Vaccinations for Colorectal Cancer: Progress, Strategies, and Novel Adjuvants

Abstract

Although cancer is a leading cause of death, significant breakthroughs have been made in its treatment in recent years. In particular, increasingly effective cancer vaccines are being developed, including some for colorectal cancer. There are also currently a variety of compounds that can act as adjuvants, such as signalling molecules called cytokines. Other adjuvants target and inhibit the specific mechanisms by which cancers evade the immune system. One of them is a galectin inhibitor, which targets galectins—proteins produced by cancer cells that can cause the death of immune cells. Likewise, immune checkpoint inhibitors affect immune checkpoints—natural host proteins that usually control inflammation but can be exploited by cancers to weaken the body’s defences. Equally, regulatory T cells may contribute to the progression of cancer by inhibiting the functions of other T cells. The main advantages of cancer vaccines include their low toxicity and their ability to strengthen the immune system. Nevertheless, significant limitations include their slow effects and their inability to treat cancer at times due to immunosuppression. Ultimately, ongoing trials provide hope for the development of more effective methods of immunotherapeutic inoculation that can target a greater variety of cancers.

IFNγ signaling integrity in colorectal cancer immunity and immunotherapy

“…Additional clinical trials are exploring other combinations. Cancer vaccines may trigger cytotoxic antitumor immune responses to multiple tumor-specific antigens, including neoantigens [ 118 ]. Current clinical trials are testing the combination of cancer vaccines and ICB in colorectal cancer patients (Table 2 ).…”

Colorectal cancer vaccines: The current scenario and future prospects

“…Based on the origin of cancer cells, cancer cell vaccines can be divided into autologous or allogeneic ones. Autologous vaccines are more specific to individuals, while allogeneic ones are more time-saving to produce, so as to benefit large-scale groups ( 39 ). The possibility of immune ignorance is reduced due to the large pool of unknown antigens.…”

Landscape of Immunotherapy Options for Colorectal Cancer: Current Knowledge and Future Perspectives beyond Immune Checkpoint Blockade

“…The survival was longer in the group of patients who received active immunotherapy [130]. Although cancer vaccine TAAs have demonstrated their capacity to strengthen the immune system and presented low toxicities, the evidence showing a reliable survival benefit is limited [131][132][133].…”