Current Options for Cancer Treatment

Standard Treatments

Cancer treatment traditionally involves surgery, chemotherapy, and radiotherapy. Despite these options, there remains a question: will a cancer vaccine ever be developed?

The Concept of a Cancer Vaccine

Understanding Vaccines

Vaccines are an effective strategy for preventing infectious diseases. They function by stimulating the immune system to respond to harmful pathogens. This success in infectious disease control has inspired researchers to investigate the potential of vaccines for cancer treatment. The objective is to create vaccines that can guide the immune system to target cancer cells specifically.

Challenges in Cancer Vaccination

For a vaccine to be effective, a robust immune system is crucial. Unfortunately, many cancer patients experience compromised immune defenses due to advanced age and the toll of the disease and its treatment. Consequently, despite over a century of research, cancer vaccines have not met expectations. However, recent advancements in medical research have uncovered insights into the immune challenges faced by cancer patients.

Recent Advances in Cancer Vaccine Development

New Research from Mount Sinai

Researchers at Mount Sinai have developed a novel vaccine and tested its efficacy in lymphoma patients, as reported in *Nature Medicine*. This innovative approach involves injecting the vaccine directly into the tumor-affected areas, aiming to elicit a robust immune response against cancer cells, differing from traditional vaccines that prevent infections.

Mechanism of Action

The cancer vaccine operates through a three-step mechanism:
1. **Injection of Flt3L**: A small molecule called Flt3L is injected into the tumor mass to recruit dendritic cells to the area.
2. **Local Radiotherapy**: This step involves administering local radiotherapy to eliminate cancer cells. The dendritic cells nearby capture and process the dead cancer cells, enabling them to differentiate between cancerous and healthy cells and instruct other immune cells to attack the tumor.
3. **Inclusion of Poly-ICLC**: This component stimulates dendritic cell activity, enhancing the immune response.

Preliminary Studies and Clinical Trials

Animal Studies

Laboratory experiments with mice having lymphoma showed promising outcomes, including tumor regression and increased survival rates. However, tumor growth recurred weeks after treatment due to cancer’s adaptive capabilities. To address this, researchers combined the vaccine with checkpoint blockade therapy, a method currently used for lymphoma treatment. This combination resulted in significantly improved outcomes in mice.

Human Clinical Trials

A clinical trial involving 11 patients with advanced-stage lymphoma assessed the vaccine’s effectiveness. Most participants experienced tumor shrinkage, with some achieving remission lasting several months to years.

Future Directions in Clinical Research

A new clinical trial is in progress to evaluate the vaccine’s effectiveness in conjunction with immunotherapy for treating lymphoma, breast cancer, and head and neck cancer.

References

Butterfield, L. H. (2015). Cancer vaccines. BMJ (Clinical Research Ed.), 350, 1-14.
Mount Sinai researchers develop treatment that turns tumors into cancer vaccine factories. https://www.eurekalert.org/pub_releases/2019-04/tmsh-msr040219.php
Hammerich, L., Marron, T. U., Upadhyay, R., Svensson-Arvelund, J., Dhainaut, M., Hussein, S., Zhan, Y., Ostrowski, D., Yellin, M., Marsh, H., Salazar, A. M., Rahman, A. H., Brown, B. D., Merad, M., & Brody, J. D. (2019). Systemic clinical tumor regressions and potentiation of PD1 blockade with in situ vaccination. Nature Medicine.
Thomas, S., & Prendergast, G. C. (2016). Cancer vaccines: A brief overview. Methods in Molecular Biology, 1403, 755–761.