Cancer is a broad term that covers a range of disorders. It can grow in practically any part of the body. The majority of the cells in the body have distinct functions and lifespans. While cell death may appear to be a negative phenomenon, it is actually a natural and helpful process known as apoptosis. 

A cell is told to die so that the body can replace it with a newer, better-functioning cell. The components that tell cancerous cells to cease proliferating and die are missing.

As a result, they accumulate throughout the body, consuming oxygen and nutrients meant for other cells. Cancerous cells can create tumors, immune system impairment, and other alterations that prohibit the body from operating normally.

Cancerous cells may emerge in one location and then move to other parts of the body via lymph nodes. These are clumps of immunological cells that can be found all over the body.

Types of cancer

The following are the basic types of Cancer. There may be other specific terms to refer to them. Read below to get a brief of their subtypes, plus the organs they affect. 

Carcinomas:- The skin or tissue covering the surface of internal organs and glands is where a carcinoma develops. Carcinomas are often solid tumors. Cancers of this class are the most frequent. Prostate cancer, breast cancer, lung cancer, and colorectal cancer are all examples of carcinomas.

• Prostate cancer - When cells in the prostate gland begin to grow out of control, prostate cancer develops. Only men have a prostate gland that produces some part of the semen.

• Breast cancer - It is a type of cancer that begins in the breast and cancer cells usually form a tumor that can be diagnosed in an x-ray or felt as a lump. It occurs mostly in women but men can get breast cancer too.

  • Lung cancer - It is cancer that develops in the tissues of the lungs, most commonly in the cells that line the airways. The two most common forms of lung cancer are - small-cell lung cancer and non-small cell lung cancer. The appearance of the cells under a microscope is used to diagnose these types.

• Colorectal cancer - The colon or the rectum is where colorectal cancer begins. Depending on where they begin, these malignancies are referred to as colon cancer or rectal cancer. Because they share many characteristics, colon cancer and rectal cancer are sometimes grouped together.

Sarcomas:- Sarcomas start in the body's supporting and connecting tissues. Fat, muscles, nerves, tendons, joints, blood arteries, lymph vessels, cartilage, and bone can all form sarcomas.

Leukemias:- Leukemia is a type of blood cancer. When healthy blood cells begin to alter and grow uncontrollably, leukemia develops. Acute lymphocytic leukemia, chronic lymphocytic leukemia, acute myeloid leukemia, and chronic myeloid leukemia are the four main kinds of leukemia.

• Acute lymphocytic leukemia - A kind of leukemia (blood cancer) that appears suddenly and grows rapidly. There are too many lymphoblasts (immature white blood cells) in the blood and bone marrow in acute lymphoblastic leukemia (ALL). 

• Chronic lymphocytic leukemia - It is a type of slow-growing leukemia that affects developing B-lymphocytes (specialized white blood cells) and it is mostly found in the blood and bone marrow. 

• Acute myeloid leukemia - Too many myeloblasts (immature white blood cells that are not lymphoblasts) are discovered in the bone marrow and blood in this aggressive (fast-growing) condition. Acute myeloblastic leukemia is also known as acute myelogenous leukemia (AML).

• Chronic myeloid leukemia - CML (chronic myeloid leukemia) is a kind of cancer that affects white blood cells and progresses slowly over a long period of time.

Lymphomas:-  Lymphoma is a malignancy that starts in the lymphatic system and spreads throughout the body. The lymphatic system is a system of tubes and glands that aid in the removal of waste from the body. Hodgkin lymphoma and Non-Hodgkin lymphoma are the two main types of lymphomas.

• Hodgkin lymphoma - Hodgkin lymphoma, often known as Hodgkin's disease, is one of several kinds of lymphoma. Lymphoma develops when healthy lymphatic cells mutate and grow out of control. This uncontrolled development can develop into a tumor, including many regions of the lymphatic system, or migrate to other parts of the body.

• Non-Hodgkin lymphoma - also called non-Hodgkin lymphoma, NHL, or just lymphoma. It is a disease that begins in white blood cells called lymphocytes, which are part of the body's immune system.

Causes

Cancer develops when normal cells are transformed into tumor cells in a multi-stage process that usually evolves from a precancerous lesion to a malignant tumor. These changes are the result of a person's hereditary factors interacting with three types of external stimuli, including:

• UV and ionizing radiation, for example, are physical carcinogens.

• Chemical carcinogens comprise asbestos, tobacco smoke components, aflatoxin (a food contaminant), and arsenic (a drinking water pollutant); while

• Biological carcinogens include infections with specific viruses, bacteria, or parasites.

Gene mutation is also a cause of cancer

The major cause of cancer is changing (mutations) in the DNA of cells. Each gene in a cell has a collection of instructions that teach the cell what functions to execute as well as how to grow and divide. Errors in the instructions can cause a cell to stop functioning normally and even cause it to become malignant.

A healthy cell can be told by a gene mutation that:

• A gene mutation might cause a cell to divide and expand more quickly. This produces a large number of new cells with the same mutation.

• Normal cells know when to cease growing so that the number of each type of cell is just perfect. Tumor suppressor genes, which tell cancer cells when to stop growing, are lost in cancer cells. Cancer cells can continue to proliferate and accumulate due to a mutation in a tumor suppressor gene.

• Other errors may not be fixed as a result of a mutation in a DNA repair gene, leading to malignant (cancerous) cells.

Symptoms

Consult your healthcare expert if you notice any of these symptoms. Some of the common signs and symptoms of cancer are:

• Some changes in bowel and urinary habits are common.

• A sore that doesn’t heal easily

• Bleeding or discharge that is unusual

• In the breast or elsewhere, there is a thickening or lump.

• Persistent cough.

If you experience any of the above-mentioned signs and symptoms, consider seeing a specialist and schedule a screening and examination.

Risk factors

While professionals have an understanding of what variables may increase your cancer risk, the majority of cancer is diagnosed in patients who have no known risk factors. The following are some of the factors that have been linked to an increased risk of cancer:

• Age - It can take decades for cancer to form. That's why the majority of cancer patients are 65 or older. While cancer is more common in older persons, it is not limited to them. Cancer can strike anyone at any age.

• Environment - The environment you live in may include dangerous substances that raise your cancer risk.

• Lifestyle choices - Certain lifestyle choices have been linked to a higher risk of cancer. Cancer can be caused by smoking, alcohol consumption, frequent blistering sunburns, being fat, and having unsafe sex.

• Family history - If your family has a history of cancer, mutations are probably passed down from generation to generation. It's important to remember that having an inherited genetic mutation doesn't indicate you'll acquire cancer.

Screening and Diagnosis

Studies demonstrate that screening tests can save lives by detecting cancer at an early stage. Screening tests for various malignancies are only suggested to persons who are at a higher risk.

The best chance for a cure is to diagnose cancer at its early stages. With this in mind, discuss the options for cancer screening with your doctor. Some of the techniques are mentioned below:- 

• Physical Examination - During a physical examination, your medical specialist may search for abnormalities that could suggest the presence of cancer, such as changes in skin color or organ enlargement. 

• Laboratory tests - Laboratory tests like - blood tests and urine tests help the healthcare professional to identify the abnormalities more easily that may have caused cancer. For example, in patients with leukemia, a common blood test sample helps in identifying the blood cell count and type of white blood cells. 

• Imaging test -  Healthcare experts perform these tests to examine your bones and internal organs in a non-invasive way. Imaging tests include CT (computerized tomography) scan, MRI (magnetic resonance imaging), ultrasound, X-ray, and PET (positron emission tomography) scan. 

• Biopsy - For laboratory tests, your specialist collects a sample and there are several ways of collecting a sample. Which biopsy procedure is right for you depends on the type of cancer and where it is located. In this procedure, lab technicians put the collected sample under the microscope and check the organization of cancer cells. 

Treatment

Experts and specialists describe the treatment according to the type of cancer and stage of cancer examined at the time of the diagnosis. 

• Chemotherapy - helps in decreasing the growth of cancer cells and aims to kill the cancerous cells. This therapy also helps in shrinking tumors with medication that targets rapidly growing cancer cells. 

• Hormone therapy - entails taking drugs that alter the way particular hormones act or prevent the body from producing them. This is a typical technique when hormones play a substantial role in prostate and breast malignancies.

• Immunotherapy - is a type of treatment that boosts the immune system and encourages it to fight malignant cells by using drugs and other treatments. Checkpoint inhibitors and adoptive cell transfer are the two examples of this therapy.

• Radiation therapy - High-dose radiation is used in radiation therapy to eliminate malignant cells. A doctor may also suggest that radiation be used to decrease a tumor before surgery or to alleviate tumor-related symptoms.

• Stem cell transplant - People with blood-related malignancies, such as leukemia or lymphoma, may benefit from a stem cell transplant. It entails eliminating cells that have been damaged by chemotherapy or radiation, such as red or white blood cells.

• Surgery - When a person has a malignant tumor, surgery is frequently a part of the treatment approach. A surgeon may also remove lymph nodes to slow or stop the disease from spreading.

• Targeted therapy - Targeted medicines work within malignant cells to stop them from proliferating and spreading. They may also help to strengthen the immune system. Small-molecule medicines and monoclonal antibodies are two examples of these therapeutics.

• Palliative therapy - Palliative care is a term that refers to a type of treatment that Palliative therapy can help with treatment side effects as well as cancer-related signs and symptoms. When a cure isn't possible, surgery, radiation, chemotherapy, and hormone treatment can all be used to relieve symptoms and slow the spread of cancer. Pain and shortness of breath may be relieved by medications.

Prevention

There are several ways that can help in reducing the risk of cancer. Some of them are broadly classified below, which you can adapt for a healthy change in your lifestyle:- 

• Maintain a healthy diet - Choose fruits, vegetables, whole grains, and beans over processed meats. 

• Screening - Talk to your healthcare professional about getting a cancer screening. Some tests can help detect cancer early on when therapy is more likely to be effective, and others can detect precancerous diseases before they progress to cancer. 

• Physically active - Getting at least 30 minutes of physical activity per day can significantly improve your overall health and well-being. Breast and colorectal cancer have been related to inactivity and obesity, and there is limited evidence of a link to lung and pancreatic cancer. Reduce stress, enhance energy, strengthen your immune system, maintain a healthy weight, and lower your risk of cancer by including exercise in your daily routine.

• Quit tobacco products - Tobacco use has been associated with numerous cancers, including lung, colorectal, breast, throat, cervical, bladder, oral, and esophageal cancers. It's never too late to make a change. Nonsmokers who are exposed to secondhand smoke are at an increased risk of lung cancer and other respiratory problems.

• Immunization - You're more likely to get cancer if you're infected with certain viruses. Hepatitis B, which raises the risk of liver cancer, and human papillomavirus (HPV), which increases the risk of cervical cancer and other malignancies, may be prevented through vaccinations. Consult your doctor to see if you should be immunized against certain viruses.