Malignant Transformation of Actinic Cheilitis: A Decade-long Retrospective Study in Southern Brazil

Background Actinic cheilitis (AC), an oral potentially malignant oral disorder (OPMD), predominantly affects fair-skinned individuals, particularly males, with a higher prevalence in their sixth and seventh decades. In the Southeast region of Brazil, oral cancer ranks as the fourth most common tumor among males, with squamous cell carcinoma (SCC) constituting 90% to 95% of lip tumor cases, primarily impacting the lower lip. This retrospective study aims to evaluate the malignant transformation rate in previously diagnosed AC patients between 2008 and 2018, utilizing biopsy records. Material and Methods We retrospectively reviewed medical records of lip lesion patients at the Department of Oral and Maxillofacial Surgery (DOMS) during the stated period, collecting demographic and medical data for analysis. Results Among the 224 analyzed AC cases, 67.8% were male, with an average age of 65 years. Approximately 87.6% of patients reported occupational exposure to AC-associated risk factors. Malignant transformations occurred in 27 patients (12.05%). Conclusions Our study underscores the possible effect of early intervention and preventive measures in stabilizing AC lesions and averting their progression to malignancy. These findings underscore the significance of prompt AC diagnosis and management to mitigate the risk of malignant transformation. Key words:Actinic cheilitis, oral squamous cell carcinoma, malignant transformation.


Introduction
Actinic cheilitis (AC) is a potentially malignant oral disorder that predominantly affects fair-skinned males.It is most prevalent during the sixth and seventh decades of life and is closely associated with occupational risks and exposure to ultraviolet (UV) radiation.AC prima-rily affects the lower lip and is commonly observed in individuals with excessive sunlight exposure, such as fishermen, farmers, and surfers, putting them at risk of progressing to lip cancer (1,2).The main cause of AC is chronic and cumulative exposure to ultraviolet radiation (UV) (3,4).Additionally, it may be linked to immuno- Malignant transformation of actinic cheilitis e667 suppressed patients and individuals with certain genetic susceptibilities (2,5).In the acute form of AC, characteristic symptoms include dryness, edema, redness, which can advance to vesicles, blisters, crusts and ulcerations (6).Removal of the etiological factor leads to a lesion regression.On the other hand, the chronic form presents as an elevated lower lip, often extending to the commissure.These diffuse, asymptomatic lesions cause atrophy of the red lip border, erasing the margin between the red and skin regions of the lower lip.They exhibit color changes with erythroleukoplastic areas, lose elasticity, and may cause erosion in some cases.One common clinical finding in AC is the loss of demarcation between the lip and skin boundaries, which can be mistaken for signs of aging, potentially leading to delayed medical attention (4).Actinic cheilitis can be classified into four grades based on distinct clinical characteristics that complement each other as the condition progresses.Grade I present with dryness, flaking and erythema on the lips.In Grade II, there is vermillion lip atrophy with pale areas and thin surface, and effacement between the mucosa and skin boundary, along with lip swelling.Grade III involves rough and scaly areas on the vermillion lip, hyperkeratotic regions, and some firmness upon palpation.In Grade IV, erosion or ulceration is found in one or more vermilion lip sites, possibly accompanied by leukoplakia in more traumatic areas and a history of cigarette consumption.These lesions indicate an ongoing malignancy process, especially if they are accompanied by firm areas upon palpation (6).The grading system helps healthcare professionals identify the severity of AC, aiding in appropriate management and intervention strategies.Histologically, actinic cheilitis is characterized by epithelial hyperkeratosis, hyperplasia, and/or atrophy.As the condition advances, dysplasia emerges as a significant histological feature.Remarkably, it has been reported that 100% of AC cases exhibit some degree of dysplasia, coupled with solar elastosis, inflammation, and vasodilation (4) .Due to these attributes, AC is classified as an oral potential malignant disorder, marked by unpredictable progression regardless of histological grading (5).Carcinogenesis typically stems from gradual exacerbation of epithelial dysplasia, often perpetuated by continuous exposure to risk factors.The treatment strategy for AC undeniably emphasizes prevention, including measures like wearing wide-brimmed hats, using caps, avoiding sun exposure, employing lip moisturizers with sun protection, and considering ointments with vitamin E. Timely initiation of AC treatment has shown efficacy in stabilizing and even reversing the clinical condition, thereby preventing its malignant evolution.Hence, the primary aim of this study was to assess the rate of malignant transformation of AC within a specia-lized cancer hospital's reference service.The garnered results hold significance in unraveling the epidemiological profile of this lesion and proposing more targeted and effective prevention strategies.

Material and Methods
A retrospective investigation was conducted, and clinical, histopathological, and demographic information were collected.

Discussion
Similar to other Oral Potentially Malignant Disorders (OPMDs), Actinic Cheilitis (AC) exhibits a gradual and unpredictable progression toward malignancy, influenced by various risk factors.The study meticulously tracked patients over a median period of 120 months, revealing an average malignant transformation rate of 12.05%.In comparison to OPMDs like leukoplakia, AC demonstrates a significantly higher likelihood of malignant transformation, emphasizing the critical need for preventive measures and early diagnostic guidance.
Unlike skin cancer, AC displays heightened aggressiveness, characterized by an increased incidence of metastasis.Both conditions share sun exposure as a common risk factor and are also linked to occupational factors.Astonishingly, despite this well-established correlation, a significant 89.8% of patients neglect sun protection, while 87.6% of cases reported engaging in risky occupations.This underestimation of risk, despite its visible nature, fosters disease progression and complicates timely diagnosis.Lip cancer emerges as the most prevalent form of oral cancer, accounting for around 30% of tumors within this region (7).This is closely followed by tongue and floor of the mouth cancers.

Table 1 :
Sample demographic profile and risk factors exposure.
The study population comprised predominantly fair skin individuals, aligning with existing literature findings.Nevertheless, other factors like education proved relevant, with 55.4% of patients having only primary education, highlighting the impact of socio-economic backgrounds.Smoking's influence surfaced in the study, with a preference for the right side among smokers, mirroring prior research.Interestingly, 51.4% of participants were smokers, 67.8% were male, and 5.4% were in their fifth decade of life.These demographics emphasize the alignment of findings with existing literature and indicate the target population for prevention.In Brazil, where agricultural and occupational sun exposure prevails, AC is prevalent among fair-skinned individuals.Early diagnosis holds the key to informed patient guidance and care.Notably, oncological interventions might lead to lasting impairments such as restricted mouth opening, possibly necessitating facial prosthetics for reconstruction. e669