“Comparative Evaluation of Laser and Surgical Treatment Modalities of Oral Leukoplakia” -A Systematic Review

Abstract

Introduction: 

Oral leukoplakia (OL) is considered a potentially malignant lesion of the oral cavity.

Aim: 

This systematic review aims to evaluate effectiveness of different laser and surgical treatment in management of OL.

Materials and Methods: 

A comprehensive search was done using the MeSH [medical subject headings] terms and keyword search in the electronic databases, namely PubMed and Google Scholar. The search was limited to articles published as full text in English, which were screened by two reviewers for eligibility.

Results: 

The search yielded nine articles out of which seven articles were only included based on the inclusion criteria. The outcome measure evaluated blood loss, pain, malignant transformation, recurrence, healing, scarring, and adverse outcomes.

Conclusion: 

Lasers are more effective in treating OL lesions, but further comparative studies needed to assess their long-term efficacy.

Key Messages:

OL is a potentially malignant disorder of the oral cavity. Main goal is to treat it to prevent it from becoming cancer, and laser has provided a promising new approach for management of OL.

INTRODUCTION

Oral leukoplakia (OL) is the most common life-threatening issue of oral mucosa. Around 16–62% of oral squamous cell carcinoma is associated with OL.[¹] Defined as a white plaque of questionable risk having excluded (other) known diseases or disorders that carry no increased risk for cancer.[²]

Etiology of OL is multifactorial. It is substantially more typical among smokers than among non-smokers. Liquor is believed to be an autonomous chance factor yet authoritative information is yet inadequate_.[³] OL is classified in two main types: homogeneous type which appears as a flat white lesion and non-homogeneous type which includes speckled, nodular, and verrucous leukoplakia.[⁴] Different treatment methods for oral leukoplakia have been accounted, i.e., systemic and topical medications, herbal medications, surgical excision, laser surgery, cryosurgery, photodynamic therapy, and many more.[⁵] The utilization of laser in the treatment of OL has been proposed in light due to its potential hemostatic impact with a bloodless field, decreased postoperative agony, edema and contamination.[⁶]

Till date, no systematic review has been performed with regard to the comparative evaluation between the superiority of lasers over scalpels. Hence, the current systematic review was initiated to assess the effectiveness of laser treatment over scalpel to enlighten an important aspect of clinicians to accomplish a treatment plan with better outcomes based on the given sample size of selected studies.

MATERIALS AND METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach was used, and a search strategy was developed using specific keywords. The population, intervention, comparisons, and outcome (PICO) search strategy was to locate all pertinent articles through the database, PubMed, and Google Scholar.

Study protocol

The current study was performed under PRISMA criteria (http://www.prismastatement.org) and was registered on the PROSPERO on 18/10/2022. The PROSPERO ID 3685605.

Focused question

The review aims to answer the following deterministic question in (PICO) format.

“In patients with OL (P) which treatment modality, laser treatment (I) or traditional scalpel excision (C) shows better outcome (O) in terms of treatment?”

Eligibility criteria

Inclusion criteria:

1. Randomized controlled trials
2. Clinical trial
3. Prospective and comparative studies with laser as intervention and scalpel as control
4. Studies published in the period from the year January 1, 2001 to October 31, 2019
5. English language.

Exclusion criteria:

1. Reviews, observational studies
2. Studies either laser or scalpel
3. Case reports and series
4. Conference proceedings
5. Letters to editor
6. Short communications and in vitro studies.

Data collection process

All reported study results were transformed into standardized extraction forms, and systematically, the required data were collected from each included study [Table 1].

Table 1: Characteristics of studies included in the systematic review

Risk of bias assessment

The assessment of the qualitative analysis was carried out in accordance with Higgins, JPT, Green, S [editors: the Cochrane Handbook for the systematic review of Interventions Versions 5.1,0 (updated October 2022) independently by two reviewers SD and AM]. The disparity during this phase was resolved by consulting an expert.

RESULTS

A total of 30 articles were identified through the electronic database [PubMed (28), Google Scholar (2)]. After screening these studies for titles, 15 studies were excluded. The remaining 15 studies were subjected for duplicate removal. Four articles were duplicates which kept coming in different search strategies. The abstract of the remaining 11 articles was read, and two of them were excluded based on abstract. The remaining nine articles were then read full text, and a final decision was made whether to include the studies. After reading full text, two articles were excluded due to case report. Finally, the remaining seven studies were selected, which met the inclusion criterion [Figure 1].

Figure 1: PRISMA flowchart

Studies analyzing recurrence and malignancy with respect to site showed buccal mucosa to be the most common site of occurrence within a mean follow-up period range 1–151 month [Table 2].

Table 2: Studies analyzing recurrence and malignant transformation with respect to locations

Significant differences (P < 0.05) in the categories of blood loss and bipolar cautery were found. No significant difference in times of excision with CO2 laser fiber (1.64 min/cm²) and the cold knife (1.70 min/cm²).[⁷]

Postoperative pain and swelling were found to be lesser with the CO2 laser treatment during the first 3 days after surgery, (P ≤ 0.05). More pain and swelling were observed in the most extensive lesions.[⁸]

CO2 laser showed better intraoperative hemostasis and reduced scarring (P =0.045) but was more time-consuming (6–10 min). Postoperative pain on the first (P =0.028) and second day (P =.533) was similar in both groups. Facial edema was less in the laser with better healing (P <.05).[⁹]

Accelerate healing process with reduced complications and recurrence using Er: YAG laser was found in a study conducted on two groups comprising verrucous and erosive-ulcerative forms of OL.[¹⁰]

Monteiro L et al.[¹¹] no significant differences found in recurrences following all treatment modalities (P = 0.179). Er: YAG laser had significantly better outcome in treating OL (P = 0.015).

Er: YAG laser was found to be similarly effective as traditional scalpel in terms of healing and recurrences rate in OL.[¹²]

One study observed pain and functional disturbances post-op for first 3 days and first, second, and fourth weeks, respectively. Diode laser found to be effective method over traditional (P = 0.001).[¹³]

Incomplete outcome data, selective reporting, and other bias showed no bias. Blinding of outcome assessment showed more than 50% unclear risk of bias. Random sequence generation, allocation concealment, and blinding of personnel showed 25% high risk of bias [Figure 2 and Graph 1].

Figure 2: Risk of bias summary

Figure

Only seven studies compared the laser and traditional excision for OL treatment, and our analysis found lasers to be effective due to its less postoperative pain, swelling, scarring, and better control on intraoperative hemostasis control.

DISCUSSION

Annual malignant transformation rate of OL is 1%, which includes all types of leukoplakia.[¹⁴] So an early detection and treatment will attempt to prevent formation of secondary oral squamous cell carcinoma.[¹³¹⁴¹⁵]

Laser-assisted ablation is more accurate in treatment of OL with less postoperative discomfort.[¹⁶] Less bleeding, facial edema postoperatively, and less scarring were found using CO2 lasers at continuous wave (5–8 W) focused mode.[⁹] This is due to lasers sealing the lymphatics and blood vessels, minimizing inflammation.[¹⁷] Pain was comparatively lesser in lasers in third and seventh day and first 3 days postoperatively compared to the traditional method, similar to the findings of Mohan R et al.[⁸¹³¹⁸] On contrast, one study found no significant difference in pain level on first- and second-day post-op.[⁹] This can be due to the patient's subjective nature of the pain. Size of lesion also plays a crucial role, Van der Hem et al.[¹⁹] observed higher postoperative pain with size ≥2 cm lesions and recommended multiple sessions of laser vaporization in large lesions.

High-grade dysplasia, non-homogeneous, multiple-focus and previous malignancies relate higher recurrence and malignant transformation.[²⁰] In one study, large size of operated lesions predictive of recurrence in 167 OL are treated with CO2 laser.[²¹] CO2 laser emerged as a promising tool for treatment of widespread dysplastic multiple-focus lesions.[²²] High recurrence seen in verrucous OL patients treated with CO2 laser or Nd:YAG surgery.[²³] 19.5% recurrences related to the grade of dysplasia seen in 123 oral dysplastic lesions.[²⁴]

Few studies report higher recurrences rates in smokers and alcohol consumers.[²⁰²²²⁵] Hence, counseling the patients and periodic follow-up is crucial.

There is no evidence that treatment prevents OL developing into OSCC.[⁴²²²⁴]

A periodic follow-up will be beneficial in terms of dysplastic changes.

CONCLUSION

This systematic review has shown that lasers are effective in treating OL lesions in comparison to the traditional scalpel. Er: YAG laser showed low recurrence with good cutting, coagulation effects, minimal tissue damage, low inflammation, and quick healing.

Overall, a low risk of bias was conducted. However, due to lack of comparative research work with large sample size and longer follow-up, this systematic review does not have any conclusive evidence for the superiority of treatment of between the two modalities. Hence, further research is suggested to evaluate and assess long-term efficacy of laser in the treatment of OL.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.