Immunotherapy represents one of the most promising advances in modern cancer treatment. It works not by directly attacking cancer cells with chemicals or radiation, but by strengthening or restoring the body’s natural defense system to recognize and fight cancer cells more effectively [1]. This precision-based approach helps the body build a sustained defense against tumors, offering a new dimension of hope for patients.
Immunotherapy has rapidly evolved to become a cornerstone of oncology, showing success across several cancer types, including melanoma, lung cancer, and many advanced-stage cancers where traditional therapies may have limited efficacy [2].
How the Immune System Works Against Cancer
The human immune system, comprised of specialized white blood cells (like T-cells), antibodies, and lymphatic organs, is designed to constantly monitor the body for infections, viruses, and abnormal cell growth. When it detects an unusual cell, the immune system typically destroys it.
However, cancer cells are deceptive. They can disguise themselves as normal cells or exploit natural “checkpoint” proteins on immune cells to evade detection. These checkpoints act like brakes, preventing the immune system from overreacting and damaging healthy tissue. Unfortunately, cancer cells often press these brakes, allowing them to escape immune attack and multiply [3].
Immunotherapy helps reawaken the immune response by targeting these specific evasion mechanisms.
Key Types of Immunotherapy Treatment
Immunotherapies are categorized based on their mechanism—whether they act directly on the immune system or directly against cancer cells.
1. Immune Checkpoint Inhibitors (ICIs)
These are a revolutionary class of drugs that block the checkpoint proteins (like PD-1, PD-L1, or CTLA-4) that cancer cells use to “turn off” the immune response. By releasing these “brakes,” ICIs enable the T-cells to attack the tumor more vigorously [3]. They are a primary treatment for many advanced solid tumors.
2. Adoptive Cell Therapy (ACT)
This personalized treatment uses a patient’s own immune cells to fight cancer.
- Chimeric Antigen Receptor (CAR) T-cell therapy is the most advanced form. T-cells are harvested from the patient, genetically modified in a laboratory to express receptors that specifically recognize cancer cells, grown in large numbers, and infused back into the patient [4]. ACT has shown remarkable success in certain blood cancers.
3. Monoclonal Antibodies (Therapeutic Antibodies)
These are laboratory-produced molecules programmed to serve as substitute antibodies that restore, enhance, or mimic the immune system’s attack. They perform various roles, such as:
- Flagging cancer cells, making them easily detectable by other immune cells.
- Blocking the connection between a cancer cell and proteins that promote cell growth.
- Delivering chemotherapy or toxins directly to the cancer cell (Antibody-Drug Conjugates).
4. Cancer Treatment Vaccines
These vaccines boost the immune system’s response to existing cancer cells. Unlike preventive vaccines, they contain antigens that teach the immune system to recognize and attack cancer-specific targets. Sipuleucel-T, used for prostate cancer, is a well-known example of a treatment vaccine [5].
5. Cytokines and Other Non-Specific Therapies
- Cytokines (e.g., interleukins and interferons): These are proteins that play important roles in normal immune responses and can be used therapeutically to stimulate the immune system to fight cancer.
- BCG (Bacillus Calmette-Guérin): A weakened form of the bacteria that causes tuberculosis, which is used to treat bladder cancer. When inserted directly into the bladder, it causes a powerful local immune response against cancer cells.
Potential Benefits and Risks of Immunotherapy
Immunotherapy offers unique advantages but also introduces specific side effects that require careful management.
|
Aspect |
Benefits |
Risks (Immune-Related Adverse Events) |
|
Efficacy |
Can lead to durable, long-term responses and immune memory against cancer. |
Autoimmune reactions can occur when the immune system mistakenly attacks healthy tissues (e.g., colitis, pneumonitis, rash, endocrinopathies) [6]. |
|
Tolerability |
Targets cancer cells selectively, often sparing healthy tissue more than chemotherapy. |
Some patients experience fatigue, mild fever, or generalized inflammation. |
|
Application |
Effective even in advanced or recurrent stages of cancer. |
Requires regular monitoring with blood tests and imaging to detect and manage these reactions early with anti-inflammatory medication (like steroids). |
The Immunotherapy Treatment Process
Treatment begins with a detailed diagnosis and evaluation by an oncologist. Biomarker testing plays a vital role because it helps determine which patients are most likely to respond to a specific ICI based on the presence of PD-L1 expression or high tumor mutational burden (TMB) [7].
The medication is typically administered intravenously and given in cycles, allowing the body rest periods to recover. Throughout the process, the oncology team monitors for side effects, measures tumor progress via imaging, and adjusts doses as needed. This monitoring is particularly critical during the first few cycles due to the risk of immune-related adverse events.
Immunotherapy’s Role in Combination Therapy
Immunotherapy often works synergistically when combined with other cancer treatments. For instance, radiation or chemotherapy can help break down tumor cells, effectively exposing hidden cancer markers (antigens). Once exposed, the activated immune system can target these cells more precisely [8]. This combined approach often aims to balance the speed of conventional therapies with the sustainable disease control offered by immune surveillance.
Conclusion
Immunotherapy has fundamentally changed the landscape of cancer care by successfully activating the body’s own powerful defense system. While the therapy is complex and requires specialized management, its potential to induce long-term remissions and improve survival in previously difficult-to-treat cancers is immense. Patients should undergo a detailed consultation with an oncology specialist to determine eligibility, receive necessary biomarker testing, and establish a personalized treatment roadmap.
After understanding immunotherapy, choosing the right cancer care facility is essential. Maharashtra offers several advanced cancer treatment hospitals providing expert oncology care and personalized treatment planning. The table below lists key cancer care hospitals across major cities in the state.
Cancer Care Hospitals in Maharashtra |
Disclaimer
The content of this blog is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. Immunotherapy eligibility and side effect management are complex medical decisions that must be made by a multidisciplinary oncology team.
References
- National Cancer Institute. (2022). Immunotherapy to Treat Cancer. Contextual Link:
- Postow, M. A., Callahan, M. K., & Wolchok, J. D. (2015). Immune checkpoint blockade in cancer therapy. Journal of Clinical Oncology, 33(17), 1974-1982. Contextual Link:
- Pardoll, D. M. (2012). The blockade of immune checkpoints in cancer immunotherapy. Nature Reviews Cancer, 12(4), 252-264. Contextual Link:
- Fesnak, A. D., June, C. H., & Levine, B. L. (2016). Engineered T cells: the promise and challenges of CAR T-cell therapy. Nature Reviews Cancer, 16(9), 566-581. Contextual Link:
- Kantoff, P. W., Higano, C. S., & Shore, N. D. (2010). Sipuleucel-T immunotherapy for castration-resistant prostate cancer. New England Journal of Medicine, 363(5), 411-422. Contextual Link:
- Puzanov, I., Diab, A., & Horvat, S. Z. (2017). Managing toxicities from immune checkpoint inhibitors: consensus recommendations from the Society for Immunotherapy of Cancer (SITC) Toxicity Management Working Group. Journal for Immunotherapy of Cancer, 5(1), 95. Contextual Link:
- Riaz, N., Morris, L., & Havel, J. J. (2017). The role of PD-L1 expression and TMB as predictive factors for response to checkpoint blockade. Nature Medicine, 23(10), 1236-1245. Contextual Link:
- Luke, J. J., & Postow, M. A. (2019). The synergy of radiation and immune checkpoint inhibition. Clinical Cancer Research, 25(11), 3209-3215. Contextual Link:
Frequently Asked Questions (FAQ’S)
Blog- Immunotherapy for Cancer: Harnessing the Body’s Natural Defences
Is Immunotherapy The Same As Chemotherapy?
No, they are fundamentally different. Chemotherapy uses cytotoxic drugs that directly destroy rapidly dividing cells (both cancerous and some healthy ones). Immunotherapy, in contrast, modulates or activates the patient's own immune system to recognize and kill cancer cells. Chemotherapy is a direct attack; immunotherapy is an indirect enhancement of the body's defenses.
Can Immunotherapy Cause Long-Term Side Effects?
Yes. While many side effects are mild and transient, the most significant risk is the development of Immune-Related Adverse Events (irAEs). These occur when the activated immune system mistakenly attacks healthy organs, potentially causing chronic inflammation (e.g., thyroiditis, adrenal insufficiency, or colitis). While most irAEs are managed successfully with steroids, close, long-term follow-up is necessary even after treatment ends to monitor for these conditions.
Does Immunotherapy Work For All Types Of Cancer?
No. Immunotherapy is highly effective in certain cancers (e.g., melanoma, lung, kidney, head/neck cancers), but responses vary significantly. Many tumors are "cold" (non-immunogenic) and do not respond well to current checkpoint inhibitors. This is why biomarker testing is essential; it helps predict the likelihood of a beneficial response before treatment begins.
What Is The "Immune Memory" Benefit Of Immunotherapy?
Immune memory is the ability of the immune system to "remember" an invading pathogen or cancer cell after an initial exposure. Immunotherapy, particularly checkpoint inhibitors, can generate long-lasting T-cells that patrol the body long after the drug is gone. This memory is key to preventing cancer recurrence and is one of the biggest advantages over temporary effects of chemotherapy.
