Oral leukoplakia and its malignant transformation as a diagnostic tool in oral squamous cell carcinoma: A retrospective clinicopathological study

Rohan Sachdev; Kriti Garg; Garima Singh

doi:10.4103/ijohr.ijohr_33_19

ORIGINAL ARTICLE

Year : 2020 | Volume : 6 | Issue : 1 | Page : 16-19

Oral leukoplakia and its malignant transformation as a diagnostic tool in oral squamous cell carcinoma: A retrospective clinicopathological study

Rohan Sachdev¹, Kriti Garg², Garima Singh³
¹ Department of Public Health, UWA School of Population and Global Health, University of Western Australia, Nedlands, Australia
² Department of Oral Medicine and Radiology, Rama Dental College, Kanpur, Uttar Pradesh, India
³ Department of Pedodontics, Rama Dental College, Kanpur, Uttar Pradesh, India

Date of Submission	20-Oct-2019
Date of Acceptance	15-Jan-2020
Date of Web Publication	16-May-2020

Correspondence Address:
Dr. Kriti Garg
117/K-68, Sarvodaya Nagar, Kanpur - 208 025, Uttar Pradesh
India

Source of Support: None, Conflict of Interest: None

Check

DOI: 10.4103/ijohr.ijohr_33_19

Abstract

Context: Oral leukoplakia is considered as potentially malignant disease and oral squamous cell carcinoma is one of the most common cancers in various countries. Aims: The aim of this study is to assess the rate of malignant transformation of oral leukoplakia in the diagnosis of oral squamous cell carcinoma. Settings and Design: A total of 165 patients were included in the study in 2-month duration. Subjects and Methods: Clinically and histopathologically confirmed cases of oral leukoplakia and other premalignant disorders were retrospectively studied. Statistical Analysis Used: Descriptive statistics included calculation of percentages. Data distribution was assessed for normality using Shapiro–Wilk test. Categorical data were compared using Chi-square test. Results: Among 165 cases, 55.46% of males were affected as compared to females and mostly patients of both sexes were of 40–50 years of age. A total of 140 oral leukoplakia cases were present with 59.28% of males and 40.71% of females, whereas only 25 other premalignant cases were reported with 44% of males and 56% of females. 69.28% and 52% of oral leukoplakia and other premalignant cases were involved in buccal mucosa. Histopathological analysis stated that out of 140 oral leukoplakia cases, 39.28% were present with malignant transformation and P value was 0.0007. Conclusions: Malignant changes of oral leukoplakia play an important role in the diagnosis of oral squamous cell carcinoma and males are more at risk to develop malignancy; therefore, close observation, early diagnosis, appropriate treatment plan, and prognosis are required to prevent malignant transformation.

Keywords: Leukoplakia, mucosal lesion, oral mucosa, squamous cell carcinoma

How to cite this article:
Sachdev R, Garg K, Singh G. Oral leukoplakia and its malignant transformation as a diagnostic tool in oral squamous cell carcinoma: A retrospective clinicopathological study. Indian J Oral Health Res 2020;6:16-9

How to cite this URL:
Sachdev R, Garg K, Singh G. Oral leukoplakia and its malignant transformation as a diagnostic tool in oral squamous cell carcinoma: A retrospective clinicopathological study. Indian J Oral Health Res [serial online] 2020 [cited 2023 Sep 25];6:16-9. Available from: https://www.ijohr.org/text.asp?2020/6/1/16/284438

Introduction

In 1978, oral leukoplakia was defined as “a white patch or plaque that cannot be characterized clinically or histopathologically as any other disease and is not associated with any physical or chemical causative agent except the use of tobacco.”^[1] Oral leukoplakia itself is rarely symptomatic and its clinical significance is almost mainly originated from its association with the development of oral squamous cell carcinoma, a disease with high morbidity and mortality.^[2] Oral squamous cell carcinoma (OSCC) is widely accepted as the most common type of head-and-neck cancer, with ~50% survival rate over 5 years.^[3],[4] Oral leukoplakia mostly occurs above the age of 30–40 years and is much more common in smokers than in nonsmokers.^[5] Few oral leukoplakia types are precancerous in nature and the reported increased risk of malignant transformation of oral leukoplakia varies in the numerous studies on this topic and ranges from 4% to 17.5%.^[6],[7] The carcinoma may develop at or near the site of the oral leukoplakia or any mucosal site in the oral cavity.^[8] The purpose of this study is to estimate the demographic prevalence and malignant transformation of oral leukoplakia in the diagnosis of OSCC.

Subjects and Methods

Study design and study population

This institutional, retrospective, clinicopathological study was performed during May to July 2019; data of 165 oral leukoplakia and other premalignant disorders (oral lichen planus, oral submucous fibrosis, and erythroplakia) were collected from the records of histopathological biopsy diagnosis of the department of oral pathology. The study included demographic data of all patients along with site of the lesion, clinical appearance, and histopathological diagnosis. The study protocol was approved by the institutional ethical board. Written informed consent was obtained from all the participants.

Inclusion and exclusion criteria

Patients aged 30–80 years of both sexes with oral leukoplakia and other premalignant disorder symptoms were included in the study. Patients with other oral lesions and systemic conditions were excluded from the study.

Statistical analysis

The data were analyzed using IBM SPSS Statistics-version 21 (IBM Corp., Released 2012. IBM SPSS Statistics for Windows, version 21.0. Armonk, NY: IBM Corp. USA). Descriptive statistics included calculation of percentages. Data distribution was assessed for normality using Shapiro–Wilk test. Categorical data were compared using Chi-square test. All values were considered statistically significant for P < 0.05.

Results

In the present study, 55.46% of males were affected as compared to females and a total of 83 patients of both sexes were of 40–50 years of age [Table 1]. In the present study, 140 oral leukoplakia cases were present with 59.28% of males and 40.71% of females, whereas only 25 other premalignant lesion cases were reported with 44% of males and 56% of females [Table 2]. In [Table 3], the most common site involved was buccal mucosa in 110 cases, followed by tongue 26 and floor of mouth 15 cases. Total 69.28% oral leukoplakia cases were present with buccal mucosa involvement while 52% cases of other premalignant lesions were involving buccal mucosa. Histopathological analysis stated that out of 140 oral leukoplakia cases, 39.28% were present with malignant transformation and the P value was 0.0007, which was found to be statistically significant [Table 4].

Table 1: The demographic data of the study participants

Click here to view

Table 2: The distribution of lesion among both the genders

Click here to view

Table 3: The distribution of lesion according to the site of oral cavity

Click here to view

Table 4: The histopathological distribution of oral leukoplakia and other premalignant disorders

Click here to view

Discussion

Oral leukoplakia is a clinical word that has been usually applied to white lesions in the mouth since it was first reported in the academic literature by Ernő Schwimmer (1837–1898) in 1877.^[2] The prevalence and incidence of oral leukoplakia varied from 0.2% to 4.9%, whereas Petti stated the global prevalence to be 2.6%.^[9],[10] Various studies reported the worldwide predominance of oral leukoplakia in an older age group beyond 40 years.^[11],[12] In the present study, 83 participants were of 40–50 years of age, which was found similar to the review by Petti in 2003, where the most common age considered was fourth to fifth decade followed by seventh decade.^[10] In the present study, 59.28% of males were commonly affected by oral leukoplakia as compared to females (40.71%), which was found to be similar to the study done by Srivastava et al. in 2018, where 24.53% were male patients and 23.6% of females were found to be affected.^[13] A study by Gupta et al. in 1980 stated oral leukoplakia incidence rate of 1.1–2.4/1000 people/year for men and 0.2–1.3/1000 people/year for women, whereas Petti in 2003 showed that the prevalence of males affected is higher (around 2.6%).^[10],[14]

Oral leukoplakia can be present on any surface of the oral cavity, with the most commonly involved locations being the buccal mucosa (21.9%–46%), mandibular alveolus (25.2%–40%), palate (27%), tongue (26%), and floor of mouth (19.3%).^{[2],[6],[7],[15]} The clinical importance of oral leukoplakia is acquired mainly from its indicator as a precursor to OSCC; therefore, in the present study, we tried to evaluate the malignant transformation rate of oral leukoplakia in the diagnosis of OSCC. Various studies stated that 15.8%–48.0% of OSCC patients were associated with oral leukoplakia when diagnosed.^{[16],[17],[18]} In 2003, Petti stated that the annual rate of oral leukoplakia malignant transformation is 1.36% (95% confidence interval: 0.69%–2.03%) in various populations and geographical regions, whereas in 2005, Mishra et al. stated that the risk of developing OSCC at lesion sites is five times higher in patients with oral leukoplakia than in patients without them.^{[10],[12],[19]} Napier and Speight reviewed the clinical predictors of malignant transformation in oral leukoplakia, such as age, gender, and lesion site, but the results from various study populations may vary.^[20] Histopathologically, oral epithelial dysplasia at present is the most important advanced indicator for determining the malignant transformation risk of oral leukoplakia.^[19] Silverman et al. in 1984 and Lee et al. in 2000 described 31.4%–36.3% risk of malignancy for patients with any degree of dysplasia.^{[7],[21],[22]} In 2009, Mehanna et al. in a meta-analysis calculated the overall mean malignant transformation rate of 12.1%.^[23] In the present study, moderate dysplasia was reported in 42.85% of cases, whereas 39.28% were of oral leukoplakia cases with malignant transformation, high degree of chances of transformation into OSCC, which was found similar to other studies. Although Schepman et al. in 1998 stated that malignant transformation is more likely to occur within dysplastic lesions, dysplasia is not a necessary condition and the risk of malignant transformation extends beyond the limits of the identified oral leukoplakia.^[15] Various studies and literature available suggested that oral leukoplakia is not only a premalignant lesion but also an indicator for increased carcinoma risk in the whole oral cavity.^[2]

Conclusions

Oral leukoplakia is a clinical diagnosis relevant to white lesions of the oral cavity that do not have an actual etiology other than tobacco. Chronic lesions present should be biopsied to confirm dysplastic changes within the lesion. Almost 50% of OSCCs are somehow associated with or initiated by oral leukoplakia. Despite the treatment modality, all oral leukoplakia patients and as males are of at higher risk to develop with dysplastic changes, should be counseled to quit the adverse habit and to be watchfully followed with a repeat biopsy protocol to prevent malignant transformation and development of OSCCs.

Acknowledgment

We would like to thank the Department of Oral Pathology for providing all histopathological data related to the study sample.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Kramer IR, Lucas RB, Pindborg JJ, Sobin LH. Definition of leukoplakia and related lesions: An aid to studies on oral precancer. Oral Surg Oral Med Oral Pathol 1978;46:518-39.
2.	Bewley AF, Farwell DG. Oral leukoplakia and oral cavity squamous cell carcinoma. Clin Dermatol 2017;35:461-7.
3.	Parkin DM, Bray F, Ferlay J, Pisani P. Global cancer statistics, 2002. CA Cancer J Clin 2005;55:74-108.
4.	Warnakulasuriya S. Global epidemiology of oral and oropharyngeal cancer. Oral Oncol 2009;45:309-16.
5.	van der Waal I. Oral Leukoplakia: Present views on diagnosis, management, communication with patients, and research. Curr Oral Health Rep 2019;6:9-13.
6.	Saito T, Sugiura C, Hirai A, Notani K, Totsuka Y, Shindoh M, et al. High malignant transformation rate of widespread multiple oral leukoplakias. Oral Dis 1999;5:15-9.
7.	Silverman S Jr., Gorsky M, Lozada F. Oral leukoplakia and malignant transformation. A follow-up study of 257 patients. Cancer 1984;53:563-8.
8.	van der Waal I. Historical perspective and nomenclature of potentially malignant or potentially premalignant oral epithelial lesions with emphasis on leukoplakia-some suggestions for modifications. Oral Surg Oral Med Oral Pathol Oral Radiol 2018;125:577-81.
9.	Mehta FS, Pindborg JJ, Gupta PC, Daftary DK. Epidemiologic and histologic study of oral cancer and leukoplakia among 50,915 villagers in India. Cancer 1969;24:832-49.
10.	Petti S. Pooled estimate of world leukoplakia prevalence: A systematic review. Oral Oncol 2003;39:770-80.
11.	Waldron CA, Shafer WG. Leukoplakia revisited. A clinicopathologic study 3256 oral leukoplakias. Cancer 1975;36:1386-92.
12.	Mishra M, Mohanty J, Sengupta S, Tripathy S. Epidemiological and clinicopathological study of oral leukoplakia. Indian J Dermatol Venereol Leprol 2005;71:161-5. [PUBMED] [Full text]
13.	Srivastava M, Singh V, Roshan R, Taufiq F. Premalignant lesions of oral cavity – A clinicopathological study. Exp Rhinol Otolaryngol 2018;1:1-3.
14.	Gupta PC, Mehta FS, Daftary DK, Pindborg JJ, Bhonsle RB, Jalnawalla PN, et al. Incidence rates of oral cancer and natural history of oral precancerous lesions in a 10-year follow-up study of Indian villagers. Community Dent Oral Epidemiol 1980;8:283-333.
15.	Schepman KP, van der Meij EH, Smeele LE, van der Waal I. Malignant transformation of oral leukoplakia: A follow-up study of a hospital-based population of 166 patients with oral leukoplakia from The Netherlands. Oral Oncol 1998;34:270-5.
16.	Scheifele C, Reichart PA. Oral leukoplakia in manifest squamous epithelial carcinoma. A clinical prospective study of 101 patients. Mund Kiefer Gesichtschir 1998;2:326-30.
17.	Haya-Fernández MC, Bagán JV, Murillo-Cortés J, Poveda-Roda R, Calabuig C. The prevalence of oral leukoplakia in 138 patients with oral squamous cell carcinoma. Oral Dis 2004;10:346-8.
18.	Hogewind WF, van der Waal I, van der Kwast WA, Snow GB. The association of white lesions with oral squamous cell carcinoma. A retrospective study of 212 patients. Int J Oral Maxillofac Surg 1989;18:163-4.
19.	Liu W, Wang YF, Zhou HW, Shi P, Zhou ZT, Tang GY. Malignant transformation of oral leukoplakia: A retrospective cohort study of 218 Chinese patients. BMC Cancer 2010;10:685.
20.	Napier SS, Speight PM. Natural history of potentially malignant oral lesions and conditions: An overview of the literature. J Oral Pathol Med 2008;37:1-0.
21.	Lee JJ, Hong WK, Hittelman WN, Mao L, Lotan R, Shin DM, et al. Predicting cancer development in oral leukoplakia: Ten years of translational research. Clin Cancer Res 2000;6:1702-10.
22.	Schepman K, der Meij E, Smeele L, der Waal I. Concomitant leukoplakia in patients with oral squamous cell carcinoma. Oral Dis 1999;5:206-9.
23.	Mehanna HM, Rattay T, Smith J, McConkey CC. Treatment and follow-up of oral dysplasia – A systematic review and meta-analysis. Head Neck 2009;31:1600-9.