Mucosite oral em pacientes com câncer de cabeça e pescoço: limitações das escalas de graduação, avaliação da terapia fotodinâmica antimicrobiana no tratamento e associação com microbioma oral

Abstract

Head and neck cancer (HNC) is one of the main causes of morbidity and mortality worldwide. Surgery, radiotherapy (RT) and chemotherapy (CT) are the main treatments used. However, patients undergoing RT and CT may present complications such as oral mucositis (OM). The most recommended therapy for OM is photobiomodulation (PBM-T). There are several scales for grading OM, however they have limitations when applied to patients with HNC. For this reason, a literature review was developed to describe the most used scales and point out the limitations. Microorganisms can aggravate OM healing. Therefore, antimicrobial photodynamic therapy (aPDT) could complement the action of PBM-T. Thus, a comparative study was carried out between the use of PBM-T alone and PBM-T + aPDT in the treatment of OM. RT-induced changes in the oral microbiome and its role in worsening complications such as OM have been described. For this reason, samples from the oral cavity of patients with HNC were collected with a swab before RT (T0), between 12 and 16 Grays (Gy) (T1), between 30 and 36 Gy (T2) and above 60 Gy (T3) for molecular characterization through amplification and sequencing of regions v1-v2 of the 16S rRNA gene. The World Health Organization - WHO, Radiation Therapy Oncology Group - RTOG and National Cancer Institute - NCI scales were the most used and all had limitations mainly associated with the difficulty of differentiating between the signs and symptoms of OM and those of the tumor, such as example dysphagia. The comparative study (isolated PBM-T X PBM-T + aPDT) consisted of 14 patients with oral and oropharyngeal cancer who underwent concomitant RT and CT, with 6 patients in the isolated PBM-T group and 8 in the PBM-T + aPDT group. The mean reduction in OM size in the intervention group was 0.70 cm² (±0.35) and 0.30 cm² (±1.10) in the control group. The mean duration was 18.37 days (±12.12) for the intervention group and 23 days (±14.78) for the control group. The intervention group had an average reduction of 3.40 points on the pain scale (±2.44), while the control group had 0.17 (±2.28). The prospective study that evaluated the oral microbiome (phylum and genus) during RT consisted of 49 patients with HNC. Intriguingly, no difference was observed in the oral microbiome of patients who had OM (n=31) and those who did not (n=18). Interestingly, a decrease in Porphyromonas (p=<0.0001), Prevotella (p=0.010), Fusobacterium (p=<0.0001) was observed at the end of RT (T3), genera associated with cancer. There is no ideal scale for assessing oral mucositis in patients with HNC. Measurement of OM lesions associated with data on pain and duration of OM may be a more effective form of evaluation. The combination of PBMT + aPDT appears to be a promising approach to decontaminate OM lesions. No difference was observed in the oral microbiome of patients with and without OM. Changes in oral microbiome composition were observed during RT.