cDNA microarray analysis of human keratinocytes cells of patients submitted to chemoradiotherapy and oral photobiomodulation therapy: pilot study.

Oral mucositis is an acute toxicity that occurs in patients submitted to chemoradiotherapy to treat head and neck squamous cell carcinoma. In this study, we evaluated differences in gene expression in the keratinocytes of the oral mucosa of patients treated with photobiomodulation therapy and tried to associate the molecular mechanisms with clinical findings. From June 2009 to December 2010, 27 patients were included in a randomized double-blind pilot study. Buccal smears from 13 patients were obtained at days 1 and 10 of chemoradiotherapy, and overall gene expression of samples from both dates were analyzed by complementary DNA (cDNA) microarray. In addition, samples from other 14 patients were also collected at D1 and D10 of chemoradiotherapy for subsequent validation of cDNA microarray findings by qPCR. The expression array analysis identified 105 upregulated and 60 downregulated genes in our post-treatment samples when compared with controls. Among the upregulated genes with the highest fold change, it was interesting to observe the presence of genes related to keratinocyte differentiation. Among downregulated genes were observed genes related to cytotoxicity and immune response. The results indicate that genes known to be induced during differentiation of human epidermal keratinocytes were upregulated while genes associated with cytotoxicity and immune response were downregulated in the laser group. These results support previous clinical findings indicating that the lower incidence of oral mucositis associated with photobiomodulation therapy might be correlated to the activation of genes involved in keratinocyte differentiation.

Cost-effectiveness of low-level laser therapy (LLLT) in head and neck cancer patients receiving concurrent chemoradiation.

BACKGROUND: Oral mucositis is a major event increasing treatment costs of head and neck squamous cell carcinoma (HNSCC) patients treated with chemoradiation (CRT). This study was designed to estimate the cost-effectiveness of low-level laser therapy (LLLT) to prevent oral mucositis in HNSCC patients receiving CRT. METHODS: From June 2007 to December 2010, 94 patients with HNSCC of nasopharynx, oropharynx, and hypopharynx entered a prospective, randomized, double blind, placebo-controlled, phase III trial. CRT consisted of conventional radiotherapy (RT: 70.2 Gy, 1.8 Gy/d, 5 times/wk)+concurrent cisplatin (100mg/m2) every 3 weeks. An InGaAlP (660 nm-100 mW-4J/cm2) laser diode was used for LLLT. RESULTS: From the perspective of Brazil's public health care system (SUS), total costs were higher in Placebo Group (PG) than Laser Group (LG) for opioid use (LG=US$ 9.08, PG=US$ 44.28), gastrostomy feeding (LG=US$ 50.50, PG=US$ 129.86), and hospitalization (PG=US$ 77.03). In LG, the cost was higher for laser therapy only (US$ 1880.57). The total incremental cost associated with the use of LLLT was US$ 1689.00 per patient. The incremental cost-effectiveness ratio (ICER) was US$ 4961.37 per grade 3-4 OM case prevented compared to no treatment. CONCLUSIONS: Our results indicate that morbidity was lower in the Laser Group and that LLLT was more cost-effective than placebo up to a threshold of at least US$ 5000 per mucositis case prevented. CLINICAL TRIAL INFORMATION: NCT01439724.

Phase III trial of low-level laser therapy to prevent oral mucositis in head and neck cancer patients treated with concurrent chemoradiation.

BACKGROUND: Oral mucositis (OM) is a complication of chemoradiotherapy treatment of head and neck squamous cell carcinoma (HNSCC) patients with no effective therapy. This study was designed to assess the efficacy of preventive low-level laser therapy (LLLT) in reducing the incidence of grade 3-4 OM. MATERIAL AND METHODS: From June 2007 to December 2010, 94 HNSCC patients entered a prospective, randomized, double-blind, placebo-controlled phase III trial. Chemoradiotherapy consisted of conventional radiotherapy plus concurrent cisplatin every 3weeks. A diode InGaAlP (660nm-100mW-1J-4J/cm(2)) was used. OM evaluation was performed by WHO and OMAS scales and quality of life by EORTC questionnaires (QLQ). RESULTS: A six-fold decrease in the incidence of grades 3-4 OM was detected in the LLLT group compared to the placebo; (6.4% versus 40.5%). LLLT impacted the incidence of grades 3-4 OM to a relative risk ratio of 0.158 (CI 95% 0.050-0.498). After treatment QLQ-C30 showed, differences favoring LLLT in physical, emotional functioning, fatigue, and pain; while the QLQ-H&N35 showed improvements in LLLT arm for pain, swallowing, and trouble with social eating. CONCLUSION: Preventive LLLT in HNSCC patients receiving chemoradiotherapy is an effective tool for reducing the incidence of grade 3-4 OM. Efficacy data were corroborated by improvements seen in quality of life.