Photobiomodulation therapy prevents dysgeusia chemotherapy induced in breast cancer women treated with doxorubicin plus cyclophosphamide: a triple-blinded, randomized, placebo-controlled clinical trial.

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.

TLR4 deficiency upregulates TLR9 expression and enhances irinotecan-related intestinal mucositis and late-onset diarrhoea.

BACKGROUND AND PURPOSE: Severe diarrhoea, a common gastrointestinal manifestation of anticancer treatment with irinotecan, might involve single nucleotide polymorphisms (SNPs) of toll-like receptors (TLRs), described as critical bacterial sensors in the gut. Here, colorectal cancer patients carrying missense TLR4 A896G (rs4986790) or C1,196T (rs4986791) SNPs and Tlr4 knockout (Tlr4-/-) mice were given irinotecan to investigate the severity of the induced diarrhoea. EXPERIMENTAL APPROACH: Forty-six patients treated with irinotecan-based regimens had diarrhoea severity analysed according to TLR4 genotypes. In the experimental setting, wild-type (WT) or Tlr4-/- mice were given irinotecan (45 or 75 mg·kg-1 , i.p.) or saline (3 ml·kg-1 ). Diarrhoea severity was evaluated by measuring intestinal injury and inflammatory markers expression after animals were killed. KEY RESULTS: All patients with TLR4 SNPs chemotherapy-treated presented diarrhoea, whereas gastrointestinal toxicity was observed in 50% of the wild homozygous individuals. Mice injected with irinotecan presented systemic bacterial translocation and increased TLR4 immunostaining in the intestine. In line with the clinical findings, Tlr4 gene deficiency enhanced irinotecan-related diarrhoea and TLR9 expression in mice. An increased myeloperoxidase activity and Il-18 expression along with IL-10 decreased production in Tlr4-/- mice also indicated an intensified intestinal damage and inflammatory response. CONCLUSION AND IMPLICATIONS: TLR4 deficiency upregulates TLR9 expression and enhances intestinal damage and the severity of late-onset diarrhoea during irinotecan-based treatment. Identifying patients genetically predisposed to chemotherapy-associated diarrhoea is a strategy toward precision medicine.