Characteristics and prognosis of primary treatment-naïve oral cavity squamous cell carcinoma in Norway, a descriptive retrospective study

Salivary metabolomics in early detection of oral squamous cell carcinoma - a meta-analysis

INTRODUCTION

Oral squamous cell carcinoma (OSCC) represents the most prevalent form of oral cancer. Potentially malignant disorders of oral mucosa exhibit an elevated propensity for malignant progression. A substantial proportion of cases are discerned during advanced stages, significantly impacting overall survival. This investigation aims to ascertain salivary metabolites with potential utility in the early detection of OSCC.

METHODS

A search encompassing PubMed, EMBASE, Scopus, Ovid, Science Direct, and Web of Science databases was conducted to identify eligible articles. The search strategy employed precise terms. The quality assessment of the included studies was executed using the QUADAS 2 ROB tool. This was registered with PROSPERO CRD42021278217.

RESULTS

Upon removing duplicate articles and publications that didn't satisfy the inclusion criteria, seven articles were included in the current study. The Random Effects Maximum Likelihood (REML) model adopted for quantitative synthesis identified Nacetyl glucosamine as the sole metabolite in two studies included in this metaanalysis. The pathways significantly influenced by these identified metabolites were delineated.

CONCLUSION

This study highlights Nacetyl glucosamine as a distinctive metabolite with the potential to serve as an early diagnostic marker for OSCC. Nevertheless, further research is warranted to validate its clinical utility.

4-nitroquinoline 1-oxide-induced oral epithelial lesions exhibit time- and stage-dependent changes in the tumor immune microenvironment

Oral tongue squamous cell carcinoma (OTSCC) is the most common cancer of the oral cavity and is associated with high morbidity due to local invasion and lymph node metastasis. Tumor infiltrating lymphocytes (TILs) are associated with good prognosis in oral cancer patients and dictate response to treatment. Ectopic sites for immune activation in tumors, known as tertiary lymphoid structures (TLS), and tumor-associated high-endothelial venules (TA-HEVs), which are specialized lymphocyte recruiting vessels, are associated with a favorable prognosis in OSCC. Why only some tumors support the development of TLS and HEVs is poorly understood. In the current study we explored the infiltration of lymphocyte subsets and the development of TLS and HEVs in oral epithelial lesions using the 4-nitroquinoline 1-oxide (4NQO)-induced mouse model of oral carcinogenesis. We found that the immune response to 4NQO-induced oral epithelial lesions was dominated by T cell subsets. The number of T cells (CD4+, FoxP3+, and CD8+), B cells (B220+) and PNAd+ HEVs increased from the earliest to the latest endpoints. All the immune markers increased with the severity of the dysplasia, while the number of HEVs and B cells further increased in SCCs. HEVs were present already in early-stage lesions, while TLS did not develop at any timepoint. This suggests that the 4NQO model is applicable to study the dynamics of the tumor immune microenvironment at early phases of oral cancer development, including the regulation of TA-HEVs in OTSCC.

The spectrum and frequency of histopathological diagnosis of oral diseases in Oslo: Implications to oral pathology syllabus

INTRODUCTION

To assure knowledge and skills in diagnostic work of oral diseases a continuously updated curriculum is essential. The first aim of the present study was to evaluate the spectrum and frequency of oral histopathological diagnoses signed out by oral pathologists at the Department of Pathology, Oslo University Hospital (OUS), Norway during a two-year period. The second aim was to compare the spectrum of histopathological diagnoses with the content of the current syllabus in oral pathology at the Faculty of Dentistry, University of Oslo (UiO).

MATERIALS AND METHODS

In this retrospective cross-sectional study, all histological diagnosis signed out during 2015 and 2016 were included. All histopathological reports were analysed with regard to clinical information and histopathological diagnosis. The spectrum of histopathological diagnoses was compared to the diagnoses presented in lectures and courses for dental and dental hygienist students at UiO.

RESULTS

Three thousand four hundred and two histopathological reports (47% males and 53% females) were included. The diagnoses were categorised into eight disease groups and the three most frequent disease groups were cysts, benign tumours/reactive lesions, and white, red, ulcerative and vesiculobullous lesions. The lateral periodontal cyst was more frequent than expected.

CONCLUSIONS

We conclude that a minor revision of the syllabus is needed, although the most frequent oral conditions presented in this study are well covered in the oral pathology teaching in Oslo. A more clinical related teaching approach should be considered by categorising oral diseases according to, for example location and age groups.

Cortactin expression in a Norwegian cohort of human papilloma virus negative oral squamous cell carcinomas of the mobile tongue

Oral squamous cell carcinoma of the tongue (OTSCC) is the most common malignancy among oral squamous cell carcinomas and is frequently associated with an unfavorable prognosis. Local spread and distant metastasis are important causes of poor prognosis in OTSCC. Cortactin amplification and overexpression, a common molecular alteration in oral squamous cell carcinomas, have been linked to invasion and metastasis of tumor cells. However, the intra-tumor expression pattern and prognostic significance of cortactin in human papillomavirus (HPV) negative OTSCC is not fully investigated. Immunohistochemical analysis using tissue microarray consisting of formalin-fixed and paraffin-embedded HPV negative OTSCC (n = 123) specimens showed overexpression of cortactin at tissue cores from invading fronts as compared to the corresponding center cores. High overall cortactin expression was found to be associated with advanced (larger) tumor size and the occurrence of distance metastasis. Kaplan-Meier survival analysis showed that patients with high overall cortactin expression were associated with reduced 5-year survival. Multivariate Cox regression analysis identified high cortactin expression to be an independent prognostic factor in OTSCC. Additionally, siRNA-mediated silencing of cortactin was found to suppress the proliferative and invasive abilities of OTSCC cells in an organotypic co-culture model. Overexpression of cortactin is a promising prognostic marker in HPV-negative OTSCC.

Tumor Microenvironment and Immune Response in Lip Cancer

Tumor-infiltrating lymphocytes (TILs) play a significant role in cancer progression and prognosis of patients. The tumor microenvironment (TME) may affect the anti-tumor immune response. We examined the TIL and tertiary lymphoid structure (TLS) density in the invading front and inner tumor stroma, and the lymphocyte subpopulation (CD8, CD4, FOXP3) density in 60 squamous cell carcinomas of the lip. Analysis was performed in parallel with markers of hypoxia (hypoxia-inducible factor (HIF1α), lactate dehydrogenase (LDHA)) and angiogenesis. Low TIL density in the invading tumor front was related with larger tumor size (p = 0.05), deep invasion (p = 0.01), high smooth-muscle actin (SMA) expression (p = 0.01), and high HIF1α and LDH5 expression (p = 0.04). FOXP3⁺ TILs infiltration and FOXP3⁺/CD8⁺ ratios were higher in inner tumor areas, linked with LDH5 expression, and higher MIB1 proliferation index (p = 0.03) and SMA expression (p = 0.001). Dense CD4⁺ lymphocytic infiltration in the invading front is related to high tumor-budding (TB) (p = 0.04) and angiogenesis (p = 0.04 and p = 0.006, respectively). Low CD8⁺ TIL density, high CD20⁺ B-cell density, high FOXP3⁺/CD8⁺ ratio and high CD68⁺ macrophage presence characterized tumors with local invasion (p = 0.02, 0.01, 0.02 and 0.006, respectively). High angiogenic activity was linked with high CD4⁺, FOXP3⁺, and low CD8⁺ TIL density (p = 0.05, 0.01 and 0.01, respectively), as well as high CD68⁺ macrophage presence (p = 0.003). LDH5 expression was linked with high CD4⁺ and FOXP3⁺ TIL density (p = 0.05 and 0.01, respectively). Further research is needed to explore the prognostic and therapeutic value of TME/TIL interactions.

The prognostic role of combining Krüppel-like factor 4 score and grade of inflammation in a Norwegian cohort of oral tongue squamous cell carcinomas

Krüppel-like factor 4 (KLF4) is a zinc-finger transcription factor involved in inflammation, cancer development, and progression. However, the relationship between KLF4, inflammation, and prognosis in oral cancer is not fully understood. KLF4 expression levels were examined in a multicenter cohort of 128 oral squamous cell carcinoma (OSCC) specimens from the tongue (OTSCC) using immunohistochemistry. In two external KLF4 mRNA datasets (The Cancer Genome Atlas/The Genotype-Tissue Expression Portal), lower KLF4 mRNA expression was found in OSCC and head and neck squamous cell carcinomas (HNSCC) than in control oral epithelium. These data indicate that down-regulation of KLF4 mRNA is linked to OSCC/HNSCC progression. Using Cox-multivariate analysis, a significantly favorable 5-year disease-specific survival rate was observed for a subgroup of patients with a combination of high levels of KLF4 expression and inflammation. OSCC cell lines exposed to IFN-γ showed a significant upregulation of nuclear KLF4 expression, indicating a link between inflammation and KLF4 expression in OSCC. Overall, the current data suggest a functional link between KLF4 and inflammation. The combination of high KLF4 nuclear expression and marked/moderate stromal inflammation might be useful as a favorable prognostic marker for a subgroup of OTSCC patients.

Association of salivary Cathepsin B in different histological grades among patients presenting with oral squamous cell carcinoma

BACKGROUND

Oral cancer is considered a major public health problem due to its high mortality and morbidity rates. Survival rate of OSCC can be significantly improved by using non-invasive tool such as salivary biomarkers for detection of OSCC which is considered a promising approach. Cathepsin B is a lysosomal cysteine protease, present in abundant quantities in lysosome of cells, tissues and different biological fluids. Increased expression of Cathepsin B was observed in many malignancies including oral cancer. The present study was designed to determine the salivary levels of Cathepsin B in different histological grades of OSCC.

METHOD

In this study, total no. of 80 research participants were enrolled which were divided into four groups. Each group comprised 20 participants, group 1 comprised 20 patients of OSCC (well differentiated), group 2 comprised 20 patients of OSCC (moderately differentiated), group 3 comprised 20 patients of OSCC (poorly differentiated) and group 4 comprised 20 healthy controls. Saliva sample was collected from all the four study groups and salivary Cathepsin B levels were analyzed by ELISA sandwich technique in duplicate.

RESULTS

Salivary levels of Cathepsin B were significantly increased with p value (< 0.001) in patients of OSCC as compared to control group according to both histological grades and tumor size. Highest mean Cathepsin B levels in well differentiated OSCC followed by poorly differentiated OSCC and moderately differentiated OSCC were observed.

CONCLUSION

Results of the present study suggests that Cathepsin B has a great value as a salivary biomarker for diagnosis and monitoring of OSCC in different histological grades. This will further lead to increase survival rate and improve the prognosis of OSCC.

Anticancer effects of picrasidine I on oral squamous cell carcinoma

Picrasidine I is a dimeric alkaloid derived from a Southern Asian plant Picrasma quassioides and demonstrated to possess pharmacological activities, such as anti-inflammatory and anti-osteoclastogenic effects. However, its potential anticancer effect remains unclear. In the present study, anticancer activity of picrasidine I was assessed by treating oral squamous cell carcinoma cells with different concentrations of picrasidine I (20, 30, and 40 μM) for 24, 48, and 72 h. The findings revealed that picrasidine I reduced the cell viability in a dose-dependent manner. Picrasidine I exerted its cytotoxic effect through arresting cell cycle at G2/M phase by downregulating cyclin A, cyclin B, CDK4, and CDK6, and inducing apoptosis in oral cancer cells. The induction of apoptosis was evidenced by increasing expression of death receptors, disruption of mitochondrial membrane potential, increased activation of PARP and caspases 3, 8, and 9, enhanced expression of proapoptotic mediators (Bak and Bim L/S), and reduced expression of antiapoptotic mediators (Bcl-2 and Bcl-xL). Moreover, analysis of MAPK signaling pathway revealed that picrasidine I-mediated proapoptotic activities by downregulating JNK phosphorylation. Taken together, the study identifies picrasidine I as a potent anticancer agent that can be used as a therapeutic intervention against oral squamous cell carcinoma.

Value of six comorbidity scales for predicting survival of patients with primary surgery for oral squamous cell carcinoma

BACKGROUND

Comorbidities influence treatment outcome of oral squamous cell carcinoma (OSCC). This study compared the predictive performance of six comorbidity scales for overall survival after surgery for OSCC.

METHODS

We retrospectively analyzed OSCC patients, surgically treated at an academic center in Belgium between January 01, 2000 and January 01, 2020. Validity of the scales was evaluated using the area under the curve (AUC) of receiver operating characteristic curves.

RESULTS

Three hundred and twenty three patients were included. Elixhauser Comorbidity Index (AUC = 0.74, 95% CI: 0.55-0.92; AUC = 0.73, 95% CI: 0.55-0.80), modified Elixhauser Comorbidity Index (AUC = 0.72, 95% CI: 0.54-0.91; AUC = 0.69, 95% CI: 0.51-0.77), and Combined Comorbidity Index (AUC = 0.76, 95% CI: 0.58-0.84; AUC = 0.76, 95% CI: 0.59-0.84) were meaningful predictors for 2 and 5-year survival, respectively.

CONCLUSION

Selected comorbidity scales were capable of predicting overall survival for OSCC patients 2 and 5 years after primary surgery.

The effect of reconstruction on positive margin rates in oral cancer: Using length of stay as a proxy measure for flap reconstruction in a national database

PURPOSE

Planned flap reconstruction, allowing aggressive resections of oral cavity squamous cell carcinoma (OCSCC), may decrease positive surgical margins. The purpose of this study was to determine if length of stay (LOS), as a proxy measure for flap reconstruction, is associated with positive margin rates in OCSCC.

MATERIALS AND METHODS

Data from the National Cancer Database was retrospectively collected for patients undergoing surgery for previously untreated clinical T1-3 OCSCC. Post-operative LOS was dichotomized between ≤4 and >4 days as a proxy measure for whether patients may have received flap reconstruction. Patients with LOS >4 days represent a diverse group, but those with a LOS ≤4 days are less likely to have undergone an oral cavity flap reconstruction.

RESULTS

10,107 patients were included, of which 5290 (52%) were clinical T1 and 4852 (48%) were clinical T2-3. 771 (8%) patients had a positive surgical margin. On multivariable logistic regression analysis, LOS ≤4 days was significantly associated with a positive margin resection in patients with clinical T2-3 tumors (OR 1.68, 95%CI 1.37-2.06) compared to patients with LOS >4 days. LOS was not associated with surgical margin status in patients with clinical T1 disease (OR 0.76, 95%CI 0.55-1.06). Patients with positive margin resections demonstrated worse overall survival (cT1: OR 1.35, 95%CI 1.06-1.72; cT2-3: OR 1.52, 95%CI 1.33-1.74).

CONCLUSIONS

LOS >4 days after oral cavity cancer resection was significantly associated with negative surgical margins in clinical T2-3 oral cavity cancer, suggesting the possibility that patients undergoing flap reconstruction after resection have fewer positive surgical margins.

Combined loss of expression of involucrin and cytokeratin 13 is associated with poor prognosis in squamous cell carcinoma of mobile tongue

BACKGROUND

This study aimed to evaluate the prognostic significance of expression levels of involucrin (IVL), cytokeratin (CK)-10 and -13 at different intratumor sites (tumor center and invading area) of oral tongue squamous cell carcinoma (OTSCC).

METHODS

IVL, CK13 and CK10 expression levels were examined in a multicenter cohort of 146 OTSCCs using immunohistochemistry. External mRNA datasets were used for expression analysis and/or to validate survival associations.

RESULTS

External transcriptomic datasets showed downregulation of IVL and KRT13 in oral malignancies including OTSCC as compared to normal controls. The combined loss of IVL and CK13 expression at the invading core but not at the center core was significantly associated with poor differentiation and reduced 5-year overall survival. Multivariate Cox analysis confirmed the loss of CK13 and IVL expression to be an independent prognostic factor. Transcriptomic dataset corroborated immunohistochemistry results.

CONCLUSIONS

Combined expression levlels of IVL and CK13 might be useful as prognostic biomarkers in OTSCC.

Validation of Selected Head and Neck Cancer Prognostic Markers from the Pathology Atlas in an Oral Tongue Cancer Cohort

The Pathology Atlas is an open-access database that reports the prognostic value of protein-coding transcripts in 17 cancers, including head and neck cancer. However, cancers of the various head and neck anatomical sites are specific biological entities. Thus, the aim of the present study was to validate promising prognostic markers for head and neck cancer reported in the Pathology Atlas in oral tongue squamous cell carcinoma (OTSCC). We selected three promising markers from the Pathology Atlas (CALML5, CD59, LIMA1), and analyzed their prognostic value in a Norwegian OTSCC cohort comprising 121 patients. We correlated target protein and mRNA expression in formalin-fixed, paraffin-embedded cancer tissue to five-year disease-specific survival (DSS) in univariate and multivariate analyses. Protein expression of CALML5 and LIMA1 were significantly associated with five-year DSS in the OTSCC cohort in univariate analyses (p = 0.016 and p = 0.043, respectively). In multivariate analyses, lymph node metastases, tumor differentiation, and CALML5 were independent prognosticators. The prognostic role of the other selected markers for head and neck cancer patients identified through unbiased approaches could not be validated in our OTSCC cohort. This underlines the need for subsite-specific analyses for head and neck cancer.

Tumor Microenvironment in Oral Cancer Following Neoadjuvant Pembrolizumab: Preliminary Analysis of the Histopathologic Findings

Background: The tumor microenvironment (TME) of oral squamous cell carcinoma (OSCC) is associated with immune suppression, one of the pathways being the programmed death receptor 1 (PD-1) and its ligands (PD-L1/PD-L2). Checkpoint inhibitors of PD-1/PD-L1, like pembrolizumab, have been recently approved for treatment of OSCC. We described the histologic findings in OSCC following neoadjuvant pembrolizumab, including identification of immune-related cell populations and cancer-associated fibroblasts (CAFs).

Materials and Methods: Patients with OSCC clinical stages 3 and 4 and a combined PD-L1 score >1 were randomized either to the standard oncologic protocol or to the pembrolizumab arm of MK-3475-689 study for Head and Neck, Lip, and Oral Cavity. The latter were given two standard doses of 200 mg of pembrolizumab, 3 weeks apart, and then underwent surgical oncologic procedure according to the initial stage. Sections from the resection specimens were analyzed for pathological response to pembrolizumab. Various populations of immune-related cells within the tumor microenvironment were characterized by immunohistochemistry, as were the CAFs.

Results: Three patients who were randomized to the pembrolizumab study were described. One patient presented with a tongue SCC, the other two had SCC of the mandibular ridge with bony involvement. Only the patient with tongue SCC showed clinical complete response. Microscopically, the tumor was replaced by a granulomatous type of inflammation. Immunohistochemical stains revealed massive T cell rich (CD3⁺) infiltrate, with approximately equal amounts of CD4⁺ and CD8⁺ cells, numerous macrophages of CD68⁺ and CD163⁺ phenotypes; no CAFs were identified. The other two patients were regarded as non-responders as at least 50% of the tumor was viable. The tumor microenvironment of these tumors was generally associated with a lesser extent of inflammatory response compared to the tongue tumor, a variable CD4⁺/CD8⁺ ratio and presence of CAFs. Neither T regulatory cells (FOXP3⁺) nor natural killer cells (CD56⁺, CD57⁺) were identified in any of the cases.

Conclusion: We showed that characterizing the specific populations of immune-related cells and CAFs after treatment with pembrolizumab, may add to our understanding of the tumor-TME interactions in this setting. These findings should be investigated in future studies on a larger number of patients.

Comparison of machine learning algorithms for the prediction of five-year survival in oral squamous cell carcinoma

BACKGROUND/AIM

Machine learning analyses of cancer outcomes for oral cancer remain sparse compared to other types of cancer like breast or lung. The purpose of the present study was to compare the performance of machine learning algorithms in the prediction of global, recurrence-free five-year survival in oral cancer patients based on clinical and histopathological data.

METHODS

Data were gathered retrospectively from 416 patients with oral squamous cell carcinoma. The data set was divided into training and test data set (75:25 split). Training performance of five machine learning algorithms (Logistic regression, K-nearest neighbours, Naïve Bayes, Decision tree and Random forest classifiers) for prediction was assessed by k-fold cross-validation. Variables used in the machine learning models were age, sex, pain symptoms, grade of lesion, lymphovascular invasion, extracapsular extension, perineural invasion, bone invasion and type of treatment. Variable importance was assessed and model performance on the testing data was assessed using receiver operating characteristic curves, accuracy, sensitivity, specificity and F1 score.

RESULTS

The best performing model was the Decision tree classifier, followed by the Logistic Regression model (accuracy 76% and 60%, respectively). The Naïve Bayes model did not display any predictive value with 0% specificity.

CONCLUSIONS

Machine learning presents a promising and accessible toolset for improving prediction of oral cancer outcomes. Our findings add to a growing body of evidence that Decision tree models are useful in models in predicting OSCC outcomes. We would advise that future similar studies explore a variety of machine learning models including Logistic regression to help evaluate model performance.

High-risk human papilloma virus was not detected in a Norwegian cohort of oral squamous cell carcinoma of the mobile tongue

OBJECTIVES

The presence of and the causative role of high-risk human papilloma virus (HPV) is a subject of controversy in oral squamous cell carcinoma (OSCC). The disagreement can be related to the misclassification of OSCC as oropharyngeal squamous cell carcinoma and/or lack of standard detection methods. This study aimed to examine the presence of transcriptionally active high-risk HPV in a homogenous Norwegian cohort of primary and second primary OSCC of the mobile tongue (oral tongue squamous cell carcinoma-OTSCC).

METHODS

Tissue microarrays containing formalin-fixed and paraffin-embedded cores of 146 OTSCC from the anterior 2/3 of the tongue (n = 128 primary and n = 18 second primary) from a multicentric Norwegian cohort were examined for the presence of high-risk HPV by DNA- and RNA-in situ hybridization (ISH) assays and p16 immunohistochemistry.

RESULTS

Transcriptionally active HPV (E6/E7 mRNA) was not identified in any of the OTSCC specimens. In parallel, no tumors were positive for HPV by DNA ISH. Although, 61 (42%) OTSCC demonstrated p16 positivity with varying staining intensity and subcellular localization, only two cases demonstrated strong and uniform p16-staining (both cytoplasmic and nuclear) in >70% of cancer cells. The absence of transcriptionally active high-risk HPV in this cohort of OTSCC indicates that high-risk HPV is an unlikely causative factor in the present material.

Tumor budding score predicts lymph node status in oral tongue squamous cell carcinoma and should be included in the pathology report

BACKGROUND

The majority of oral cavity cancers arise in the oral tongue. The aim of this study was to evaluate the prognostic value of tumor budding in oral tongue squamous cell carcinoma, both as a separate variable and in combination with depth of invasion. We also assessed the prognostic impact of the 8th edition of the American Joint Committee on Cancer's TNM classification (TNM8), where depth of invasion (DOI) supplements diameter in the tumor size (T) categorization.

METHODS

Patients diagnosed with primary oral tongue squamous cell carcinoma were evaluated retrospectively. Spearman bivariate correlation analyses with bootstrapping were used to identify correlation between variables. Prognostic value of clinical and histopathological variables was assessed by Log rank and Cox regression analyses with bootstrapping using 5-year disease specific survival as outcome. The significance level for the hypothesis test was 0.05.

RESULTS

One-hundred and fifty patients had available material for microscopic evaluation on Hematoxylin and Eosin-stained slides and were included in the analyses. Reclassification of tumors according to TNM8 caused a shift towards a higher T status compared to the previous classification. The tumor budding score was associated with lymph node metastases where 23% of the patients with low-budding tumors had lymph node metastases, compared with 43% of those with high-budding tumors. T-status, lymph node status, tumor budding, depth of invasion, and the combined tumor budding/depth of invasion score were all significantly associated with survival in univariate analyses. In multivariate analyses only N-status was an independent prognosticator of survival.

CONCLUSION

Reclassification according to TNM8 shifted many tumors to a higher T-status, and also increased the prognostic value of the T-status. This supports the implementation of depth of invasion to the T-categorization in TNM8. Tumor budding correlated with lymph node metastases and survival. Therefore, information on tumor budding can aid clinicians in treatment planning and should be included in pathology reports of oral tongue squamous cell carcinomas.

A combined histo-score based on tumor differentiation and lymphocytic infiltrate is a robust prognostic marker for mobile tongue cancer

We wanted to evaluate the prognostic value of common histopathological variables in a large cohort of patients with cancer in the mobile tongue as such information can be important for treatment stratification of the individual patient, especially for patients with low-stage disease. In addition, we wanted to investigate whether an alternative scoring model with fewer options would compromise the prognostic value. One hundred fifty patients with oral tongue squamous cell carcinomas that were treated in curative intent and with available HE-stained tumor sections were included. We reclassified all tumors and performed univariate and multivariate survival analyses of histopathological and clinical variables. For the complete cohort, lymph node status, grade of differentiation, perineural infiltration, and lymphocytic infiltration were independent prognosticators. In the low-stage disease group, independent prognostic factors were tumor size, grade of differentiation, and lymphocytic infiltrate. For patients with low-stage disease, a histo-score combining the scores for tumor differentiation and lymphocytic infiltrate identified a group of patients with particularly low survival, as patients with moderately or poorly differentiated tumors and little lymphocytic infiltrate had a less favorable 5-year survival outcome than patients in the high-stage disease group. This study shows that a histo-score combining tumor differentiation and lymphocytic infiltration should be given special consideration in treatment planning. Our results also illustrate that many variables can be scored with fewer options than previously suggested to increase their reproducibility, and still maintain their prognostic value.