Cancer

Definition

Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells in the body. When the normal regulatory mechanisms that control cell division fail, cells can proliferate excessively, leading to the formation of tumors that can invade surrounding tissues and spread to other parts of the body. Environmental exposures, such as chemicals, radiation, and lifestyle factors, significantly influence cancer risk and outcomes.

5 Must Know Facts For Your Next Test

1. Environmental factors account for an estimated 80-90% of cancer cases, highlighting the significant role that exposure to carcinogens plays in cancer development.
2. Certain lifestyle choices, such as smoking, diet, and physical activity, can increase or decrease an individual's risk of developing cancer.
3. Exposure to ultraviolet (UV) radiation from sunlight is a well-known risk factor for skin cancers, while occupational exposure to chemicals like asbestos is linked to lung cancer.
4. Preventive measures such as vaccination against certain viruses (like HPV) and regular screenings can help reduce cancer incidence and improve outcomes.
5. Research has shown that socioeconomic factors also play a role in cancer disparities, as individuals from lower socioeconomic backgrounds often face higher exposure to environmental risks and less access to healthcare.

Review Questions

• How do environmental exposures contribute to the risk of developing cancer?
  • Environmental exposures contribute to cancer risk by introducing carcinogens into the body, which can damage DNA or promote abnormal cell growth. For example, exposure to chemical pollutants in the air or water, as well as lifestyle factors like smoking and diet, are linked to increased cancer rates. Understanding these connections helps public health efforts target interventions and reduce overall cancer risk in populations.
• Discuss how epigenetics may play a role in the relationship between environmental exposures and cancer development.
  • Epigenetics involves changes in gene expression caused by environmental factors without altering the DNA sequence itself. Certain environmental exposures, such as pollution or dietary components, can lead to epigenetic modifications that influence how genes associated with cell growth and repair are expressed. This connection between environmental factors and epigenetic changes offers insight into how lifestyle and surroundings might increase cancer susceptibility.
• Evaluate the impact of socioeconomic factors on cancer incidence and outcomes, particularly concerning environmental exposures.
  • Socioeconomic factors significantly affect cancer incidence and outcomes through disparities in exposure to environmental risks, healthcare access, and health education. Individuals from lower socioeconomic backgrounds often live in areas with higher pollution levels and less access to preventive care. These factors contribute not only to increased cancer risk but also to poorer treatment outcomes and survival rates. Addressing these disparities requires targeted public health initiatives aimed at improving living conditions and access to healthcare for vulnerable populations.

Related terms

carcinogen: A substance or agent that can cause cancer in living tissue, often through damaging DNA or promoting abnormal cell growth.

tumor: An abnormal mass of tissue that can be benign (non-cancerous) or malignant (cancerous) and can disrupt normal body functions.

epigenetics: The study of changes in gene expression that do not involve alterations to the underlying DNA sequence, which can be influenced by environmental factors and contribute to cancer development.