Understanding Cancer Development

• Cancer is a group of diseases involving uncontrolled and unregulated cell growth.
• Cancer ranks as the second most common cause of death in the United States.
• Defective cell proliferation (growth) and differentiation are the two main dysfunctions in cancer development.
• Cancer cells proliferate at the same rate as normal cells from the tissue they originate from, but they do so indiscriminately and continuously.
• Differentiation is the process where undifferentiated cells mature and specialize to perform specific functions.
• Protooncogenes are normal genes regulating cell growth and differentiation.
• Mutations can activate protooncogenes into oncogenes, which induce tumors.
• Tumor suppressor genes regulate cell growth; their inactivation leads to a loss of tumor suppressing action.
• Cancer development is a multistep process involving initiation, promotion, and progression.
• Initiation is a mutation in the cell’s genetic structure, either inherited or from errors during DNA replication and is irreversible
• Promotion involves the reversible proliferation of altered cells.
• Progression includes increased tumor growth rate, invasiveness, and metastasis.
• The immune system is crucial in protecting the body from cancer.
• Immunologic surveillance is the immune system's response to malignant cell antigens.
• Tumor-associated antigens (TAAs) are altered cell surface antigens displayed by cancer cells due to malignant transformation.
• The immune system responds to TAAs through immunologic surveillance.
• Cancer cells evade the immune system through various mechanisms.
• Some cancer cells secrete substances that suppress the immune system.
• Some cancer cells change their surface to avoid immune system detection.
• Some cancer cells induce immune system tolerance to their TAAs.
• Cancers are classified by anatomic site, histology (grading), and disease extent (staging).
• Cancers are identified by their tissue of origin.
• Carcinomas originate from embryonal ectoderm and endoderm.
• Sarcomas originate from embryonal mesoderm, including connective tissue, muscle, bone, and fat.
• Lymphomas and leukemias originate from the hematopoietic system.
• Grade I cancer cells differ slightly from normal cells (well differentiated).
• Grade II cancer cells are more abnormal (moderately differentiated).
• Grade III cancer cells are very abnormal (poorly differentiated).
• Grade IV cancer cells are immature and primitive (undifferentiated), making the origin cell difficult to determine.
• Staging classifications describe the extent of the disease.
• The TNM classification system determines the anatomic extent of the disease.
• T stands for tumor size and invasiveness.
• N stands for presence/absence of regional spread to lymph nodes.
• M stands for metastasis to distant organ sites.
• Cancer can be prevented with lifestyle changes: avoid carcinogens, eat a balanced diet, exercise regularly, maintain a healthy weight, get adequate rest, manage stress, have regular physical exams, know your family history, practice self-examination, and seek medical care if cancer is suspected.
• Regular screening exams enable early cancer detection.
• Mammograms screen for breast cancer.
• Pap tests screen for cervical cancer.
• Colonoscopies screen for colon and rectal cancer.
• Prostate-specific antigen (PSA) blood tests screen for prostate cancer.
• Low-dose helical CT scans screen for lung cancer.
• Cancer treatment goals are cure, control, and palliation.
• Cure-focused treatment aims to eradicate the cancer.
• Control is aimed when the cancer cannot be completely eradicated but can be managed with therapy.
• Palliation aims to relieve symptoms and improve quality of life when cancer is advanced.
• Four main treatment modalities are surgery, radiation therapy, chemotherapy, and immunotherapy; targeted therapies are also under development.
• Surgery can prevent, diagnose, stage, treat, or palliate cancer.
• Radiation therapy employs high-energy radiation beams to destroy cancer cells.
• External (teletherapy) and internal (brachytherapy) methods are used for radiation therapy delivery.
• Chemotherapy uses drugs to kill cancer cells, administered orally, intravenously, or intrathecally.
• Immunotherapy uses the body’s immune system to fight cancer, involving interferons, interleukins, and monoclonal antibodies.
• Targeted therapy focuses on specific cell receptors and pathways crucial for cancer growth.
• Hematopoietic stem cell transplantation (HSCT) treats hematologic cancers, transplanting stem cells from a donor to a recipient.
• Stem cell sources for HSCT include bone marrow, peripheral blood, and umbilical cord blood.
• Cancer treatment can cause side effects like fatigue, nausea/vomiting, mucositis, skin reactions, bone marrow suppression, and peripheral neuropathy.
• Fatigue is a common side effect of cancer treatment.
• Chemotherapy, radiation therapy, and surgery can cause nausea and vomiting.
• Mucositis is the inflammation and ulceration of the digestive tract's mucous membranes.
• Radiation and chemotherapy can cause skin reactions.
• Bone marrow suppression can lead to anemia, neutropenia, and thrombocytopenia.
• Peripheral neuropathy is nerve damage causing pain, numbness, and tingling in the extremities.
• Cancer can cause psychological and emotional effects.
• Patients may experience anxiety, depression, fear, and anger and changes in body image and self-esteem.
• Nurses support patients and families, educate about cancer and treatment, administer treatments, monitor side effects, help manage side effects, advocate for patients, and help patients cope with psychological and emotional effects.
• Cancer is complex, with various types and stages, and treatment options are constantly improving.
• Nurses play a vital role in cancer patient care.
• Cancer is a significant health problem in the United States; incidence rates are increasing due to the aging population and lifestyle factors.
• Cancer is a leading cause of death in the United States.
• Improved screening tests and treatments have led to increased survival rates.
• Cancer includes more than 200 different diseases with uncontrolled cell growth.
• Cancer commonly refers to a malignant neoplasm.
• A neoplasm is an abnormal tissue mass resulting from excessive cell division or a failure of cells to die when they should, and can be benign or malignant.
• Benign neoplasms are well-differentiated compared to malignant neoplasms which range from well-differentiated to undifferentiated.
• Malignant tumors can invade and metastasize, unlike benign tumors.
• Promoters are agents causing initiated cells to proliferate.
• Progression is the last stage in cancer's natural development.
• Metastasis is the spread of cancer cells from the primary tumor to distant sites, commonly the lungs, liver, bone, brain, and adrenal glands.
• Immunologic surveillance involves the immune system recognizing and destroying foreign cells, including cancer cells.
• Cancer cells evade the immune system by suppressing the immune response, developing tolerance to TAAs, and hiding from the immune system.
• Cancers are classified by tissue of origin, histologic grade, and disease extent.
• Histologic grading assesses the differentiation degree of cancer cells.
• Staging determines the disease extent.

Explore the basics of cancer, a disease characterized by uncontrolled cell growth. Learn about defective cell proliferation and differentiation. Study the roles of protooncogenes, oncogenes, and tumor suppressor genes in cancer development.