What is Cancer: Causes, Signs & Symptoms, Prevention, Early Detection, and Treatment

World Cancer Day 2023: It is observed on 4 February to increase global awareness of cancer. The day originated in 2000 at the first World Summit Against Cancer and it was held in Paris. According to the WHO, if cases of cancer continue to grow at the reported rate then the number of deaths worldwide from cancer will increase to more than 16.3 million by 2040.

कैंसर का इलाज संभव है यदि शुरुवात में ही इसकी पहचान हो सके #WorldCancerDay #SwasthaBharat#beatNCDs pic.twitter.com/mZLuKdSEkb

— Ministry of Health (@MoHFW_INDIA) February 4, 2023

Also, as per WHO, as many as 40 percent of deaths from cancer are preventable. Therefore, spreading awareness is significant and has become a prominent role of various cancer and health organisations across the world. World Cancer Day is an annual reaffirmation of the importance of this goal.

This year's World Cancer Day campaign theme is "Close the Care Gap". It focuses on spreading awareness of this equity gap that affects almost everyone, in high as well as low- and middle-income countries. 

What is Cancer?

It is a disease which is caused when changes in a group of cells occur inside the body and lead to uncontrolled, abnormal growth forming a lump known as a tumour. This is true for all cancers except leukaemia which is a cancer of the blood. If a tumour is left untreated, it grows, and spread into the surrounding normal tissue, or to other parts of the body through the bloodstream and lymphatic systems and so can affect the digestive, nervous, and circulatory systems or release hormones that may affect the function of the body.

Tumours of Cancer can be divided into three groups namely benign, malignant or precancerous.

About Benign tumour

Benign tumours are not cancerous and threaten life rarely. They grow slowly inside the body and also do not spread to other parts of the body. Usually, they are made up of cells that are quite similar to normal or healthy cells. The problem occurs only when they grow very large, becoming uncomfortable or pressing on any other organs. For example a brain tumour inside the skull.

READ| What is Glioblastoma or GBM Grade IV cancer?

About Malignant tumour

Malignant tumours grow faster than benign tumours. They have the ability to spread and destroy neighbouring tissue. Malignant tumours cells can break off from the main or primary tumour and can spread to various parts of the body through a process called metastasis. They invade healthy tissue at the new site and continue to divide and grow. Secondary sites are called metastases and the condition is referred to as metastatic cancer.

About Precancerous (or premalignant) 

It is a condition that involves abnormal cells which may or are likely to develop into cancer.

How is cancer caused?

Due to various factors it can be caused and as many other illnesses. Most of the cancers are the result of exposure to various causal factors. But it is important to remember that while some factors cannot be modified but one third of the cases of cancer can be prevented by reducing the behavioural and dietary risks.

Some modifiable risk factors are as follows:

Alcohol

Being overweight or obese

Diet and nutrition

Physical activity: Regular physical activity helps to reduce the excess fat in the body and the cancer risks associated with this will also be reduced like in developing colon, breast, and endometrial cancers.

Tobacco

Ionising radiation: Cancer can also be caused due to manmade sources of radiation and are a risk for workers including radon, X-rays, gamma rays, and other forms of high-energy radiation.

Workplace hazards

Infection: As per reports, around 2.2 million cancer deaths annually occur due to infectious agents. That is cancer can not be caught like an infection but the virus can cause changes in cells that make them more likely to become cancerous.

Some of the non-modifiable risk factors are as follows:

Age: It is said that various types of cancer become more prevalent with age. The longer people live, the more exposure to carcinogens and more time for genetic changes or mutations to occur within their cells.

Cancer-causing substances (Carcinogens): These are the substances that change how a cell behaves and increase the chances of developing cancer.

Genetics

Immune system: People who have weak immune systems are more at risk of developing some types of cancer.

What is ‘High Grade’ Metastatic Cancer?

What are the Signs and Symptoms of Cancer?

Cancers are of various types and so the symptoms also vary and depend on where the disease is located. Some key signs and symptoms are as follows:

Unusual lumps or swelling

Changes in bowel habit

Coughing

Breathlessness or difficulty swallowing

Unexplained weight loss 

Fatigue

Pain or ache

A new mole or changes to a mole

Complications with urinating

Unusual breast changes 

A sore or ulcer that won’t heal

Heartburn or indigestion: Persistent or painful heartburn or indigestion

Heavy night sweats

Prevention and Early Detection of Cancer

It is said that over a third of all cancers can be prevented by reducing exposure to risk factors like tobacco, obesity, physical activity, infections, alcohol, environmental pollution, occupational carcinogens, and radiation. Also, prevention of certain cancers may be effective through vaccination against the Hepatitis B Virus (HBV), and the Human Papilloma Virus (HPV). They help to protect against liver cancer and cervical cancer respectively. 

There are various cancers that can be identified early and help to improve the chances of successful treatment outcomes, often at lower costs and with fewer or less significant side effects for patients. There are some cost-effective tests that help detect colorectal, breast, cervical and oral cancers early. Also, further tests are being developed for other cancers. It is important to check with the doctor for guidance on the national recommendations regarding vaccinations, testing and screenings.

Treatment of Cancer

Treatment of cancer depends on the type of cancer, location of cancer, how big it is, whether it has spread, and also on general health. 

General types of treatments are Surgery, Chemotherapy,  radiotherapy, hormone therapy, immunotherapy, and gene therapy.

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