Lung cancer remains a significant global health challenge. The high mortality rate is primarily caused by late diagnoses and the limitations of conventional therapies. Photodynamic therapy (PDT), which uses photosensitizing compounds, specific wavelengths of light, and oxygen to generate cytotoxic reactive oxygen species (ROS) that selectively destroy cancer cells, has emerged as a promising, minimally invasive alternative. Despite its advantages, traditional PDT has limitations. These include the limited penetration depth of light and the hypoxic nature of the tumor microenvironment. Nanotechnology has transformed PDT by enabling the precise delivery of photosensitizers, improving their stability, overcoming physiological barriers, and allowing for deeper tissue targeting. This review analyzes the molecular mechanisms of PDT, the evolution of photosensitizer and nanoparticle design, strategies to overcome PDT limitations, and the impact of the tumor microenvironment. Additionally, the potential of combining PDT with other cancer therapies, such as chemotherapy, immunotherapy, targeted therapy, radiotherapy, and gene therapy, is being investigated. While preclinical successes are remarkable, clinical implementation of nanoparticle-based PDT faces complex regulatory pathways, manufacturing scalability challenges, and the need for robust long-term safety data. Integrating artificial intelligence (AI) and biomarker discovery will accelerate the development of personalized treatments and usher in a new era of targeted oncology for lung cancer patients.

Background: Mammary ductal hyperplasia represents a spectrum of benign proliferative breast lesions, some of which pose elevated risks for malignant transformation into ductal carcinoma in situ and invasive breast cancer. This narrative review explores why only specific types, particularly those with atypia, exhibit higher progression potential, synthesizing epidemiologic, histopathologic, molecular, and environmental insights. Methods: We reviewed key literature from databases, including PubMed, focusing on classification, risk stratification, genetic/epigenetic mechanisms, tumor microenvironment dynamics, and modifiable factors influencing progression. Results: Benign breast lesions are categorized into non-proliferative, proliferative without atypia, and proliferative with atypia, such as atypical ductal hyperplasia and atypical lobular hyperplasia. Atypia represents a morphologic continuum toward low-grade ductal carcinoma in situ, driven by genetic alterations, epigenetic reprogramming, and changes in the tumor microenvironment, including stromal remodeling, immune infiltration, hypoxia-induced angiogenesis, and extracellular matrix degradation. Dietary factors, such as high-fat intake and obesity, exacerbate progression through inflammation, insulin resistance, and adipokine imbalance, while environmental toxins, including endocrine disruptors, pesticides, and ionizing radiation, amplify genomic instability. Conclusions: Understanding differential risks and mechanisms underscores the need for stratified surveillance, biomarker-driven interventions, and lifestyle modifications to mitigate progression. Future research should prioritize molecular profiling for personalized prevention in high-risk hyperplasia.

Background: Mammary ductal hyperplasia represents a spectrum of benign proliferative breast lesions, some of which pose elevated risks for malignant transformation into ductal carcinoma in situ and invasive breast cancer. This narrative review explores why only specific types, particularly those with atypia, exhibit higher progression potential, synthesizing epidemiologic, histopathologic, molecular, and environmental insights. Methods: We reviewed key literature from databases, including PubMed, focusing on classification, risk stratification, genetic/epigenetic mechanisms, tumor microenvironment dynamics, and modifiable factors influencing progression. Results: Benign breast lesions are categorized into non-proliferative, proliferative without atypia, and proliferative with atypia, such as atypical ductal hyperplasia and atypical lobular hyperplasia. Atypia represents a morpho-logic continuum toward low-grade ductal carcinoma in situ, driven by genetic alterations, epigenetic reprogramming, and changes in the tumor microenvironment, including stromal remodeling, immune infiltration, hypoxia-induced angiogenesis, and extracellular matrix degradation. Dietary factors, such as high-fat intake and obesity, exacerbate progression through inflammation, insulin resistance, and adipokine imbalance, while environmental toxins, including endocrine disruptors, pesticides, and ionizing radiation, amplify genomic instability. Conclusions: Understanding differential risks and mechanisms underscores the need for stratified surveillance, biomarker-driven interventions, and lifestyle modifications to mitigate progression. Future research should prioritize molecular profiling for personalized prevention in high-risk hyperplasia.