OncologyDr. Mohit AgarwalCancer Treatment

Principal Director & Unit Head - Medical Oncology, Fortis Hospital, Shalimar Bagh, New Delhi, India

Part 5 of 18 in Cancer: Myths Facts and Advances

What Are the Risk Factors for Cancer Beyond Smoking?

August 7, 2026

Beyond smoking, the major risk factors for cancer include alcohol, certain viruses, obesity, a high-calorie diet and specific lifestyle factors, with each cancer type also carrying its own particular set of risk factors. Because of this variation, cancer is treated as a highly specialised field rather than a single disease.

What Are the Main Modifiable Risk Factors for Cancer?

Dr. Mohit Agarwal of Fortis Hospital, Shalimar Bagh, lists tobacco, alcohol, certain viruses, unhealthy lifestyles, obesity and a high-calorie, restricted diet as major contributors to cancer risk, alongside factors specific to individual cancer types. Addressing these modifiable factors is one of the most practical ways to lower the population-level burden of cancer treatment in India.

Why Is Every Cancer Considered a Different Disease?

Once a cancer diagnosis is made, it should not be treated as a single, uniform disease with a single outcome. Every organ in the body behaves differently in terms of the cancer that develops there, how that cancer behaves, what the likely outcome is, and what treatment approach is required. This is why oncology is organised as a highly specialised field rather than a general one.

How Should Patients Think About Their Personal Cancer Risk?

Rather than assuming cancer is a single, unavoidable fate, patients are encouraged to understand which modifiable risk factors apply to them specifically, since tobacco, alcohol, diet, weight and viral exposure are all factors an individual can influence. This more precise understanding of risk is also the starting point for informed decisions about cancer treatment in India, should it ever be needed.

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This article is based on a Jivo Masterclass session conducted by Dr. Mohit Agarwal, Principal Director and Unit Head, Medical Oncology, Fortis Hospital, Shalimar Bagh, New Delhi, India. The article has been summarised with the assistance of an AI tool from the original masterclass recording. Watch the full Masterclass recording

This guide is based on a live Jivo Masterclass — Dr. Mohit Agarwal taught doctors across Africa on September 7, 2025.

FROM THE LIVE Q&A

JI

Jivo Doctor Partner (name unclear from transcript)

Doctors practising in Africa face the challenge of exact diagnosis in the absence of PET-CT scan machines, which are not available in most countries, forcing guesswork. If the protocol decided in the home country is chemotherapy, what is the difference between chemotherapy administered in a country like Nigeria or Ethiopia compared to an advanced centre like Fortis Shalimar Bagh, and how can that gap be filled?

MA

Dr. Mohit Agarwal

If you don't have a PET-CT, the second-best modality is a CT scan of the probable areas — chest, abdomen, and maybe head and neck depending on the cancer — which will give some answers on staging. As for treatment: chemotherapy is calculated as per the height, weight and profile of the patient, not given as a simple fixed dose. There are specific mixing criteria — it cannot be mixed like an antibiotic — and India has specific mixing units where care is taken over contamination and dosing. Drugs also have to be given over an appropriate infusion time, since infusing over the wrong duration causes more side effects. We also have monitoring systems running during chemotherapy to catch problems early, and targeted therapies and immunotherapies have specific temperature and light-sensitivity handling requirements that are important to follow correctly.

See all 6 questions from this masterclass →

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Frequently Asked Questions

Isn't the next generation sequencing procedure going to take a long time before giving the patient medication? How many days does it take to get the precise DNA gene mutation result and start the exact medication?

Previously it used to take 30 days, and it still does in most institutes, but with the advanced machines we now have, our turnaround time is only about five to six working days — even including a Sunday, a comprehensive NGS report is usually ready by about the seventh day.

Can you give an approximate idea of the cost range for cancer treatment, since doctors often get asked this even before a formal case file is created?

The cost is very different for every cancer and every stage — it can vary from a few thousand rupees to a million rupees. The good news is that targeted therapy and immunotherapy drugs, which used to be very costly, now have more reasonable generic alternatives. For example, a drug that used to cost about $5,000 for a single dose as immunotherapy now costs just around $1,000 for a single dose. We also try to provide assistance programmes through indications approved by the companies that manufacture these drugs, to help patients financially.

Do we have targeted therapy and immunotherapy for all forms of cancer, or only for a few?

It is not available for everyone blanketly — you first need to identify the target on the cell, which is where NGS and special staining come in. Not every individual harbours those targets, but many do, and we then use specific targeted drugs. Immunotherapy is not available for all cancers either, but with present indications it is available for the majority of advanced cancers — about 70% of advanced cancers would be candidates for some form of immunotherapy. There are specific criteria that must be met; giving it without meeting those criteria would not help the patient and would just be a financial waste.

What investigations help us identify targets on cancer cells?

We take a biopsy from the specimen, cut it into sections, make blocks, and apply immunohistochemistry staining, which lets us identify targets on the cells. We then do mutation testing to see what mutations are present in the genes, to identify further targets we can address. We also do PD-L1 testing, which tells us whether the patient can receive immunotherapy. It is a combination of these staining protocols along with NGS that tells us the best way forward for the patient.

Could you elaborate more on the next generation sequencing (NGS) you mentioned?

We take the biopsy specimen and extract the DNA from the cancer cell, then sequence it to identify where something has gone wrong in the DNA or RNA, which tells us why that individual developed the cancer. Through this we identify specific mutations that may be the probable reason. Research is ongoing to counteract every change found on NGS, but currently we have a few drugs available for certain specific mutations — if we find one of those, we give that specific drug and the patient benefits.

What are the major modifiable risk factors for cancer besides smoking?

Alcohol, certain viruses, obesity, a high-calorie diet and specific lifestyle factors, alongside risk factors unique to each particular cancer type.

Why is cancer treated as a specialised field rather than a single disease?

Because every organ behaves differently in terms of the cancer that develops there, how it behaves, its likely outcome and the treatment approach required, so oncology is organised around this variation rather than a general model.

How should someone think about their personal risk of developing cancer?

By identifying which modifiable factors, such as tobacco, alcohol, diet, weight and viral exposure, actually apply to them, since understanding personal risk factors is the starting point for informed decisions about care.

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