The Basics of Cancer

What is Cancer?

Cancer is uncontrolled cell growth. In a healthy body, cells replicate at a well-defined pace (called the cell cycle), ensuring that resources are properly distributed. To keep this cycle in check, the body uses various checkpoints to prevent cells from growing too much.

Source: ProProfs

In cancerous cells, these ‘checkpoints’ have partially or completely lost their function, allowing for cancerous cells to rapidly grow. This is why cancer is so deadly, because not only are cancerous cells sapping important nutrients from the body because of their rapid growth, but they are also not doing the jobs they were made to do.

Strangely enough, our bodies encounter many cancer cells on the daily. However, the vast majority of these cancer cells are detected and killed by your immune system. However, in rare circumstances, cancer cells learn how to hide from the immune system. It is when cancer cells become undetectable by immune cells that they become a problem. When undetectable by the immune system, cancer cells can’t be killed by the body, because it doesn't know they’re there. This means that these hidden cancer cells are free to grow and spread, sapping the body of precious resources.

Cancer can come from any cell type at any stage of life (even embryonically), but occurs at vastly different rates in different types of cells. Cells that are more exposed to the environment, or cells that are supposed to divide frequently (like skin cells) are generally more likely to become cancer cells.

What are the Symptoms of Cancer?

General symptoms

Since cancer can impact every tissue in the body, cancers generally have symptoms that are unique to their respective organs. However, the following symptoms are associated with cancer in general, meaning that if you see or feel any of these for an extended period of time, it's definitely worth getting it screened. Also, a more in depth checklist of symptoms organized by their organ system can be found in the Cancers of Organ System section!

• Palpable lump in an unusual area
• Pain / soreness for an extended period
• Unexplainable fatigue/shortness of breath
• Blood in places it shouldn't be (urine, stool, vomit, semen, vaginal discharge, etc.)
• Significant changes in stool shape, consistency, or frequency of bowel movements
• Unexplained weight loss
• Abnormal changes in bladder habits
• Changes in skin texture or color
• Persistent cough or hoarseness

When to see a doctor

Having any one of these symptoms doesn’t necessarily mean that you have cancer. Even a lump could be a cyst or abscess rather than a tumor. However, if you feel that any one of these symptoms is abnormal for your body, trust your intuition. You know yourself best, so if you think something isn’t quite right, get it checked out.

“You are your best doctor.” — Dr. John Kiluk, MD, FACS, Surgical Oncology, Moffitt, 2025.

It can be easy to brush off symptoms, especially since many of the symptoms of cancer are not particularly unique to cancer. However, if you feel like a symptom may be even slightly abnormal for your body, it is always better to get screened. Worst case you lose some time and energy, best case you save your life.

What Causes Cancer?

Genetic and epigenetic factors

As previously mentioned, a disruption of the cell cycle can lead to cancer. The cell cycle is maintained by specific proteins, like the p53 protein, which are produced using your DNA. Specific mutations in one’s DNA can lead to an increase in the likelihood of developing cancer. For example, mutations in DNA can create a new protein that bypasses checks in the cell cycle, or can inactivate a protein that helps prevent DNA damage. Some individuals are more prone to developing these mutations than others, meaning that they are born with a naturally higher risk of cancer. You may have heard of this before, such as the BRCA1 and its multiple alleles.

Environmental risks

The environment that one is in can also increase the likelihood of developing cancer. The most notable environmental factors that can lead to an increase in cancer include: air quality, water quality, access to healthcare, food quality, sun exposure, exposure to harmful chemicals or radiation, among many others.

Behavioral factors

Unsurprisingly, the behaviors that one performs can impact their chances of getting cancer. Some actions, like smoking, tanning, or drinking, drastically increase your chances of developing cancer. Read more about this in the “How do you prevent cancer?” section!

Random mutations (chance)

Sometimes getting cancer is due to chance. Whenever a cell divides, it has to replicate all of its DNA. When replicating, small mutations often occur. Generally, these mutations are harmless, but sometimes, due to sheer chances, these mutations can activate cancer-causing genes. These are usually controlled for and managed, but sometimes a cell will mutate just right, creating the perfect cellular cocktail to create cancer.

How do you Prevent Cancer?

Lifestyle changes, vaccinations, and understanding your own risks

While it’s nearly impossible to tell what causes any person’s cancer, there is a clear relationship between carcinogen exposure and the development of cancer. Thus, the first thing that you can do to minimize your chances of getting cancer is understanding the risks unique to your own environment. There are a variety of behavioral and environmental factors that greatly increase one’s risk of developing cancer, including:

• Smoking, vaping, and other tobacco products (such as dip)
• Tanning (which is essentially UV radiation)
• Drinking
• Obesity/sedentary lifestyle (↑ inflammation and carcinogenic foods intake)
• Stress (impairs immune system)

It would be naive to try to stop or eliminate any of these behaviors. One doesn’t just ‘unstress’ completely, and drinking can be fun. But at the end of the day, any reduction of these behaviors will reduce your risk of cancer. So, you don’t have to stop drinking or smoking, but reducing your alcohol and tobacco intake in any amount will decrease your chances of lung, breast, gastrointestinal, liver and pancreatic cancers. No matter what, if you choose to reduce these behaviors in any amount (even one less drink per night), you should be proud of the steps you’re taking to prevent cancer.

How is Cancer Named?

The name of a cancer is made up of two to three parts: a Latin prefix (first part), sometimes an infix (middle part), and a suffix (end part). Generally, the prefix (first part) refers to the organ or cell type that the cancer is made of. If present, the infix (middle part) will usually clarify the type of tumor that is present. Finally, the suffix (end part) is typically -oma, meaning ‘tumor’. For example, the cancer Angiosarcoma can be broken down into three parts:

• Angio – “vessel” (prefix)
• Sarc – “flesh” or “soft tissue” (infix)
• Oma – “tumor” (suffix)

Putting it all together, angiosarcoma means vessel soft tissue tumor, or a cancer originating in the blood/lymphatic vessels.