Figure 1.

Global statistics, survival rate, and pathophysiological features of oral squamous cell carcinoma (OSCC). Top left: countries with higher cases of OSCC diagnosed around the world. Top right: the main risk factors involved in OSCC development and progression. Bottom left: chances of survival 5 years after being diagnosed with OSCC. Note that early diagnosis of OSCC is crucial to ensure over 80% survival chance after 5 years. The general statistics show a 50% survival rate after 5 years, given that OSCC is usually diagnosed late. Bottom right: development of OSCC from a normal oral epithelium. The normal epithelium, composed of epithelial cells known as keratinocytes, is located over a basement membrane that separates the epithelium from the connective tissue composed of fibroblasts, immune cells and vessels. Exposure to carcinogens derived from the risk factors of the top right panel generate a potentially malignant lesion, characterized by an altered cellular morphology that starts affecting the inner layers of the epithelium close to the basement membrane, progressing toward the outer layers of the epithelium. Continuous exposure to carcinogens leads to OSCC development, a phenomenon that alters all the epithelial cell layers both genetically and morphologically. Interplay between connective tissue cells and OSCC cells is also observed, which assists OSCC growth and metastasis.