Recurrence rates after surgical removal of oral leukoplakia-A prospective longitudinal multi-centre study.

Ebba Kjellström,Anikó Kovács,Göran Kjeller,Magdalena Korytowska,Lars Sand,Daniel Giglio,Jonas Sundberg,Jenny Öhman,Bengt Hasséus,Erik Holmberg,Johan Blomgren,Mats Wallström,Jan-Michaél Hirsch,John Bratel

doi:10.1371/journal.pone.0225682

Abstract

Oral leukoplakia (OL) is a potentially malignant oral disorder. The Gold Standard treatment is to remove surgically the OL. Despite optimal surgery, the recurrence rates are estimated to be 30%. The reason for this is unknown. The aim of this study was to investigate the clinical factors that correlate with recurrence after surgical removal of OL. In a prospective study data were collected from 226 patients with OL. Forty-six patients were excluded due to incomplete records or concomitant presence of other oral mucosal diseases. Overall, 180 patients proceeded to analysis (94 women and 86 men; mean age, 62 years; age range, 28-92 years). Clinical data, such as gender, diagnosis (homogeneous/non-homogeneous leukoplakia), location, size, tobacco and alcohol use, verified histopathological diagnosis, and clinical photograph, were obtained. In patients who were eligible for surgery, the OL was surgically removed with a margin. To establish recurrence, a healthy mucosa between the surgery and recurrence had to be confirmed in the records or clinical photographs. Statistical analysis was performed with the level of significance set at P<0.05. Of the 180 patients diagnosed with OL, 57% (N = 103) underwent surgical removal in toto. Recurrence was observed in 43 OL. The cumulative incidence of recurrence of OL was 45% after 4 years and 49% after 5 years. Fifty-six percent (N = 23) of the non-homogeneous type recurred. Among snuff-users 73% (N = 8) cases of OL recurred. A non-homogeneous type of OL and the use of snuff were significantly associated with recurrence after surgical excision (P = 0.021 and P = 0.003, respectively). Recurrence was also significantly associated with cancer transformation (P<0.001). No significant differences were found between recurrence and any of the following: dysplasia, site of lesion, size, multiple vs. solitary OL, gender, age, use of alcohol or smoking. In conclusion, clinical factors that predict recurrence of OL are non-homogeneous type and use of snuff.

Highlights

Oral leukoplakia (OL) is a potentially malignant oral disorder (PMOD) that sometimes transforms into oral squamous cell carcinoma (OSCC)
The present study shows that a high proportion (42%) of OL cases recurred despite complete surgical removal
While this is in line with the results reported by Brouns et al [11], we found higher recurrence rates than those reported by other groups [13, 19, 21]

Summary

Introduction

Oral leukoplakia (OL) is a potentially malignant oral disorder (PMOD) that sometimes transforms into oral squamous cell carcinoma (OSCC). OL, which is defined as “a white plaque of questionable risk, (other) known diseases or disorders that carry no increased risk of cancers having been excluded” [1], is one of the most frequent PMODs seen in the oral cavity. The global prevalence of OL is approximately 2.6% [2]. OL may present as homogeneous or non-homogeneous (Fig 1A and 1B). Homogeneous leukoplakia, which is the most common form, is manifested as a flat and uniform white plaque with a smooth surface and well-defined margins. Non-homogeneous OL appears as a white plaque and areas of erythema accompanied by areas that contain nodules and/or verrucous parts with ill-defined margins [3]

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Conclusion