Inflammation and Neoplasms: A Comprehensive Guide to Pathogenesis, Symptoms, and Prevention
Pathogenesis of Inflammation:
- Vascular Changes: Vasodilation occurs, increasing blood flow, leading to congestion. Dilated capillaries become more permeable, allowing fluids to leak out and cause swelling.
- Cellular Changes: Leukocytes adhere to the vessel walls (leukocyte marginalization). They then cross the endothelium and migrate to the site of infection through a process called diapedesis. At the site of the lesion, leukocytes phagocytize foreign particles and live agents, a process known as phagocytosis.
- Tumor Changes: Accumulation of water, acids, and fibrinogen in the injured area causes redness and swelling.
Symptoms of Inflammation:
- Tumor: Swelling due to the accumulation of blood and exudate at the site of inflammation.
- Rubor: Redness caused by vasodilation and increased blood flow.
- Calor: Heat produced by increased blood flow and metabolism during phagocytosis.
- Dolor: Pain caused by irritation of sensory fibers.
- Functio Laesa: Loss of mobility in the affected area.
- Other Symptoms: Fever, general malaise, fatigue, anorexia, and weight loss.
Neoplasms:
Cancer is a mass of abnormal cells that grow at an increased and uncontrolled rate, invading the surrounding normal tissues. These cells lack biological function, have an increased metabolism, consume more nutrients and energy, and produce waste substances with negative effects.
- Tumor: In the narrow sense, a tumor is any mass caused by an increase in the number of cells, regardless of whether they are benign or malignant. A malignant tumor, capable of invasion and metastasis to sites other than the primary tumor, is considered cancer.
- Benign: Non-cancerous. Benign tumors can be removed or excised, and in most cases, they do not recur. Benign tissue cells do not spread to other parts of the body (no metastasis). Benign tumor cells remain together and are often surrounded by a containment membrane or capsule. Benign tumors are not usually life-threatening but can cause problems if they compress adjacent organs. Examples include fibroid tumors of muscle tissue, osteoma (tumor originating in bone), angioma (tumor composed of small blood vessels), and papilloma (mass protruding through the skin, like a wart).
- Malignant Tumor or Cancer: From Greek, meaning “crab.” Cancer cells can invade and damage tissues of organs near the tumor. They divide more rapidly than benign cells and look different from the tissues from which they originated. Malignant tumors can enter the lymphatic system or bloodstream (metastasize). Examples include carcinoma (cancer originating in the epithelium, the most common type of cancer that can appear on the skin, lung, breast, and colon) and sarcoma (appears in the supporting connective tissue, or soft tissue, such as the lung).
Neoplasia: Literally means “new growth” or “new formation” but is used only in the context of cell proliferation. The terms neoplasia or malignant cell proliferation, when used in isolation, refer to cancer.
Incidence of Cancer:
Cancer medicine involves a set of symptoms, prognosis, and treatment options that vary depending on the anatomical location, cell type, and patient history. In 2004, cancer was the second leading cause of death, affecting 160,000 people and causing 97,000 deaths (32% men and 20% women). Percentage of deaths by cancer type:
- Men: Lung (27%), colorectal, prostate, hematologic
- Women: Breast (16%), colorectal, hematologic, lung
Levels of Prevention:
Prevention measures aim to prevent the onset of disease, reduce risk factors, halt the disease’s advance, and manage its consequences once established (WHO 1998).
- Primary Prevention: Measures taken before the disease occurs. Objective: To promote the emergence and consolidation of healthy lifestyle patterns in social, economic, and cultural development, known to contribute to maintaining health and reducing disease risk.
- Health Promotion: The process of enabling individuals to exercise greater control over their own health and potentially improve it (Ottawa Charter 1985, WHO). Health promotion aims to improve and increase levels of positive health.
- Primary Prevention: The set of measures applied in the management of the health-disease process before the individual becomes sick. These actions aim to prevent the occurrence of diseases and maintain health. The goal is to limit the incidence of the disease by controlling causes and risk factors. Examples include condom use for HIV prevention, routine immunization, and food hygiene.
- Secondary Prevention: Actions aimed at early detection of disease and timely treatment. Includes actions to recover health. The goal is to cure patients and prevent more serious consequences of the disease through early diagnosis and treatment. Usually applied to diseases whose natural history includes an early period that is easy to diagnose and treat. Requirements of a secondary prevention program include a safe and accurate method of detecting the disease, preferably in a preclinical stage, and effective treatment available. Examples include screening for breast cancer and diagnosing diabetes in early stages.
- Tertiary Prevention: Actions to reduce the prevalence of chronic disability in a population. Minimizing consecutive invalidities from disease. When the disease is usually chronic and fully developed, apply effective treatments, nursing care, and rehabilitation measures to alleviate disability, try to have fewer relapses, and achieve a better quality of life. Examples include health education to promote self-care for diabetics and rehabilitation of patients with polio, stroke, or loss of limbs. The goal is to slow the progression or complications of established disease.