How Can the Immune System Fight Cancer? – Insights from Dr. Sajjan Rajpurohit

Cancer is a lifestyle-related disease, and in today’s world, a strong immune system is our best defence—not just against infections but also against cancer. In a conversation with Samara Mahindra, Dr. Sajjan Rajpurohit, a leading oncologist, discusses the role of immunity in cancer prevention and treatment.

Why Is Immunity Important in Fighting Cancer?

Dr. Rajpurohit explains,

 “Cancer is multifactorial, and one of the key factors in its development is immune dysregulation. As people age, especially beyond 65, their immunity weakens, making them more susceptible to cancer. A healthy immune system can identify and destroy abnormal cells before they turn cancerous.”

“Immunity is not just about medicines,” says Dr. Rajpurohit. “It’s about lifestyle choices that keep our defence mechanisms strong.”

In other words, our bodies constantly produce abnormal cells, but a well-functioning immune system detects and eliminates them. When immunity is weakened —due to age, stress, poor lifestyle, or medical treatments—these abnormal cells multiply unchecked, leading to cancer. Dr. Rajpurohit further explains that modern lifestyle factors- such as poor diet, sedentary lifestyle and chronic stress directly weaken our immune system, making the body more vulnerable to cancer.

“ We see more cancer cases today not just because of genetics, but because our daily habits disrupt immune balance.”

He says. Processed foods , lack of sleep, and constant exposure to pollution create chronic inflammation, which disturbs immune function and creates an environment where cancer cells can grow.

How Can We Strengthen Our Immune System?

As immunity plays an important role in preventing and fighting cancer, Dr Rajpurohit emphasises a holistic approach: 

• Nutrition – A balanced diet rich in antioxidants, vitamins (like C and D), and minerals supports immune function.
• Exercise – Regular physical activity enhances immune surveillance against cancer cells.
• Stress Management – Chronic stress weakens immunity, so practices like meditation and yoga help.
• Sleep – Quality sleep is essential for immune regeneration.
• Avoiding Toxins – Reducing alcohol, smoking, and processed foods lowers cancer risk.

Immunity in Cancer Treatment

For cancer patients, maintaining a solid immunity is critical—whether undergoing chemotherapy, immunotherapy, or other treatments. Dr. Rajpurohit highlights that supportive care, including proper nutrition and stress reduction, improves treatment outcomes and quality of life.

Samara Mahindra adds,

 “It’s encouraging to see doctors like Dr. Rajpurohit who focus not just on treatment but on the overall well-being of patients.”

A strong immune system is our first line of defence against cancer. By adopting a healthy lifestyle, managing stress, and staying active, we can empower our bodies to fight abnormal cells effectively. As Dr. Rajpurohit says,

“Prevention begins with immunity.”