Combined expression of p53, cyclin D1 and epidermal growth factor receptor improves estimation of prognosis in curatively resected oral cancer

Immunohistochemical Expression of Epidermal Growth Factor Receptor (EGFR) in Oral Squamous Cell Carcinoma and Oral Potentially Malignant Disorders

BACKGROUND

Increased epidermal growth factor receptor (EGFR) expression has been implicated in several tumors and is associated with increased tumor advancement as well as a potential drug target. The objective of the study was to compare the immunohistochemical expression of EGFR in oral squamous cell carcinoma (OSCC) with oral potentially malignant disorders (OPMDs) and their demographic and pathologic parameters.

METHODS

This study was a comparative cross-sectional analytical study. It was conducted at the Department of Pathology, Peshawar Medical College, Riphah International University, Islamabad, Pakistan, from March 2021 to February 2022. The sample size was calculated through G Power. Thirty-eight cases of oral squamous cell carcinoma and 38 cases of oral potentially malignant disorders (OPMDs) were included in the study. Statistical analysis was performed using the Statistical Package for Social Sciences version 20.0. χ 2 tests and Fisher exact tests were applied to compare categorical variables.

RESULTS

Mean age of OSCC was 61.6±13.9, with age range from 26 to 90 years. The male-to-female ratio for OSCC was 2.16:1. Buccal mucosa was the most common site involved (34.2%). The most common histologic type was well-differentiated OSCC (71.05%) followed by poorly differentiated (16%) and moderately differentiated (13.15%). The mean age of OPMDs cases was 59.16 ± 10.81 with a male-to-female ratio of 1:1.2. Buccal mucosa was the common site (55.3%), followed by the tongue (18.4%). The OPMDs with dysplasia were 55.2%, and without dysplasia were 44.8%. A total of 55.7% of cases of OSCC showed positive EGFR expression as compared with 36.9% OPMDs cases. A higher number of low-grade OSCC cases showed increased EGFR positivity (59.3%) as compared with high grade (45.45%). EGFR positivity in OPMD cases without dysplasia was 41.2% as compared with cases with dysplasia (33.3%). The EGFR expression in OPMD cases was higher in the ≤50 age group ( P =0.001) and in females ( P =0.032), which was statistically significant.

CONCLUSIONS

EGFR expression by Immunohistochemistry may not be a helpful prognostic marker to determine the risk of OPMDs progressing to higher grades of dysplasia or invasive cancer. However, further studies relating this tumor marker to stage, lymph node metastasis, hematogenous metastasis, survival outcomes, and treatment response may give useful information regarding the utility of this marker.

p53, Cytokeratin 19 Expression in Oral Squamous Cell Carcinoma and Correlation with Histopathologic Grading: An Immunohistochemical Study

The purpose of this study was to examine the immunohistochemical expression of p53 and cytokeratin 19 (CK19) in normal oral mucosa (NOM) and oral squamous cell carcinoma (OSCC) and their association with histopathological differentiation grade. The secondary goal was to see if there was any correlation between p53 and CK19 expression in NOM and OSCC. A hospital-based retrospective analysis was conducted in which 40 NOM and 45 OSCC samples were acquired from archives and stained with mouse monoclonal antibodies p53 and CK19. For both the NOM and OSCC groups, the proportion of positively stained cells, staining intensity, and staining index were calculated. p53 immunoexpression revealed that 85% of positively stained cells in the NOM basal layer had a low staining index (mean ± SD 1.87 ± 0.34), whereas 66.7% of positively stained cells in the OSCC had a high staining index (mean ± SD 5.63 ± 3.02). When NOM and OSCC were compared, there was a statistically significant difference in staining intensity. However, despite a linear increase in the percentage of positive cells from well to poorly differentiated, the comparison between histopathological grades was non-significant. CK19 exhibited 18.5% positively stained cells in the NOM basal layer with a low staining index (mean ± SD 1.57 ± 0.53), whereas OSCC samples showed 4.44% immunopositivity with a high staining index. p53 is a marker of oral carcinogenesis independent of histological grade and CK19 expression. Further, CK19 is a marker of dysfunctional epithelial differentiation but lacks sensitivity and specificity; however, it demands further multicentric studies with a large sample size to draw definitive conclusions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-04092-7.

Prognostic and Clinicopathological Significance of Epidermal Growth Factor Receptor (EGFR) Expression in Oral Squamous Cell Carcinoma: Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to evaluate the current evidence in relation to the clinicopathological and prognostic significance of epidermal growth factor receptor (EGFR) overexpression in patients with oral squamous cell carcinoma (OSCC). We searched MEDLINE/PubMed, Embase, Web of Science, and Scopus for studies published before November 2022. We evaluated the quality of primary-level studies using the QUIPS tool, conducted meta-analyses, examined inter-study heterogeneity via subgroup analyses and meta-regressions, and performed small-study effects analyses. Fifty primary-level studies (4631 patients) met the inclusion criteria. EGFR overexpression was significantly associated with poor overall survival (hazard ratio [HR] = 1.38, 95% confidence intervals [CI] = 1.06-1.79, p = 0.02), N+ status (odds ratio [OR] = 1.37, 95%CI = 1.01-1.86, p = 0.04), and moderately-poorly differentiated OSCC (OR = 1.43, 95% CI = 1.05-1.94, p = 0.02). In addition, better results were obtained by the application of a cutoff point ≥10% tumor cells with EGFR overexpression (p < 0.001). In conclusion, our systematic review and meta-analysis supports that the immunohistochemical assessment of EGFR overexpression may be useful as a prognostic biomarker for OSCC.

Association of Surgical Margins and Pathological Staging with Epidermal Growth Factor Receptor Expression in Oral Squamous Cell Carcinoma- A Prospective Cohort Study

Oral squamous cell carcinoma (SCC) is one among the most frequent cancers across the globe. The postoperative overall survival (OS) has not improved over years much despite of advanced surgical techniques and various anticancer drugs. A better and good understanding of molecular mechanisms and identification of potential oncogenes in OSCC may provide new therapeutic decisions such as target therapy in management of these cancer patients. To find whether there is any association between surgical margins and pathological staging with epidermal growth factor receptor expression affecting the prognosis in oral squamous cell carcinomas. A prospective cohort study was performed in 25 patients with biopsy proven oral squamous cell carcinoma who presented to our hospital from July 2017 to June 2019. The data collected from their report were pTNM staging, surgical margins (anterior, posterior, superior and inferior) and scoring of EGFR expression. Surgical margins with EGFR expression was found to have p-value of 0.023 and pTNM staging with EGFR expression was found to have p-value of 0.051 which were statistically significant. This study concludes that there is strong association of EGFR expression with pTNM and surgical margins which may influence the prognosis of the patient. This study helps us to understand the need of adding EGFR targets like cetuximab along with radiation instead of conventional cisplatin therapy.

Prognostic Role of Combined EGFR and Tumor-Infiltrating Lymphocytes in Oral Squamous Cell Carcinoma

Background

Epidermal growth factor receptor (EGFR) is well known as a general prognostic biomarker for head and neck tumors, however the specific prognostic value of EGFR in oral squamous cell carcinoma (OSCC) is controversial. Recently, the presence of tumor-infiltrating T cells has been associated with significant survival advantages in a variety of disease sites. The present study will determine if the inclusion of T cell specific markers (CD3, CD4 and CD8) would enhance the prognostic value of EGFR in OSCCs.

Methods

Tissue microarrays containing 146 OSCC cases were analyzed for EGFR, CD3, CD4 and CD8 expression using immunohistochemical staining. EGFR and T cell expression scores were correlated with clinicopathological parameters and survival outcomes.

Results

Results showed that EGFR expression had no impact on overall survival (OS), but EGFR-positive (EGFR+) OSCC patients demonstrated significantly worse progression free survival (PFS) compared to EGFR-negative (EGFR-) patients. Patients with CD3, CD4 and CD8-positive tumors had significantly better OS compared to CD3, CD4 and CD8-negative patients respectively, but no impact on PFS. Combined EGFR+/CD3+ expression was associated with cases with no nodal involvement and significantly more favorable OS compared to EGFR+/CD3- expression. CD3 expression had no impact on OS or PFS in EGFR- patients. Combinations of EGFR/CD8 and EGFR/CD4 expression showed no significant differences in OS or PFS among the expression groups.

Conclusion

Altogether these results suggest that the expression of CD3+ tumor-infiltrating T cells can enhance the prognostic value of EGFR expression and warrants further investigation as prognostic biomarkers for OSCC.

Immunohistochemical study of epidermal growth factor receptor, human epidermal growth factor receptor 2/neu, p53, and Ki67 in oral squamous cell carcinoma

Introduction:

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor occurring in the oral cavity.

Aim:

The present study was conducted to evaluate the biomarkers such as epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2/neu), p53 and Ki67 expression in OSCC cases, and its correlation with other well-established clinicopathological parameters.

Materials and Methods:

Seventy cases of OSCC cases diagnosed between 2015 and 2019 were included in the study. A technique of manual tissue microarray was employed for the analysis of expression of IHC markers such as EGFR, HER2/neu, p53, and Ki67 in all cases. Results were subjected to the statistical analysis.

Results:

A statistically significant positive association was noted between EGFR expression and tumor grade, tumor stage, and p53 immunoexpression in OSCC cases. Increased EGFR expression was noted insignificantly in OSCC cases with lymph node (LN) metastasis and Ki67 positive cases. Statistically significant positive association was noted between HER2/neu expression and tumor grade and stage of oral SCC cases. Increased HER2/neu expression was noted insignificantly in OSCC cases with LN metastasis, p53 and Ki67 positive OSCC cases. A statistically significant positive association was noted between percent of tumor cells expressing EGFR, HER2/neu, p53 and Ki67, and grade of OSCC.

Conclusion:

This study intends to document prognostic utility of EGFR and HER2/neu expression in OSCC cases in the Indian setting and contribute to the data pool which could aid in formulating individual tailored therapy that includes targeted therapy in oral SCC cases.

Immunohistochemical Expression of Five Protein Combinations Revealed as Prognostic Markers in Asian Oral Cancer

Oral squamous cell carcinoma (OSCC) has a high mortality rate (∼50%), and the 5-year overall survival rate is not optimal. Cyto- and histopathological examination of cancer tissues is the main strategy for diagnosis and treatment. In the present study, we aimed to uncover immunohistochemical (IHC) markers for prognosis in Asian OSCC. From the collected 742 synthetic lethal gene pairs (of various cancer types), we first filtered genes relevant to OSCC, performed 29 IHC stains at different cellular portions and combined these IHC stains into 398 distinct pairs. Next, we identified novel IHC prognostic markers in OSCC among Taiwanese population, from the single and paired IHC staining by univariate Cox regression analysis. Increased nuclear expression of RB1 [RB1(N)↑], CDH3(C)↑-STK17A(N)↑ and FLNA(C)↑-KRAS(C)↑were associated with survival, but not independent of tumor stage, where C and N denote cytoplasm and nucleus, respectively. Furthermore, multivariate Cox regression analyses revealed that CSNK1E(C)↓-SHC1(N)↓ (P = 5.9 × 10^–5; recommended for clinical use), BRCA1(N)↓-SHC1(N)↓ (P = 0.030), CSNK1E(C)↓-RB1(N)↑ (P = 0.045), [CSNK1E(C)-SHC1(N), FLNA(C)-KRAS(C)] (P = 0.000, rounded to three decimal places) and [BRCA1(N)-SHC1(N), FLNA(C)-KRAS(C)] (P = 0.020) were significant factors of poor prognosis, independent of lymph node metastasis, stage and alcohol consumption. An external dataset from The Cancer Genome Atlas HNSCC cohort confirmed that CDH3↑-STK17A↑ was a significant predictor of poor survival. Our approach identified prognostic markers with components involved in different pathways and revealed IHC marker pairs while neither single IHC was a marker, thus it improved the current state-of-the-art for identification of IHC markers.

Immunohistochemical expression levels of cyclin D1 and CREPT reflect the course and prognosis in oral precancerous lesions and squamous cell carcinoma

Cyclin D1 is the most essential progressive regulator of the cell cycle, and its transcription is enhanced by CREPT (cell cycle-related and expression-elevated protein in tumour). These molecules regulate cell growth, and their aberrant expression can cause malignant transformation. In this study, the expression of these molecules was explored to investigate the molecular alterations in oral precancerous lesions and squamous cell carcinoma. Cyclin D1 and CREPT expression was examined immunohistochemically in tissue specimens from 55 patients with oral epithelial precursor lesions (OEPLs) and 84 patients with oral squamous cell carcinoma (OSCC). Associations between the results and clinicopathological variables were examined. Cyclin D1 and CREPT expression levels were higher in OSCC than in OEPLs. Furthermore, there were statistically significant differences in cyclin D1 expression among the different grades of OEPLs and OSCC lesions. In OSCC, there were statistically significant differences in CREPT expression according to sex, T stage, and degree of differentiation. In addition, the expression of both molecules was significantly correlated with postoperative metastasis and modes of invasion. The expression of cyclin D1 and CREPT was found to depend upon the state of development and progression of the oral epithelial lesions, and clinicopathological behaviours might be affected by these molecules in OSCC.

The prognostic value of cyclin D1 expression in the survival of cancer patients: A meta-analysis

BACKGROUND

The relationship between the expression of cyclin D1 and cancer prognosis and outcomes in different malignancies has not been fully elucidated.

AIMS

In the presented meta-analysis, we assessed the association between the expression level of cyclin D1 with overall survival (OS) in several cancers.

METHODS

Eligible studies were identified using PubMed, EMBase, Scopus, Web of Sciences and Cochrane Library databases. For the prognostic meta-analysis, study-specific hazard ratios (HRs) of tissue cyclin D1 for survival were obtained. Finally we pooled data derived from one hundred and eight studies comprising 19,224 patients with 10 different cancer types.

RESULTS

In the pooled analysis, high expression of cyclin D1 was significantly related to a poor OS with a pooled HR of 1.11 (95% CI: 1.02-1.20, P = 0.015; random-effects). Sub-group analysis revealed that high expression of cyclin D1 was related to worse OS of head and neck cancers (HR = 2.08, 95% CI: 1.75-2.47; P < 0.001), but not in breast (HR = 1.033, 95% CI: 0.873-1.223, P = 0.702), gastrointestinal (HR = 1.025, 95% CI:0.824-1.275; P = 0.825), bladder (HR = 0.937, CI: 0.844-1.041; P = 0.225) and in lung cancer patients (HR = 1.092, CI: 0.819-1.455; P = 0.549).

CONCLUSION

Further large, prospective, and well-designed trials are warranted to elucidate the precise clinical importance of cyclin D1 overexpression in the prognosis of cancer patients receiving different treatment regimens.

Upregulation of ADAM10 in oral squamous cell carcinoma and its correlation with EGFR, neoangiogenesis and clinicopathologic factors

ADAM10 (a disintegrin and metalloproteinase-10) is a known sheddase for EGFR (epidermal growth factor receptor) ligands and has been suggested to modulate angiogenesis. We aimed to evaluate the expression of ADAM10 in patients with oral squamous cell carcinoma (OSCC) and to determine its correlation with EGFR, CD105 and clinicopathologic parameters. Fifty primary OSCCs with clinical data were graded according to the histologic risk assessment (HRA) model and subjected to immunohistochemical staining using antibodies against ADAM10, EGFR1 and CD105. ADAM10 was assessed in both epithelial and stromal components. The associations among all three proteins and clinicopathologic factors including tumor size, lymph node status and distant metastasis (TNM) were statistically analyzed (P < 0.05). Epithelial-ADAM10, stromal-ADAM10 and EGFR were overexpressed in 92%, 40% and 56% of the OSCCs, respectively. EGFR expression occurred in peripheral and diffuse patterns, which were also separately considered in our analyses. A significant correlation was found between ADAM10 and CD105 (r = -0.455; P < 0.001). Lymphocytic infiltration scores (P = 0.04) and tumor size (P = 0.001) showed significant differences between EGFR+ and EGFR- tumors, but none of the other variables had any relationships with either clinicopathologic factors or each other (P > 0.05). ADAM10 was upregulated in OSCC but had no correlation with survival-associated factors such as TNM or the HRA model. At the protein level, epithelial ADAM10 negatively regulated neoangiogenesis, but its interaction with EGFR was minimal. Reduction in host immunologic responses was associated with a decrease in EGFR. These findings, if corroborated, could be interesting in combination therapies used for cancer treatment.

Expression of immunohistochemical markers in non-oropharyngeal head and neck squamous cell carcinoma in Ghana

Background

Head and neck cancers include carcinomas of the oral cavity, larynx, sinonasal tract and nasopharynx. Studies on molecular expression of prognostic tumour markers in Ghana are scarce. The purpose of this study was to determine the expression of p53, p16, EGFR, Cyclin-D1 and HER2 among patients with non-oropharyngeal head and neck squamous cell carcinoma (HNSCC).

Methodology

Tissue microarrays from 154 histologically confirmed non-oropharyngeal HNSCC at the Komfo Anokye Teaching Hospital from 2006–2014 were constructed using duplicate cores of representative and viable areas from tumours. Expression of EGFR, p53, p16, Cyclin-D1 and HER2 was evaluated using immunohistochemistry.

Results

For non-oropharyngeal HNSCC, majority of the cases (66.2%; 102/154) had stage IV disease. EGFR was the most expressed molecular marker (29.4%; 25/85) followed by p53 (24.0%; 29/121), p16 (18.3%; 23/126) and Cyclin-D1 (10.0%; 12/120). HER2 was not expressed in any of the cases. There was a significantly (p = 0.022) higher expression of Cyclin-D1 in tumours of the oral cavity (19.6%; 9/46) than in those of the larynx (4.7%; 2/43) and nose (3.2%; 1/31). Tumours in stages I–III were more frequently positive for p16 (28.6%; 12/42) than tumours in stage IV (13.1%; 11/84).

Conclusion

Expression of p53, EGFR, p16 and Cyclin-D1 in non-oropharyngeal HNSCC in Ghana is largely similar to what has been reported in published studies from other countries.

Prognostic and clinicopathological significance of cyclin D1 expression in oral squamous cell carcinoma: A systematic review and meta-analysis

OBJECTIVES

To evaluate the prognostic significance of cyclin D1 (CD1) overexpression in OSCC.

MATERIAL AND METHODS

We searched studies published before August 2017 (Pubmed, Embase, Web of Science, Scopus). We evaluated the quality of the studies included (Quality in Prognosis Studies [QUIPS] tool). The impact of CD1 overexpression on overall survival and disease-free survival, T status, N status, stage, and histological degree was meta-analyzed. We analyzed heterogeneity among studies, conducted sensitivity analyses, analyzed small-study effects, and conducted subgroup analyses.

RESULTS

31 studies (2942 patients) met inclusion criteria. Qualitative evaluation demonstrated that not all studies were performed with the same rigor, finding the greatest risk of bias in the study confounding domain. Quantitative evaluation showed that CD1 overexpression had a strong statistical association with worse overall survival (HR = 2.00, 95% CI = 1.59-2.51, p < 0.001), worse disease-free survival (HR = 1.46, 95% CI = 1.13-1.87, p = 0.003), higher T status (OR = 1.51, 95% CI = 1.07-2.13, p = 0.02), N+ status (OR = 2.16, 95% CI = 1.60-2.92, p < 0.001), advanced stage (OR = 1.44, 95% CI = 1.15-1.81, p = 0.002), and high histological grade (OR = 1.60, 95% CI = 1.12-2.29, p = 0.010). We observed heterogeneity in all parameters except for disease-free survival and clinical stage. We found effect of small studies on T and N status. The tonguel SCC subgroup showed the strongest association between CD1 overexpression and worse development. In addition, application of a cutoff point ≥10% tumor cells with nuclear CD1 expression maintained most of the significant associations reported.

CONCLUSIONS

These findings indicate that immunohistochemical assessment of CD1 overexpression may be useful as a prognostic biomarker for OSCC.

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.

Effect of neoadjuvant chemotherapy and its correlation with HPV status, EGFR, Her-2-neu, and GADD45 expression in oral squamous cell carcinoma

Background

Head and neck cancers are the commonest cancer in Southeast Asia. Despite being a surface cancer, it is associated with significant morbidity as despite early detection by the patients they often report for treatment late and hence are associated with poor prognosis. The role of neoadjuvant chemotherapy in head and neck cancer is still under evaluation; there is a large subgroup of population that does not respond to chemotherapy, and hence, most studies have failed to show any survival benefit. This study evaluated the role of neoadjuvant therapy with docetaxel and carboplatin in patients with oral cancer and correlated the response to human papilloma virus, EGFR1, EGFR2, and GADD45 expression.

Methods

A total of 24 locally advanced, non-metastatic oral cancer patients were included in the study. Tumor biopsies were taken prior to the start of neoadjuvant therapy for expression of EGFR, Her-2-Neu, and GADD45 by immunohistochemistry and for HPV by PCR. The response was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) criteria after three cycles of chemotherapy. Statistical analysis was performed using correlation and Kaplan–Meier analysis; the difference in survival was calculated with log rank test.

Results

A total of 21 male and 3 female with a mean age of 53.12 years were enrolled. Sixty-five percent of these received three cycles of chemotherapy. Five patients were positive for HPV 16 and none for HPV 18. Twenty-two of 24 patients showed GADD45 expression, 3 showed expression of Her-2-Neu while all 24 showed expression for EGFR1 protein. Two-year overall survival was 81%; GADD45 expressions were found to significantly affect the overall and disease-free survival, while any of the other protein expression studied and HPV status was not significant.

Conclusion

The result of the present study shows significant downgrading of the oral cancers with neoadjuvant chemotherapy suggesting its utility in borderline operable cases. However, the response of chemotherapy does not appear to be related to the expression of EGFR, Her-2-Neu, and GADD45 protein or presence of HPV. Bone involvement, perineural invasion, and GADD45 expression significantly predict OS and DFS. All patients who did not express Gadd45 died before 2 years. Study with more subjects and longer follow-up should be carried out to elucidate this relation further.

Prevalence and types of high-risk human papillomaviruses in head and neck cancers from Bangladesh

BACKGROUND

There is a dramatic rise in the incidence of Human papillomavirus (HPV) - associated head and neck squamous cell carcinoma (HNSCC) in the world, with considerable variation by geography, gender and ethnicity. Little is known about the situation in Bangladesh, where tobacco- and areca nut-related head and neck cancers (HNCs) are the most common cancers in men. We aimed to determine the prevalence of HPV in HNSCC in Bangladesh and to explore the possible value of cell cycle markers in clinical diagnostic settings.

METHODS

One hundred and ninety six archival HNSCC tissue samples were analysed for the presence of HPV DNA. The DNA quality was assured, and then amplified using a nested PCR approach. The typing of HPV was performed by automated DNA sequencing. Cellular markers p53, Cyclin D1 and pRb were tested on all samples by immunohistochemistry (IHC), as well as p16 as a putative surrogate for the detection of HPV.

RESULTS

HPV DNA was detected in 36/174 (~21%) samples: 36% of cancers from the oropharynx; 31% of oral cancers, and 22% from the larynx. HPV-16 was most common, being present in 33 samples, followed by HPV-33 (2 samples) and HPV-31 (1 sample). Twenty-eight out of 174 samples were positive for p16, predominantly in HPV-positive tissues (p < 0.001). No statistically significant association was observed between the cellular markers and HPV DNA positive cases. However, p16 positivity had excellent predictive value for the presence of HPV by PCR.

CONCLUSION

There is a significant burden of HPV-associated HNSCC in Bangladesh, particularly in the oropharynx but also in oral and laryngeal cancers. Whilst a combination of PCR-based DNA detection and p16 IHC is useful, the latter has excellent specificity, acceptable sensitivity and good predictive value for carriage of HPV in this population and should be used for prognostic evaluation and treatment planning of all HNSCC patients in South Asia, as in the Western world.

An integrated method for the identification of novel genes related to oral cancer

Cancer is a significant public health problem worldwide. Complete identification of genes related to one type of cancer facilitates earlier diagnosis and effective treatments. In this study, two widely used algorithms, the random walk with restart algorithm and the shortest path algorithm, were adopted to construct two parameterized computational methods, namely, an RWR-based method and an SP-based method; based on these methods, an integrated method was constructed for identifying novel disease genes. To validate the utility of the integrated method, data for oral cancer were used, on which the RWR-based and SP-based methods were trained, thereby building two optimal methods. The integrated method combining these optimal methods was further adopted to identify the novel genes of oral cancer. As a result, 85 novel genes were inferred, among which eleven genes (e.g., MYD88, FGFR2, NF-κBIA) were identified by both the RWR-based and SP-based methods, 70 genes (e.g., BMP4, IFNG, KITLG) were discovered only by the RWR-based method and four genes (L1R1, MCM6, NOG and CXCR3) were predicted only by the SP-based method. Extensive analyses indicate that several novel genes have strong associations with cancers, indicating the effectiveness of the integrated method for identifying disease genes.

Understanding molecular markers in recurrent oral squamous cell carcinoma treated with chemoradiation

Introduction

Oral cancer accounts for approximately 2.1% of all cancers worldwide. In India, oral squamous cell carcinoma (OSCC) is the most common cancer with half a million new cases diagnosed every year. More than 50% of patients eventually develop local recurrence or metastasis usually within the first 2-years following completion of treatment. It is beneficial to analyze the prognostic significance of Cyclin D1, p53 and EGFR which are critical mediators in the pathogenesis of OSCC. The objective of this study was to assess the association of expression of these markers with recurrence and pattern of recurrence in OSCC patients undergoing chemoradiation.

Materials and Methods

A Total 290 OSCC cases of locally advanced stage (III, IV) oral cancer with World Health Organization (W.H.O.) performance status of grade 0/1 in the year 2009–2012 were enrolled in the study. Treatment response was assessed according to W.H.O. criteria. Cyclin D1, EGFR and p53 expression in tumor tissue was estimated by immunohistochemical (IHC) method and quantified as percentage positive nuclei.

Results

During the 2-years follow up, 56 (19.3%) patients recurred, out of which, 47 (83.9%) were locoregional and 9 (16.1%) distant sites. On correlating, χ² test showed significant (P < 0.05 or P < 0.01 or P < 0.001) association of marker expressions (Cyclin D1, EGFR and p53) with recurrence. The strong positive expressions of all three markers showed significant association with early time of recurrence. The multivariate logistic regression analysis showed significant (P < 0.05 or P < 0.01 or P < 0.001) association of recurrence with primary site, differentiation, Cyclin D1 and p53 expressions indicating these as an independent predictors of recurrence in OSCC. The Cyclin D1, EGFR and p53 expressions also showed significant (P < 0.001) poor survivals (OS, DFS and RFS) in patients with positive/strong positive expressions than negative expression suggesting their prognosis in OSCC.

Conclusion

Our results signifies that tumors over expressing Cyclin D1, EGFR and p53 are resistant to chemoradiation and are associated with increased risk of locoregional recurrence and metastasis in OSCC patients undergoing chemoradiation.

The prognostic implication of the expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in primary locally advanced oral squamous cell carcinoma cases: a tissue microarray study

Oral squamous cell carcinomas comprise a heterogeneous tumor cell population with varied molecular characteristics, which makes prognostication of these tumors a complex and challenging issue. Thus, molecular profiling of these tumors is advantageous for an accurate prognostication and treatment planning. This is a retrospective study on a cohort of primary locally advanced oral squamous cell carcinomas (n = 178) of an Indian rural population. The expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in a cohort of primary locally advanced oral squamous cell carcinomas was evaluated. A potential biomarker that can predict the tumor response to treatment was identified. Formalin-fixed paraffin-embedded tumor blocks of (n = 178) of histopathologically diagnosed cases of locally advanced oral squamous cell carcinomas were selected. Tissue microarray blocks were constructed with 2 cores of 2 mm diameter from each tumor block. Four-micron-thick sections were cut from these tissue microarray blocks. These tissue microarray sections were immunohistochemically stained for EGFR, p53, Bcl-2, cyclin D1 and p16. In this cohort, EGFR was the most frequently expressed 150/178 (84%) biomarker of the cases. Kaplan-Meier analysis showed a significant association (p = 0.038) between expression of p53 and a poor prognosis. A Poisson regression analysis showed that tumors that expressed p53 had a two times greater chance of recurrence (unadjusted IRR-95% CI 2.08 (1.03, 4.5), adjusted IRR-2.29 (1.08, 4.8) compared with the tumors that did not express this biomarker. Molecular profiling of oral squamous cell carcinomas will enable us to categorize our patients into more realistic risk groups. With biologically guided tumor characterization, personalized treatment protocols can be designed for individual patients, which will improve the quality of life of these patients.

Impact of EGFR and p53 expressions on survival and quality of life in locally advanced oral squamous cell carcinoma patients treated with chemoradiation

EGFR and p53 are molecular markers which play important role in tumor progression and development. The objective of this study was to assess the association between EGFR and p53 expression and survival, and to determine whether EGFR and p53 expression levels were associated with differences quality of life in OSCC patients undergoing chemoradiation. A total of 120 OSCC patients aged 20-67 y and stage III/IV were recruited. Treatment response was assessed according to W.H.O. (1979). EGFR and p53 expression in tumor tissue was estimated by immunohistochemical (IHC) method and quantified as percentage positive nuclei. Molecular marker expressions of both EGFR and p53 were found significantly (P < 0.01 or P < 0.001) associated with overall response, survivals and quality of life. Neither EGFR nor p53 expression was associated with hematologic or non-hematologic toxicity. EGFR and p53 molecular marker expressions may have significant association with survival and QOL in OSCC patients undergoing chemoradiation.

Gefitinib, Methotrexate and Methotrexate plus 5-Fluorouracil as palliative treatment in recurrent head and neck squamous cell carcinoma

This study compared the efficacy and toxicity of Gefitinib, Methotrexate and Methotrexate plus 5-Fluorouracil (5-FU) in patients of recurrent squamous cell carcinoma of head and neck (SCCHN) treated with palliative intent. Patients with recurrent SCCHN not amenable to curative treatment were randomly assigned to Gefitinib, Methotrexate or Methotrexate plus 5-FU arm. The primary end point was overall survival. Secondary end points of interest were objective response rate, toxicity and quality of life. Total 117 patients were analyzed. Median overall survival and objective response rates were 8.8 months, 7.8 months and 8.1 months and 7.7%, 5.0% and 7.9% in Gefitinib, Methotrexate and Methotrexate plus 5-FU arms respectively with no statistically significant difference between 3 arms. Gefitinib had different toxicity profile compared with other arms. Majority of toxicities were Grade 1 or Grade 2. Gefitinib had significant improvement in quality of life during initial months over Methotrexate. There was no suggestion that Gefitinib significantly prolonged overall survival compared with Methotrexate and Methotrexate plus 5-FU. However, improved Quality of Life with manageable toxicities was observed.

Correlation between expressions of Cyclin-D1, EGFR and p53 with chemoradiation response in patients of locally advanced oral squamous cell carcinoma

Introduction

Cyclin-D1, p53 and EGFR are molecular markers that regulate the cell cycle and play an important role in tumor progression and development. The present study evaluates the prognostic significance of these markers with chemoradiation response in patients of locally advanced oral squamous cell carcinoma (OSCC).

Material and method

A total of 97 OSCC patients (females = 19 and males = 78), aged 20–67 years and stage III/IV were recruited. Treatment response was assessed according to WHO criteria. Cyclin-D1, p53 and EGFR expressions in tumor tissue was estimated by immunohistochemical (IHC) method and quantified as percentage positive nuclei.

Results

The positive expression rates of molecular markers were 86.6% for Cyclin-D1, 92.8% for EGFR and 85.6% for p53. The strong positive expressions of both Cyclin-D1 and p53 showed significant association with poor response. The Cox multivariate regression analysis showed coexpressions of Cyclin-D1 and p53 a significant and independent predictor of overall survival (OR = 1.90, 95% CI = 1.45–4.82, p = 0.046) after adjusting the demographic, clinicopathological and radiological response. The strong positive expressions of Cyclin-D1 and p53 and coexpressions of Cyclin-D1, EGFR and p53 showed significant (p < 0.05 or p < 0.01 or p < 0.001) and lower survival as compared to negative or moderate positive expressions and coexpressions, respectively.

Conclusion

Expressions and coexpressions of Cyclin-D1 and p53 may serve as a prognostic marker in OSCC patients.

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Cyclin-D1, p53 and EGFR are molecular markers that regulate the cell cycle.

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Coexpressions of Cyclin-D1, EGFR & p53 serve as prognostic marker in advanced OSCC.

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p53 alone may serve as prognostic marker in patients of locally advanced OSCC.

Oral and oropharyngeal cancer

Oral and oropharyngeal cancer (OPC) is a complex and often relentless malignancy prone to local invasion and dissemination. Despite advances in understanding of the disease and improved therapeutic interventions, it continues to be diagnosed at an advanced stage and the survival rate remains poor. The financial cost of treating OPC may be the highest of all cancers in the United States and survivors often experience major detriments to quality of life. Major risk factors for OPC are tobacco, alcohol, areca nut, and human papillomavirus infection. This article updates medical practitioners on the causes, presentation, diagnosis, and management of OPC.

Role of EGFR as a prognostic factor for survival in head and neck cancer: a meta-analysis

The prognostic role of epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinoma (HNSCC) remains controversial. The goal of this study was to summarize existing evidence regarding whether EGFR overexpression is a prognostic factor in HNSCC. Relevant studies were identified using Pubmed, Ovid, and Web of Science databases. A meta-analysis was conducted on the prognostic value of EGFR expression for overall survival (OS) and disease-free survival (DFS). Thirty-seven studies were included. Primary analysis indicated that EGFR overexpression was associated with reduced OS (hazard ratio [HR]: 1.694, 95% confidence interval [CI]: 1.432–2.004). DFS, on the other hand, was not associated with EGFR expression after adjusting for publication bias (HR: 1.084, 95% CI: 0.910–1.290). Subgroup analysis gave a statistically significant pooled HR for OS in laryngeal carcinoma (HR: 2.519, 95% CI: 1.615–3.928) and in oropharyngeal carcinoma (HR: 2.078, 95% CI: 1.605–2.690). The pooled HR was statistically significant for DFS with respect to oropharyngeal carcinoma (HR: 1.055, 95% CI: 1.020–1.092), but not laryngeal carcinoma (HR: 1.750, 95% CI: 0.911–3.360). When dividing studies based on the immunohistochemistry (IHC) scoring system, only the group that evaluated EGFR expression according to the intensity and extent of staining showed no between-study heterogeneity for both OS and DFS. Overall, EGFR overexpression was associated with shortened OS, but not DFS. Future studies are needed that stratify patients by specific tumor sites. Furthermore, when estimating protein level by the IHC method, it is advisable to consider both intensity and extent of staining.

Cyclin D1 overexpression is associated with poor clinicopathological outcome and survival in oral squamous cell carcinoma in Asian populations: insights from a meta-analysis

Background

The clinicopathological significance of cyclin D1 overexpression and prognosis of oral squamous cell carcinoma has not been fully quantified. We performed a comprehensive meta-analysis for evaluation of cyclin D1 overexpression in oral squamous cell carcinoma to determine the strength of this association.

Methods

Using both medical subheadings and free terms, we searched PubMed, Embase and the Institute for Scientific Information Web of Science for all eligible studies published before Nov. 2013. We retrieved 1674 citations, determining that 15 met the selection criteria. We used the odds ratio (OR) and hazard ratio (HR) as the common measures of association to quantitatively determine the correlation between cyclin D1 overexpression and outcomes of oral cancer. We performed a meta-analysis and heterogeneity, sensitivity, and subgroup analyses to clarify and validate the pooled results.

Results

The pooled results provided compelling evidence that cyclin D1 overexpression was significantly correlated with increased tumor size (OR = 1.617, 95% confidence interval [CI] = 1.046–2.498, p = 0.031), lymphoid node metastasis (OR = 2.035, 95% CI = 1.572–2.635, p<0.001), tumor differentiation (OR = 1.976, 95% CI = 1.363–2.866, p<0.001), and advancement of clinical stages (OR = 1.516, 95% CI = 1.140–2.015, p = 0.004), and adversely influenced overall survival of OSCC patients (HR = 1.897, 95% CI = 1.577–2.282, p<0.001). The strength of association varied in different oral cavity subsites.

Conclusion

Our findings indicated that cyclin D1 expression correlates with detrimental clinicopathological outcome and poor prognosis in oral squamous cell carcinoma. Our results may be useful in the management of oral cancer.

Prognostic features, human papillomavirus status, and epidermal growth factor receptor expression in oral squamous cell carcinoma in young adults

PURPOSE

There is still debate in literature about the survival outcomes of patients who have cancer of the oral cavity when young. Hence the aims were (1) to estimate disease-free survival, overall survival, and cause-specific survival in patients who developed oral cavity squamous cell carcinoma between 18 and 40 years of age and (2) to assess the clinicopathologic factors including detection of human papillomavirus and epidermal growth factor receptor (EGFR) overexpression in primary lesions affecting recurrence.

METHODS

This is a retrospective case-note review and reevaluation of histopathologic slides of patients treated more than 25 years. Descriptive statistics, Cox proportional hazard models, and Kaplan-Meier survival curves were used for statistical analysis.

RESULTS

A total of 62 patients were treated, with mean follow-up of 11.4 years. Forty-five were oral tongue tumors and 43 had stage I or II disease. The 5-year disease-free survival was 73.5%. The 10-year overall survival and cause-specific survival rates were 81.8% and 83.4%, respectively. Smoking and alcohol intake were not seen as risk factors in this population. Multivariate modeling identified only nodal involvement as significantly associated with overall survival and only extracapsular spread as significantly associated with locoregional recurrence. At 5 years after treatment, the cause-specific survival was 100% for patients with low EGFR expression and 81.1% for patients with high EGFR expression (hazard ratio for high vs low, 3.1; 95% confidence interval, 0.4-406.9; P = .46). Human papillomavirus was not detected in all but 2 tumor specimens.

CONCLUSIONS

Survival outcomes are quite good in young patients with oral cancer.

Expression of insulin-like growth factor II mRNA-binding protein 3 in squamous cell carcinomas of the head and neck

BACKGROUND

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) was found overexpressed in various cancer types suggesting its possible role in carcinogenesis. Analysis of IMP3 expression in head and neck squamous cell carcinomas (HNSCC) is rare so that we evaluated it using tissue microarray method.

METHOD

Immunohistochemical analysis of IMP3 was performed on samples from over 400 patients. The expression was measured semiquantitative, subsequently divided into four categories (negative, weak, medium, or strong) and correlated with several available clinicopathologic parameters.

RESULTS

For HNSCC, positive IMP3 expression was observed in patients with all tumor stages (pT1-4) and nodal stages (pN0-3), showing also significant statistical correlation (P=0.023 and P=0.0013, respectively). No further correlations were found. Separate analysis according to tumor localization (oral cavity, oropharyngeal, and laryngeal) showed a significant correlation of positive IMP3 expression and overall survival (P=0.038) only in patients with tumors of the oral cavity. Multivariate analysis showed IMP3 as an independent predictive marker for oral squamous cell carcinomas (OSCC).

CONCLUSION

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) expression might be used as an independent prognostic factor in the subgroup of OSCC.

Prognostic significance of immunohistochemical biomarkers in oral squamous cell carcinoma

Advances in understanding of the molecular mechanisms underlying oral squamous cell carcinoma (OSCC) have resulted in an increasing number of biomarkers that can be used to predict the behaviour of this disease. The authors conducted a literature review of studies examining the role of immunohistochemistry-based protein biomarkers in predicting OSCC outcome. Only articles published in PubMed-indexed journals over the past 5 years were considered. 22 molecular biomarkers were identified and classified into five groups based on their biological functions: cell cycle acceleration and proliferation; tumour suppression and apoptosis; hypoxia; angiogenesis; and cell adhesion and matrix degradation. The cell cycle acceleration and proliferation biomarkers showed the most divergent prognostic findings. Studies on tumour suppression and apoptosis biomarkers were the most prevalent. There were only a few studies examining molecular biomarkers of hypoxia and angiogenesis, and studies examining cell adhesion and matrix degradation biomarkers have shown that this group has the greatest potential for assessing prognostic parameters. Amongst the several proteins analysed, the immunohistochemical expression levels of epithelial growth factor receptor (EGFR), p53, and matrix metalloproteinases (MMPs) have demonstrated the greatest potential for survival prediction in OSCC, but this review demonstrates that their prognostic relevance is debatable and requires further standardisation.

Clinical, pathological and molecular determinants in squamous cell carcinoma of the oral cavity

Squamous cell carcinoma of the oral cavity (OCSCC) is the most frequently observed form of head-and-neck cancer in Southeast Asia and is the sixth most common cancer worldwide. Most cases of this preventable disease are caused by alcohol consumption, smoking and betel nut chewing. The survival rates of patients with advanced OCSCC have not increased significantly in recent years. While treatments for OCSCC are similar worldwide, survival rates differ by geographical area. The various genetic profiles and individual genetic susceptibility for carcinogens may account for this discrepancy. In some respects, molecular alteration or accumulation affects tumor progression and the clinical outcomes among patients with OCSCC. Clarifying the tumor behavior of oral cancer, with regard to pathological features or molecular aspects, could help clinicians to judge, tailor and adopt more effective therapeutic strategies to treat oral cancer.

Prognostic significance of molecular markers in oral squamous cell carcinoma: a multivariate analysis

BACKGROUND

Multiple marker accumulation impacts tumor progression and biologic phenotypes affect clinical outcome of patients with head and neck cancer. Hence, this study investigated a battery of molecular markers that may help to reflect biologic aggressiveness and predict prognosis.

METHODS

Epidermal growth factor receptor (EGFR), Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb, Ki-67, and Bcl-2 were localized immunohistochemically in 135 oral squamous cell carcinoma patients to assess prognostic value.

RESULTS

In univariate analysis of total patients, p53, Stat3, and p16 predicted both relapse-free survival (RFS) and overall survival (OS). In Cox multivariate analysis, after adjusting for tumor size, nodal status, and lymphatic permeation, p53 was independently associated with RFS and OS, and p16 with RFS only. In only early-stage patients, in univariate analysis, nuclear Stat3 was significant for RFS and OS.

CONCLUSION

Immunostaining of p53, p16, and Stat3 might serve as potential adjuncts in pathologic evaluation of oral tumors to predict risk of relapse.

Histological significance of p53 gene expression in squamous cell carcinoma of the buccal mucosa

INTRODUCTION

Oral Squamous Cell Carcinoma (SCC) results from genetic mutations which activate the oncogenes and inactivate the tumor suppressor gene namely TP53. Despite the use of multimodality treatments the prognosis of oral SCC has not changed significantly.

PURPOSE

To evaluate 1) if there is any correlation between the two prognostic indicators i.e. p53 over expression and histological grade of the tumor 2) if any of the parameters of histological grading correlate significantly with p53 over expression. This information would help in understanding the exact role of TP53 gene mutation in cellular progression of oral SCC.

METHOD

Study was conducted on 90 resected specimens of Stage IV SCC of buccal mucosa. Slides from these specimens were evaluated for histological grading by Anneroth's method and p53 over expression by Immunohistochemistry.

RESULTS

Statistically significant co-relation was seen between the total histological grade and p53 over expression. Also 4 individual histological parameters which indicated high cellular turnover were also significantly associated with p53 over expression.

CONCLUSION

TP53 mutation histologically signifies an early event in cellular progression of oral SCC.

Epidermal growth factor receptor expression in serous ovarian carcinoma: an immunohistochemical study with galectin-3 and cyclin D1 and outcome

This study investigated the expression of epidermal growth factor receptor (EGFR), galectin-3 and cyclin D1 in a cohort of ovarian serous carcinomas with regard to outcome and clinicopathologic parameters. Formalin-fixed paraffin-embedded archival tissues of fifty ovarian serous carcinomas were stained with anti-bodies to EGFR, Gal-3, and cyclin D1 by automated immunohistochemistry. Additionally, 10 benign serous cystadenomas and 10 typical serous borderline ovarian tumors were included in the study. Immunostaining was scored with regard to quantity and intensity of positively stained nuclei. Staining patterns were recorded. The EGFR expression was scored negative in all serous cystadenomas and serous borderline ovarian tumors. Membranous and cytoplasmic EGFR immunoreactivity was determined in 64% of ovarian serous carcinomas; it was related to high grade (P=0.0005) and poor outcome (P=0.0137) but not with stage (P=0.5118). Galectin-3 and cyclin D1 immunostaining decreased from serous cystadenomas and serous borderline ovarian tumors to the carcinomas significantly (P=0.0022 and P=0.0083, respectively). Galectin-3 immunostaining of any pattern (nuclear and cytoplasmic as well as merely cytoplasmic taken together) was not related to grade or stage in cancers; mere cytoplasmic expression was associated with poor outcome (P=0.0097). Cyclin D1 immunoreactivity in predominantly nuclear pattern was increased in low-grade carcinomas (P=0.0378) but was not related to stage and outcome (P=0.6578 and P=0.0675, respectively). This study indicates that with regard to EGFR and cytoplasmic galectin-3 immunoexpression, multiple marker testing may be an adjunct in the identification of high-risk ovarian serous cancers.

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.

Advances in the biology of oral cancer

The incidence of oral cancer remains high and is associated with many deaths in both Western and Asian countries. Several risk factors for the development of oral cancer are now well known, including smoking, drinking and consumption of smokeless tobacco products. Genetic predisposition to oral cancer has been found in certain cases but its components are not yet entirely clear. In accordance with the multi-step theory of carcinogenesis, the natural history of oral cancer seems to gradually evolve through transitional precursor lesions from normal epithelium to a full-blown metastatic phenotype. A number of genomic lesions accompany this transformation and a wealth of related results has appeared in recent literature and is being summarized here. Furthermore, several key genes have been implicated, especially well-known tumor suppressors like the cyclin-dependent kinase inhibitors, TP53 and RB1 and oncogenes like the cyclin family, EGFR and ras. Viral infections, particularly with oncogenic HPV subtypes and EBV, can have a tumorigenic effect on oral epithelia and their role is discussed, along with potential therapeutic interventions. A brief explanatory theoretical model of oral carcinogenesis is provided and potential avenues for further research are highlighted.

SCF Fbx4/alphaB-crystallin cyclin D1 ubiquitin ligase: a license to destroy

Cyclin D1 is an allosteric regulator for cyclin-dependent kinases 4 and 6 (CDK4/6). The cyclin D/CDK4 kinase promotes G1/S transition through the posttranslational modification and the subsequent inactivation of the retinoblastoma (Rb) protein and related family members (p107 and p130). Accumulation of cyclin D1 is tightly regulated through various mechanisms including transcription, protein localization and ubiquitin-dependent proteolysis. While regulators of cyclin D1 gene expression have been under considerable scrutiny, the identity of the protein complex that targets cyclin D1 protein for degradation, the putative E3 ubiquitin ligase, has remained obscure. In a recent report, Lin et al describe the identification and characterization of a novel SCF, wherein FBX4 and alphaB-crystallin serve as specificity factors that direct ubiquitination of phosphorylated cyclin D1. As cyclin D1 overexpression in human cancer has been postulated to occur through the loss of degradation machinery, the identification of the SCFFbx4/alphaB-crystallin ligase will allow new experimental approaches that address mechanisms of cyclin D1 overexpression in human cancer.