What Is Cancer and How Does It Work on a Biological Level?

In 2024, the National Cancer Institute’s Surveillance, Epidemiology, and End Results Program reported that an estimated 2 million Americans will be diagnosed with some form of cancer. While these numbers can be distressing to read, there is a silver lining: in the past 30 years, 4 million lives have been saved, in part because of an early cancer diagnoses. Early detection and advances in treatment have allowed doctors to catch cancer early on and care for patients until they enter remission.

While countless Americans have been affected by cancer or know someone who has, few people understand how it works. Learn more about cancer, including the lifestyle factors and genetics that cause it. This guide will dive into cancer development on a cellular level.

What Is Cancer?

Cancer refers to a group of cells in your body that develop abnormally. Your body is made up of trillions of cells that are constantly growing, shedding, and dying each day. The vast majority of the cells are healthy and support the various systems in your body. Occasionally, something goes wrong and an abnormal cell is created. In most cases, these cells die; however, when they do not, they can continue to reproduce as cancer.

The abnormal cells can simply crowd out other cells or they can be harmful to your body. These abnormal cells can also travel to other systems, so cancer spreads and advances over time.

There are more than 200 known types of cancer. A cancer diagnosis usually reflects where the abnormal cells started, even if they have spread to other systems and organs.

What Is a Tumor?

When a group of abnormal cells comes together, it is known as a tumor. A tumor can be a soft or firm mass located where the abnormal cells are. When people hear the word tumor, they often associate it with cancer because of the abnormal cell development; however, many tumors are not cancerous.

Doctors try to catch tumors early on because they're often easier to remove when they are smaller. A surgeon might have a less invasive procedure because of a small tumor and there is less risk of harming the patient. Catching a tumor when it is still small can also help doctors determine whether it is cancerous.

What Is a Malignancy?

Given the opportunity, a malignant cancer will grow and metastasize throughout your body. For example, ovarian cancer might start in the ovaries and then spread to the fallopian tubes, uterus, and cervix. The malignant cells will eventually leave the reproductive system and harm other parts of the body.

Malignant cells are uncontrollable and usually reproduce more quickly than benign cells unless a patient undergoes treatment, such as chemotherapy or radiation, to kill the cells. When these cells stop spreading, the patient enters remission. This does not mean that the cancer is cured and the cells can start spreading again in the future, returning to malignancy.

The Structure of a Cancerous Cell

Even though cells are microscopic and are the building blocks of your body’s systems, they also are made up of different components. Here are a few ways that cancer cells differ from healthy ones.

• The nucleus, which is responsible for holding on to genetic information in the cell, may be unusually large.
• The cell itself is unusually shaped or has a different density than healthy ones around it.
• The cytoplasm inside is differently colored or pale compared to your other cells.
• The rate at which cells divide, known as mitosis, increases. This is why some cancer cells can grow quickly and spread.

When your doctor takes a sample from your tumor, they will look to see if any cells look different from healthy ones. This is an indicator that the tumor could be cancerous.

How Does Cancer Start?

The cells within your body reproduce through mitosis, which occurs when the cell doubles the genetic information inside and then splits in half. Cancer starts when cells divide abnormally or fail to pass on the correct genetic information. Instead of dying, the abnormal cells will also reproduce, causing the cancer to spread.

A variety of factors can cause cancer. Some people might be genetically prone to this disease, while others can develop it through lifestyle choices like smoking. If you know that cancer runs in your family, schedule regular appointments with your doctor and communicate your risks. They might recommend annual blood tests so they can catch cancer early on.

How Does Cancer Spread?

Cancer cells do not act like normal, healthy cells in your body. Instead of staying in one place like they should, cancer cells can break off and spread to other systems. This is how you can develop cancer in one part of your body and have it moved to another. The process of cancer cells spreading through your body is known as metastasis.

Benign vs. Malignant Neoplasms (Tumors)

When a tumor forms in your body, your doctor will take a sample of the cells and test them to see whether they are cancerous or not. If your tumor is simply a group of abnormal cells that are not cancerous, then it is benign. If the cells in the tumor are cancerous, then it is malignant.

Your treatment plan will depend on whether your tumor is benign or malignant. In some cases, your doctor might leave a benign tumor in your body, especially if it is small and no longer growing. This mass of cells isn't actively harming you. However, if the tumor is malignant, your doctor will want to remove it if possible and will recommend cancer treatment.

If you have a benign tumor, your doctor will want to monitor it. Some benign tumors can become malignant over time.

Types of Cancer

Doctors usually name cancer based on where it is found. For example, a breast cancer diagnosis occurs when the cancer cells or tumor are first found in the chest. On a higher level, Cancer Research UK highlights five main groups of cancer that alert doctors to where the cells are located and how they spread.

• Carcinoma begins on the skin or tissue that lines your organs.
• Sarcomas form in connective tissue, like cartilage or fat.
• **Leukemia **affects white blood cells.
• Lymphomas start in the immune system.
• Central nervous system cancers form in the brain or spinal cord.

If you're diagnosed with any of these types of cancer, your doctor will walk you through what it means and where the cells were first detected. They will also help you understand your treatment options and guide you through the process of getting better.

There is no cure for cancer, but patients can enter remission. This means the symptoms are reduced and cancerous cells are no longer detected. Patients can stay in remission for a few months or the rest of their lives. Your doctor will do their best to help you navigate your way through cancer and reach the remission stage.

Disclaimer:

The information provided on this website is for general informational purposes only. It is not intended as medical advice and should not be used as a substitute for professional consultation, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. If you think you may have a medical emergency, call your doctor or emergency services immediately.