Cancer chemotherapy and beyond: Current status, drug candidates, associated risks and progress in targeted therapeutics

Abstract

Cancer is an abnormal state of cells where they undergo uncontrolled proliferation and produce aggressive malignancies that causes millions of deaths every year. With the new understanding of the molecular mechanism(s) of disease progression, our knowledge about the disease is snowballing, leading to the evolution of many new therapeutic regimes and their successive trials. In the past few decades, various combinations of therapies have been proposed and are presently employed in the treatment of diverse cancers. Targeted drug therapy, immunotherapy, and personalized medicines are now largely being employed, which were not common a few years back. The field of cancer discoveries and therapeutics are evolving fast as cancer type-specific biomarkers are progressively being identified and several types of cancers are nowadays undergoing systematic therapies, extending patients' disease-free survival thereafter. Although growing evidence shows that a systematic and targeted approach could be the future of cancer medicine, chemotherapy remains a largely opted therapeutic option despite its known side effects on the patient's physical and psychological health. Chemotherapeutic agents/pharmaceuticals served a great purpose over the past few decades and have remained the frontline choice for advanced-stage malignancies where surgery and/or radiation therapy cannot be prescribed due to specific reasons. The present report succinctly reviews the existing and contemporary advancements in chemotherapy and assesses the status of the enrolled drugs/pharmaceuticals; it also comprehensively discusses the emerging role of specific/targeted therapeutic strategies that are presently being employed to achieve better clinical success/survival rate in cancer patients.

Keywords: Antimicrobial peptides; Cancer therapies; Clinical trials; Combination therapy; Immunotherapy; Patient survival; Personalized medicine; Targeted drug delivery.

Figure 1

Schematic diagram showing different intrinsic and extrinsic biological/molecular events potentiating the transformation of a normal cell to the cancer cell, while the lower part of this diagram showing different hallmarks of a transformed cancer cell.

Figure 2

Schematic diagram showing the basic principles of chemotherapy (A), different classes of chemotherapeutic agents/drugs (B), and immunotherapeutic mechanism(s) of targeting cancer cells (C).

Figure 3

Schematic diagram showing targeted cancer therapeutic approaches. (A) Model showing targeted drug delivery approach of anti-cancer drugs/chemical agents conjugated with receptor substrate specific to the cancer cell receptor. (B) Model showing the building of a personalized medicine approach based on omics data and drug response study targeting specific mutation/signature in individual patients for precision cancer therapeutics. (C) Model showing immunotherapeutic regime involving reprogramming of T-cells to target cancer cells by a chimeric antigen receptor for their application in cancer immunotherapy.

Figure 4

Advantages of antimicrobial peptides as anti-tumor agents.