Cancer is a deadly disease that threatens our lives, yet many people lack knowledge about it. In this post, I aim to provide useful information and present cancer from an evolutionary perspective.
To understand cancer, we must grasp how our body functions. Our body consists of over 100 trillion cells that work together for our organism to operate. These cells follow "social cues" dictating their survival and division. Disobedient cells face penalties, such as activating a cell suicide program to prevent uncontrolled division. Cell reproduction is crucial to our survival, but strict control mechanisms maintain order. These intricate cellular mechanisms have evolved to see us through the first 50 years of our lives and they work remarkably well.
However, evolution has not exerted much selective pressure to limit cancer beyond our reproductive years. While the chances of being diagnosed with cancer increase after 50, it's not a guaranteed outcome. Many individuals live long, cancer-free lives. The same applies to animals, like mice, which tend to develop cancer in their later years. However, most wild mice do not live long enough to experience cancer, as they often succumb to other causes like hunger, cold, or predators. Evolution has prioritized energy allocation for survival and reproduction during youth, rather than investing in tissue maintenance and cancer prevention later in life. This strategy maximizes reproductive success, weighing the costs and benefits of tumor suppression.
How does cancer develop?
Our bodies are exposed to environmental factors and DNA mutations caused by radiation and chemicals. Normally, our cells can repair DNA damage and eliminate affected cells. However, if damaged cells aren't eliminated, they can accumulate mutations and lose control, leading to uncontrolled proliferation and cancer. Mutations compromising the structure or function of control mechanisms increase the risk. Fortunately, nature has provided safeguards to prevent cancer, such as the abundance of non-coding DNA that is less prone to harmful mutations. Additionally, cells have limited replication ability due to telomeres, which protect chromosomes but shorten with each replication, reducing the risk of cancer.
To understand our vulnerability to cancer, we need to grasp the concept of multiple mutations in cells. Mutated cells are typically less fit than their surroundings, leading to competition for nutrients. When we're young and fit, the competition is fierce, making it difficult to develop cancer. However, as we age and our cell fitness declines, damaged cells have a better chance of survival and initiating cancer. Cancer encompasses over 200 different types, grouped based on the tissues they originate from: Carcinomas: Develop in epithelial cells that cover external and internal body surfaces, such as lung, breast, and colon cancer. Sarcomas: Originate in supportive tissues like bone, muscle, and fat. Lymphomas: Form in lymph nodes and the immune system. Leukemia: Arises in blood cells in the bone marrow. These different types require specific treatments due to their varying behavior. Targeting cancer cells can be challenging, as they exploit the body's necessary "social cues" like hormones and growth factors. Cancer cells can evolve over time, acquiring new abilities and becoming self-sufficient in growth signaling, leading to rapid expansion and resistance to treatment. Even when a therapy works, a single mutated cell can reignite cancer, which is why doctors use the term "remission" rather than "cured."
How to reduce the risk of cancer?
While some cancer risk factors are beyond our control, like genetics and accidental exposure to carcinogens, we can focus on what we can do to lower our chances of getting cancer. It may not sound groundbreaking, but common sense plays a key role. Sometimes we need others to remind us of what we already know. Just like when a doctor advises weight loss and exercise, deep down, we knew it all along. There are no magic pills or effortless solutions to prevent cancer. It requires effort on our part to maintain a healthy lifestyle, which includes physical exercise and a balanced diet. You don't need a gym membership you'll never use; the best exercise is the one you will actually do. Incorporate small changes like taking the stairs instead of the elevator or walking for a significant amount of time each day. Regular physical activity not only helps control weight but also improves blood circulation and promotes tissue repair by enhancing stem cell access. Establishing a routine is beneficial as our bodies thrive on consistency, whether it's meal times or exercise schedules. A strong immune system is crucial in preventing cancer, as it acts as our first line of defense. A balanced diet and sufficient sleep support the smooth functioning of our immune system. Additionally, early diagnosis can be life-saving. It's not just about the carrots you eat but also being proactive in seeking medical attention and screenings.
