5th March 2024

Cancer Biology

Cancer is an all-encompassing condition affecting multiple systems and is typically clonal in origin. Cell division is a tightly controlled process with multiple checkpoints within the cycle to ensure cell division does not progress unchecked. Multiple enzymatic pathways also help with DNA mutation recognition and repair. Errors within any of these pathways can result in the development of tumours. Studies have looked into the features that cancer displays, and the typical hallmarks of cancer are highlighted in the image below.

In essence, somatic cells would need to acquire the ability to bypass the normal cell regulation processes. This will require the cell to acquire multiple specific genetic mutations. Increased cell turnover and genetic instability are common findings in all tumour cells as this encourages the generation of genetic mutations necessary for the tumour cells to bypass standard cell regulations. Environmental factors like diet, smoking, alcohol and sun exposure can increase tumorigenesis risks.

A better understanding of the cancer hallmarks has allowed us to identify the responsible signalling proteins, receptors and enzymes that permit the cancer cell to allow it to escape the usual cell cycle regulations. New treatment options have been developed to target these receptors and proteins, allowing treatment tailored towards the patient’s malignancy.

Novel immunotherapies have been developed to target molecules that drive some of the hallmarks of cancer, including checkpoint inhibition ( allows WCC to target cancer cells that would usually evade the immune system with examples including pembrolizumab), monoclonal Ab targeting specific cell receptors ( e.g., trastuzumab, rituximab), tyrosine kinase inhibitors ( split into EGFR inhibitors, PDGF inhibitors and VEGF inhibitors as examples). While it is important to acknowledge that these treatments are available, the specifics of these treatments are outside the scope of the MRCP part 1 examination.

Image Source: Wikimedia Commons (2021). The Hallmarks of cancer & The Hallmarks of aging, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:The_Hallmarks_of_cancer_%26_The_Hallmarks_of_aging.jpg (Accessed: 5 January 2024).