Cancer
What It Is and How to Fight It

Our bodies are made up of about 100 trillion cells. These cells need to renew themselves, and to do this, they divide and produce new cells that replace dead or damaged ones. Within the 23 pairs of chromosomes that make up the cell genome, there are genes that regulate cell life and death, either promoting or inhibiting cell division. When this regulatory mechanism is disrupted for any reason, cells begin to reproduce too quickly, autonomously, and uncontrollably, forming tumors.

4 de diciembre de 2024

A Genetic Disease, But Not Hereditary

The term cancer comes from the Greek word for “crab.” It was first used to describe a malignant tumor with extensions spreading out from the center of the tumor, resembling the legs of a crab.

Cancer Is Caused by Changes in Genetic Material

This genetic material acts like an instruction manual that guides all the functions of our cells: what they should do, how to do it, and when. Some of these instructions—called genes—control cell multiplication. External factors (like tobacco, ultraviolet light, etc.) can introduce changes in genetic material. These changes are called mutations. A mutation is like replacing a word in the instruction manual, changing the meaning of the message. When a mutation occurs in the genes that regulate cell multiplication, the cell can lose control over this process and begin multiplying uncontrollably.

Why Isn’t Cancer Hereditary if It’s Genetic?

Mutations that cause cancer occur during an individual’s lifetime. Since these mutations affect the cells that make up the body (somatic cells) but not the germ cells (sperm and eggs), they are not hereditary. Only mutations affecting the genetic material of sex cells can be passed from parents to children.

Are There Hereditary Cancers?

When cancer is said to be hereditary, it actually means that a person has a predisposition to develop it. Luckily for us, we have two copies of each of our genes, one from our mother and one from our father. This is a safety mechanism: if we inherit a defective gene, the other copy can compensate. Similarly, if one copy undergoes a mutation, the other can take over. Most people have two healthy copies of the genes that control cell division. However, some people carry defective copies, meaning they only have one functional copy. As a result, they are more likely to be left without functional genes if a mutation occurs. These individuals also pass these defective copies to 50% of their offspring. So, while cancer itself is not hereditary, the tendency to develop it can be.

Some viruses can cause cancer by introducing their genetic material into ours, leading to mutations or activating cancer-causing genes.

Benign or Malignant Tumor?

A tumor is considered benign as long as its cells remain isolated and concentrated in one area of the body. However, because the cells multiply very quickly, their genome duplication can result in many errors (new mutations). Some of these mutations can enable the cells to move beyond the tumor. This is when the tumor becomes malignant. Metastasis occurs when tumor cells spread through the body—via the circulatory system, for example—and form tumors in different parts of the body. Tumors in vital organs can be fatal.

Of the 100 trillion cells in our body, it only takes one to lose control over its division to cause cancer.

Typically, cells that have lost control are eliminated by the immune system or other effective mechanisms. The problem ends there, without us even knowing. But when these mechanisms fail, that’s when a tumor develops.

Risk Factors

Many factors can cause mutations in the cell genome, potentially leading to cancer. Some of these carcinogenic agents are:

Tobacco

Pollution

UV radiation (part of sunlight)

Certain chemical components used in agriculture and livestock farming

How Can We Prevent Cancer?

Although the cause of most malignant tumors is unknown, different genetic, environmental, and lifestyle factors that favor the development of certain types of cancer have been identified. The most significant factor is tobacco, which is mainly related to lung, larynx, esophagus, and bladder cancer. Other factors related to cancer include diet, sun exposure, and certain chemicals.

Seven out of ten cancers could be prevented.
Smoking is the leading preventable cause of cancer.
The clear increase in lung cancer among women is directly related to the rise in smoking in this population.

It is estimated that one in three people will develop some type of cancer during their lifetime.

EUROPEAN CODE AGAINST CANCER

The European Code Against Cancer includes measures related to healthy lifestyle habits that reduce the risk of cancer.

Do not smoke. If you smoke, quit. If you can’t quit, do not smoke around nonsmokers.
Maintain a healthy weight and avoid obesity.
Engage in vigorous physical activity every day.
Eat a variety of fruits and vegetables daily, at least five servings each day. Limit your intake of foods high in saturated fats.
Limit alcohol consumption; the best way to prevent cancer is to avoid alcoholic drinks.
Avoid excessive sun exposure. It is especially important to protect children and teenagers.
Strictly follow regulations to prevent occupational and environmental exposure to carcinogenic substances, including ionizing radiation.

How Is Cancer Treated?

Various treatments are used to eliminate all cancer cells from our body, combined according to the type of cancer and its spread throughout the body. There are local treatments and systemic (whole-body) treatments. Local treatments include surgery and radiotherapy, which aim to remove the tumor or eliminate cancer cells by irradiating a specific area of the body. Systemic treatment, mainly chemotherapy, aims to eliminate cancer cells that have already spread throughout the body, so the drugs need to reach the bloodstream and distribute to the tissues. Other systemic treatments include hormones or immunotherapy, which aims to stimulate the immune system to fight cancer cells.

As the cellular and molecular mechanisms of cancer are better understood, new drugs that act more specifically on cancer cells are being discovered. In the past four decades, treatments have been discovered that can cure diseases that were once always fatal, such as testicular cancer, lymphomas, or leukemias. Currently, there are many research lines in cancer treatment, including gene therapy, which aims to modify the genetic material of cancer cells to change their behavior.

Since the 1990s, the overall cancer cure rate has been 50%. The survival rate for cancer patients in Spain is comparable to that of the most developed countries.

Why Does Chemotherapy Cause Hair Loss?

Cancer cells multiply very quickly, so they need to generate many proteins and genetic material (DNA).

Cancer cells multiply very quickly, so they need to generate many proteins and genetic material (DNA). Chemotherapy kills cancer cells by disrupting their synthesis process. However, other cells in our body also multiply quickly and are particularly sensitive to the effects of chemotherapy, including hair follicles. This is why hair loss, or alopecia, is a very common side effect of chemotherapy. Fortunately, this hair loss is reversible; hair grows back after the treatment ends.

How Does Cancer Affect Spaniards?

In Spain, it is estimated that almost one in two men and one in three women will be diagnosed with cancer at some point in their lives, according to the latest data.

Given the alarming forecast for the Spanish population—with high prevalence among men and women—cancer has been the leading cause of death since 1999. The most frequent cancers in men are prostate, colon and rectum, lung, and urinary bladder cancer, while in women, they are breast, colon and rectum, lung, and uterine cancer. The incidence of colon cancer is notably high in both sexes, highlighting the importance of early detection and prevention.