Cancer Myths, Facts and Advances

The cancer myths and facts that matter most come down to four points. A healthy life lowers the risk of cancer but does not remove it. Only about 5 to 10 per cent of cancers are carried in the genes. Smoking is the most important modifiable cause. And cancer is not a death sentence: treated properly, outcomes are good, especially in stages one to three.

That is the case made by Dr. Mohit Agarwal, Principal Director & Head Medical Oncology, Fortis Hospital, Shalimar Bagh, New Delhi, India. He opens his teaching on cancer with a deliberately plain definition. Before any biology, he says, cancer is a scary word. Much of his clinical work is spent dismantling the fear that the word carries, because fear produces bad decisions: patients who delay a biopsy, families who assume a death sentence, smokers who see no reason to stop. His masterclass for doctors across Africa was organised around the questions patients actually put to him in his outpatient clinic, and the answers he gives them.

This guide covers the first half of that conversation: who develops cancer and why, which risks can be removed, which symptoms demand investigation, and how screening and vaccination change the odds. Two companion articles go further. Does a Biopsy Spread Cancer? Staging and Surgery Myths deals with biopsy, staging and local treatment. Personalised Cancer Treatment: From Chemotherapy to NGS covers chemotherapy, targeted therapy, immunotherapy, genomic testing and cost.

Cancer myths and facts: who gets cancer

Can a healthy lifestyle prevent cancer?

A healthy lifestyle lowers the risk of cancer but cannot rule it out. "I have lived a healthy life, so how can I have cancer?" is among the most common questions Dr. Agarwal hears. The patient has lived carefully and has never needed so much as a paracetamol for a fever. How, then, can the diagnosis be cancer?

His answer separates two ideas that patients tend to merge. Good immunity and a healthy life lower the chance of almost every disease, cancer included. They do not remove it. A disciplined life improves the odds; it is not a guarantee.

Is cancer hereditary?

Most cancer is not hereditary. The mirror-image fear concerns family history: "My mother had cancer, so I will get it too." Dr. Agarwal's example is a woman diagnosed with breast cancer at 65 whose first question is whether her daughter is now destined to develop the same disease. His answer is a firm no. A cancer in the family does not mean it will pass to the next generation or to siblings.

The numbers explain why. Only about 5 to 10 per cent of cancers are carried in the genes. A further 5 to 10 per cent occur in family clusters. The large majority are sporadic, meaning they arise without any inherited predisposition. For most families, one relative's cancer does not mean an inherited cancer gene is being passed down.

When is genetic testing for cancer recommended?

Genetic testing is warranted when the pattern of cancer suggests an inherited cause. Dr. Agarwal sets out the patterns that should prompt a clinician to look for one:

• Cancer across two or more generations of the same family.
• Cancer at an unusually young age, for example breast, ovarian or colon cancer in a patient under 30.
• Male breast cancer. It surprises many patients that men develop breast cancer at all, and when they do, a genetic cause is a real possibility.
• Two different primary cancers in one person, such as breast and ovarian, or colon and ovarian.

Formal guidelines draw these criteria more broadly than a single age cut-off. Criteria from the US National Comprehensive Cancer Network (NCCN), for instance, recommend genetic testing for breast cancer diagnosed at 50 or younger, for any ovarian cancer and for any male breast cancer. The practical message is the same: these patterns justify testing.

Which cancer risk factors can be removed?

Across all age groups and ethnicities, the most important modifiable cause of cancer is smoking, and it is entirely preventable. Dr. Agarwal illustrates the point with images of a normal lung beside a smoker's lung: after years of smoking, tar collects on the lung surface, and the white deposits that follow are cancer. The damage is not confined to the lung; smoking drives cancer in multiple other organs.

His message to smokers has four parts:

• The risk is large. About half of long-term smokers will be killed by smoking before their time.
• Lung cancer is a major share of that toll. Roughly 15 to 20 per cent of smokers die of lung cancer.
• The deaths come at the worst time. Most occur in middle age, during a person's most productive years.

The fourth part is the encouraging one. Stopping works. Once a person quits, the damage begins to reverse.

He also shows a patient of his with oral cancer who needed an opening created in the neck to breathe, and who was breathing through that opening. He presents the case as a measure of how strong tobacco addiction is, and as something that has to be prevented.

Second-hand smoke: why older smokers should still stop

Some older patients argue that they have lived well, do not want another 15 or 20 years, and would rather keep smoking. Dr. Agarwal's reply moves the argument away from the smoker. A non-smoker's risk of lung cancer rises by about 30 per cent if someone smokes in the home. The global toll is large: the World Health Organization attributes about 1.3 million deaths a year to second-hand smoke exposure among non-smokers. His line to such patients is simple: if you do not love yourself, at least love your family.

Cancer risk factors beyond smoking

Beyond smoking, Dr. Agarwal lists tobacco in other forms, alcohol, viral infections, lifestyle factors including obesity and a high-calorie diet, and risk factors specific to individual cancers. He stresses that each cancer behaves differently. Every organ produces a different disease, with its own pattern of spread, treatment options and outcomes. That is why oncology is a specialist field, and why a diagnosis of cancer, in itself, says little about prognosis.

The seven warning signs of cancer

Seven symptoms should be treated as red flags for cancer, and any patient presenting with one of them should be investigated rather than reassured. Dr. Agarwal asks clinicians to keep this list in mind:

• A change in bowel or bladder habit, whether constipation or diarrhoea, that is unusual for the patient.
• A sore that does not heal.
• Unusual bleeding or discharge.
• Thickening or a lump in the breast or elsewhere.
• Difficulty in swallowing, or persistent indigestion.
• A wart or mole that changes: bleeding, growing, or even disappearing.
• A persistent, nagging cough or hoarseness of voice.

These seven signs are the long-established public-health checklist for cancer. Their value lies in their ordinariness: each is easy to attribute to something benign, which is precisely why patients and doctors miss them.

One trap deserves special mention: normal routine blood tests do not rule out cancer, a point taken up in the article on biopsy, diagnosis and staging.

Cancer screening guidelines: a test for healthy people

Cancer screening is for healthy individuals with no symptoms, not for patients, and its purpose is to find cancer when the tumour is small, potentially curable and treatable with minimal intervention. In Dr. Agarwal's experience, it is widely misunderstood on exactly this point. A mammogram, for example, is simply an X-ray of the breast, but it detects what a hand examination cannot, and it detects it earlier. If screening protocols were followed properly and most cancers were found at the right time, he argues, today's high death rates would fall dramatically, by as much as 80 percent in his estimate.

The schedule he recommends:

• Breast cancer: mammography every year for women over 40, a practice he believes every country should follow.
• Cervical cancer: a Pap smear, in which a sample of cells is taken from the cervix, from the age of 21. It is a simple, inexpensive and widely available test.
• Prostate cancer: a PSA (prostate-specific antigen) blood test for men over 50. Professional guidance such as the American Cancer Society's advises starting the discussion earlier, at 45, for men at higher risk, including men of African descent and those with a close relative diagnosed young.
• Lung cancer: CT screening of the chest for long-term smokers. The US Preventive Services Task Force (USPSTF) standard is an annual low-dose CT for adults aged 50 to 80 with a smoking history of at least 20 pack-years (one pack a day for 20 years, or the equivalent) who still smoke or quit within the past 15 years.

The HPV vaccine against cervical cancer: who should get it

The HPV (human papillomavirus) vaccine protects against cervical cancer, and WHO recommends it routinely for girls aged 9 to 14. Dr. Agarwal is emphatic about the vaccine. Given as a full course, it offers durable protection: in clinical trials it prevented close to all of the cervical precancers caused by the HPV types it covers. He finds it hard to understand why women still develop cervical cancer when such a vaccine exists, and believes it should be promoted to everyone.

The WHO recommendation targets girls before exposure to HPV, and the vaccine is licensed in some countries for use up to the age of 45. Boys are increasingly vaccinated as well, because HPV also causes a share of oral and throat cancers. The HPV vaccine is not the only vaccine that prevents cancer: the hepatitis B vaccine protects against liver cancer by preventing chronic hepatitis B infection.

Is cancer a death sentence?

Cancer is not a death sentence. Dr. Agarwal closes the loop on his opening definition: cancer may be a scary word, but it is not a sentence. Treated properly, by experts following guidelines, outcomes are good, especially in stages one to three, and even some patients with stage four disease now live for many years.

His illustration is a patient he began treating for stage four lung cancer in 2010. With the drugs available at the time, he told the patient to expect one to two years. By the end of that year, a new oral drug that acted on the specific genetic change in the patient's tumour became available, and he started it. The disease stayed controlled until 2015, when it began to progress. By then two further drugs were available, he switched to them, and the patient is still alive. The treatment throughout has been a daily oral pill, taken much as a patient takes medicine for diabetes or hypertension. Dr. Agarwal is candid that this outcome reflects advanced treatment given correctly and a measure of luck, but it shows how far the ceiling has moved in oncology.

The mechanisms behind that shift, from genetic testing to targeted drugs and immunotherapy, are the subject of the companion article on personalised cancer treatment.

Online second opinions and doctor-to-doctor care

For doctors in Africa whose patients may never travel, Dr. Agarwal's team offers international online opinions. The referring doctor deposits a nominal fee and sends the reports, and the team reviews them and provides whatever guidance the reports allow. The fee is kept low; its purpose is to ensure that cases sent are serious ones, because reviewing a full set of reports and deciding a plan takes considerable effort. He set out this arrangement in the masterclass Live Discussion.

He sees structured doctor-to-doctor collaboration as the need of the day. Removing middlemen is part of the case, but the larger point is continuity. Treatment does not end when a patient flies home; new problems arise day to day. Local doctors are very competent to manage them, but sometimes need the treating oncologist's input. If both doctors are in contact from day one, the oncologist knows the patient's journey and can guide the local team accurately. When a patient is weighing travel abroad, Dr. Agarwal is willing to consult online with the referring doctor first, on the prognosis and on what to tell the patient, so that the obstacles and apprehensions are dealt with before anyone boards a plane.