Cancer Overview and Epidemiology

Cancer Overview

• Cancer is a constellation of diseases characterized by uncontrolled growth of malignant cells, affecting all ages.
• Clinical presentation varies, from acute to chronic, depending on cancer type, stage, and molecular characteristics.
• Cancer is the leading cause of death globally, with increasing incidence.

Epidemiology

• Common cancers include lung, breast, colorectal, prostate, skin, and stomach.
• Incidence, prevalence, and mortality vary by sex, socioeconomic status, and carcinogen exposure.
• Women are more prone to breast, colorectal, or lung cancer; men are more prone to lung, prostate, or colorectal cancer.
• Cervical cancer is highly prevalent in less developed countries, now surpassed by lung cancer.
• Cancer incidence is higher in developed countries due to longer lifespans and weakened immune surveillance with age.
• Developing countries have lower cancer rates but higher mortality due to poor healthcare infrastructure.
• Infections (hepatitis, HPV) account for 25% of cancers in developing nations.
• Carcinogen exposure varies by region, leading to differing cancer patterns (e.g., stomach, esophageal, liver cancers are more prevalent in East Asia).

Prevalence in the United States

• Cancer is the second leading cause of death.
• More prevalent in older adults due to increased cell mutations with age (78% diagnosed in those 55+).
• 5-year survival rate >68% (increased from 50% in the 1970s).
• Common adult cancers (by incidence): prostate, breast, lung.
• Common cancers by sex: Men - prostate, lung, colorectal; Women - breast, lung, colorectal; Children - leukemia, brain tumors.

Risk Factors

• Carcinogens: Internal or external exposures causing DNA damage and mutations. Examples include ionizing radiation, benzene, HPV, sun exposure, and tobacco.
• Non-modifiable risk factors: Age and genetic predisposition (5-10% of cancers). Genetic counseling is valuable for individuals with family history and known genetic syndromes.
• Modifiable risk factors: Lifestyle factors including sedentary lifestyle, poor diet, and smoking.
• Modifiable risk factors related to other diseases increase cancer risk.
• Risk factors are considered cumulative, increasing the risk of cancer.

Genetic Connections

• Features of hereditary cancer include multiple tumors, tumors in atypical locations, tumors in unusual ages, tumors of different types (rare histology), or tumors in the uncommon sex.
• Family history also factors in (e.g., multiple first-degree relatives with tumors of the same site).

Pathophysiology

• Carcinogenesis: Begins with carcinogen exposure causing mutations, potentially bypassed by the immune system. Cancer cells then proliferate and progress, often with identifying genetic alterations.

• Cancer Characteristics: Marked by uncontrolled cell growth and altered cell differentiation.

• Uncontrolled cell growth: Lack of contact inhibition, apoptosis, and anchorage dependence; leading to dysplasia and neoplasia.

• Altered cell differentiation: Lose expected function; called anaplasia. Extent of differentiation is important for grading malignant neoplasms

• Metastasis: Spread of cancer cells locally or via the lymphatic or blood system. Predictable patterns (e.g., prostate cancer to rectum, colorectal to liver). Metastatic cells retain similar, but not necessarily identical, molecular characteristics to their origin.

Types of Cancer

• Solid tumors: Originate from specific organs, forming masses.
• Hematological malignancies: Arise from blood cells or immune organs like lymph nodes.
• Subcategories: leukemia (blood cells), lymphoma (lymphatic system), myeloma (plasma cells).
• Classification by organ or tissue origin (carcinomas, sarcomas)

Staging

• Classification of cancer based on tumor size, number of lymph nodes involved, and presence of metastases (TNM system). Stages are generally I-IV, with larger, more widespread stages presenting later in the disease process.

Clinical Presentation

• CAUTION symptoms: "Warning signs" of cancer (see Box 13.1). Symptoms lasting >2 weeks warrant evaluation.
• Constitutional symptoms: Fatigue, weight loss, fever, night sweats.
• Malignancy-specific signs: Symptoms linked to the location of the primary or metastatic tumor; e.g., brain cancer causing neurological symptoms.
• Oncological Emergencies: Acute complications. Can be categorized as structural, metabolic, or hematological. They require prompt intervention.

Prevention

• Primary Prevention: Modifies risk factors (e.g., smoking cessation), immunizations (e.g., HPV).
• Secondary Prevention: Early detection via screening tests (high sensitivity, specificity, and cost-effectiveness).
• Tertiary Prevention: Reducing morbidity/mortality once diagnosed.

Diagnosing Cancer

• Initial assessment based on CAUTION symptoms or other unusual signs.
• Tests: Laboratory (blood tests, tumor markers), imaging (CT, MRI, PET), biopsy, endoscopic procedures for appropriate evaluation and confirmation.

Treatment

• Varies by type, stage, and sometimes by molecular markers. Goals include cure, remission, disease control, or palliation (relief of symptoms).
• Treatment modalities include surgery, radiation, medical treatments, and cellular therapies.
• Neoadjuvant: Treatment to shrink the tumor before definitive removal.
• Adjuvant: Treatment to decrease the risk of recurrence after the initial treatment.
• Surgical Treatment: Total or partial excision of the tumor, potentially with reconstruction.
• Radiation Treatment: External beam, internal brachytherapy, systemic radiation.
• Antineoplastic/Targeted Therapies: Various classifications including chemotherapy, immunotherapies, and targeted therapy.
• Cellular Therapies/Bone Marrow Transplants: For certain cancers and hematological disorders.

Nursing Management

• Nurses manage patients across various settings, specializing in cancer-related issues.
• Consider unique considerations related to cancer (e.g., pain management, altered bowel function).

This quiz covers the basics of cancer, including its characteristics, types, and epidemiological data. Learn about the incidence and prevalence of various cancers across different demographics and healthcare systems. Understand the global landscape of cancer and its impact on different populations.