Harnessing blue light photobiomodulation for cancer therapy: Evidence from a systematic review

Cancer is a chronic disease responsible for millions of deaths annually. Its multifaceted profile, with diverse types and anatomical locations, complicates treatment, often limited to surgery, radiotherapy, and chemotherapy. These treatments are frequently associated with increased tumor aggressiveness and recurrence, highlighting the urgent need for new, less invasive therapies. Recent studies suggest that blue light (BL; 450-470 nm) may offer anti-tumor and pro-apoptotic effects, making it a promising alternative for cancer treatment. However, its cellular and molecular mechanisms remain unclear. This qualitative systematic review, conducted in accordance with PRISMA guidelines, analyzed 37 in vitro and in vivo studies published between 2002 and 2024, retrieved from databases including MEDLINE/PubMed, EMBASE, and LILACS, with a focus on the effects of photobiomodulation (PBM) with blue light (450-470 nm) in pre-clinical cancer models. BL demonstrated anti-tumor potential by reducing cell viability, proliferation, migration, and invasion, as well as increasing ROS production and inducing apoptosis. In animal models, BL also inhibited tumor growth, metastasis, and improved survival. Despite the encouraging findings, considerable methodological heterogeneity and insufficient reporting of dosimetric parameters compromise the reproducibility and comparability of results across studies. These findings underscore the therapeutic potential of BL in oncology and highlight the need for standardized protocols to support clinical translation.