Therapeutic laser in breast cancer

Abstract

Introduction: Breast cancer, due to its high incidence, morbidity and mortality pose a serious public health problem. Treatment involves chemotherapy, radiotherapy, surgery and hormone therapy, which are indicated as single or combined. As a result of cancer treatment, several complications have been reported. In this context, physical therapy can greatly influence the prevention, mitigation, treatment and rehabilitation of complications. Numerous physical therapy resources has been used in practice, but there is little scientific evidence about its therapeutic benefits, clinical indications and collateral effects and there are also a concern regarding the use of resources that promote deep heat in body regions with potential secondary implants. Among the physical therapy equipment that theoretically promotes deep heat is low power laser (LLLT). Objective: This paper aims to contribute knowledge of the effects of the laser in patients with a history of breast cancer that may benefit from physical therapy using low-power laser. Methods: In the first article, we performed a systematic literature review on the use of low power laser in the treatment of lymphedema after breast cancer. In the second article, an experimental study was conducted (basic research) using cell line of human breast cancer (MCF-7). Results: In 96-well plates, cells were plated in triplicate per group: Group 0j, negative control group, Group 4J cells radiate with 4 Joules per 20 seconds Group 8J, cells irradiated with 8 joules for 40 seconds, Group 12J, the cells were irradiated with 12 joules for 60 seconds. Conclusion: The low-power laser has been used as a resource in the physical therapy clinical practice, especially in patients with lymphedema secondary to breast cancer. However, there is no current scientific evidence to justify holding the laser at the expense of other features already included in the international literature for the treatment of lymphedema, such as complex physical therapy. Considering the cell viability, our results found no statistically significant difference in the irradiation of the tumor cell line of human breast MCF-7 with low power laser (AlGaInP), suggesting a possible security in the use of this therapeutic approach in patients with breast cancer. Regarding the transepithelial electrical resistance (TEER), we observed a dose-dependent increase in the groups irradiated with LLLT compared to negative control group, ie, the laser could be understood as a protective factor in the occurrence of possible neoplastic disseminations. However, we emphasize that these results only suggest a possible safety in the use of laser in patients with breast cancer.