Introduction to Cancer: Types, Symptoms, Diagnosis, and Treatment | Max Hospital

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An Introductory Guide to Cancer

By Dr. Bhuvan Chugh in Cancer Care / Oncology

Dec 27 , 2023 | 12 min read


India witnesses approximately 1,200,000 new cancer cases each year. According to the latest data from the National Cancer Registry, 1 in 8 men and 1 in 9 women in India are projected to develop some form of cancer during their lifetime.

The incidence and types of cancer that are diagnosed are influenced by a multitude of factors, including age, gender, ethnicity, local environmental conditions, dietary habits, and genetic predisposition. Among males in India, lung cancer holds the highest incidence, followed by oral cavity and throat cancers. Among females, cervical cancer and breast cancer are the most commonly diagnosed forms.

What is Cancer? 

Cancer is a condition characterised by the abnormal behaviour of certain cells within the body. In a healthy person, cells follow a specific pattern of growth, division, and eventually, natural death, which is essential to maintain proper bodily function. However, in the case of cancer, these cells deviate from this normal behaviour, undergoing uncontrollable and abnormal growth.

Difference Between Cancer Cells and Normal Cells

Normal Cells Cancer Cells
Growth Follow a controlled pattern Grow uncontrollably, ignoring signals
Communication Interact effectively with other cells Fail to respond to signals, act isolated
Cell Repair and Death Undergo self-repair or apoptosis Do not engage in self-repair or apoptosis.
Attachment Secrete adhesive substances Lack adhesive properties, can detach
Appearance Uniform size, orderly appearance Heterogeneous in size, significant variation
Maturation Undergo maturation process Remain undifferentiated due to rapid growth

Tissue Changes that are ‘Not’ Cancer

Not all changes in body tissues are indicative of cancer. However, certain changes should be monitored as they have the potential to develop into cancer if left untreated. Let's explore some examples of tissue changes that are not cancerous but may warrant attention due to their potential to progress:

Hyperplasia: Hyperplasia occurs when cells within a tissue multiply at a faster rate than normal, leading to an accumulation of extra cells. However, when examined under a microscope, the cells and tissue's structure will still appear normal.

Dysplasia: Dysplasia is a more advanced condition compared to hyperplasia. There is also an accumulation of extra cells, but these cells appear abnormal, and there are changes in the way the tissue is organised. In general, the more abnormal the cells and tissues appear, the higher the likelihood of cancer development.

Carcinoma in Situ: Carcinoma in situ is an even more advanced condition. While sometimes referred to as “stage 0 cancers,” it's important to note that it's not technically cancer because the abnormal cells do not invade nearby tissues to the same extent as cancer cells do. However, since some carcinomas can progress to become invasive cancers, they are typically treated.

Types of Cancer

Cancers are named after the organs or tissues in which they originate. The specific type of cell that gives rise to cancer, such as epithelial or squamous cells, is also used in the classification.

1. Carcinoma: The Most Common Type

Carcinoma is the most prevalent type of cancer. It primarily consists of epithelial cells that line both the inner and outer surfaces of the body. A variant known as basal cell carcinoma is also noteworthy.

2. Sarcoma: Affecting Bone and Soft Tissues

Sarcomas are cancers that develop in bone and soft tissues, encompassing muscle, fat, blood vessels, lymphatics, as well as fibrous tissues like tendons and ligaments.

3. Leukaemia: Blood-Related Cancer

Leukaemia is a form of cancer that originates in the blood-forming tissues of the bone marrow. Unlike other cancers, leukaemia does not form solid tumours. Instead, it results in the accumulation of abnormal white blood cells (leukaemia cells and leukemic blast cells) in the blood and bone marrow, displacing normal blood cells.

Choose the Best Blood Cancer Treatment Hospital in Delhi, India

4. Lymphoma: Involving Lymphocytes

Lymphoma is characterised by the malignancy of lymphocytes, a type of white blood cell crucial for the immune system. In this type of cancer, abnormal cells accumulate in the body's lymph nodes, lymphatic vessels, and other organs.

5. Multiple Myeloma: Affecting Plasma Cells

Multiple myeloma originates in plasma cells, another type of immune cell. The abnormal plasma cells, referred to as myeloma cells, accumulate in the bone marrow, forming tumours throughout the skeletal system.

6. Melanoma: Skin and Beyond

Melanoma is a cancer that begins in specialised melanocytes, cells responsible for producing melanin. While most melanomas develop in the skin, they can also occur in other pigmented tissues, including the eye.

Related: Bone Marrow Cancer Treatment in Delhi, India

7. Brain and Spinal Cord Tumours: Diverse Forms

Tumours originating in the brain and spinal cord manifest in various forms. They are classified based on the cell type of origin and the location within the central nervous system where they first appear.

Other Types of Cancer

  • Germ Cell Tumours: These tumours initiate in the cells responsible for sperm or ovum production and can appear in various body locations, potentially being benign or malignant.
  • Neuroendocrine Tumours: These tumours arise from cells that secrete hormones into the bloodstream in response to nervous system signals. They may lead to a wide range of symptoms due to the excessive hormone production.
  • Carcinoid Tumours: Carcinoid tumours, a subset of neuroendocrine tumours, typically grow slowly and are commonly found in the gastrointestinal system. In some cases, they can metastasize to the liver or other body parts.

Checkout - Gastrointestinal Cancer Treatment 

Symptoms of Cancer

Cancer can present with a variety of signs and symptoms, which may vary depending on the specific area of the body that is affected. To help better recognize potential warning signs, here is a list of common indicators that are not exclusive to cancer but should prompt you to seek medical attention:

  • Changes in Bowel or Bladder Habits: Look out for unexplained changes like persistent diarrhoea or constipation, frequent urgency when urinating, or any other unusual bowel or bladder irregularities.
  • Non-Healing Sores: It's important to pay attention to any sore on the body that doesn't seem to heal as expected.
  • Unusual Bleeding or Discharge: Any unexplained bleeding or discharge, such as blood in urine, stool, between menstrual periods, vomit, or cough, should be investigated.
  • Thickening or Lump: If you notice any unexplained lump or thickening in any part of the body, you should consult a medical professional promptly.
  • Wart or Mole Changes: Any noticeable changes in the size, shape, or colour of warts or moles should be examined by a doctor.
  • Nagging Cough, Breathlessness, or Hoarseness: Medical advice should be sought if one has a cough or experiences breathlessness for more than two weeks, or if you notice blood in the phlegm.
  • Fatigue or Unexplained Swelling: Keep an eye out for fatigue that doesn't improve with rest, or areas of swelling that can be felt under the skin.
  • Weight Fluctuations: Significant unintentional weight loss or gain should be investigated.
  • Skin Changes: Changes in the skin, including yellowing, darkening, redness, non-healing wounds, or alterations in existing birthmarks, require medical attention.
  • Persistent Indigestion After Eating: If one experiences ongoing discomfort or indigestion after eating, they should consult a healthcare professional.
  • Unexplained Persistent Fever or Night Sweats: Prolonged, unexplained fever or night sweats should not be ignored.
  • Unexplained Persistent Muscle or Joint Pain: One should seek medical evaluation for persistent, unexplained muscle or joint pain.

If someone experiences any of these symptoms, it's essential for them to consult their doctor promptly. The doctor will ask questions, perform physical examinations, and may recommend further diagnostic tests. If cancer is suspected, the patient may be referred to one of the best oncologists in India for specialised evaluation and treatment.

Find out which cancer screening treatments and tests are best for you.

Read more - Spotting Signs of Cancer

Common Causes of Cancer

The primary cause of cancer is mutations, or alterations in the DNA within an individual's cells. These genetic mutations may either be inherited or acquired after birth due to exposure to certain substances and environmental factors.

Carcinogens, which are substances known to increase the risk of cancer, can be categorised into three main groups:

  • Physical Carcinogens: These encompass exposure to radiation and ultraviolet (UV) light, like that from the sun, which can be harmful to the skin.
  • Chemical Carcinogens: Examples include cigarette smoke, asbestos, alcohol, air pollution, and certain chemicals found in contaminated food and drinking water. These are substances that, when encountered, can potentially lead to cancer.
  • Biological Carcinogens: This category involves viruses, bacteria, and parasites that are linked to an increased risk of cancer development.

Risk Factors of Cancer

The risk of developing cancer is influenced by various factors, and understanding these risk factors is crucial. Some common risk factors that can increase the likelihood of developing cancer include:

  • Tobacco Use: Smoking and the use of tobacco products significantly elevate the risk of various types of cancer.
  • High Alcohol Consumption: Excessive alcohol intake is associated with an increased risk of certain cancers, including those of the mouth, throat, and liver.
  • Lack of Physical Activity: A sedentary lifestyle can be a risk factor, as regular physical activity has been shown to reduce the risk of certain cancers.
  • Exposure to Air Pollution: Prolonged exposure to polluted air, especially in urban areas, may contribute to cancer risk, particularly lung cancer.
  • Exposure to Radiation: Occupational or medical exposure to radiation, such as X-rays and certain treatments, can increase the risk of cancer.
  • Unprotected Exposure to UV Light: Excessive and unprotected exposure to UV light, like sunlight and tanning beds, is linked to skin cancer.

How Does Cancer Grow and Spread?

  • Abnormal Cell Division: Normal cells grow, divide, and replace damaged ones according to their life cycle. Cancer, caused by DNA mutations, disturbs this process. Mutations allow cells to survive when they should die and create unnecessary new cells, resulting in uncontrollable growth and tumour formation.
  • Creation of Tumours: Tumours can pose health problems, but not all are cancerous. Benign tumours remain localised, while malignant tumours invade neighbouring tissues, potentially causing more severe issues.
  • Metastasis: Metastasis involves cancer cells spreading through the bloodstream or lymphatic system. Metastatic cancers are more advanced and challenging to treat, often associated with higher fatality rates. 

Read more - How Cancer Starts, Grows and Spreads?

Diagnosis of Cancer 

Various methods and techniques are employed to identify the presence of cancer cells and tumours in the human body. When seeking the best cancer hospital in India for diagnosis and treatment, it's essential to consider the hospital's expertise in utilising these methods. 


A biopsy is a medical procedure where a sample of tissue is collected from the suspicious area and examined under a microscope. Pathologists analyse the tissue sample to check for the presence of cancer cells, helping to confirm the diagnosis.

Histopathological Studies of Tissue

Histopathological studies involve the microscopic analysis of tissue samples. Pathologists study these samples to detect abnormal cellular changes that are indicative of cancer. This technique is crucial for understanding the characteristics of cancerous tissues.

Radiography Techniques

Radiography techniques, such as X-rays, are often used to capture images of affected areas in the body. These images help in the identification of abnormalities, including tumours or irregular masses that might be indicative of cancer.

Computed Tomography (CT)

Computed Tomography, commonly known as CT or CAT scans, provides detailed cross-sectional images of the body. It aids in the detection and localization of cancerous growths. CT scans are particularly valuable for visualising solid organs and bones.

Magnetic Resonance Imaging (MRI)

MRI is another imaging technique that provides high-resolution images for the assessment of cancer, especially in soft tissues. It offers excellent contrast and is highly effective in identifying abnormalities in various parts of the body.

Molecular Biology Techniques

Advanced molecular biology techniques have revolutionised cancer detection. These methods involve the analysis of genetic and molecular markers to identify cancer-related mutations and abnormalities. By studying the DNA and RNA of cells, scientists can pinpoint specific genetic changes associated with different types of cancer.

Cancer Stages

Cancer staging systems play a pivotal role in guiding healthcare providers as they chart a course of treatment and offer patients a prognosis, or an anticipated outcome. Among the various staging systems, the TNM classification is the most widely employed. It simplifies the complex reality of cancer progression into three key factors:

  • T represents the primary tumour.
  • N indicates lymph nodes and signals whether the cancer has extended to these vital components of the immune system.
  • M is for metastasis, indicating the spread of cancer to distant parts of the body.

Most cancer types are categorised into four primary stages. The specific stage assigned to a patient depends on several factors, including the tumour's size and its location within the body:

  • Stage I: At this stage, cancer is confined to a small, localised area, without any evidence of spreading to nearby lymph nodes or other tissues.
  • Stage II: Cancer has experienced some growth, but it still remains localised and hasn't extended to other areas of the body.
  • Stage III: Cancer has grown larger, possibly involving nearby lymph nodes or adjacent tissues.
  • Stage IV: This advanced stage indicates that cancer has spread to other organs or distant areas of the body, a condition often termed metastatic cancer.

In addition to these four primary stages, there's also Stage 0, which characterises the earliest phase of cancer. In Stage 0, the cancer is restricted to the site where it originated, making it highly treatable. Many practitioners categorise Stage 0 cancers as precancerous, indicating their potential to progress if not addressed.

Treatment of Cancer 

Cancer treatment is a collaborative effort that involves various approaches, each tailored to address specific aspects of the disease. In this comprehensive guide, we will explore the primary methods of cancer treatment, their objectives, and how they contribute to the well-being of cancer patients.

Primary Treatment

The primary objective of cancer treatment is to completely eradicate cancer from the body or destroy all cancer cells. While various treatment options can serve as primary treatments, the most common approach for the most prevalent types of cancer is surgery.

Adjuvant Treatment

Adjuvant therapy focuses on eliminating any residual cancer cells after primary treatment to reduce the risk of cancer recurrence.

Palliative Care

Palliative care treatments are designed to alleviate side effects resulting from treatment or symptoms caused by cancer itself. They encompass a range of interventions, including surgery, radiation, chemotherapy procedure, and hormone therapy, which can provide relief from pain and discomfort.


The primary goal of surgery is the complete removal of malignant tissue, whenever possible.


Chemotherapy employs drugs to target and eliminate cancer cells.

Radiation Therapy

Radiation therapy uses high-energy rays, such as X-rays or protons, to obliterate cancer cells.

Bone Marrow Transplant

A bone marrow transplant, also known as a stem cell transplant, involves using either the patient's own bone marrow stem cells or those from a donor to restore healthy blood cell production.

Immunotherapy Procedure

Immunotherapy, a biological treatment, leverages the body's immune system to combat cancer. It addresses the challenge where the immune system fails to recognize cancer as a threat, allowing it to proliferate unchecked.

Hormone Therapy

Certain cancers, such as breast and prostate cancer, are influenced by hormones. Hormone therapy works by removing these hormones from the body or blocking their effects, thereby halting the growth of cancer cells.

Targeted Drugs

Targeted drug therapy focuses on specific abnormalities within cancer cells to inhibit their growth.


Cryoablation is a treatment that uses cold temperatures to destroy cancer cells. A cryoprobe, a thin needle, is inserted directly into the cancerous tumour. It's filled with gas to freeze the tissue, which is then thawed and repeated multiple times in the same session to effectively eliminate cancer cells.

Radiofrequency Ablation

Radiofrequency ablation uses electrical energy to heat and destroy cancer cells. A doctor inserts a thin needle through the skin or an incision in the cancerous tissue, and radiofrequency energy is applied to the needle to heat the tissue, causing the cells to die.