Introduction to cancer and treatment approaches

Abstract Cancer is the uncontrolled growth and development of cells in the body, and is one of the foremost reasons of deaths throughout the world. There are over 100 different types of cancers that are categorized on the basis of the affected tissue or organ of the human body. Cancer, a multifactorial malady involves multifarious changes in the genome due to interactions with the individual’s environment. The hallmarks of the cancer are uninhibited replication, inability to respond to growth signals, resulting in arrest of the cell division, continuous angiogenesis, resistance to apoptosis, and the ability to infiltrate other tissues. Currently, cancers can be cured by means of both conventional tonic approaches, i.e., surgery, radiation therapy and chemotherapy, and nonconventional or complementary therapeutic methods, including hormone therapy, immunotherapy, nanotherapy, etc. These well-established therapeutic interventions specifically target the tumors and either inhibit or slow down the growth rate of cells, but incompetent to completely provide protection. Nevertheless, these existing cancer cure practices cause adverse side effects, and largely distress the normal cells, tissues, and organs. Selecting the best cancer therapy approach depends on various factors, such as the type of malignancies, growth stages, age, management frequencies, dosage of medicines, and healthiness of patients. More recently, various molecular-based approaches are being increasingly researched, including gene therapy, targeted silencing by siRNAs, the expression of genes triggering apoptosis and wild tumor suppressors. This chapter discusses about the cancer biology and various conventional and modern treatment approaches to combat diverse forms of cancer.