Long-term treatment outcome of oral premalignant lesions
Introduction
The main purpose of identifying oral premalignant lesions is to prevent malignant transformation by initiating adequate intervention. It is widely approved that the oral premalignant lesions, leukoplakia and erythroplakia, show a significant tendency to malignant transformation. For the most common lesion, leukoplakia, the malignant transformation rate has been reported from 0.13% to 17.5%.1 Various treatment modalities for oral leukoplakia have been reported, but there is currently no consensus on the most appropriate treatment.2, 3
The treatment modalities include change of lifestyle factors such as tobacco and alcohol intake,4, 5 medication with retinoids or antimycotics,6, 7, 8 surgical excision,9, 10, 11, 12 cryosurgery,12, 13, 14, 15, 16 laser evaporation17, 18, 19 or laser excision.18, 20, 21, 22 The outcome of these interventions appears to vary, and long-term follow-up studies are few. After surgical intervention, recurrencies and cancer development in areas of excised lesions have been reported in as much as 10–20% and 3–9%, respectively,10, 23, 24 but no randomized clinical trials have been reported so far.25
Moreover, a number of paradigms about premalignant lesions, including factors significant for malignant development, have not been convincingly approved. These factors include clinical type,4, 26, 27, 28, 29, 30, 31, 32 demarcation, size,33, 34 site,27, 35, 36 presence and grade of epithelial dysplasia,4, 11, 27, 37, 38, 39, 40 and smoking.41 Some of the factors have even been questioned in the past. This applies to site, 31 smoking,4, 31, 42, 43 and epithelial dysplasia. 4, 30, 31, 38, 40, 41, 43, 44, 45, 46, 47, 48, 49, 50, 51
To challenge the above paradigms the hypothesis behind the present study was that the outcome after follow-up of oral premalignant lesions is independent of clinical type, demarcation, size, site, histopathology, smoking and surgery.
Therefore, the aim of the present study was to learn the long-term outcome of oral premalignant lesions, including leukoplakia and erythroplakia, after surgical intervention and after follow-up without surgery and to relate the outcome to factors supposed to be significant for malignant development including clinical type, demarcation, size, site, presence of epithelial dysplasia, smoking and surgery.
Section snippets
Lesions
In this retrospective study, a total of 269 lesions comprising 188 (70%) homogenous, 66 (25%) non-homogenous leukoplakias, and 15 (6%) erythroplakias in a total of 236 patients (132 women and 104 men; mean age: 60.8 yrs, range 23–92 yrs), referred between 1977 and 1997, were included. The clinical diagnosis of the lesions was based on the criteria provided by Axéll et al.,52 adjusted to the most recent definition,53 adopted by WHO,54 and histopathological diagnosis of epithelial dysplasia was
Lesions with surgical intervention
The outcome of surgical treatment of the various types of lesions is presented in Figures 5A–C, 6A and B, 7A and 8A. Out of the 94 surgically treated lesions approximately two thirds had a successful treatment outcome characterized by normal mucosa or skin graft (Fig. 8A). The successful outcome was equally distributed among homogenous and non-homogenous leukoplakias, with erythroplakia showing slightly less.
Recurrences occurred in 12 cases (13%) (eight non-homogenous and two homogenous
Discussion
The present study includes two groups of patients with premalignant lesions. One group had surgical intervention whereas the other group had no surgical treatment. The study is not a randomized clinical trial and the two groups under investigation are not directly comparable, because the composition of lesions in the groups is different. Surgically treated lesions comprised 49% non-homogenous leukoplakias in contrast to 12% non-homogenous leukoplakias in the group of non-surgically treated
Acknowledgements
We are most grateful for the contribution of the late Professor J.J. Pindborg and to associate Professor F. Praetorius by making the histopathologic diagnosis of several of the biopsies included in the present study.
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