As an oncologist, one of the most exciting and transformative developments in the field of cancer treatment over the past few decades has been the rise of immunotherapy. When at first, the primary options for treating cancer were surgery, chemotherapy, and radiation. While these treatments remain essential, immunotherapy has emerged as a powerful fourth option that is revolutionizing how we approach cancer care.
In this blog, I want to explain how it works, its role in modern cancer treatment, and how it offers hope to patients in ways that were unimaginable a few decades ago. For patients and caregivers, understanding the fundamentals can help you make informed decisions about treatment options and provide a clearer view of what the future of cancer care might look like.
What is Immunotherapy?
Immunotherapy is a type of cancer treatment that harnesses the power of the body’s immune system to fight cancer cells. Unlike chemotherapy or radiation, which directly target cancer cells, it works by strengthening or modifying the immune system so it can recognize and attack cancer cells more effectively.
The immune system is our body’s natural defense against infections, diseases, and abnormal cells. However, cancer cells have a clever way of hiding from the immune system, often by producing proteins that prevent immune cells from recognizing them as threats. Immunotherapy helps by either boosting the immune system’s overall activity or specifically targeting those proteins to unmask the cancer cells, allowing the immune system to destroy them.
Types of Immunotherapy
It comes in several forms, each with its own mechanism for activating the immune system. Here are some of the most common types that I often discuss with my patients:
- Checkpoint Inhibitors: One of the key functions of the immune system is the ability to recognize which cells are healthy and which are harmful. Cancer cells often take advantage of “checkpoints” that regulate immune responses, effectively turning them off. Checkpoint inhibitors are drugs that block these checkpoints, allowing immune cells to attack cancer cells more effectively. Drugs like pembrolizumab and nivolumab are examples of checkpoint inhibitors that are being used in treating various cancers.
- CAR T-cell Therapy: This form of immunotherapy involves collecting a patient’s T-cells (a type of immune cell), genetically modifying them in a lab to better recognize cancer cells, and then reinfusing them into the patient. CAR T-cell therapy has shown remarkable success in treating certain blood cancers like leukemia and lymphoma. However, it is a highly specialized treatment and not yet widely available for all types of cancer.
- Cancer Vaccines: Cancer vaccines work similarly to vaccines for infectious diseases, but instead of preventing illness, they stimulate the immune system to attack existing cancer cells. Unlike traditional vaccines, cancer vaccines are often personalized based on the specific type of cancer and the proteins expressed by cancer cells in a given patient.
- Monoclonal Antibodies: Monoclonal antibodies are lab-made molecules that can attach themselves to specific targets on cancer cells. Once attached, they can recruit immune cells to attack the cancer or block signals that help the cancer cells grow. Some monoclonal antibodies also carry toxins directly to cancer cells, providing a targeted form of chemotherapy.
How Immunotherapy is Changing Cancer Treatment
Immunotherapy has transformed the way we think about cancer treatment. Traditional therapies like chemotherapy and radiation often have significant side effects because they affect both cancerous and healthy cells. Immunotherapy, on the other hand, is generally more targeted, meaning it can offer effective cancer control with fewer side effects in some cases.
What excites me most about immunotherapy is its potential for durable responses. In some cases, patients who have undergone & experience long-term remission, even after treatment has stopped. This is because the immune system, once trained to recognize cancer cells, may continue to patrol the body for these cells long after the treatment ends. In my practice, I have seen patients with advanced cancers, who had few treatment options left, experience remarkable recoveries thanks to immunotherapy.
However, while it holds great promise, it’s important to remember that it is not a miracle cure. Not every patient responds to immunotherapy, and its effectiveness can vary depending on the type of cancer and individual factors like the patient’s immune system. Research is ongoing, and we are learning more every day about how to optimize these treatments and identify the patients who are most likely to benefit.
Who Can Benefit from Immunotherapy?
In my practice, I frequently evaluate patients to see if immunotherapy might be a viable treatment option for them. Currently, immunotherapy has shown the most success in treating cancers like melanoma, non-small cell lung cancer, bladder cancer, and certain types of lymphoma. However, clinical trials are exploring its use in many other types of cancer, and new approvals are being granted regularly.
One of the biggest challenges with immunotherapy is that it doesn’t work for everyone. Some patients’ immune systems do not respond as expected, and we don’t always know why. That’s why testing for certain biomarkers, like PD-L1 expression, is important. These biomarkers can help predict whether a patient is likely to benefit from specific immunotherapies.
Additionally, patients with autoimmune diseases or those who have had organ transplants may not be suitable candidates for immunotherapy due to the risk of overstimulating the immune system. These are conversations I always have with my patients to ensure we are selecting the best and safest treatment options for them.
Managing the Side Effects of Immunotherapy
While immunotherapy tends to have fewer side effects than chemotherapy, it’s not without its risks. Because immunotherapy works by stimulating the immune system, there is the potential for the immune system to attack healthy cells as well. Common side effects include fatigue, skin rashes, and flu-like symptoms, but more serious effects like inflammation of the lungs (pneumonitis), liver (hepatitis), or other organs can occur.
It’s important for patients undergoing immunotherapy to stay in close communication with their healthcare team and report any unusual symptoms. Early intervention can help manage these side effects and prevent more serious complications.
The Future of Immunotherapy
One of the most exciting aspects is its future potential. As research advances, we are likely to see immunotherapy become more personalized, with treatments tailored specifically to each patient’s unique genetic makeup and cancer type. There are also promising developments in combining immunotherapy with other treatments, such as chemotherapy or radiation, to enhance its effectiveness.
In my opinion, the future of cancer treatment lies in a combination of approaches. While it’s a game-changer, it is most effective when used alongside other therapies. Ongoing clinical trials are exploring new combinations and protocols that could further improve outcomes for cancer patients.
Conclusion
Immunotherapy has opened up a new frontier in cancer treatment, offering hope to patients who might not have had viable options in the past. As an oncologist, I find it deeply rewarding to see how immunotherapy can harness the power of the immune system to fight cancer in ways we never thought possible.
For patients and caregivers, understanding how it works and who it can benefit is crucial in making informed treatment decisions. While it’s not a one-size-fits-all solution, immunotherapy is a powerful tool that will undoubtedly continue to shape the future of cancer care.
Tags: Immunotherapy, cancer treatment, modern cancer therapies, immune system and cancer, checkpoint inhibitors, CAR T-cell therapy, monoclonal antibodies, cancer vaccines, side effects of immunotherapy, oncology