractionated radiotherapy, if compared with conventional radiotherapy in the subgroup of patients with high EGFR expression. In this review, we will describe the genetic factors able to guide treatment choice, with a focus on EGFR expression.

Prognostic and predictive value of EGFR in head and neck squamous cell carcinoma

EGFR is an extensively studied biomarker in head and neck squamous cell carcinoma (HNSCC). In this review, we discuss the prognostic and predictive role of EGFR in HNSCC, focusing on the different molecular alterations in specific treatment modalities such as radiotherapy alone (RT), combination of surgery, RT and chemotherapy (CT), EGFR inhibitors. We considered EGFR at different molecular levels: protein expression, protein activation, gene copy number, polymorphisms, mutation, EGFRvIII expression and EGFR ligand expression.

Considering RT alone, evidence supports the predictive and prognostic role of high EGFR expression only when evaluated by quantitative assays: this may help select the patients who can mostly benefit from accelerated treatment. Conversely, no predictive biomarkers are available when treatment is a combination of surgery, CT and RT. For this combined treatment, several studies indicate that EGFR expression represents a good prognostic parameter only when measured by a “quantitative” or at least semi-quantitative method. With respect to EGFR inhibitors, neither EGFR expression nor increased gene copy number represent prognostic/predictive factors.

If validated, nuclear EGFR, TGFα levels, EGFR phopshorylation and polymorphisms could represent additional prognostic factors in relation to combination of surgery, CT and RT, while EGFR polymorphisms and high amphiregulin levels could have prognostic value in patients treated with EGFR inhibitors.

Role of EGFR as prognostic factor in head and neck cancer patients treated with surgery and postoperative radiotherapy: proposal of a new approach behind the EGFR overexpression

In an era of personalized treatment, there is a great interest in identifying factors which might predict patient response to radiotherapy (RT). The role of epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinoma (HNSCC) remains still controversial. We performed a retrospective analysis on the prognostic value of EGFR in HNSCC patients treated with surgery and postoperative RT through a semiquantitative immunohistochemical analysis of EGFR membrane expression. We retrospectively analyzed 65 HNSCC patients treated in our Institute from 1997 to 2003 who underwent adjuvant RT after surgery. Median follow-up was 43.5 months (range 0.2-173 months). None of these patients were treated with postoperative concomitant chemotherapy. Tumor samples were obtained from surgical specimens. Membrane features (intensity, extension) of EGFR expression were evaluated, and a statistical analysis (univariate and multivariate) was conducted to correlate these parameters with overall survival (OS) and disease-free survival (DFS). Patients with an intense and complete labeling of EGFR presented worse OS and DFS compared with groups obtained by all other possible combination, and the difference was borderline statistically significant (P = 0.08 for OS and P = 0.006 for DFS). Moreover, a stratification of patients was performed considering EGFR expression on the tumor tissue and classifying its distribution as "homogeneous" or "heterogeneous." We found that patients showing an "heterogeneous" EGFR expression distribution had worse OS and DFS compared to the "homogeneous" group of patients. Based on our results, EGFR expression, especially referring to membrane features (semiquantitative analysis), might have a prognostic value for OS and DFS in locally advanced HNSCC treated with surgery and adjuvant RT. Prospective trials could be useful to confirm the prognostic role of EGFR expression and also to assess a predictive role to select that might benefit from more aggressive treatments.

[50th anniversary of cisplatin]

We have just celebrated the 50th anniversary of cisplatin cytotoxic potential discovery. It is time to take stock… and it seems mainly positive. This drug, that revolutionized the treatment of many cancer types, continues to be the most widely prescribed chemotherapy. Despite significant toxicities, resistance mechanisms associated with treatment failures, and unresolved questions about its mechanism of action, the use of this cytotoxic agent remains unwavering. The interest concerning this "old" invincible drug has not yet abated. Indeed many research axes are in the news. New platinum salts agents are tested, new cisplatin formulations are developed to target tumor cells more efficiently, and new combinations are established to increase the cytotoxic potency of cisplatin or overcome the resistance mechanisms.

Comprehensive profiling of EGFR/HER receptors for personalized treatment of gynecologic cancers

The primary gynecologic cancers include cancers of the endometrium, ovary, and cervix. Worldwide, cervical cancer is the most common gynecologic cancer, whereas endometrial cancer is the most common in the US. Ovarian cancer is the fifth most deadly cancer in women, with 5-year survival rates for advanced disease at only 27 %. As such, there is an urgent need for reliable screening tools and novel targeted therapeutic regimens for these malignancies. The epidermal growth factor receptor (EGFR)/human EGFR (HER) family of receptors has been associated with the development and progression of many solid tumors. Despite clear roles for these receptors in other cancers, the expression of HER family members in gynecologic cancers and their relationship with disease stage, grade, and response to treatment remain controversial. In this review, we describe the existing evidence for the use of HER family members as diagnostic and prognostic indicators as well as their potential as therapeutic targets in gynecologic cancers.

Expression of EGFR and HPV-associated p16 in oropharyngeal carcinoma: correlation and influence on prognosis after radiotherapy in the randomized DAHANCA 5 and 7 trials

AIM

EGFR and HPV-associated p16 are among the most investigated biomarkers in head and neck cancer. The aim was to investigate the correlation and interaction between these two markers and to evaluate their potential prognostic significance when combined.

MATERIALS AND METHODS

336 Oropharyngeal carcinomas treated with primary radiotherapy (66-68 Gy, 2fx/day, 10-12 Gy/week) and with known EGFR/p16-status estimated semiquantitatively by immunohistochemistry were included in the study. Data were evaluated by EGFR-expression (high/low) and p16-status (positive/negative) consequently dividing tumours into four groups by combination of the biomarkers. Patient/tumour characteristics and complete 5-year follow-up were available.

RESULTS

Low EGFR-expression was significantly more common in p16-positive tumours compared to p16-negative, p < 0.0001. p16 positivity showed a strong prognostic impact (p < 0.0001, HR = 0.22 [0.13-0.38]), whereas EGFR was a weak prognostic marker when local control was used as endpoint (p = 0.03, HR = 0.53 [0.29-0.94]). Combination of EGFR/p16 did not add significant information to p16 alone and by multivariable analysis only p16 showed significant prognostic information for all evaluated endpoints.

CONCLUSIONS

Both EGFR and p16 bear prognostic information in oropharyngeal cancer, although p16 is, by far, the strongest prognostic factor. The markers seem to be correlated and this might have influence when evaluating the effect of EGFR inhibition in oropharyngeal tumours.

The status of targeted agents in the setting of neoadjuvant radiation therapy in locally advanced rectal cancers

Radiotherapy has a longstanding and well-defined role in the treatment of resectable rectal cancer to reduce the historically high risk of local recurrence. In more advanced borderline or unresectable cases, where the circumferential resection margin (CRM) is breached or threatened according to magnetic resonance imaging (MRI), despite optimized local multimodality treatment and the gains achieved by modern high quality total mesorectal excision (TME), at least half the patients fail to achieve sufficient downstaging with current schedules. Many do not achieve an R0 resection. In less locally advanced cases, even if local control is achieved, this confers only a small impact on distant metastases and a significant proportion of patients (30-40%) still subsequently develop metastatic disease. In fact, distant metastases have now become the predominant cause of failure in rectal cancer. Therefore, increasing the intensity and efficacy of chemotherapy and chemoradiotherapy by integrating additional cytotoxics and biologically targetted agents seems an appealing strategy to explore-with the aim of enhancing curative resection rates and improving distant control and survival. However, to date, we lack validated biomarkers for these biological agents apart from wild-type KRAS. For cetuximab, the appearance of an acneiform rash is associated with response, but low levels of magnesium appear more controversial. There are no molecular biomarkers for bevacizumab. Although some less invasive clinical markers have been proposed for bevacizumab, such as circulating endothelial cells (CECS), circulating levels of VEGF and the development of overt hypertension, these biomarkers have not been validated and are observed to emerge only after a trial of the agent. We also lack a simple method of ongoing monitoring of 'on target' effects of these biological agents, which could determine and pre-empt the development of resistance, prior to radiological and clinical assessessments or even molecular imaging. These shortcomings probably explain our current relative lack of success in the arena of combining these agents with chemoradiation.

Biomarkers of epithelial-mesenchymal transition in squamous cell carcinoma

An understanding of the process by which tumor cells destroy the basement membrane of the surface epithelium, invade, and metastasize is essential to the development of novel treatment of head and neck squamous cell carcinoma (HNSCC). In recent years, there has been increased interest in the role of epithelial-mesenchymal transition (EMT) in invasion. EMT is a process that describes the development of motile, mesenchymal-like cells from non-motile parent epithelial cells. There are 3 known types of EMT that mediate development, wound healing, and carcinogenesis. This review summarizes studies of known EMT biomarkers in the context of HNSCC progression. The biomarkers discussed come from a wide range of proteins, including cell-surface proteins (E-cadherin, N-cadherin, and Integrins), cytoskeletal proteins (α-Smooth Muscle Actin, Vimentin, and β-catenin), extracellular matrix proteins (Collagens, Fibronectin, and Laminin), and transcription factors (SNAIL1, SNAIL2, TWIST, and LEF-1). Overall, the findings of these studies suggest that EMT mediates HNSCC progression. The mechanistic role of the EMT markers that have been associated with HNSCC should be more clearly defined if new anti-HNSCC therapies to block EMT progression are to be developed.

Correlation between EGFr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

Purpose

To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr) and the reduction of the effective doubling time (T_D) during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT) is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC).

Methods

A survey of the published papers comparing 3-years of local regional control rate (LCR) for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of T_D were obtained by a model incorporating the overall time corrected biologically effective dose (BED) and a 3-year clinical LCR for high and low EGFr groups of patients (H_EGFr and L_EGFr), respectively. By obtaining the T_D from the above analysis and the sub-sites’ potential doubling time (T_pot) from flow cytometry and immunohistochemical methods, we were able to estimate the average T_D for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (D_prolif), was estimated.

Results

The averages of T_D were 77 (27-90)_95% days in L_EGFr and 8.8 (7.3-11.0)_95% days in H_EGFr, if an onset of accelerated proliferation T_K at day 21 was assumed. The correspondent H_EGFr sub-sites’ T_D were 5.9 (6.6), 5.9 (6.6), 4.6 (6.1), 14.3 (12.9) days, with respect to literature immunohistochemical (flow cytometry) data of T_pot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The D_prolif for the H_EGFr groups were 0.33 (0.29), 0.33 (0.29), 0.42 (0.31), 0.14 (0.15) Gy/day if α = 0.3 Gy^-1 and α/β = 10 Gy were assumed.

Conclusions

A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced T_D and D_prolif for each head and neck sub-site.

Predicting recurrence after radiotherapy in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Radiotherapy is a mainstay of treatment, either alone for early stage tumors or combined with chemotherapy for late stage tumors. An overall 5-year survival rate of around 50% for HNSCC demonstrates that treatment is often unsuccessful. Prediction of outcome is, therefore, aimed at sparing patients from ineffective and toxic treatments on the one hand, and indicating more successful treatment modalities on the other. Both functional and genetic assays have been developed to predict intrinsic radiosensitivity, hypoxia, and repopulation rate. Few, however, have shown consistent correlations with outcome across multiple studies. Messenger RNA and microRNA profiling show promise for predicting hypoxia, whereas epidermal growth factor receptor expression combined with other measures of tumor differentiation grade shows promise for predicting repopulation rate. Intrinsic radiosensitivity assays have not proven useful to date, although development of repair protein foci assays indicates promise from preclinical studies. Assays for cancer stem cell content have shown promise in several clinical studies. In addition, 2 assays showing robustness as predictors for outcome in HNSCC are human papilloma virus status and epidermal growth factor receptor expression. Neither these nor stem cell assays, however, can as yet reliably indicate alternative and better treatments for poor prognosis patients. It would be of great value to have assays that predict the benefit for an individual from combining new molecularly targeted agents with radiotherapy to increase response, in particular those that exploit tumor mutations to provide tumor specificity. Predictive assays are being developed for detecting defects in repair pathways for single- and double-strand DNA breaks, which should allow selection of drugs targeting the appropriate backup pathway, thus exploiting the concept of synthetic lethality. This is one of the most promising areas for prediction, both currently and in the future.

Modelling the correlation between EGFr expression and tumour cell radiosensitivity, and combined treatments of radiation and monoclonal antibody EGFr inhibitors

Purpose

To estimate the effects of heterogeneity on tumour cell sensitivity to radiotherapy combined with radiosensitizing agents attributable to differences in expression levels of Epidermal Growth Factor Receptor (EGFr).

Materials and methods

Differences in radiosensitivity are not limited to cells of different cancer histotypes but also occur within the same cancer, or appear during radiotherapy if radiosensitizing drugs are combined with ionizing radiation. A modified biologically effective dose (MBED), has been introduced to account for changes in radiosensitivity parameters (α and α/β) rather than changes in dose/fraction or total dose as normally done with standard biologically effective dose (BED). The MBED approach was applied to cases of EGFr over-expression and cases where EGFr inhibitors were combined with radiation. Representative examples in clinical practice were considered.

Results

Assuming membrane EGFr over-expression corresponds to reduced radiosensitivity (α_H = 0.15 Gy^-1 and α_H/β_H = 7.5 Gy) relative to normal radiosensitivity (α = 0.2 Gy^-1 and α/β = 10 Gy), an increased dose per fraction of 2.42 Gy was obtained through the application of MBED, which is equivalent to the effect of a reference schedule with 30 fractions of 2 Gy. An equivalent hypo-fractionated regime with a dose per fraction of 2.80 Gy is obtained if 25 fractions are set. Dose fractionations modulated according to drug pharmacokinetics are estimated for combined treatments with biological drugs. Soft and strong modulated equivalent hypo-fractionations result from subtraction of 5 or 10 fractions, respectively.

Conclusions

During this computational study, a new radiobiological tool has been introduced. The MBED allows the required dose per fraction to be estimated when tumour radiosensitivity is reduced because EGFr is over-expressed. If radiotherapy treatment is combined with EGFr inhibitors, MBED suggests new treatment strategies, with schedules modulated according to drug pharmacokinetics.

Expression of EGFR under tumor hypoxia: identification of a subpopulation of tumor cells responsible for aggressiveness and treatment resistance

PURPOSE

Overexpression of epidermal growth factor receptor (EGFR) and tumor hypoxia have been shown to correlate with worse outcome in several types of cancer including head-and-neck squamous cell carcinoma. Little is known about the combination and possible interactions between the two phenomena.

METHODS AND MATERIALS

In this study, 45 cases of histologically confirmed squamous cell carcinomas of the head and neck were analyzed. All patients received intravenous infusions of the exogenous hypoxia marker pimonidazole prior to biopsy. Presence of EGFR, pimonidazole binding, and colocalization between EGFR and tumor hypoxia were examined using immunohistochemistry.

RESULTS

Of all biopsies examined, respectively, 91% and 60% demonstrated EGFR- and pimonidazole-positive areas. A weak but significant association was found between the hypoxic fractions of pimonidazole (HFpimo) and EGFR fractions (F-EGFR) and between F-EGFR and relative vascular area. Various degrees of colocalization between hypoxia and EGFR were found, increasing with distance from the vasculature. A high fraction of EGFR was correlated with better disease-free and metastasis-free survival, whereas a high degree of colocalization correlated with poor outcome.

CONCLUSIONS

Colocalization of hypoxia and EGFR was demonstrated in head-and-neck squamous cell carcinomas, predominantly at longer distances from vessels. A large amount of colocalization was associated with poor outcome, which points to a survival advantage of hypoxic cells that are also able to express EGFR. This subpopulation of tumor cells might be indicative of tumor aggressiveness and be partly responsible for treatment resistance.

Epidermal growth factor receptor protein detection in head and neck cancer patients: a many-faceted picture

PURPOSE

Epidermal growth factor receptor (EGFR) overexpression is associated with poor prognosis in head and neck squamous cell carcinoma (HNSCC). Despite intensive biomarker studies, a consensual method for assessing EGFR protein expression is still lacking. Here we set out to compare three EGFR detection methods in tumor specimens from HNSCC patients.

EXPERIMENTAL DESIGN

Tumors were prospectively excised from a series of 79 high-risk HNSCC patients enrolled in a GORTEC-sponsored clinical trial. EGFR expression was determined using a ligand-binding assay on membranes, Western blotting (WB) on membranes and total homogenates, and immunohistochemistry (IHC) on tissue microarrays. In addition, phosphorylated EGFR (pEGFR) was measured by WB on membranes.

RESULTS

Distributions and ranges of tumor EGFR expression were method dependent. Moderate positive correlations (Spearman coefficient r ≈ 0.50) were observed between EGFR expression measured by the binding assay and WB or IHC. pEGFR levels positively and significantly correlated with total EGFR expression measured by WB or ligand binding, but not by IHC. The highest correlation (r = 0.85) was observed between EGFR and pEGFR levels, both measured by WB on membranes. Interestingly, the fraction of phosphorylated receptor (pEGFR/EGFR both measured by WB on membranes) significantly declined with increasing tumor EGFR expression, by all assessment methods used.

CONCLUSION

This study shows significant correlations between EGFR detection methods. The observed relationships between EGFR and pEGFR indicate that high-throughput pEGFR/EGFR analyses merit further investigations and consideration for routine use in patient samples.

Epithelial-mesenchymal-transition induced by EGFR activation interferes with cell migration and response to irradiation and cetuximab in head and neck cancer cells

BACKGROUND AND PURPOSE

The role of epithelial-mesenchymal transition (EMT) in the poor outcome of EGFR-overexpressing SCCHN was evaluated.

MATERIAL AND METHODS

SCCHN cell lines were characterized for their cell morphology and expression of EGFR and the EMT-associated factors E-cadherin, vimentin and Snail1. The migratory potential of cells was assessed in motility assays. Response to irradiation and cetuximab was determined using clonogenic survival assays.

RESULTS

High basal expression of E-cadherin but low to absent vimentin expression could be observed in all SCCHN cell lines. Although E-cadherin expression levels did not change after treatment with EGF we observed a significant change in cell morphology resembling EMT. SCCHN cells with high basal levels of Snail1 resulting from constitutive EGFR activation were characterized by mesenchymal-like morphology, elevated migratory potential, reduced sensitivity to irradiation and cetuximab but increased sensitivity to the combined treatment.

CONCLUSIONS

Autocrine activation of EGFR leading to EMT is associated with a metastatic phenotype and reduced sensitivity of SCCHN cells to single-modality treatment with cetuximab or irradiation. The potential of Snail1 as biomarker for selection of patients who will mostly benefit from a combination of cetuximab and radiotherapy has to be evaluated in future clinical studies.

Simultaneous over activation of EGFR, telomerase (h TERT), and cyclin D1 correlates with advanced disease in larynx squamous cell carcinoma: a tissue microarray analysis

Overexpression of Epidermal Growth Factor Receptor (EGFR) and also of cell cycle control proteins, such as cyclin D1 is a frequent event in squamous cell carcinoma of the larynx (LSSC). Our aim was to correlate their protein levels with telomerase catalytic subunit (h-TERT) expression. Using tissue microarray technology, fifty-five paraffin embedded histologically confirmed primary LSSCs and also ten dysplastic lesions were cored at a diameter of 1.5 mm. Immunohistochemistry (IHC) was performed by the use of anti-EGFR, anti-cyclin D1, and anti-h TERT monoclonal antibodies. Chromogenic in situ hybridization (CISH) analysis was also applied using EGFR gene and chromosome 7 probes, respectively. EGFR, cyclin D1 and h-TERT protein overexpression was observed in 48/55 (87.2%), 19/55 (34.5%) and 21/55 (38.1%) carcinoma cases, respectively. EGFR protein expression was statistically associated with grade (P=0.01), and also with stage (P=0.001) of the examined tumors. Borderline statistical significance was assessed correlating overall cyclin D1 expression to h TERT expression (P=0.06). Simultaneous up regulation of the three proteins was established in 7/55 (12.7%) cases, correlated to the stage of the tumors (P=0.05). EGFR gene amplification was observed in 7/65 (10.7%) carcinomas and dysplasias, whereas chromosome 7 aneuploidy was detected in 4/65 (6.1%) of those cases.Simultaneous up regulation of EGFR, cyclin D1 and h TERT proteins correlates with advanced stage in LSCC. EGFR gene amplification and not only protein over expression maybe is the eligible criterion for targeted therapeutic strategies in those patients.

Predicting the effect of accelerated fractionation in postoperative radiotherapy for head and neck cancer based on molecular marker profiles: data from a randomized clinical trial

PURPOSE

To determine the prognostic and predictive values of molecular marker expression profiles based on data from a randomized clinical trial of postoperative conventional fractionation (p-CF) therapy versus 7-day-per-week postoperative continuous accelerated irradiation (p-CAIR) therapy for squamous cell cancer of the head and neck.

METHODS AND MATERIALS

Tumor samples from 148 patients (72 p-CF and 76 p-CAIR patients) were available for molecular studies. Immunohistochemistry was used to assess levels of EGFR, nm23, Ki-67, p-53, and cyclin D1 expression. To evaluate the effect of fractionation relative to the expression profiles, data for locoregional tumor control (LRC) were analyzed using the Cox proportional hazard regression model. Survival curves were compared using the Cox f test.

RESULTS

Patients who had tumors with low Ki-67, low p-53, and high EGFR expression levels and oral cavity/oropharyngeal primary cancer sites tended to benefit from p-CAIR. A joint score for the gain in LRC from p-CAIR based of these features was used to separate the patients into two groups: those who benefited significantly from p-CAIR with respect to LRC (n = 49 patients; 5-year LRC of 28% vs. 68%; p = 0.01) and those who did not benefit from p-CAIR (n = 99 patients; 5-year LRC of 72% vs. 66%; p = 0.38). The nm23 expression level appeared useful as a prognostic factor but not as a predictor of fractionation effect.

CONCLUSIONS

These results support the studies that demonstrate the potential of molecular profiles to predict the benefit from accelerated radiotherapy. The molecular profile that favored accelerated treatment (low Ki-67, low p-53, and high EGFR expression) was in a good accordance with results provided by other investigators. Combining individual predictors in a joint score may improve their predictive potential.

Epidermal growth factor receptor-targeted therapy

High epidermal growth factor receptor (EGFR) expression is a feature of human tumours and is an adverse prognostic factor for radiotherapy outcome. High expression is associated with benefit from accelerated radiotherapy in patients with head and neck squamous cell carcinoma. Anti-EGFR strategies potentiate the effects of radiotherapy and the inhibition of deoxyribonucleic acid repair appears to be important amongst a wide range of mechanisms, which include effects on angiogenesis, differentiation and the immunological response. There is considerable interest in exploring combined modality therapies involving radiation and EGFR antagonists for the curative treatment of cancer patients. Important issues in designing new trials are to investigate optimal scheduling and to establish biobanks to develop biomarkers for future patient selection.

Expression of cell cycle associated proteins influences radiocurability of T2N0 squamous cell carcinoma of the larynx

Cell cycle modulators are important in carcinogenesis and may be of prognostic and therapeutic relevance. This study has examined the influence of the proliferation index (Ki-67) and immunocytochemical expression of epidermal growth factor receptor (EGFR), cyclin D1, and retinoblastoma protein on recurrence rates at the primary site in 50 patients with T2N0 laryngeal carcinomas treated with radical irradiation. Pre-treatment biopsies were retrieved and sections scored for the four immunocytochemical markers. Statistical analysis for association, interaction and survival was performed. Five cases showed loss of expression of Rb protein. The median Ki-67 index was 50%, the median cyclin D1 index 21% and the median EGFR index 47% of cells. EGFR and cyclin D1 expression were positively correlated and, whilst local recurrence tended to occur with a Ki-67 labelling index of <50%, this was not statistically significant. When interactions were examined using Multiple Logistic Regression it was found that there was a direct relationship between EGFR and cyclin D1 expression. If the EGFR index was >20% and the cyclin D1 index >10%, then the odds ratio in favour of a primary site recurrence was very high (5.32 +/-0.41). This study demonstrates that the relationship between EGFR index and cyclin D1 index has a very strong association with primary site recurrence for T2 N0 laryngeal carcinomas treated by irradiation.

Neoadjuvant cisplatin chemotherapy before chemoradiation: a flawed paradigm?

Effective chemotherapy (CT) treatment of solid tumors emerged with the introduction of anthracyclines and platinum CT in the late 1970s, at first with palliative intent, and later extended into the adjuvant setting. High response rates led to the belief that systemic CT might improve locoregional control and also decrease the risk of distant metastases. A new strategy advocated cisplatin-based neoadjuvant CT (NACT) before definitive local treatment-either surgery or radiotherapy (RT). Response to NACT was viewed as a favorable prognostic sign, which allows the selection of patients most likely to benefit from RT or chemoradiotherapy (CRT). The aim of this discussion is to raise the debate regarding NACT in reducing metastases, improving local control and selecting out good responders for nonsurgical treatment in the following sites: head and neck, esophagus, cervix, anus, nasopharynx, and bladder; as well as non-small-cell lung cancer. NACT has almost invariably failed to deliver an improved outcome in terms of disease-free survival (DFS) or overall survival (OS) when delivered before RT or CRT in all solid tumor sites. The evidence that NACT may improve outcome in terms of DFS or OS is strongest when it is administered before surgical resection, but remains scant before RT or CRT. Taxane-containing regimens look more promising than does cisplatin NACT, but have not been shown to improve on concurrent CRT. Future meta-analyses should compare induction CT followed by RT and induction followed by CRT versus RT or CRT alone.