Tumors are genetic disorders as mutation is the etiologic factor that initiates and maintains the neoplastic process. The majority of tumors has a multifactorial inheritance, so inherited genetic predisposition is transformed in manifest disease by cancerigenic exogenous factors. The characteristics of the neoplastic process constitute the targets for older and newer therapeutic interventions. The most recently introduced strategies are the use of monoclonal antibodies and different immune therapy methods, some of which are already part of the clinical practice; however, gene therapy that targets mutation may become in the future the ultimate solution for the treatment of cancer. Due to the recent advances in molecular biology the management of neoplastic disorders is changing. Different molecular mechanisms characterise identical forms of cancer, and the identification of tumor markers with new microarray techniques makes personalised medicine possible by chosing the optimal therapeutic strategy in every patient and form of cancer.