Basal Ki67 expression measured by digital image analysis is optimal for prognostication in oral squamous cell carcinoma

Proliferating Lymphatic Endothelial Cells as a Prognostic Marker in Head and Neck Squamous Cell Carcinoma

Podoplanin and Ki-67 are two important markers of cancer progression. The aim of this study is to evaluate double immunostaining for Ki-67 and podoplanin in head and neck squamous cell carcinoma (HNSCC), and to observe the involvement of lymphagiogenesis in tumoral and peritumoral areas, as well as the density of tumor proliferation correlated with histopathological grading. A total of 50 patients with HNSCC were included in this study. We carried out a morphological evaluation of tissue samples, after that, cases were selected for double Ki-67 and podoplanin immunostaining. Podoplanin expression was significantly correlated with histopathological grade (p < 0.05; p = 0.037) and expression of Ki-67 (p < 0.05; p = 0.050). A high expression of podoplanin, as well as of the proliferation factor Ki-67, was observed in histopathological grade G3 and the correlation between these (p < 0.05; p = 0.028), and implication of LMVD and LVI was not significant (LMVD p = 0.577; LVI p = 0.976). This study demonstrated the importance of double immunolabeling in assessing lymphagiogenesis and tumor proliferation in correlation with histopathological grades in HNSCC.

Ki-67 assessment-agreeability between immunohistochemistry and flow cytometry in canine lymphoma

Recent literature suggests a combination of flow cytometric determination of Ki-67 and immunophenotype as a reliable tool to classify canine lymphomas. Immunohistochemistry (IHC) on histological samples is the gold standard technique assessing Ki-67 index. Agreement between IHC and FCM derived Ki-67 indices has never been investigated. The aim of this study was to investigate the agreement between IHC and FCM in the assessment of Ki-67 expression/index, in order to evaluate whether FCM may serve as a non-invasive alternative method for the estimation of proliferative activity in canine lymphoma. Dogs with previously untreated canine lymphoma undergoing diagnostic lymphadenectomy were prospectively enrolled. Ki-67 expression/index was assessed by FCM and IHC and expressed as percentage of positive cells. 39 dogs classified by histopathology matched the inclusion criteria. With both methods, Ki-67 expression/index was higher in intermediate/high-grade lymphomas. Spearman's coefficient of correlation was ρ = 0.57; (95% CI0.33-0.75) suggesting a moderate correlation. A Bland-Altman plot revealed a negative constant bias of -3.55 (95% CI: -10.52 to 3.42) with limits of agreement from -45.71 to 38.61. The study confirmed agreement albeit with wide confidence intervals between the values of Ki-67 expression/index assessed with FCM and IHC. Discrepancies were observed in a subset of cases. Possible explanation could be that Ki-67 index in IHC is determined in the most proliferative areas of the slide, which could introduce kind of sampling bias, whereas FCM evaluates many more cells in cell suspension. Further studies are warranted to investigate this phenomenon.

A comparative study of osteopontin expression, Ki67 index and prognosis in squamous cell carcinoma and cysts of the oral cavity

Background

Recent studies have shown a strong relationship between the expression of osteopontin and oral carcinogenesis. Osteopontin (OPN) has been shown to play a major role in regulating the aggressiveness of cancer cells and promote tumor growth. Odontogenic cysts are an essential aspect of oral and maxillofacial pathology. They are relatively frequent lesions with different clinical behavior. Some of them may have a proliferative pattern of growth and neoplastic nature. Evaluation of osteopontin expression with Ki-67 index may help examine clinical behavior and recurrence of oral squamous cell cancer and radicular cyst patients.

Methods

A total of 44 oral cavity cancer cases and 21 cysts samples were analyzed by immunohistochemical staining. Data used for analysis were derived from medical records. The following information was obtained from all patients’ medical records: survival, age, sex, lymph node status, tumor size, and location, as well as grade and histologic type of tumor. Expression status of OPN and Ki-67 was statistically assessed.

Results

Our data demonstrated that for summary immunoreactive scores of OPN and Ki-67 expressions in OSCC vs. RC patients statistical significance was found for both markers’ between OSCC and RC groups. Moreover, osteopontin is significantly higher expressed in larger OSCC tumors.

Conclusions

In conclusion, the role of OPN expression both in oral squamous cancer cells and radicular cyst and possible correlation with demographic and clinicopathological features remain undetermined in some aspects, further high-powered studies to develop a more standardized assessment of Ki-67 and osteopontin expression in OSCC and are needed.

Comparison of Histological and Proliferation Features of Canine Oral Squamous Cell Carcinoma Based on Intraoral Location: 36 Cases

Grade and labeling indices for immunohistochemical tumor proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) were evaluated in 36 cases of canine oral squamous cell carcinoma (OSCC) based upon intraoral location. Grade was significantly associated with location ( P = .035). Grade II tumors were most frequently diagnosed. Grade I tumors were identified in the gingiva and the buccal mucosa, and grade III tumors were seen in the gingiva and the tonsillar region. Animals with tumors arising from the tonsils and of the tongue tended to be older ( P = .007), and those in the former group were more likely to have metastatic disease at the time of diagnosis ( P = .001). Mean expression of PCNA and Ki-67 proliferation index (PI) for all tumors were 62.54% and 50.70%, respectively, and there was a statistical significant association between the 2 variables ( R = .70; P < .001). Proliferation index was not associated with any of the intraoral locations evaluated, but higher PCNA PI was significantly associated with grade ( P = .031). Ki-67 PI was significantly associated with lymph node metastasis at the time of diagnosis, especially for OSCC of gingival location ( P = .028). The results obtained in this study are preliminary but clinically relevant, since they provide information that can explain differences in biologic behavior among intraoral locations and contribute to more accurate tumor staging to support the choice for different treatment strategies available for OSCC.

The association of Bcl-xL and p53 expression with survival outcomes in oropharyngeal cancer

BACKGROUND

The role of molecular biomarkers in oropharyngeal squamous cell carcinoma (OPSCC) has recently been increasingly recognized. There is conflicting evidence in the literature with regards to the prognostic value of p53 and Bcl-xL.

OBJECTIVE

The purpose of this study was to investigate the association between p53 and Bcl-xL expression profiles and survival outcomes in OPSCC.

METHODS

Patients diagnosed with OPSCC and treated with curative intent between 1998 and 2009 were included in the study. Patient demographics, disease, treatment, and oncologic outcomes were collected prospectively. A tissue microarray (TMA) from patients' biopsies or surgical specimens was retrospectively constructed. The expression levels of p53, Bcl-xL, and p16 were digitally quantified and correlated to patient survival outcomes.

RESULTS

One hundred and sixty-six patients were included (mean age 56.7 years; standard deviation (SD) ± 10.0; 78% male). High expression of Bcl-xL (p= 0.04) was significantly associated with nodal disease at presentation, and decreased overall survival (OS) (p= 0.04). Combined expression of low Bcl-xL and low p53 conferred a survival advantage in non-smokers (p= 0.04). Multivariate analysis supported smoking and p16 status as independent prognosticators for OS.

CONCLUSIONS

This study suggests that biomarker profiling using Bcl-xL and p53 levels may be of prognostic value in select patients with OPSCC.

Zwitterionic starch-based hydrogel for the expansion and "stemness" maintenance of brown adipose derived stem cells

Brown adipose derived stem cells (BADSCs) have become a promising stem cell treatment candidate for myocardial infarction because of their efficiently spontaneous differentiation capacity towards cardiomyocytes. The lack of existing cell passage protocols motivates us to develop a neotype 3D cell expansion technique for BADSCs. In this study, "clickable" zwitterionic starch based hydrogels are developed using methacrylate modified sulfobetaine derived starch with dithiol-functionalized poly (ethylene glycol) as crosslinker via the "thiol-ene" Michael addition reaction. Moreover, CGRGDS peptide is immobilized into the hydrogel via a similar "clickable" approach. Their Young's moduli range from 22.28 to 74.81 kPa depending on the concentration of precursor solutions. Excellent anti-fouling property is also presented owing to the introduction of zwitterionic moieties. BADSCs are homogeneously encapsulated in the hydrogels and then routinely cultured for 10 days. Results suggest a capacious cell proliferation and the extent increases with either the decrease of mechanical strength or the introduction of CGRGDS. More excitingly, the cell "stemness" is well maintained during this period and the expanded cells released from the hydrogels well keep the efficiently spontaneous cardiomyogenic differentiation capacity. Therefore, it is suggested that zwitterionic starch based hydrogel is able for the expansion and "stemness " maintenance of BADSCs.

Cell proliferation is associated with intensity of tumor budding in oral squamous cell carcinoma

BACKGROUND

Tumor budding is a morphological marker of cancer invasion, defined as the presence of isolated or small clusters of neoplastic cells at the tumor invasive front. This study aimed to evaluate the association between intensity of tumor budding and cell proliferation in oral squamous cell carcinoma (OSCC).

METHODS

Immunohistochemistry was employed in 163 OSCC samples to detect the cell proliferation marker Ki-67 and multicytokeratin (to identify OSCC cells in tumor budding evaluation). The Mann-Whitney test was used to evaluate differences in the cell proliferation index between samples with high-intensity tumor budding and samples with low-intensity or no tumor budding. In samples with high-intensity tumor budding, the Wilcoxon test was used to evaluate differences in the cell proliferation index between the budding area and the area outside the budding. The chi-square test assessed the association between cell proliferation index and intensity of tumor budding.

RESULTS

The cell proliferation index was higher in samples with high-intensity tumor budding than in samples with low-intensity or no tumor budding (P < .05). Tumors with high-intensity tumor budding showed a higher cell proliferation index in the budding area than in the area outside the budding (P < .05). Finally, samples showing high-intensity tumor budding were associated with high cell proliferation index (P < .05).

CONCLUSION

Cell proliferation is positively associated with intensity of tumor budding in OSCC. Moreover, in tumors showing high-intensity tumor budding, the budding area is the location of higher cell proliferation. These findings reinforce the hypothesis that tumor budding is associated with the biological behavior of OSCC.

Impact of tumoral carbonic anhydrase IX and Ki-67 expression on survival in oral squamous cell carcinoma patients

Oral squamous cell carcinoma (OSCC) is the most commonly diagnosed type of head and neck cancer, accounting for ~300,000 new cases worldwide annually. Carbonic anhydrase IX (CAIX) and Ki-67 have been associated with reduced disease-specific survival (DSS) in patients with OSCC. We previously proposed a combined CAIX and Ki-67 signature of 'functional hypoxia' and sought to replicate this association in a larger independent cohort of patients with OSCC at the Fred Hutchinson Cancer Research Center (FHCRC) in Seattle. The study population included patients with incident primary OSCC treated at the University of Washington Medical Center and the Harborview Medical Center in Seattle between December 2003 and February 2012. Archived tumor blocks were obtained with tissue samples from 189 patients, and triplicate 0.6 mm cores were assembled into tissue microarrays (TMAs). Fluorescence immunohistochemistry and AQUAnalysis® were used to quantify the expression of tumoral CAIX (tCAIX) and stromal CAIX (sCAIX) and tumoral Ki-67 for each TMA core. Hazard ratios for DSS were calculated using Cox proportional hazards analysis. High tCAIX and sCAIX expression levels were associated with reduced DSS (aHR=1.003, 95% CI:1.00-1.01 and aHR=1.010, 95% CI:1.001-1.019, per AQUA score unit, respectively). Ki-67 expression was not associated with survival (aHR=1.01, 95% CI:0.99-1.02) in the FHCRC cohort. DSS for patients with high sCAIX and low Ki-67 did not differ from that of other patient groups. Elevated tCAIX was associated with reduced DSS as a continuous and as a dichotomized (75%) variable. sCAIX was associated with DSS as a continuous variable but not when dichotomized (75%). However, the previously proposed 'functional hypoxia' signature was not replicated in the current FHCRC study. The failure to replicate our prior observation of poorer survival in patients with combined high sCAIX and low tumoral Ki-67 was likely due to the absence of an association between tumoral Ki-67 and DSS in this cohort. However, the association between DSS and tCAIX and sCAIX supports a role for CAIX in OSCC clinical outcomes.

Validation of immunoexpression of tenascin-C in oral precancerous and cancerous tissues using ImageJ analysis with novel immunohistochemistry profiler plugin: An immunohistochemical quantitative analysis

BACKGROUND

Immunohistochemistry (IHC) is a molecular technique that has grown tremendously over the years. However, the assessment is only qualitative which is subjective and causes errors. Due to this limitation, several excellent markers have not gained importance and reached clinical trials. Hence, we aimed to quantify IHC by ImageJ analysis with a novel IHC profiler plugin. ImageJ has not been tried in oral precancerous tissues with minimal attempt for matrix markers.

AIM

This study aimed to validate the quantification of immunoexpression of tenascin-C (TN-C) in oral precancerous tissues and oral squamous cell carcinoma (OSCC) using ImageJ software with IHC profiler plugin.

MATERIALS AND METHODS

After IHC staining for TN-C and image acquisition, ImageJ analysis was performed as per the standard recommended algorithm. Assessment was done by two observers by blinding the histopathological diagnosis. The immunoscore was assessed for interobserver variability using Kohen's kappa statistics.

RESULTS

All our cases were in agreement and found to be statistically significant with P < 0.005. Moderate agreement was for mild dysplasia, moderate dysplasia and oral lichen planus. Substantial agreement was for oral submucous fibrosis and OSCC and almost perfect agreement noted for cases of severe dysplasia.

CONCLUSION

IHC can now be quantified using freely downloadable software ImageJ analysis in oral precancerous tissues and OSCC. This software with good threshold control can quantify matrix marker such as TN-C. Hence, herewith, we propose that IHC markers should be quantified using ImageJ by our entire oral pathology fraternity so as to have a standard immunoscore for all markers.

Current relevance of hypoxia in head and neck cancer

Head and Neck cancer (HNC) is a complex mix of cancers and one of the more common cancers with a relatively poor prognosis. One of the factors that may assist us in predicting survival and allow us to adjust our treatment strategies is the presence of tumor hypoxia. In this overview we aim to evaluate the current evidence and potential clinical relevance of tumor hypoxia in head and neck cancer according to an extensive search of current literature.An abundance of evidence and often contradictory evidence is found in the literature. Even the contradictory evidence and comparisons are difficult to judge as criteria and methodologies differ greatly, furthermore few prospective observational studies exist for verification of the pre-clinical studies. Despite these discrepancies there is clear evidence of associations between prognosis and poor tumor oxygenation biomarkers such as HIF-1α, GLUT-1 and lactate, though these associations are not exclusive. The use of genetic markers is expanding and will probably lead to significantly more and complex evidence. The lack of oxygenation in head and neck tumors is of paramount importance for the prediction of treatment outcomes and prognosis. Despite the wide array of conflicting evidence, the drive towards non-invasive prediction of tumor hypoxia should continue.

Quantum dots-based double imaging combined with organic dye imaging to establish an automatic computerized method for cancer Ki67 measurement

As a widely used proliferative marker, Ki67 has important impacts on cancer prognosis, especially for breast cancer (BC). However, variations in analytical practice make it difficult for pathologists to manually measure Ki67 index. This study is to establish quantum dots (QDs)-based double imaging of nuclear Ki67 as red signal by QDs-655, cytoplasmic cytokeratin (CK) as yellow signal by QDs-585, and organic dye imaging of cell nucleus as blue signal by 4′,6-diamidino-2-phenylindole (DAPI), and to develop a computer-aided automatic method for Ki67 index measurement. The newly developed automatic computerized Ki67 measurement could efficiently recognize and count Ki67-positive cancer cell nuclei with red signals and cancer cell nuclei with blue signals within cancer cell cytoplasmic with yellow signals. Comparisons of computerized Ki67 index, visual Ki67 index, and marked Ki67 index for 30 patients of 90 images with Ki67 ≤ 10% (low grade), 10% < Ki67 < 50% (moderate grade), and Ki67 ≥ 50% (high grade) showed computerized Ki67 counting is better than visual Ki67 counting, especially for Ki67 low and moderate grades. Based on QDs-based double imaging and organic dye imaging on BC tissues, this study successfully developed an automatic computerized Ki67 counting method to measure Ki67 index.

Comparison of digital image analysis and visual scoring of KI-67 in prostate cancer prognosis after prostatectomy

Background

The tumor proliferative index marker Ki-67 was shown to be associated with clinically significant outcomes in prostate cancer, but its clinical application has limitations due to lack of uniformity and consistency in quantification. Our objective was to compare the measurements obtained with digital image analysis (DIA) versus virtual microscopy (visual scoring (VS)).

Methods

To do so, we compared the measurement distributions of each technique and their ability to predict clinically useful endpoints. A tissue microarray series from a cohort of 225 men who underwent radical prostatectomy was immunostained for Ki-67. The percentage of Ki-67 positive nuclei in malignant cells was assessed both by VS and DIA, and a H–score was calculated. The distribution and predictive ability of these scoring methods to predict biochemical recurrence (BCR) and death from prostate cancer (DPCa) were compared using Mann–Whitney test and C-index.

Results

The measurements obtained with VS were similar to the DIA measurements (p = 0.73) but dissimilar to the H-score (p < 0.001). Cox regression models showed that Ki-67 was associated with BCR (HR 1.46, 95 % CI 1.10-1.94) and DPCa (HR 1.26, 95 % CI 1.06-1.50). C-indexes revealed that Ki-67 was a better predictor of DPCa (0.803, 0.8059 and 0.789; VS, DIA and H-score, respectively) than of BCR (0.625, 0.632 and 0.604; VS, DIA and H-score, respectively).

Conclusion

The measurement distributions and the predictive abilities of VS and DIA were similar and presented the same predictive behaviour in our cohort, supporting the role of Ki-67 proliferative index as an important prognostic factor of BCR and DPCa in prostate cancer post RP.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6656878501536663

Electronic supplementary material

The online version of this article (doi:10.1186/s13000-015-0294-0) contains supplementary material, which is available to authorized users.

Fractal analysis of nuclear histology integrates tumor and stromal features into a single prognostic factor of the oral cancer microenvironment

Background

The lack of prognostic biomarkers in oral squamous cell carcinoma (OSCC) has hampered treatment decision making and survival in OSCC remains poor. Histopathological features are used for prognostication in OSCC and, although useful for predicting risk, manual assessment of histopathology is subjective and labour intensive. In this study, we propose a method that integrates multiple histopathological features of the tumor microenvironment into a single, digital pathology-based biomarker using nuclear fractal dimension (nFD) analysis.

Methods

One hundred and seven consecutive OSCC patients diagnosed between 1998 and 2006 in Calgary, Canada were included in the study. nFD scores were generated from DAPI-stained images of tissue microarray (TMA) cores. Ki67 protein expression was measured in the tumor using fluorescence immunohistochemistry (IHC) and automated quantitative analysis (AQUA®). Lymphocytic infiltration (LI) was measured in the stroma from haematoxylin-eosin (H&E)-stained TMA slides by a pathologist.

Results

Twenty-five (23.4%) and 82 (76.6%) patients were classified as high and low nFD, respectively. nFD was significantly associated with pathological tumor-stage (pT-stage; P = 0.01) and radiation treatment (RT; P = 0.01). High nFD of the total tumor microenvironment (stroma plus tumor) was significantly associated with improved disease-specific survival (DSS; P = 0.002). No association with DSS was observed when nFD of either the tumor or the stroma was measured separately. pT-stage (P = 0.01), pathological node status (pN-status; P = 0.02) and RT (P = 0.03) were also significantly associated with DSS. In multivariate analysis, nFD remained significantly associated with DSS [HR 0.12 (95% CI 0.02-0.89, P = 0.04)] in a model adjusted for pT-stage, pN-status and RT. We also found that high nFD was significantly associated with high tumor proliferation (P < 0.0001) and high LI (P < 0.0001), factors that we and others have shown to be associated with improved survival in OSCC.

Conclusions

We provide evidence that nFD analysis integrates known prognostic factors from the tumor microenvironment, such as proliferation and immune infiltration, into a single digital pathology-based biomarker. Prospective validation of our results could establish nFD as a valuable tool for clinical decision making in OSCC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1380-0) contains supplementary material, which is available to authorized users.

Ki67 is a promising molecular target in the diagnosis of cancer (review)

The expression of Ki67 is strongly associated with tumor cell proliferation and growth, and is widely used in routine pathological investigation as a proliferation marker. The nuclear protein Ki67 (pKi67) is an established prognostic and predictive indicator for the assessment of biopsies from patients with cancer. Clinically, pKi67 has been shown to correlate with metastasis and the clinical stage of tumors. In addition, it has been shown that Ki67 expression is significantly higher malignant tissues with poorly differentiated tumor cells, as compared with normal tissue. According to its predictive role, pKi67 expression identifies subpopulations of patients who are more likely to respond to a given therapy. The Ki67 labeling index is an independent prognostic factor for survival rate, which includes all stages and grade categories. There is a correlation between the ratio of Ki67‑positive malignant cells and patient survival. It has been shown that blocking of Ki67 either by microinjection of antibodies or through the use of antisense oligonucleotides leads to the arrest of cell proliferation. Specifically, antisense oligonucleotides and antibodies against pKi67 have been shown to inhibit the progression of the cell cycle. The Ki67 protein is well characterized at the molecular level and is extensively used as a prognostic and predictive marker for cancer diagnosis and treatment. Increasing evidence indicates that Ki67 may be an effective target in cancer therapy. It therefore merits further development, including testing in more sophisticated in vitro and appropriate in vivo models. This review provides an overview of recent advances in this field.

Variability in measuring the Ki-67 labeling index in patients with breast cancer

BACKGROUND

Luminal-type breast cancer is divided into types A and B, depending on the Ki-67 labeling index (LI). However, the area at which Ki-67 is measured and the choice of specimen greatly affects the results. The aim of the present study was to evaluate the Ki-67 LI variability using different measurement methods and specimens. We also evaluated how the chemotherapy indication changed for luminal-type breast cancer using the different measurements.

MATERIALS AND METHODS

The Ki-67 levels in 87 patients with breast cancer were assessed, and the Ki-67 LI was calculated. Five measurement sites were randomly selected, including the most densely labeled areas (hot spots) in both core needle biopsy (CNB) and surgical specimens.

RESULTS

The intraclass correlation coefficient of the CNB and surgical specimens was 0.91 and 0.95, respectively. If the hot spot was used, the correlation coefficient (CC) between the CNB and surgical specimens was 0.635. If the average score was used, the CC was 0.730. If the average score was used, the CNB specimens indicated that 49 patients had a high Ki-67 LI, and 48 patients had a high Ki-67 LI using surgical specimens. If the hot spot was used, 60 patients using the CNB specimens and 58 patients using the surgical specimens had a high Ki-67 LI. If the average score was used, 17 patients were identified as being in different groups, and if the hot spot was used, 16 patients were identified as being in different groups, depending on the specimens that were used.

CONCLUSION

The results differed according to the method and specimen type that was used.

Multi-level gene expression signatures, but not binary, outperform Ki67 for the long term prognostication of breast cancer patients

Proliferation-related gene signatures have been proposed to aid breast cancer management by providing reproducible prognostic and predictive information on a patient-by-patient basis. It is unclear however, whether a less demanding assessment of cell division rate (as determined in clinical setting by expression of Ki67) can function in place of gene profiling. We investigated agreement between literature-, distribution-based, as well as signature-derived values for Ki67, relative to the genomic grade index (GGI), 70-gene signature, p53 signature, recurrence score (RS), and the molecular subtype models of Sorlie, Hu, and Parker in representative sets of 253 and 159 breast cancers with a median follow-up of 13 and 14.5 years, respectively. The relevance for breast cancer specific survival was also addressed in uni- and bivariate Cox models. Taking both cohorts into account, our broad approach identified ROC optimized Ki67 cutoffs in the range of 8-28%. With optimum signature-reproducing cutoffs, similarity in classification of individual tumors was higher for binary signatures (72-85%), than multi-level signatures (67-73%). Consistent with strong agreement, no prognostic superiority was noted for either Ki67 or the binary GGI, 70-gene and p53 signatures in the Uppsala dataset by bivariate analyses. In contrast, Ki67-independent prognostic capacity could be demonstrated for RS and molecular subtypes according to Sorlie, Hu and Parker in both datasets. Our results show that the added prognostic value of binary proliferation-related gene signatures is limited for Ki67-assessed breast cancers. More complex, multi-level descriptions have a greater potential in short- and long-term prognostication for biologically relevant breast cancer subgroups.

Prognostic utility of basaloid differentiation in oropharyngeal cancer

Background

Human papillomavirus (HPV) is recognized as the key risk factor for a distinct subset of oropharyngeal squamous cell carcinoma. P16 is a reliable, sensitive surrogate marker for HPV and confers a positive prognostic advantage. Basaloid differentiation on hematoxylin and eosin (H&E) staining is anecdotally noted by some pathologists to be associated with p16 positivity. This association, however, has not been adequately quantified in the literature, nor has the prognostic implications of basaloid differentiation been described.

Objectives

1) To correlate the H&E staining feature of basaloid differentiation with p16 positivity in oropharyngeal cancer. 2) To investigate the prognostic utility of basaloid differentiation in oropharyngeal cancer survival.

Methods

Retrospective cross-sectional study of all patients diagnosed with and treated for oropharyngeal cancer at a single tertiary cancer center from 2002 to 2009. Tissue microarrays (TMAs) were generated from 208 oropharyngeal tumor specimens stained with H&E and immunohistochemical markers. These oropharyngeal TMAs were utilized in several previous publications. Samples were scored for basaloid differentiation by a pathologist blinded to the p16 result. A multivariate survival analysis with Cox-regression and Kaplan-Meier survival analysis was performed.

Results

In the 208 samples, basaloid differentiation correlated with p16 positivity (Spearman’s rho 0.435). Basaloid differentiation and p16 positivity were both independent predictors of improved survival. The 5 year disease specific survival (DSS) was 73% for p16 positive tumors and 35% for p16 negative tumors (p < 0.001). Similarly, the 5 year DSS of basaloid differentiated tumors was 74% compared to 41% for non-basaloid tumors (p = 0.001). Patients with p16 positive and basaloid differentiated tumors had the best survival outcomes with a 5 year DSS of 80%.

Conclusions

Basaloid differentiation is a feature on H&E which correlates with p16 positivity and is a simple, inexpensive, independent, positive prognostic indicator of comparable magnitude to p16 status. Due to the added prognostic value of basaloid differentiation, this feature should be routinely reported by qualified pathologists.

Prognostic value of podoplanin expression in oral squamous cell carcinoma--a regression model auxiliary to UICC classification

Podoplanin, a type I transmembrane glycoprotein with an effect of platelet aggregation, has been reported to be one of the possible prognostic factors of oral squamous cell carcinoma (OSCC). However, the biological significance of podoplanin is largely unclear. The aim of this study was to develop a practical model for the prediction of prognosis using the grade of podoplanin expression, and also to evaluate the biological function of podoplanin. Eighty-two specimens of patients with previously untreated OSCC, who underwent either biopsy or surgery, were histopathologically and immunohistochemically analyzed. These 82 cases were composed of 66 well-differentiated, 10 moderately differentiated and 6 poorly differentiated OSCC. Podoplanin was successfully immunostained in 78 specimens, and was detected in most cases, but the frequency of positive cells varied. The prognosis of patients with more than 50 % podoplanin-positive tumor cells was significantly poorer than that of the other patients. Multivariate hazards regression analysis suggested that a linear combination of covariates, OSCC patients with more or less than 50 % podoplanin expression, age of more or less than 70 years old, mode of invasion and T3, T4 or T2 versus T1 of the UICC T-stage classification was the most effective model for evaluating the prognosis of OSCC patients. Additionally, podoplanin expression had a significant relationship to UICC clinical stage and the expression of Ki-67. An effective regression model using podoplanin expression was developed for evaluating the prognosis of OSCC and the biological significance of podoplanin was suggested to be associated with the growth and/or progression of OSCC.

Molecular predictors of locoregional and distant metastases in oropharyngeal squamous cell carcinoma

Background

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing due to fundamental changes in oncogenesis related to effects of the human papilomavirus (HPV). Virally-mediated tumours behave and respond to treatment differently than their classic, carcinogenically-mediated counterparts despite similar stage and grade of disease. This difference in behaviour has lead to investigation of etiologies of OPSCC at the molecular level.

Molecular biomarkers offer potential insight into the behaviour of OPSCC. Identifying a subset of patients that are more likely to have recurrence and distant metastasis is valuable for prognostication and treatment planning. There is limited information regarding the profiles of these biomarkers in locoregional and distant metastases in OPSCC.

Objective

This study was designed to identify biomarker profiles predictive of locoregional and distant metastases and recurrence in OPSCC.

Methods

Cross-sectional study of a prospectively-collected oropharyngeal tumour database was undertaken. All patients with OPSCC presenting to the University of Alberta Hospital from 2002-2009 were included in the study. Data collection from the Alberta Cancer Registry, including demographics, nodal status, distant metastases, treatment, recurrence, and survival, was undertaken. Tissue micro-arrays (TMAs) were constructed for each tumour specimen using triplicate cores (0.6mm) of formalin-fixed, paraffin-embedded (FFPE) pre-treatment tumour tissue. TMAs were processed using immunohistochemistry for p16, EGFR, Ki67, p53, and Bcl-XL. Positivity for each biomarker was determined using quantified AQUAnalysis ® scores on histoplots. Multivariate statistics were utilized to assess the relationship between each biomarker and locoregional and distant metastases, as well as recurrence-free survival (RFS).

Results

High expression of p16 (p=0.000) and Bcl-XL (p=0.039) independently demonstrated a significant association with nodal disease at presentation. Kaplan-Meier analysis demonstrated improved RFS in patients with high p16 and decreased RFS in patients with high p53 expression. Cox regression analysis supported p16 as an independent prognosticator for improved RFS. p53 demonstrated an association with recurrence, but when compared to p16 status, nodal status, and staging, was not an independent predictor of recurrence.

Conclusions

Biomarker profiling using p16, Bcl-xL, and p53 may be useful in prognostication and treatment planning in patients with OPSCC.

The prognostic impact of a combined carbonic anhydrase IX and Ki67 signature in oral squamous cell carcinoma

Background:

Tumour hypoxia is associated with impaired apoptosis, resistance to therapy and poor prognosis. We previously reported that high stromal expression of the endogenous marker of hypoxia, carbonic anhydrase IX (CAIX), is associated with significantly reduced survival in oral squamous cell carcinoma (OSCC). In addition to hypoxia, CAIX expression is regulated by proliferation-associated signalling. We hypothesised that incorporating Ki67, a proliferation marker, into our existing CAIX-based stratification of OSCC would identify patients with the least favourable prognosis.

Methods:

Surgically resected tumours from 60 OSCC patients were analysed for CAIX, Ki67 and BAX expression using fluorescence immunohistochemistry and automated quantitative analysis (AQUA).

Results:

In patients expressing high stromal CAIX (sCAIX), stratification by tumour Ki67 expression revealed significantly distinct survival outcomes (P=0.005). In our OSCC cohort, below-median Ki67 and top-quartile sCAIX expression (Ki67^losCAIX^hi) were associated with significantly worse disease-specific survival in univariate (HR 7.2 (2.5–20.4), P=0.001) and multivariate (HR 4.2 (1.4–12.8), P=0.011) analyses. Hypoxia is associated with decreased BAX expression; the Ki67^losCAIX^hi group was more strongly associated with low BAX expression than high sCAIX alone.

Conclusion:

These data suggest that combined analysis of tumour Ki67 and sCAIX expression may provide a more clinically relevant assessment of tumour hypoxia in OSCC.

Prognostic molecular markers in cancer - quo vadis?

Despite the tremendous number of studies of prognostic molecular markers in cancer, only a few such markers have entered clinical practise. The lack of clinical prognostic markers clearly reflects limitations in or an inappropriate approach to prognostic studies. This situation should be of great concern for the research community, clinicians and patients. In the present review, we evaluate immunohistochemical prognostic marker studies in oral squamous cell carcinomas (OSCC) from 2006 to 2012. We comment upon general issues such as study design, assay methods and statistical methods, applicable to prognostic marker studies irrespective of cancer type. The three most frequently studied markers in OSCC are reviewed. Our analysis revealed that most new molecular markers are reported only once. To draw conclusions of clinical relevance based on the few markers that appeared in more than one study was problematic due to between-study heterogeneity. Currently, much valuable tissue material, time and money are wasted on irrelevant studies.