Shared epigenetic alterations between oral cancer and periodontitis: A preliminary study.

INTRODUCTION: We recently developed a non-invasive sampling procedure for oral squamous cell carcinoma (OSCC) detection based on DNA methylation analysis of a panel of 13 genes. Oral cancer, as well as acute and chronic inflammatory diseases, may influence the methylation level of several genes in the oral cavity. In the present study, we evaluated the presence of periodontal disease (PD) and the methylation status using our 13-gene panel. METHODS: Oral brushing specimens were collected from three different patient groups: 23 gingival OSCC patients, 15 patients affected by PD, and 15 healthy volunteers lacking evidence of PD. DNA methylation analysis was performed and each sample was determined to be positive or negative based on a predefined cut-off value. RESULTS: Positive results were found for 23/23 OSCC patients, 3/15 PD patients, and 0/15 samples from healthy volunteers. The GP1BB and MIR193 genes in the PD group exhibited mean methylation levels similar to OSCC patients. ZAP70 showed different methylation levels among three groups. CONCLUSION: Preliminary data identified shared epigenetic alterations between PD and OSCC patients in two inflammatory genes (GP1BB and MIR193). This study may help to identify potential links between the two diseases and serve as a starting point for the future research focused on pathogenesis.

Patient-reported outcome measures after periodontal surgery.

OBJECTIVES: The present study aimed to explore the impact of different periodontal surgical treatments on the quality of life and postoperative morbidity. MATERIALS AND METHODS: The present study is a single-center, prospective, observational cohort trial. One hundred fifty-five patients, referred to the Periodontal Department of Bologna University who needed periodontal surgical treatment, were recruited. The self-reported perception of the postoperative course was assessed using the following anonymous questionnaires: Italian oral health impact profile (I-OHIP-14), visual analog scale (VAS) to evaluate the intensity of the pain, and 5-point Likert scale. RESULTS: Patients reported a mean OHIP-14 total score of 9.87±8.5 (range 0-42), significantly influenced by the female sex, flap extension, and periodontal dressing. A mean VAS score of 2.96±2.39 (range 0-9) was calculated, and was found to be influenced by the presence of vertical releasing incisions and palatal flap extension. Of the 155 subjects, 40 (25.8%) patients reported bleeding as a post-surgical complication, 96 (61.9%) swelling, 105 (67.7%) eating discomfort, and 44 (28.4%) reported speech discomfort. CONCLUSIONS: Within the limitations of the nature of the present study, periodontal surgical procedures have a low impact on patients' quality of life evaluated through the OHIP-14 and VAS pain questionnaires. CLINICAL RELEVANCE: Periodontal surgical procedures are safe procedures, with a limited duration of postoperative discomfort as well as the incidence of complications.

Anxiety and depression in keratotic oral lichen planus: a multicentric study from the SIPMO.

OBJECTIVES: Oral lichen planus with exclusive keratotic reticular, papular, and/or plaque-like lesions (K-OLP) is a clinical pattern of OLP that may be associated with a complex symptomatology and psychological alteration. The aim of the study was to evaluate the prevalence of anxiety (A) and depression (D) in patients with K-OLP, analyzing the potential predictors which can affect mental health status. METHODS: Three hundred K-OLP patients versus 300 healthy controls (HC) were recruited in 15 Italian universities. The Numeric Rating Scale (NRS), Total Pain Rating Index (T-PRI), and Hamilton Rating Scales for Depression and for Anxiety (HAM-D and HAM-A) were administered. RESULTS: The K-OLP patients showed statistically higher scores in the NRS, T-PRI, HAM-D, and HAM-A compared with the HC (p-value < 0.001**). A and D were found in 158 (52.7%) and 148 (49.3%) K-OLP patients. Strong linear correlations were identified between HAM-A, HAM-D, NRS, T-PRI, and employment status and between HAM-D, HAM-A, NRS, T-PRI, employment status, and female gender. Multivariate logistic regression revealed that HAM-D and HAM-A showed the greatest increase in the R2 value for A and D in the K-OLP patients, respectively (DR2 = 55.5% p-value < 0.001**; DR2 = 56.5% p-value < 0.001**). CONCLUSIONS: The prevalence of A and D is higher in the K-OLP patients compared with the HC, also found in K-OLP subjects without pain, suggesting that the processing of pain may be in a certain way independent of the processing of mood. CLINICAL RELEVANCE: Mood disorders and pain assessment should be carefully performed in relation to K-OLP to obtain a complete analysis of the patients.

Assessment of sleep disturbance in oral lichen planus and validation of PSQI: A case-control multicenter study from the SIPMO (Italian Society of Oral Pathology and Medicine).

BACKGROUND: The wellbeing of oral lichen planus patients (OLPs) may be strongly influenced by a poor quality of sleep (QoS) and psychological impairment. The aims were to analyze the prevalence of sleep disturbance, anxiety, and depression in OLPs and to validate the Pittsburgh Sleep Quality Index (PSQI) in OLPs. METHODS: Three hundred keratotic OLPs (K-OLPs), 300 with predominant non-keratotic OLP (nK-OLPs), and 300 controls were recruited in 15 Italian universities. The PSQI, Epworth Sleepiness Scale (ESS), Hamilton Rating Scales for Depression and Anxiety (HAM-D and HAM-A), Numeric Rating Scale (NRS), and Total Pain Rating Index (T-PRI) were administered. RESULTS: Oral lichen planus patients had statistically higher scores than the controls in the majority of the PSQI sub-items (p-values < 0.001**). Moreover, OLPs had higher scores in the HAM-D, HAM-A, NRS, and T-PRI (p-values < 0.001**). No differences in the PSQI sub-items' scores were found between the K-OLPs and nK-OLPs, although nK-OLPs suffered from higher levels of anxiety, depression, and pain (p-values: HAM-A, 0.007**, HAM-D, 0.009**, NRS, <0.001**, T-PRI, <0.001**). The female gender, anxiety, depression (p-value: 0.007**, 0.001**, 0.020*) and the intensity of pain, anxiety, and depression (p-value: 0.006**, <0.001**, 0.014*) were independent predictors of poor sleep (PSQI > 5) in K-OLPs and nK-OLPs, respectively. The PSQI's validation demonstrated good internal consistency and reliability of both the total and subscale of the PSQI. CONCLUSIONS: The OLPs reported an overall impaired QoS, which seemed to be an independent parameter according to the regression analysis. Hence, clinicians should assess QoS in OLPs and treat sleep disturbances in order to improve OLPs management.

Where do you live? North versus Central-South differences in relation to Italian patients with oral lichen planus: a cross-sectional study from the SIPMO (Italian Society of Oral Pathology and Medicine).

BACKGROUND: Oral lichen planus (OLP) is an immune-mediated inflammatory chronic disease of the oral mucosa, with different patterns of clinical manifestations which range from keratotic manifestations (K-OLP) to predominantly non-keratotic lesions (nK-OLP). The aim of the study was to analyze the differences in the clinical, psychological profile and symptoms between Italian patients of the North and Central-South with K-OLP and nK-OLP. METHODS: 270 K-OLP and 270 nK-OLP patients were recruited in 15 Italian universities. The Numeric Rating Scale (NRS), Total Pain Rating Index (T-PRI), Hamilton Rating Scales for Depression and for Anxiety (HAM-D and HAM-A), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS) were administered. RESULTS: The Central-South K-OLP (CS-K-OLP) patients reported a higher frequency of pain/burning compared with the K-OLP patients of the North (N-K-OLP) with higher scores in the NRS and T-PRI (p value < 0.001**). The CS-K-OLP and the CS-nK-OLP patients showed higher scores in the HAM-D, HAM-A, PSQI and ESS compared with the Northern patients (p value < 0.001**). Multivariate logistic regression revealed that the NRS and T-PRI showed the greatest increase in the R2 value for the CS-K-OLP (DR2 = 9.6%; p value < 0.001**; DR2 = 9.7% p value < 0.001**; respectively) and that the oral symptoms (globus, itching and intraoral foreign body sensation) and PSQI showed the greatest increase in the R2 value for the CS-nK-OLP (DR2 = 5.6%; p value < 0.001**; DR2 = 4.5% p value < 0.001** respectively). CONCLUSIONS: Pain and mood disorders are predominant in patients with OLP in the Central-South of Italy. Clinicians should consider that the geographical living area may explain the differences in oral symptoms and psychological profile in OLP.

Psychological profile and unexpected pain in oral lichen planus: A case-control multicenter SIPMO studya.

OBJECTIVES: To analyze psychological profiles, pain, and oral symptoms in patients with oral lichen planus (OLP). MATERIALS AND METHODS: 300 patients with keratotic OLP (K-OLP; reticular, papular, plaque-like subtypes), 300 patients with predominant non-keratotic OLP (nK-OLP; erythematosus atrophic, erosive, ulcerative, bullous subtypes), and 300 controls were recruited in 15 universities. The number of oral sites involved and oral symptoms were recorded. The Numeric Rating Scale (NRS), Total Pain Rating Index (T-PRI), Hamilton Rating Scales for Depression and for Anxiety (HAM-D and HAM-A), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS) were administered. RESULTS: The OLP patients, especially the nK-OLP, showed higher scores in the NRS, T-PRI, HAM-D, HAM-A and PSQI compared with the controls (p-value < .001** ). A positive correlation between the NRS, T-PRI, HAM-A, HAM-D, and PSQI was found with the number of oral symptoms and number of oral sites involved. Pain was reported in 67.3% of nK-OLP and 49.7% of K-OLP cases with poor correspondence between the site of lesions and the site of the symptoms. CONCLUSIONS: Mood disorders are frequently associated with OLP with an unexpected symptomatology correlated with the number of oral symptoms and with the extension of disease suggesting a peripheral neuropathy.

Pre-Operative Evaluation of DNA Methylation Profile in Oral Squamous Cell Carcinoma Can Predict Tumor Aggressive Potential.

BACKGROUND: Prognosis of oral squamous cell carcinoma (OSCC) is difficult to exactly assess on pre-operative biopsies. Since OSCC DNA methylation profile has proved to be a useful pre-operative diagnostic tool, the aim of the present study was to evaluate the prognostic impact of DNA methylation profile to discriminate OSCC with high and low aggressive potential. METHODS: 36 OSCC cases underwent neoplastic cells collection by gentle brushing of the lesion, before performing a pre-operative biopsy. The CpG islands methylation status of 13 gene (ZAP70, ITGA4, KIF1A, PARP15, EPHX3, NTM, LRRTM1, FLI1, MiR193, LINC00599, MiR296, TERT, GP1BB) was studied by bisulfite Next Generation Sequencing (NGS). A Cox proportional hazards model via likelihood-based component-wise boosting was used to evaluate the prognostic power of the CpG sites. RESULTS: The boosting estimation identified five CpGs with prognostic significance: EPHX3-24, EPHX3-26, ITGA4-3, ITGA4-4, and MiR193-3. The combination of significant CpGs provided promising results for adverse events prediction (Brier score = 0.080, C-index = 0.802 and AUC = 0.850). ITGA4 had a strong prognostic power in patients with early OSCC. CONCLUSIONS: These data confirm that the study of methylation profile provides new insights into the molecular mechanisms of OSCC and can allow a better OSCC prognostic stratification even before surgery.

Intratumoral Heterogeneity in Recurrent Metastatic Squamous Cell Carcinoma of the Oral Cavity: New Perspectives Afforded by Multiregion DNA Sequencing and mtDNA Analysis.

PURPOSE: Improvements in sequencing technologies have shown that genetic differences among neoplastic cells can reflect clonal expansion. Intratumor heterogeneity (ITH) has been suggested to explain differences in prognosis and treatment response, indicating that personalized medicine is the goal of the future. This study evaluated ITH in 5 patients with recurrent metastatic oral squamous cell carcinoma (OSCC) and tracked the evolution from non-neoplastic tissue to neoplastic events developing after primary tumor formation. PATIENTS AND METHODS: Representative regions were macrodissected from specimens obtained from patients with OSCC of the tongue (n = 4) and floor of the mouth (n = 1). ITH and tumor evolution were explored by analyzing DNA mutations disclosed by next-generation sequencing of specific driver genes combined with changes in the mtDNA D-loop hypervariable region. Phylogenetic trees were generated employing MAFFT tool with UPGMA/Jukes-Cantor serving as the substitute model. RESULTS: High levels of heterogeneity were observed within and among tumors. ITH emerged as metastatic and recurrent events progressed, but the evolutionary patterns differed. In some patients, specific subclones persisted during tumor relapse. Neighboring tissue also was heterogeneous at the premalignant level. CONCLUSIONS: A multiregion approach yielded more representative data than did single samples when tumors were subjected to molecular investigation. Persistent mutations that might be targeted by individualized medicine were thus exposed. Mitochondrial DNA is a useful adjunct tool when studying the phylogenetic evolution of subclones. The clinical implications of "field" heterogeneity should be studied in depth.

A Noninvasive Test for MicroRNA Expression in Oral Squamous Cell Carcinoma.

MicroRNAs have recently been proposed as non-invasive biomarkers in Oral Squamous Cell Carcinoma (OSCC). The aim of this study was to analyze the expression of a panel of miRNAs in epithelial cells collected by oral brushing from OSCCs from regenerative areas after OSCC surgical resection and from their respective normal distant mucosa. Oral brushing specimens were collected from 24 healthy donors, 14 OSCC patients with specimens from tumour and normal distant mucosa, and from 13 patients who had OSCC resection, with samples from regenerative areas after OSCC resection and normal distant mucosa. Expression levels of eight targets (miR-21, miR-375, miR-345, miR-181b, miR-146a, miR-649, miR-518b, and miR-191) were evaluated by real-time Polymerase Chain Reaction (PCR). A highly significant between-group difference was found for miR-21 (F = 6.58, p < 0.001), miR-146a (F = 6.974, p < 0.001), and miR-191 (F = 17.07, p < 0.001). The major difference was observed between samples from healthy donors and from OSCC brushing, whereas no significant differences were observed between areas infiltrated by OSCC and their respective normal distant mucosa. Furthermore, altered expression of miR-146a and miR-191 was also observed in regenerative areas after OSCC resection. CONCLUSIONS: Oral brushing could be proposed as a noninvasive method to study microRNA expression in oral mucosa in OSCC patients.

Topical applications of heterologous platelet rich plasma (PRP) for refractory gingival lesions in autoimmune blistering diseases.

BACKGROUND: Recalcitrant gingival erosions, blisters and desquamative gingivitis are common features in oral autoimmune blistering diseases (AIBD). First line treatments include high-dosage corticosteroids and other immunosuppressive drugs, with several side effects and elevated number of recurrences. Autologous platelet-rich plasma (PRP) has been recently introduced as an alternative treatment and its use seems to be promising and safe. METHODS: In this study we describe the use of topical application of heterologous PRP in nine patients affected by mucous membrane pemphigoid, with gingival lesions refractory to previous treatments. Topical applications of PRP were performed once a week for 2 months and the endpoint for clinical evaluation was set 3 months after the last session. Oral disease severity score (ODSS) and VAS scores for pain measurement were recorded before and after treatment. RESULTS: The procedure was painless, well accepted, and free from adverse reactions. All patients (100%) reported a reduction in VAS whereas reduction in ODSS was observed in 89% of patients. CONCLUSIONS: Within the limits of the study, topical heterologous PRP is a safe and promising procedure to be studied in future controlled randomized trials as adjuvant treatment for refractory gingival lesions in patients with AIBDs.

Thirteen-gene DNA methylation analysis of oral brushing samples: A potential surveillance tool for periodic monitoring of treated patients with oral cancer.

BACKGROUND: We evaluated the prognostic role of 13-gene DNA methylation analysis by oral brushing repeatedly performed during the follow-up of patients surgically treated for oral cancer. METHODS: This is a nested case-control study including 61 patients for a total of 64 outcomes (2/61 patients experienced multiple relapses). Samples were collected at baseline (4-10 months after OSCC resection) and repeatedly every 4-10 months until relapse or death. DNA methylation scores were classified as persistently positive, persistently negative, or mixed. RESULTS: Twenty cases who had persistently positive scores and 30 cases with mixed scores had, respectively, an almost 42-fold (p < 0.001) and 32-fold (p = 0.006) higher likelihood of relapse, compared to 14 patients with persistently negative scores. The last score before reoccurrence was positive in 18/19 secondary events. CONCLUSIONS: The 13-gene DNA methylation analysis may be considered for the surveillance of patients treated for oral carcinoma.

Pre-operative incisional biopsy of oral squamous cell carcinoma: high podoplanin expression is related to perineural invasion and may be a useful predictor of disease progression.

OBJECTIVE: Immunohistochemical analysis of podoplanin expression as a pre-operative molecular marker for perineural invasion (PNI) may represent an attractive strategy for surgical management of oral squamous cell cancer (OSCC). We evaluated the relationship between podoplanin expression and PNI in pre-operative incisional biopsies of OSCC. STUDY DESIGN: After performing pathological staging and histologic and immunohistochemical evaluation of 83 surgical specimens, we performed multivariable logistic regression analysis to examine the relationship between PNI and independent variables. To evaluate the utility of podoplanin immunopositivity for discrimination of PNI status pre-operatively, we calculated the sensitivity, specificity, positive predictive value, and negative predictive value. We performed receiver operating characteristic curve analysis to evaluate the diagnostic accuracy of podoplanin immunopositivity for predicting PNI alone and in combination with age, T stage, N stage, and index site. RESULTS: We observed podoplanin expression in 42 (50.6%) of all the 83 pre-operative incisional biopsies and 29 of the pre-operative biopsies of the 31 (93.5%) postoperative specimens with PNI. The rate of podoplanin expression was significantly higher in patients with pT3 to pT4 stage and pN+ stage disease. Podoplanin positivity in the pre-operative biopsy showed high sensitivity in predicting PNI in the surgical specimen. CONCLUSION: Podoplanin expression appears to be an independent pre-operative variable significantly related to PNI and a possibly valuable prognostic marker for therapeutical planning and surgical treatment of OSCC.

Direct healthcare costs of oral cancer: A retrospective study from a tertiary care center.

The aim of this study was to retrospectively evaluate the direct costs of OSCC treatment and postsurgical surveillance in a tertiary hospital in northeast Italy. Sixty-three consecutive patients surgically treated for primitive OSCC at S. Orsola Hospital in Bologna (Italy) between January 2018 and January 2020 were analyzed. Billing records of the Emilia Romagna healthcare system and institutional costs were used to derive specific costs for the following clinical categories: operating theatre costs, intensive and ordinary hospitalization, radiotherapy, chemotherapy, postsurgical complications, visits, and examinations during the follow-up period. The study population comprised 17 OSCC patients classified at stage I, 14 at stage II, eight at stage III, and 24 at stage IV. The estimated mean total direct cost for OSCC treatment and postsurgical surveillance was €26 338.48 per patient (stage I: €10 733, stage II: €19 642.9, stage III: €30 361.4, stage IV: €39 957.2). An advanced diagnosis (stages III and IV), complex surgical procedure, and loco-regional recurrences resulted in variables that were significantly associated with a higher cost of OSCC treatment and postsurgical surveillance. Redirection of funds used for OSCC treatment to screening measures may be an effective strategy to improve overall health outcomes and optimize national health resources.

Surgical management of gingival recessions in patients with refractory gingival pemphigus vulgaris: A multidisciplinary challenge.

BACKGROUND: Mucogingival surgery for root coverage of gingival recessions (GRs) is usually performed in patients with unremarkable periodontal and systemic health. However, the predictable results of surgical procedures and increasingly high aesthetic expectations of patients necessitate optimal management of GR also in patients with systemic conditions that affect the oral cavity. In patients with pemphigus vulgaris (PV), mucosal fragility and complicated surgical management of inflamed soft tissues are major challenges. METHODS AND RESULTS: A 36-year-old female patient with PV and deep GR on the mandibular incisors is presented. After initial unresponsiveness to steroids and immunosuppressants, complete clinical remission was achieved through repeated rituximab infusions and topical platelet-rich plasma. After > 1 year of stable clinical remission off therapy the patient successfully underwent surgical procedures for vertically coronally advanced flap with connective tissue graft. CONCLUSIONS: To the best of our knowledge, no studies have described the surgical management of GR in PV patients. Although controlled studies are required to confirm present results, complete and stable clinical remission is necessary to avoid complications. Collaboration among dermatologists, oral medicine specialists, and periodontologists is essential to determine whether mucogingival surgery for root surface exposure is indicated for PV patients. KEY POINTS: Why are these cases new information? This is the first report of root coverage in a patient with oral PV What are the keys to the successful management of these cases? The achievement of complete and stable clinical remission from oral PV Multidisciplinary collaboration among dermatologists, oral medicine specialists, and periodontologists What are the primary limitations to success in these cases? The refractoriness of gingival lesions induced by PV Poor mucogingival conditions of inflamed gingival tissues exacerbated by PV.

Histological and immunohistochemical evaluation of new epithelium after removal of oral leukoplakia with Nd:YAG laser treatment.

Laser excision has been used with increasing success to treat oral leukoplakia. The aim of the present study was to evaluate whether clinical healing of a leukoplakia after laser surgery is associated with a normal functional status of the new epithelium and whether pathological alterations in these parameters are related to the risk of local recurrence. The study population consisted of 13 consecutive patients with oral leukoplakia in which clinical healing was achieved after laser therapy using an Nd:YAG laser (Model 6000, Laser Sonics, Cooper Laser Sonics). At the end of the therapy, all patients underwent a second biopsy of the clinically healthy tissue. Epithelial cell turnover was evaluated before and after laser surgery by Ki67 protein expression, and positive staining of more than 20% was considered abnormal. All patients were followed on a monthly basis. Eight patients had abnormally high Ki67 values before laser therapy (mean 27.4 ± 6.2%), but the levels decreased significantly after treatment (17.6 ± 8.5%; t = 2.6, p < 0.05). High Ki67 values persisted in three patients, and local recurrences in the new epithelium was observed in two of these patients. Kaplan-Meier statistics showed that the between-group difference was statistically significant (Chi square 7.3; p < 0.01). In conclusion, this is the first prospective study to show that clinical healing of leukoplakia treated by laser surgery may be accompanied by altered cell turnover in 20% of the cases. Ki67, as a marker of proliferative status, may be a prognostic indicator in the mucosa replacing the lesion.

A 13-Gene DNA Methylation Analysis Using Oral Brushing Specimens as an Indicator of Oral Cancer Risk: A Descriptive Case Report.

Analysis of genetic or epigenetic markers from saliva or brushing specimens has been proposed as a diagnostic aid to identify patients at risk of developing oral cancer. However, no reliable non-invasive molecular method for this purpose is commercially available. In the present report, we describe the potential application of a procedure based on a 13-gene DNA methylation analysis using oral brushing samples from a patient affected by oral leukoplakia who developed two metachronous oral carcinomas during the follow-up period. A positive or a negative score was calculated for each brushing sample based on a predefined cut-off value. In this patient, a positive score was detected in the oral leukoplakia diagnosed more than 2 years before the development of oral squamous cell carcinoma and subsequently in clinically healthy mucosa 8 months before the appearance of a secondary tumor. This suggests a potential role of our procedure as an indicator of oral cancer risk.

Cancerization of cutaneous flap reconstruction for oral squamous cell carcinoma: report of three cases studied with the mtDNA D-loop sequence analysis.

AIMS: Tissue defects, resulting from surgical resection of oral squamous cell carcinoma (OSCC), are reconstructed routinely with skin grafts. OSCC arising from the grafted skin has been described; however, it is still unclear whether primary and second tumours have a common clonal origin. The aim of this study was to evaluate the clonal relationship between the primary OSCC and secondary neoplastic changes appearing in the skin graft in three patients, by screening the mitochondrial DNA D-loop region (mtDNA). METHODS AND RESULTS: In all three cases, the neoplastic lesions arising in the skin graft showed a clonal relationship with the previous OSCC and, on the basis of the results obtained by mtDNA analysis, could be considered to be a recurrence of the primary OSCC rather than a second primary OSCC. CONCLUSIONS: Starting from a field of genetically altered cells in the oral mucosa, the spread of the clonal cell population to the cutaneous flap might be stimulated by cytokines produced by the grafted skin. More studies are needed to evaluate the molecular relationship between primary and second OSCC to identify patients at higher risk of developing a second tumour in the skin graft.

Ki-67 from clinically and histologically "normal" distant mucosa as prognostic marker in early-stage (T1-T2N0) oral squamous cell carcinoma: a prospective study.

PURPOSE: The aggressive behavior and long-term prognosis of oral squamous cell carcinoma (OSCC) have recently been related to the mucosa surrounding the primary mass, consisting of genetically altered cells that might be responsible for cancer progression. Early-stage T1-T2N0 OSCCs have been associated with a good prognosis; however, a certain percentage of them can be complicated by locoregional metastases. The purpose of our study was to determine whether an abnormal proliferative status can be found in clinically and histologically "normal" mucosa situated in areas distant from the primary tumor. We also sought to determine whether this is associated with a poor prognosis in terms of local recurrence or lymph node metastasis. PATIENTS AND METHODS: The prospective study included 42 consecutive patients with T1N0M0 (n = 19) and T2N0M0 (n = 23) OSCC. Disease-free survival endpoints were defined as the duration between surgical resection and the diagnosis of recurrence, lymph node metastasis, or last follow-up visit. Proliferative status in distant areas (opposite cheek) was evaluated by Ki-67 expression. RESULTS: The mean Ki-67 value (17.6% ± 8.2%) in the distant mucosa was significantly greater (F = 13.87; P < .01) than that found in the controls (9.8 ± 3.1). "Abnormally high" Ki-67 values were detected in 13 patients with OSCC (30%). Four patients developed locoregional recurrence during follow-up. Kaplan-Meier analysis showed that Ki-67 in the distant mucosa was a significant independent prognostic factor for disease-free survival. CONCLUSIONS: A certain percentage of patients surgically treated for early T1-T2 OSCC will have an abnormal proliferative status in areas very distant from the primary tumor that seems to be related to a poor prognosis.