Abstract: Malignant tumors are highly heterogeneous in terms of molecular phenotypes such that personalized therapy will become the standard for tumor therapy. Molecular classifications of cancer based on differences in biological behavior are important for selecting treatment strategies and prognostication. The unique optical and chemical properties of quantum dots have been widely used in biomedical applications such as tumor diagnosis, monitoring, pathogenesis, treatment, molecular pathology, and heterogeneity based on biological markers. In this study, we discuss the application of quantum dot-based nanotechnology and the molecular classification of cancer in personalized oncology.