Comprehensive Clinical Guide & Frequently Asked Questions (FAQs)
Medically Reviewed By: Dr. Neeraj Goel, MCh (GI Surgery)
Designation: Director – GI Oncology, GI & HPB Surgery
Hospital: Dharamshila Narayana Superspeciality Hospital, Delhi
Review Date: October 2, 2026
Cancer immunotherapy is a biological cancer treatment that harnesses, enhances, and directs the patient's own immune system to recognize, attack, and eliminate malignant cells. While traditional cytotoxic chemotherapy directly poisons rapidly multiplying cells and radiation damages localized cellular DNA, immunotherapy trains specialized immune effector cells (principally cytotoxic T lymphocytes) to seek out and destroy cancer cells anywhere in the body.
Malignant cells survive and proliferate by exploiting biological 'brakes'—molecular checkpoints—that deceive immune defenses into recognizing tumors as harmless self-tissue. Immunotherapy dismantles these camouflage mechanisms, revitalizing exhausted immune defenses. In modern gastrointestinal, hepatobiliary, and abdominal surgical oncology, immunotherapy has produced remarkable clinical breakthroughs, downstaging locally advanced colon, stomach, esophageal, and liver cancers, achieving durable remission, and in specific molecular subtypes (such as MSI-H/dMMR rectal cancer), completely clearing tumors. Working alongside medical oncologists at Dharamshila Narayana Superspeciality Hospital, Dr. Neeraj Goel integrates precision biomarker-driven immunotherapy with advanced robotic and minimally invasive cancer surgery.
Tumor cells frequently express immunosuppressive surface ligands that bind to receptors on T cells, effectively 'turning off' immune surveillance. Immunotherapy uses humanized monoclonal antibodies and biological agents to block these pathways:
In a healthy individual, the immune system detects mutant cells and destroys them via cancer immunosurveillance. However, as tumors progress, they undergo immune editing: downregulating major histocompatibility complex (MHC-I) molecules to hide from immune detection, recruiting immunosuppressive regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) into the tumor microenvironment, and upregulating PD-L1. Checkpoint inhibitors block these deceptive interactions, restoring natural anti-tumor immunity and establishing durable immune memory.
Unlike chemotherapy, immunotherapy does not cause routine hair loss, severe nausea, or profound bone marrow suppression. However, because it activates the immune system throughout the entire body, it can trigger Immune-Related Adverse Events (irAEs)—inflammation where hyper-stimulated T cells target healthy tissues.
Immunotherapy is selected based on comprehensive molecular and genomic pathology:
Immunotherapy is administered as a gentle intravenous (IV) infusion in specialized outpatient daycare facilities, eliminating overnight hospital stays.
In modern surgical oncology, immunotherapy is transforming resectability and long-term cure rates:
Because immunotherapy relies on an active immune system, overall patient wellness is paramount. Patients are encouraged to maintain balanced nutrition, support a diverse gut microbiome through dietary fiber (as gut microbiota significantly influences immunotherapy efficacy), avoid unnecessary broad-spectrum antibiotics that disrupt gut flora, and carry an 'Immunotherapy Wallet Card' to alert emergency physicians to treat any sudden autoimmune symptoms with corticosteroids.
Dr. Neeraj Goel is an accomplished Senior GI & HPB Surgical Oncologist who combines advanced robotic surgical resections with cutting-edge biomarker-driven systemic therapies. With extensive clinical training across leading international cancer institutes and over two decades of high-volume surgical experience, Dr. Goel works closely with top medical oncologists at Dharamshila Narayana Superspeciality Hospital, Delhi. His focus on comprehensive molecular profiling, organ-preserving oncological surgery, and diligent irAE management ensures patients receive world-class, individualized cancer care.
Chemotherapy uses cytotoxic chemical drugs that directly attack and destroy all rapidly dividing cells in the body, including healthy cells like hair follicles and bone marrow. Immunotherapy, on the other hand, is a biological treatment that does not poison cells directly; instead, it empowers and reactivates the patient's own immune system (especially T cells) to recognize, target, and kill cancer cells. As a result, immunotherapy avoids typical chemotherapy side effects like severe nausea, hair loss, and low blood counts.
Immune checkpoint inhibitors are specialized monoclonal antibodies (such as Pembrolizumab, Nivolumab, and Atezolizumab) that block specific proteins on cancer cells and immune cells, such as PD-1, PD-L1, and CTLA-4. These checkpoint proteins act like molecular 'brakes' that cancer cells exploit to hide from immune attacks. By blocking these brakes, checkpoint inhibitors 'take the handcuffs off' your immune system, allowing your killer T cells to attack the tumor vigorously.
No. Immunotherapy works exceptionally well for certain cancers and molecular profiles, but it is not effective for everyone. It is most effective in tumors that have specific biomarkers, such as Microsatellite Instability-High (MSI-H), Mismatch Repair Deficiency (dMMR), high Tumor Mutational Burden (TMB-High), or elevated PD-L1 expression. Your surgical and medical oncology team will perform genomic testing on your tumor biopsy to confirm whether immunotherapy is the right choice for you.
Immunotherapy is administered as a painless intravenous (IV) infusion through a small cannula in your arm or via an implanted Chemoport. Treatment is conducted in an outpatient daycare suite, taking approximately 30 to 60 minutes per session. You do not need to be admitted overnight and can safely return home and resume your regular daily activities immediately after the infusion.
The treatment frequency depends on the specific medication and protocol, typically scheduled once every 2, 3, 4, or 6 weeks. In early-stage cancers where it is given before or after surgery, the course usually lasts 6 to 12 months. In advanced or metastatic cancer, immunotherapy is often continued for up to 2 years, provided the tumor remains controlled and side effects are manageable.
No. Unlike traditional chemotherapy, immunotherapy rarely causes hair loss (alopecia) or intense nausea and vomiting. Most patients feel energetic and maintain their appetite throughout treatment. The most common mild side effects are mild fatigue, skin rashes, dry skin, or transient flu-like symptoms following the infusion.
Because immunotherapy boosts the immune system, hyperactive immune cells can occasionally mistake healthy tissues for foreign invaders, causing inflammation. These are known as Immune-Related Adverse Events (irAEs). Common examples include inflammation of the colon (colitis, causing diarrhea), lungs (pneumonitis, causing dry cough/breathlessness), liver (hepatitis), thyroid gland (thyroiditis), or skin (rash). Most irAEs are mild, easily monitored, and rapidly reversed with temporary corticosteroid medications when caught early.
Pseudoprogression is a temporary phenomenon where a tumor appears larger or new spots appear on follow-up scans, not because the cancer is growing, but because thousands of active immune cells have rushed into the tumor bed to attack it. Over subsequent scans, this swelling subsides as the tumor shrinks. Oncologists use specialized imaging criteria (iRECIST) to differentiate pseudoprogression from true cancer progression.
Administering immunotherapy before surgery can shrink locally advanced tumors, clear tumor cells from surrounding blood vessels and lymph nodes, and dramatically increase the chances of complete surgical removal (R0 resection). In certain cancers—particularly MSI-H/dMMR rectal or colon cancer—neoadjuvant immunotherapy has proven so powerful that it can completely eradicate the tumor, allowing some patients to avoid radical surgery or permanent stomas altogether.
Yes, combining modalities is standard in modern oncology. Chemotherapy rapidly debulks large tumors and releases cancer antigens into the bloodstream, making it easier for immunotherapy to stimulate immune defenses. Once the tumor has responded, minimally invasive robotic surgery can remove any remaining tumor tissue cleanly, followed by adjuvant immunotherapy to prevent future recurrence.
You must contact your oncology team or visit the emergency department immediately if you experience: severe watery diarrhea (more than 4 to 6 bowel movements a day), severe belly pain with bloody stools, new or worsening shortness of breath or cough, extreme fatigue and dizziness (signs of hormone gland inflammation), yellowing of your eyes or skin (jaundice), or high fever with chills.
Always inform any healthcare provider that you are receiving cancer immunotherapy. You should carry an 'Immunotherapy Wallet Card' detailing your drug, oncologist's contact, and emergency instructions. It is critical that other doctors do not mistake autoimmune side effects (like colitis or pneumonitis) for simple infections, and that systemic corticosteroids are prescribed under the guidance of your oncology team.
