Cancer

Cancer is one of the major public health problems worldwide and is currently considered the second cause of death after cardiovascular diseases. In Venezuela, between 45,000 and 50,000 new cases each year have been reported (not including skin cancer cases) of which over 20,000 resulted in death, which makes cancer in Venezuela one of the primary causes of morbidity and mortality. Until recently, prostate and cervical cancer were the most common cancers observed in men and women respectively; however, now the number of breast cancer cases has increased rapidly and it is estimated that within a few years this type of cancer will overtake cervical cancer. Statistics show that globally there are 1.38 million new cases of breast cancer each year, and 458,000 deaths, making it the most frequent in women, in developed and developing countries.

In 2003, Dr. Convit at the Institute of Biomedicine, began the first studies on a treatment based on immunotherapy for breast cancer and a few cases for colon, stomach and brain, which was documented in 2006 in the Official Medical Journal of Venezuela. (http://publicaciones.jacintoconvit.com/2006/?i=art2)

This proposal aims to stimulate the patient's immune response in order to activate the cell proliferation and elimination of the tumor cells. For the time being, this immunotherapy is experimental and continues under the process of validation.

The Jacinto Convit Foundation mainly works to continue the scientific protocol that Dr. Convit began in cancer immunotherapy more than a decade ago. Additionally, it is developing a program that can contribute to the prior step of treatment, which is to offer an early, more precise and personalized diagnosis of the disease. Therefore the Foundation has established two main objectives:

1. Perform validation of the experimental studies in animal models with the immunotherapy treatment developed by Dr. Convit. This study is based in the induction of primary tumors in experimental animals, and the use of the therapy to induce immunological cellular responses that are more aggressive against tumor cells. These studies are being coordinated with the Jose Maria Vargas Medical School of the Central University of Venezuela.

2. Establish a Molecular Diagnosis Unit based on conventional and cutting edge molecular techniques (i.e. pyrosequencing) to make a significant contribution to the diagnosis and prognostics for the different types of pediatric cancers, as well as the child's susceptibility to the treatment. This platform is being developed with the collaboration of the Children's Hospital JM de los Rios and the SANA Civil Association, as well as other institutions and donors.

¿What is cancer?

Cancer is a term used to describe diseases in which abnormal cells divide uncontrollably and can invade other tissues. Cancer cells can spread to other parts of the body through the bloodstream and lymphatic system. There are presently more than 100 different types of cancer, most of which take on the name of the organ or cell in which it develops. For example, the cancer that develops in the mammary glands is called breast cancer while the cancer that develops in the colon is called colon cancer.

¿How does cancer develop?

Cancer originates in normal cells in the body. Normal cells multiply continuously, fulfilling a programmed and orderly cycle of growth, development and death. During this cycle the cells must go through different checkpoints. Cellular checkpoints are mechanisms that ensure the constancy of cell division, verifying whether the processes in each stage of the cell cycle have been accurately completed before progressing to the next stage. Many checkpoints have been identified. Cancer happens when the control and regulation of the cell cycle is lost, generating an uncontrolled growth of cells in the body which divide too quickly. It can also occur when cells that should be eliminated from the body don't go through the cell death stage and continue to multiply constantly.

Cancer is the uncontrolled growth of abnormal cells in the body, where a normal cell turns into an altered cell and develops in what is known as a tumor cell. During this process which develops in stages, the tumor cells begin to grow in a rapid and uncontrolled manner, overstepping their boundaries and capable of invading adjacent parts of the initial organ or spreading to other organs, a process known as metastasis. Metastases are the major cause of cancer-related deaths. In some cases, cancer cells can spread to other parts of the body through the bloodstream and lymphatic system.

The cause of transformation of a cell to a cancer cell is generally due to an alteration or genetic mutation (DNA), that is never repaired and with the ability to divide itself, generating new cells that have the same DNA alteration. In most cases, these cancer cells form a tumor, although some types of cancer such as leukemia rarely form tumors.

¿What causes cancer?

Cells undergo alterations caused by a set of interacting factors, such as patient-specific factors (genetic predisposition, age, ethnicity, geographic location, etc.) and environmental factors (food, tobacco and alcohol consumption, chemical food additives, pollution, medications and therapy, infections, etc). Tobacco and alcohol consumption, a poor diet and physical inactivity are the main risk factors for cancer in the world.

Cancer can arise spontaneously and in response to a chemical, physical (mutagenic substance) or biological agent (infectious agent). Among the mutagens are: physical agents (X-rays, ionizing radiation, etc.) and chemical agents (alkylating agents, aromatic amines, etc.). Some examples of biological agents are the human papilloma virus and bacteria such as Helicobacter pylori, among others.

¿Is there treatment for cancer?

A variety of cancer treatments are currently available. However, the application and type of treatment varies according to the type of cancer and its stage. The stage of a cancer refers to how much it has grown and to whether the cancer cells have spread or not from their original location. If the cancer is confined to one spot and has not spread, the most common treatment is to remove the tumor by surgery. Cancer cells that have spread to local lymph glands can also be removed by this method. If, however, the cancer cannot be completed removed by surgery, treatment options include radiation, chemotherapy or a combination of both. Some cancers require a combination of surgery, radiation and chemotherapy. Lymphomas (lymph node cancer) are rarely treated with surgery; chemotherapy and radiation therapy are most often applied to treat this type of cancer.

Although chemotherapy and radiotherapy are the main cancer treatments applied, in the past several years the use of immunotherapy has been proposed as an alternative treatment. This therapy is being widely studied worldwide and considered as the biggest scientific breakthrough of the year by the prestigious Journal of Science in 2013 (http://news.sciencemag.org/breakthrough-of-the-year-2013). In recent reports, immunotherapy has been described as the new era for cancer treatment that has a completely different approach to traditional treatments, because it targets the immune system of the patient to stimulate it, instead of targeting the tumor only.

Presently, there are many types of immunotherapy, all aimed at eliminating cancer cells. Among these are:

• Monoclonal Antibodies: which are a type of protein produced in the laboratory that can bind to specific proteins of cancer cells (generally absent in normal cells), triggering the destruction of the cancer cell due to the patient's own immune system.

• Non-specific immunotherapies: these activate the overall immunological system to induce the destruction of the cancer cells. Most non-specific immunotherapies are administered after or simultaneously with other cancer treatments such as chemotherapy or radiotherapy.

• Vaccines: they expose a protein (antigen) to the immune system activating it and allowing it to recognize and destroy that specific protein or related cells. For cancer cases there are two types of vaccines, one for prevention, applied to someone without symptoms to avoid the developments of the disease; and one for treatment, that helps the immune system to attack the disease, helping it identify the cancer cells in order to destroy them and avoid recurrence of the disease.

¿How can morbidity and mortality caused by cancer be prevented?

Most cancers are most likely to be cured if detected early and treated properly. Over 30% of all cancer deaths could be prevented by modifying or avoiding key risk factors, such as tobacco and alcohol consumption, obesity, poor diet, physical inactivity and specific viral infections.

Prevention strategies

• Vaccines for human papilloma virus (VHP) and hepatitis B virus (HBV)

• Monitoring of occupational risks

• Reduction of direct exposure to sunlight.

• Prevention of the major risk factors above

Early Detection

Cancer mortality can be reduced if cases are detected and treated early. Early detection activities have two components:

• Early diagnosis: Knowledge of the signs and symptoms (as in cervix, breast or mouth cancers) facilitates the diagnosis and treatment before the disease reaches an advanced stage. Early diagnosis programs are particularly important in underprivileged communities where most cases are diagnosed in advanced stages and there are no screening programs.

• Screening: It is the systematic application of screening tests in an asymptomatic population in order to identify those patients who have abnormalities indicative of a specific cancer or precancerous lesions so they can be diagnosed and treated early. Screening programs are especially effective in the case of common cancers for which there are cost-effective, affordable, and acceptable tests for the majority of the population at risk.

¿Can children get cancer?

Yes, they can. Childhood cancer or pediatric cancer is cancer in children and young people. It's important to point out that when cancer affects a child or young person, it does so differently than in adults. A child with cancer must be accurately diagnosed and treated by a team of specialists in pediatric oncology. In most cases, there is a better prognosis in childhood cancer than in adults. Therefore, it is essential that all children have access to adequate treatment at the right time.

The most common cancers in children and adolescents are Leukemias (blood cancers) and solid tumors in the brain and central nervous system. Each cancer behaves differently, but they all have one common characteristic: the uncontrolled proliferation of abnormal cells.

REGIONAL HEALTH SERVICES DERMATOLOGY (UPDATED SEPTEMBER 2019)