HPV E1 qPCR, a Low-Cost Alternative Assay to Roche Diagnostic Linear Array is Effective in Identifying Women at Risk for Developing Cervical Cancer.

OBJECTIVE: Since a quantitative polymerase chain reaction (qPCR) assay targeting the E1 region of HPV genome is cost-effective/simple to perform, we evaluated the agreement between the Roche Diagnostics Linear Array (RDLA) genotyping test and qPCR-based E1 assay to detect HR-HPV genotypes that are included or not included in HPV vaccines and compared their accuracy to detect CIN 2+. METHODS: Study population included 257 African American (AA) and 266 Caucasian American (CA) diagnosed with intraepithelial neoplasia (CIN) grades ≤CIN 1 or ≥CIN 2 (CIN 2+) and tested for HPV by the RDLA and E1 assay. The concordance was determined using Gwet's AC1. The calculated positive predictive value (PPV) and negative predictive value (NPV) of the two assays were used to determine their suitability to detect CIN lesions. RESULTS: Overall, the E1 assay showed substantial agreement with the RDLA assay to detect any HR-HPV genotype and the agreement was higher in women diagnosed with CIN 2+ than ≤CIN 1. The concordance was largely higher in Cas than in Aas. The NPV and PPV values to detect CIN lesions were similar between the two assays. CONCLUSION: Utilization of the HPV E1 assay as a tool for CC screening could be a cost-effective approach that applies to both vaccinated and unvaccinated populations.

A higher degree of expression of DNA methyl transferase 1 in cervical cancer is associated with poor survival outcome.

BACKGROUND: Even though novel therapies based on aberrant DNA methylation could be of particular importance for the treatment of cervical cancer (CC) because the oncoproteins E6/E7 of high-risk human papillomaviruses, the causative agents for developing CC, have the capacity to bind and upregulate DNA methyltransferases (DNMTs), to our knowledge, no previous studies have evaluated the expression of this enzyme in CC in relation to survival outcomes. The purpose of the study was to evaluate the expression of DNMT1 in CC and its association with survival outcomes. METHODS: The study population consisted of 76 women treated for primary CC and followed up by the University of Alabama at Birmingham (UAB) cancer registry. The expression of DNMT1 was examined using immunohistochemistry, and the degree of expression of DNMT1 was expressed as a percentage of cells positive for DNMT1 and its intensity. Cox proportional hazards model was used to assess the relationship between the degree of expression of DNMT1 and overall survival after adjusting for relevant covariates. RESULTS: The expression of DNMT1 was significantly higher in CC cells compared to that in the normal cervical epithelium. A higher percentage of cells positive for DNMT1 and a higher intensity score for DNMT1 were significantly associated with poor survival outcome (hazard ratio [HR] =4.3, P=0.03 and HR =4.9, P=0.02, respectively). CONCLUSION: Our findings suggested that the degree of expression of DNMT1 could be considered as a target in the epigenetic treatment of CC. Replication of our results in other study populations with CC could create the opportunity of using DNMT inhibitors to treat CC.

Granular Cell Tumor Within an Ovarian Mature Cystic Teratoma: Report of a Unique Case and Review of the Literature.

Granular cell tumors involving the female reproductive tract are rare, with only a small number of cases described. Of the reported cases, none are documented within an ovarian mature cystic teratoma (MCT). This report documents a case of a granular cell tumor, incidentally discovered within an ovarian MCT in a 50-yr-old woman undergoing a supracervical hysterectomy and left salpingo-oophorectomy. Although malignant transformation and other secondary ovarian neoplasms in MCT have been well documented, synchronous nonovarian benign neoplasms are reported much less frequently. The histogenesis of secondary tumors arising in MCT is incompletely understood, and the current case provides additional insight, especially pertaining to schwannian and neuroectodermal tumors arising in this setting. The current case, to the best of our knowledge, represents the first report of a granular cell tumor involving a mature teratoma of any site, with the diagnosis being supported by morphologic and immunohistochemical staining characteristics.

An examination of racial differences in 5-year survival of cervical cancer among African American and white American women in the southeastern US from 1985 to 2010.

Disparities in Cervical Cancer (CC) mortality outcomes between African American (AA) and White women have been studied for decades. However, conclusions about the effect of race on CC survival differ across studies. This study assessed differences in CC survival between AA and White women diagnosed between 1985 and 2010 and treated at two major hospitals in the southeastern US. The study sample included 925 AA and 1192 White women diagnosed with cervical adenocarcinoma, adenosquamous cell carcinoma, or squamous cell carcinoma. Propensity score adjustment and matching were employed to compare 5-year survival between the two racial groups. Crude comparisons suggested relevant racial differences in survival. However, the racial differences became of small magnitude after propensity-score adjustment and in matched analyses. Nonlinear models identified age at diagnosis, cancer stage, mode of treatment, and histological subtype as the most salient characteristics predicting 5-year survival of CC, yet these characteristics were also associated with race. Crude racial differences in survival might be partly explained by underlying differences in the characteristics of racial groups, such as age at diagnosis, histological subtype, cancer stage, and the mode of treatment. The study results highlight the need to improve access to early screening and treatment opportunities for AA women to improve posttreatment survival from CC.

Mammary analog secretory carcinoma, low-grade salivary duct carcinoma, and mimickers: a comparative study.

Mammary analog secretory carcinoma (MASC) is a recently recognized low-grade salivary carcinoma characterized by a specific ETV6 rearrangement. We describe 14 new MASCs and examine their immunophenotypic and genetic profiles in the context of look-alikes, namely, low-and high-grade salivary duct carcinoma and acinic cell carcinoma. ETV6 rearrangement, and robust expression of mammaglobin and S100, were demonstrated in 11/11, 14/14, and 12/14 MASCs, respectively. All low-grade salivary duct carcinomas coexpressed S100/mammaglobin (6/6); none harbored ETV6 rearrangements (0/5). Given that S100/mammaglobin coexpression and absence of zymogen granules are features of both MASC and low-grade salivary duct carcinoma, these two are best distinguished histologically. The former is predominantly an extraductal neoplasm with bubbly pink cytoplasm, whereas the latter is a distinct intraductal micropapillary and cribriform process. Querying ETV6 gene status may be necessary for difficult cases. No acinic cell carcinoma expressed mammaglobin (0/13) or harbored an ETV6 rearrangement (0/7); only 1/13 acinic cell carcinomas weakly expressed S100. DOG1 expression was limited or absent among all tumor types, except acinic cell carcinoma which expressed DOG1 diffusely in a canalicular pattern. Therefore, histology and immunohistochemistry (mammaglobin, S100, DOG1) suffices in distinguishing acinic cell carcinoma from both MASC and low-grade salivary duct carcinoma. HER2 (ERBB2) amplification was detected in only 1/10 acinic cell carcinomas, but none of the MASCs or low-grade salivary duct carcinomas tested. High-grade salivary duct carcinomas frequently expressed mammaglobin (11/18) and harbored HER2 amplifications (13/15); none harbored ETV6 rearrangements (0/12). High-grade salivary duct carcinomas can easily be distinguished from these other entities by histology and HER2 amplification.

Folate and vitamin B12 may play a critical role in lowering the HPV 16 methylation-associated risk of developing higher grades of CIN.

We previously reported that a higher degree of methylation of CpG sites in the promoter (positions 31, 37, 43, 52, and 58) and enhancer site 7862 of human papillomavirus (HPV) 16 was associated with a lower likelihood of being diagnosed with HPV 16-associated CIN 2+. The purpose of this study was to replicate our previous findings and, in addition, to evaluate the influence of plasma concentrations of folate and vitamin B12 on the degree of HPV 16 methylation (HPV 16m). The study included 315 HPV 16-positive women diagnosed with either CIN 2+ or ≤CIN 1. Pyrosequencing technology was used to quantify the degree of HPV 16m. We reproduced the previously reported inverse association between HPV 16m and risk of being diagnosed with CIN 2+. In addition, we observed that women with higher plasma folate and HPV 16m or those with higher plasma vitamin B12 and HPV 16m were 75% (P < 0.01) and 60% (P = 0.02) less likely to be diagnosed with CIN 2+, respectively. With a tertile increase in the plasma folate or vitamin B12, there was a 50% (P = 0.03) and 40% (P = 0.07) increase in the odds of having a higher degree of HPV 16m, respectively. This study provides initial evidence that methyl donor micronutrients, folate and vitamin B12, may play an important role in maintaining a desirably high degree of methylation at specific CpG sites in the HPV E6 promoter and enhancer that are associated with the likelihood of being diagnosed with CIN 2+.

Mandatory fortification with folic acid in the United States appears to have adverse effects on histone methylation in women with pre-cancer but not in women free of pre-cancer.

OBJECTIVE: To evaluate whether mandatory fortification of grain products with folic acid in the US is associated with changes in histone methylation in cells involved in cervical carcinogenesis. METHODS: Cervical specimens obtained before (1990 to 1992) and after mandatory folic acid fortification (2000 to 2002) were used to examine the degree of histone methylation (H3 Lys-9) by immunohistochemistry. 91 women (51 before and 40 after fortification) were diagnosed with cervical intraepithelial neoplasia (CIN) grade 3 or carcinoma in situ (CIS) and sections utilized in the study also contained normal, reactive or metaplastic cervical epithelium, CIN 1 or CIN 2. 64 women (34 before and 30 after fortification) were free of CIN and these sections contained only normal or reactive cervical epithelium. Immunohistochemical staining for H3 Lys-9, its assessment in different cell or lesion types and data entry were blinded for fortification status. For each cell type or lesion category we used PROC MIXED in SAS with the specimen identifier as a random effect and the robust variance estimator to estimate age- and race-adjusted intensity score for H3 Lys-9 in the pre- and post-fortification periods. RESULTS: Degree of H3 Lys-9 methylation was significantly higher (P < 0.0001) in ≥CIN 2 lesions (CIN 2, CIN 3 and CIS) than in ≤CIN 1 lesions (CIN 1, normal, reactive and metaplastic), in both pre- and post-fortification CIN 3/CIS specimens. Age- and race-adjusted mean H3 Lys-9 score was significantly higher in all cell or lesion types in CIN 3/CIS specimens obtained in the post-fortification period compared to pre-fortification period (P < 0.05, all comparisons). In contrast, in specimens obtained from women free of CIN, Lys-9 methylation in normal/reactive cervical epithelium was significantly lower in post-fortification specimens than in pre-fortification specimens (P = 0.03). CONCLUSIONS: Higher levels of Lys-9 methylation in ≥CIN 2 compared to ≤CIN 1 lesions suggest that higher Lys-9 methylation is associated with progression of lower grade CIN to higher grade CIN. Higher Lys-9 methylation in cervical tissues of women diagnosed with CIN 3 in the post-fortification period than in pre-fortification period suggest that fortification may adversely affect histone methylation in already initiated cells. Lower Lys-9 methylation in normal/reactive cervical cells of women free of CIN in the post-fortification period than pre-fortification on the other hand suggests that fortification is likely to protect against initiation of carcinogenic process in the cervix. These results suggest that mandatory fortification with folic acid in the US seems to have different effects on cancer depending on the stage of carcinogenesis. Because this is the first study to report folic acid fortification-associated differences in histone methylation and because of the limitations inherent to the approach we have taken to demonstrate these differences, validation of the results in other study populations or with other techniques for assessing histone methylation is necessary.

Recurrent retroperitoneal sarcoma: impact of biology and therapy on outcomes.

BACKGROUND: Local recurrence remains the major cause of death in patients with retroperitoneal sarcoma (RPS). There is no consensus regarding management of patients with recurrent RPS. STUDY DESIGN: We performed a retrospective review of patients with recurrent RPS managed at 2 tertiary care centers between 1983 and 2008. Presentation, treatments, and outcomes were analyzed. RESULTS: Seventy-eight patients were identified and analyzed. Sixteen patients (22%) presented with concurrent metastatic disease; survival in this subset of patients was poor (median 12 months). Forty-eight patients underwent resection of the first local recurrence of RPS. Palliation of tumor-related symptoms was achieved in 79% with operation. Survival was significantly better in patients having complete (p = 0.001) and incomplete resection (p = 0.02) compared with patients having biopsy only. Among patients with first local recurrence, high grade tumor (p = 0.0001) and no resection (p = 0.007) were significantly associated with reduced survival. On multivariate analysis, radiation therapy, multifocality, histologic subtype, and time to local recurrence did not significantly correlate with survival. Second and third local recurrences occurred at shorter intervals compared with first local recurrence and were less likely to be completely resectable. Patients undergoing resection of second and third local recurrences had survival similar to that in patients undergoing resection of first local recurrence. CONCLUSIONS: Tumor biology (high grade) is a significant prognostic factor for patients with recurrent RPS. Resection should be considered in patients with first and subsequent local recurrences (even if multifocal) of RPS because it is associated with improved survival. Operation should also be considered for palliation of symptoms in patients in whom resection is not possible.

Issues in collecting, processing and storing human tissues and associated information to support biomedical research.

The availability of human tissues to support biomedical research is critical to advance translational research focused on identifying and characterizing approaches to individualized (personalized) medical care. Providing such tissues relies on three acceptable models - a tissue banking model, a prospective collection model and a combination of these two models. An unacceptable model is the "catch as catch can" model in which tissues are collected, processed and stored without goals or a plan or without standard operating procedures, i.e., portions of tissues are collected as available and processed and stored when time permits. In the tissue banking model, aliquots of tissues are collected according to SOPs. Usually specific sizes and types of tissues are collected and processed (e.g., 0.1 gm of breast cancer frozen in OCT). Using the banking model, tissues may be collected that may not be used and/or do not meet specific needs of investigators; however, at the time of an investigator request, tissues are readily available as is clinical information including clinical outcomes. In the model of prospective collection, tissues are collected based upon investigator requests including specific requirements of investigators. For example, the investigator may request that two 0.15 gm matching aliquots of breast cancer be minced while fresh, put in RPMI media with and without fetal calf serum, cooled to 4°C and shipped to the investigator on wet ice. Thus, the tissues collected prospectively meet investigator needs, all collected specimens are utilized and storage of specimens is minimized; however, investigators must wait until specimens are collected, and if needed, for clinical outcome. The operation of any tissue repository requires well trained and dedicated personnel. A quality assurance program is required which provides quality control information on the diagnosis of a specimen that is matched specifically to the specimen provided to an investigator instead of an overall diagnosis of the specimen via a surgical pathology report. This is necessary because a specific specimen may not match the diagnosis of the case due to many factors such as necrosis, unsuspected tumor invasion of apparently normal tissue, and areas of fibrosis which are mistaken grossly for tumor. Aliquots for quality control (QC) may or may not be collected at the time of collection and in some cases, QC may not occur until specimens are distributed to investigators. In establishing a tumor repository, multiple issues need to be considered. These include the available resources, long term support, space and equipment. The needs of the potential users need to be identified as to the types of tissues and services needed and the annotation expected. Other specific issues to be considered include collection of specimens potentially infected with blood borne pathogens (e.g., hepatitis B), charge back mechanisms, informatics needs and support, and investigator requirements (e.g., recognition of repository contributions in publications). In general, the repository should not perform the research of the investigators, but should provide the infrastructure necessary to support the research of the investigator. Thus, the goals of the repository must be established. Similarly, ethical and regulatory issues must be evaluated. In general, tissue repositories need ethical (e.g., IRB) and privacy (e.g., HIPAA) review. Also, safety issues need to be considered as well as how biohazards will be addressed by investigator-users. Considerations involving the transfer of specimens to other organization usually require a material transfer agreement (MTA). A MTA should address biohazards as well as indemnification. Thus, many issues must be considered and addressed in order to establish and operate successfully a biorepository.

Organizational issues in providing high-quality human tissues and clinical information for the support of biomedical research.

Superior-quality human tissues are required to support many types of biomedical research. To be useful optimally in supporting research, not only must these tissues be accurately diagnosed, but also the specific aliquots of tissue supplied to investigators must be accurately described as part of the quality control analysis of the tissue. Tissues should be collected, processed, and stored uniformly. Some tissues are provided to investigators from tissue banks for which tissues have been collected and processed according to standard operating procedures (SOPs) of the tissue bank. Other tissues provided to support research are collected and processed according to SOPs modified to meet investigator needs and requirements, i.e., prospective collection/processing. These different models of tissue collection require different goals, designs, and SOPs. The objectives of tissue repositories also vary based on the types of tissues provided (e.g., fresh tissue aliquots, fixed paraffin-embedded tissue, paraffin tissue sections, etc.) and how the tissues are to be used in research. For example, the potential use of tissues affects the need for extensive annotation of the specimen including both clinical information (e.g., clinical outcomes) and demographics. Specifically, if the tissues are to be used for extraction of proteins or basic studies of disease processes, less clinical information, if any, may be needed than if the tissues are to be used for the correlation of an aspect of the disease process with clinical outcome or response to a specific therapy. In this review, we describe, based on our experience, the major issues that should be addressed in designing and establishing a tissue repository.

Histologic grading of invasive lobular carcinoma: does use of a 2-tiered nuclear grading system improve interobserver variability?

The Nottingham histologic grade (NHG) is a prognostic marker for infiltrating ductal carcinoma. Its usefulness for invasive lobular carcinoma (ILC) has been less clear, given that 2 of the 3 parameters, tubule formation and mitotic activity, show little variation in ILC, placing much of the emphasis on nuclear grade. We have previously reported a trend for improved overall and relapse-free survival in patients with ILC of low nuclear grade, as classified by a 2-tiered nuclear grading system. Given the inherent potential for interobserver variability with any grading system, the goal of this study is to compare interobserver variability in the grading of ILC using a 2-tiered nuclear grade vs the NHG. Thirty-eight cases of ILC were graded independently by 5 pathologists using NHG criteria. Tumors were also categorized by a nuclear grading system as low grade (grade 1 nuclei) or high grade (grades 2-3 nuclei). Pairwise kappa values and interobserver agreement rates were calculated for both NHG and nuclear grade. Results were compared using the paired t test. Mean interobserver agreement rates and kappa values improved with use of the nuclear grading system as compared to NHG (83% vs 70%, 0.4738 vs 0.3228, respectively). The differences between the 2 were statistically significant. Because histologic grade has significant prognostic implications for patients with breast cancer, accurate reporting is paramount. For ILC, where use of the NHG places substantial weight on nuclear pleomorphism, a 2-tiered nuclear grading system may reduce interobserver variability yet still provide useful prognostic information.

Lower risk of cervical intraepithelial neoplasia in women with high plasma folate and sufficient vitamin B12 in the post-folic acid fortification era.

The purpose of this study was to determine the influence of plasma folate and vitamin B12 concentrations on cervical cancer risk in the U.S. after the folic acid fortification era. The study included 376 premenopausal women of childbearing age who tested positive for infections with high-risk (HR) human papillomaviruses (HPVs) and were diagnosed with cervical intraepithelial neoplasia (CIN) grade 2 or higher (CIN 2+, cases) or 19.8 ng/mL) who also had sufficient plasma vitamin B12 (>or=200.6 pg/mL) had 70% lower odds of being diagnosed with CIN 2+ (P = 0.04) when compared with women with plasma folate of

How to efficiently obtain human tissues to support specific biomedical research projects.

The purpose of this article is to facilitate access of biomedical researchers to human tissues by describing the types of tissue resources available to researchers, common problems with tissue requests that may limit tissue availability to specific investigators, and steps that can be taken to simplify requests to avoid these problems and enhance access to tissue. Types of human tissue resources available to investigators are described and reviewed, and the experience of the University of Alabama Tissue Collection and Banking Facility (TCBF) is described. Our experience indicates that typical problems with requests for tissue fall into the following categories: (1) size and number of specimens, (2) type (rarity and availability), (3) time constraints, (4) demand versus supply, (5) limitations and goals of the resource, and (6) time and resources that can be devoted to a specific request. Investigators should review their requests for human tissues to support their research if they are not receiving adequate quantities of tissue. This review is best accomplished by discussing their requests with the tissue resource and correcting specific limitations that block access to the tissues they need.

Using a higher cutoff for the percentage of HER2+ cells decreases interobserver variability in the interpretation of HER2 immunohistochemical analysis.

The effect of using a 30% cutoff for the proportion of HER2+ cells on the interobserver variability in the interpretation of HER2 immunohistochemical results was evaluated. Immunostained sections from 96 cases of breast carcinoma were reviewed by 10 pathologists and scored as positive (3+) when uniform strong membranous staining was identified in at least 10% of tumor cells; the actual percentage of cells with such staining was also estimated. The agreement rates and the kappa values using a 30% cutoff were compared with those using a 10% cutoff. These proved to be higher in 62% and 66% of measurements, respectively, with average interobserver rates and kappa values of 72% and 0.54 using the 30% cutoff and 70% and 0.49 using the 10% cutoff (P=.001 for all comparisons). Using a 30% cutoff for the percentage of HER2+ cells by immunohistochemical analysis modestly decreased interobserver variability in the interpretation of HER2 immunohistochemical results.

Live/real time three-dimensional transthoracic echocardiographic description of chordoma metastatic to the heart.

We describe live/real time three-dimensional transthoracic echocardiographic features of a chordoma metastatic to the heart and correlate its appearance with the surgical pathology.

Mandatory fortification with folic acid in the United States is associated with increased expression of DNA methyltransferase-1 in the cervix.

OBJECTIVE: The objective of this study was to evaluate whether mandatory fortification of grain products with folic acid in the United States is associated with changes in DNA methyltransferase-1 (Dnmt-1) expression in cells involved in cervical carcinogenesis. METHODS: Archived specimens of cervical intraepithelial neoplasia (CIN) diagnosed before (1990-1992) and after (2000-2002) mandatory folic acid fortification were used to examine the expression of Dnmt-1 in specific lesions involved in cervical carcinogenesis by immunohistochemistry. The total number of lesions examined was 101 in the prefortification period and 96 in the postfortification period. Immunohistochemical staining for Dnmt-1, its assessment, and data entry were blinded with regard to the fortification status. RESULTS: Age- and race-adjusted mean percentage of cells positive for Dnmt-1 or the Dnmt-1 score was significantly higher in all lesion types (i.e., normal cervical epithelium, reactive cervical epithelium, metaplastic cervical epithelium, CIN, or carcinoma in situ) detected in the postfortification period compared with the prefortification period (P < 0.05, all comparisons). The degree of Dnmt-1 was significantly higher (P < 0.0001) in CIN > or = 2 lesions compared with CIN < or = 1 lesions, regardless of the fortification group. CONCLUSION: These results suggest that mandatory fortification with folic acid in the United States seems to have resulted in a change in the degree of expression of Dnmt-1 in cells involved in cervical carcinogenesis. Because the approach we have taken to demonstrate these differences have limitations inherent to a study of this nature and this is the first study to report a folate fortification associated change in Dnmt-1, validating these results in other study populations and/or with other techniques of assessing Dnmt-1 will increase the scientific credibility of these findings.

Patterns of global DNA and histone methylation appear to be similar in normal, dysplastic and neoplastic oral epithelium of humans.

Although there is growing interest in the possibility that alterations in histone methylation may play a role in carcinogenesis, it has not been explored adequately in humans. Similarly, there are no reports of associations between this and a similar epigenetic event, DNA methylation. Using immunohistochemical staining, we compared the methylation of DNA and histones in histopathologically normal oral epithelium, dysplastic oral lesions, and squamous cell cancers (SCCs) from subjects with squamous cell cancer (n=48) with those of normal oral epithelium from subjects without oral cancer (n=93) who were matched on age and race. Monoclonal antibodies specific for 5 methyl cytosine (5-mc), lysine 4 of histone H_3 (H_3-Lys4), and lysine 9 of histone H_3 (H_3-Lys9) were used in this study. The percentages of cells positive and a weighted average of the immunostaining intensity scores were calculated for each of these tissues, and Spearman correlation analyses were employed to study associations between DNA and histone methylation. Correlations between DNA and histone methylation, H_3-Lys4 and H_3-Lys9 were positive and statistically significant in all tissue types; they were strongest in normal oral epithelium from non-cancer subjects (r=0.63, p < 0.001 and r=0.62, p < 0.001 respectively). Similarly, the positive correlations between H_3-Lys4 and H_3-Lys9 were statistically significant in all tissue types and strongest in normal oral epithelium from non-cancer subjects (r=0.77, p< 0.001). Patterns of DNA and histone methylation are similar in tissues across the spectrum of oral carcinogenesis, and there is a significant positive association between these two epigenetic mechanisms.

Pattern of nonspecific (or global) DNA methylation in oral carcinogenesis.

BACKGROUND: Although alterations in nonspecific (or global) DNA methylation (GDM) in specific cells are known to be involved in the process of lung carcinogenesis, similar associations have not been evaluated in other smoking-related cancers of the head and neck. METHODS: We evaluated the status of GDM by using monoclonal antibodies specific for 5-methylcytosine (5-mc) in oral squamous cell carcinoma (SCC) specimens of 48 cigarette smokers who had SCC develop and in 93 age-, race-, and sex-matched smokers who did not. RESULTS: Percentages of cells positive for 5-mc immunostaining of DNA of SCC and dysplastic lesions were significantly higher than those of normal oral epithelial cells from cancer subjects and from noncancer subjects. The degree of DNA methylation was unrelated to DNA content. CONCLUSIONS: The pattern of GDM in oral SCCs is different from that of lung SCCs. The differences in nutrient risk factor profiles that are related to GDM and differential activity of DNA methyltranferases between oral and lung SCCs may explain these observations.