RESUMO
PURPOSE: To evaluate the effectiveness of photobiomodulation (PBMT) in preventing dysgeusia in breast cancer patients treated with doxorubicin-cyclophosphamide (AC). METHODS: This is a phase II, randomized, triple-blind, placebo-controlled clinical trial involving 112 breast cancer patients treated with AC. The patients were divided equally into two groups: a test group treated with 2 J red laser and 3 J infrared laser on 21 points that were symmetrically distributed on the tongue on day 0 of four cycles of AC, and an equal placebo group treated with simulated PBMT to blind the patient, evaluator, and statistician. The clinicopathological and sociodemographic data, results of taste test, and subjective taste analysis, and the QoL, ECOG performance status, body mass index, and other side effects were recorded. The data were analyzed using ANOVA-RM/Bonferroni, Friedman/Dunn, and chi-square/Fisher's exact tests. RESULTS: PBMT patients showed less objective and subjective taste loss (p<0.05). On the other hand, the placebo group showed a higher ECOG status (p=0.037) and more significant weight loss (p<0.001) after four cycles of AC. The QoL was significantly higher in the PBMT group (p<0.05) at all assessment periods, and PBMT treatment also reduced the incidence of cachexia (p=0.020), anorexia (p<0.001), diarrhea (p=0.040), oral mucositis (p=0.020), and vomiting (p=0.008). CONCLUSION: PBMT reduced the taste loss and improved the overall health status and QoL of patients with breast cancer treated with AC. TRIAL REGISTRATION: Brazilian Clinical Trials Registry ( www.ensaiosclinicos.gov.br ) approval number RBR-9qnm34y, registered on 01/05/2021.