Cell Cycle PDF

Cell Cycle The cell cycle is like a life cycle for cells. It involves growth and development so a cell can create two identical daughter cells. Interphase 1. G1 Phase (Gap 1): The cell grows and performs normal functions. It also prepares for DNA replication. 2. S Phase (...

Cell Cycle The cell cycle is like a life cycle for cells. It involves growth and development so a cell can create two identical daughter cells. Interphase 1. G1 Phase (Gap 1): The cell grows and performs normal functions. It also prepares for DNA replication. 2. S Phase (Synthesis): DNA replication occurs, and each chromosome is duplicated, forming two sister chromatids. 3. G2 Phase (Gap 2): The cell continues to grow, makes proteins, and prepares for cell division. M Phase (Mitosis) Mitosis is the process where a single cell divides to form two identical daughter cells. It includes several sub-phases: 1. Prophase: Chromosomes condense, the nuclear membrane begins to break down, and the mitotic spindle starts to form. 2. Metaphase: Chromosomes line up along the center of the cell (metaphase plate). 3. Anaphase: Sister chromatids are pulled apart towards opposite poles of the cell. 4. Telophase: The chromatids reach the poles and the nuclear membrane starts to reform around each set of chromosomes. Cytokinesis This is the final step, where the cytoplasm divides, and two separate daughter cells are formed. It usually overlaps with telophase. 1. G1 Checkpoint (Start Checkpoint) Checks for: ○ Nutrients: The cell needs enough nutrients to grow and divide. ○ Growth Factors: External signals (growth factors) that tell the cell to divide. ○ DNA Damage: Ensures the DNA is free from damage before replication begins. ○ Cell Size: The cell must be large enough to divide properly. If these conditions aren't met, the cell may enter a G0 phase, which is a resting state. In this phase, the cell is not actively preparing for division. 2. S Phase Checkpoint Checks for: ○ DNA Synthesis: This checkpoint ensures the DNA is replicating correctly during the S phase. Any mistakes in DNA replication need to be repaired before the cell can continue. 3. G2 Checkpoint Checks for: ○ Cell Size: Ensures the cell is large enough for mitosis. ○ DNA Replication: Makes sure that DNA replication is completed correctly without errors. ○ DNA Damage: Verifies that there are no remaining DNA errors after the S phase. If DNA damage is detected, the cell may pause to repair it. 4. Metaphase Checkpoint (Spindle Assembly Checkpoint)  Checks for: ○ Chromosome Spindle Attachment: Ensures that all chromosomes are properly attached to the spindle fibers in preparation for segregation. If any chromosomes are improperly attached, the cell won't proceed with mitosis. G0 (Resting-State) If a cell doesn’t pass through the G1 checkpoint, it may enter the G0 phase, a state where the cell is not actively dividing or preparing for division. Cells in G0 can remain in this resting state for extended periods or be triggered back into the cell cycle when needed (e.g., when the body needs more cells). Interphase - the longest cells G1 - where cells 2nd stage prepared Metaphase - spindle attachment (normal) dapat hanapin / checkpoint (Pagdating sa G2 tapos kulang, dadagdagan pa) S-phase - where cells duplicating Identical daughter cells should be identical Remember that cancer cells daughter cells Group of cells = tissue Mitosis - the shortest cells phase IN SITU - means localized (only in one place) (Apoptosis - break the cycle/kapag hindi natuloy/cell death) Stage 2- localised spread COFFEE - ANTIOXIDANT Carcinogenesis (Cancer Development) Carcinogenesis is a 3-step process: 1. Initiation: Cancer-causing agents (chemicals, physical, or biological) alter DNA. 2. Promotion: Ongoing exposure to harmful agents causes abnormal genes to be expressed. 3. Progression: Cancer cells grow uncontrollably, spreading to other areas (metastasis). Oncology and Cancer Terminology Oncology is the study of cancer, and its detection, treatment, and management. Root Words: ○ Neo- = new ○ Plasia = growth ○ Plasma = Substance ○ Oma = tumor ○ Statis- location ○ A = none ○ Ana- = lack ○ Hyper- = excessive ○ Meta- = change ○ Dys = bad/deranged REMEMBER THAT CANCER CELLS: Cancer starts when a cell's DNA is mutated, causing it to grow uncontrollably and spread to other tissues, possibly leading to death. Types of cancer: ○ Carcinomas arise from epithelial tissue.  ○ Sarcomas arise from connective tissue. ○ Lymphomas/myelomas come from the immune system cells. Cancer Warning Signs (C-A-U-T-I-O-N-S) C: Change in bowel/bladder A: A lesion that doesn't heal U: Unusual bleeding T: Thickening or lump I: Indigestion/difficulty swallowing O: Changes in wart/mole N: Nagging cough or hoarseness U: Unexplained anemia S: Sudden weight loss Tumors and Cancer Types Benign neoplasm: Slow-growing, not cancerous. Malignant neoplasm: Aggressive, spreads to other tissues (metastasis). Metastasis: Cancer cells spread via blood or lymph to other parts of the body. Tumor Grading Grade 1 (Well Differentiated): Cell Appearance: The tumor cells are only slightly abnormal and closely resemble normal cells. Prognosis: Generally, Grade 1 tumors tend to grow and spread more slowly. Grade 2 (Moderately Differentiated): Cell Appearance: The tumor cells are more abnormal and have a noticeable difference from normal cells. Prognosis: Grade 2 tumors tend to grow at a moderate rate. Grade 3 (Poorly Differentiated): Cell Appearance: The tumor cells are very abnormal and don't resemble normal cells as much. Prognosis: Grade 3 tumors tend to grow and spread more rapidly compared to lower-grade tumors. Grade 4 (Undifferentiated/Immature): Cell Appearance: The cells are very immature and have little to no resemblance to normal cells. Prognosis: Grade 4 tumors are typically the most aggressive, growing and spreading very quickly. These tumors often present the most challenging treatment outcomes. Cancer Staging One of the most commonly used staging methods is the TNM system, which evaluates three main factors: Tumor (T), Nodes (N), and Metastases (M). 1. Tumor (T): This refers to the size of the primary tumor and how far it has spread in the area where it started. T0: No evidence of a primary tumor. Tis: Carcinoma in situ (early-stage cancer where abnormal cells are present but have not spread beyond the layer of tissue in which they originated, i.e., "limited to surface cells").  T1-T4: These numbers describe the size and extent of the tumor. T1 indicates a small tumor, while T4 represents a large or deeply invasive tumor. 2. Node (N): This indicates whether cancer has spread to nearby lymph nodes, which are part of the body’s immune system and act as a potential route for cancer cells to travel. N0: No lymph node involvement (the cancer hasn’t spread to nearby nodes). N1-N4: Increasing degrees of lymph node involvement. As the number increases, the number of affected lymph nodes and the extent of the spread increase. Nx: The lymph nodes cannot be assessed, possibly due to lack of information or difficulty in evaluating them. 3. Metastases (M): This measures whether the cancer has spread to distant parts of the body, far from the original tumor. M0: No evidence of distant metastases (the cancer has not spread to distant parts of the body). M1: Evidence of distant metastases (the cancer has spread to other parts of the body beyond the primary site). Staging Summary: The cancer stage is typically described as a combination of these factors (T, N, M), such as: Stage 0: Carcinoma in situ (Tis, N0, M0) Stage I: Small tumor, no lymph node involvement, no distant spread (T1-T2, N0, M0) Stage II: Larger tumor or limited lymph node involvement, no distant spread (T2-T3, N1, M0) Stage III: More extensive local spread or involvement of more lymph nodes, no distant spread (T3-T4, N2-N3, M0) Stage IV: Cancer has spread to distant parts of the body (any T, any N, M1) Numerical Cancer Staging System Stage 0: (localized to surface cells). Stage 1: Limited to the tissue of origin, evidence of tumor growth. Stage 2: Local spread to nearby tissues. Stage 3: Extensive local and regional spread, including lymph nodes. Stage 4 Distant metastasis (spread to distant organs or areas). Pathophysiology of Cancer  Cancer cells: Grow uncontrollably and invade other tissues. They spread through the blood and lymphatic systems to other organs (liver, lungs, brain, etc.), potentially interfering with vital functions. Cancer Genetics Oncogenes: Genes that cause cancer. They can be normal genes that become overly active or mutated. Tumor suppressor genes: Normally prevent cell division. In cancer, these genes stop working. Risk Factors for Cancer Breast Cancer Risk Factors: Early pregnancy (before 20), family history, obesity, smoking, alcohol use, and others. Cancer Types: Includes DCIS (Ductal Carcinoma in Situ), LCIS (Lobular Carcinoma in Situ), and others. Carcinoma of the Breast: Risk Factors Diet: Coffee may reduce risk; alcohol increases risk. Obesity: Increases risk, especially after menopause. Exercise: Protective against breast cancer. Breastfeeding: Longer breastfeeding reduces risk. Environmental Toxins: Potential risk factors, particularly during sensitive developmental stages. Tobacco: Increases risk, especially in younger women or those with family history. Hormonal and Genetic Factors: Major contributors to breast cancer risk. Cancer of the Breast Symptoms: Lump, nipple inversion, skin changes, etc. Types: Invasive and non-invasive cancers, with metastatic spread mainly through lymph nodes. Staging: Describes how far the cancer has spread (0–IV). Interventions and Management Surgical Options: ❖ Lumpectomy: Tumor removal with minimal tissue loss.  ❖ Partial/Segmental Mastectomy (Quadrantectomy): Removal of a larger portion of the breast. ❖ Total Mastectomy: Removal of the entire breast. ❖ Modified Radical Mastectomy: Removal of the entire breast and lymph nodes. ❖ Radical Mastectomy: Removal of the entire breast, lymph nodes, and chest muscles (rarely performed today). Nonsurgical Options: ❖ Chemotherapy, radiation, hormonal therapy. Nursing Care for Cancer Patients Monitor for complications like lymphedema (swelling), hematoma (bruising), and infection. Supportive Care: Provide emotional support, explain treatments, and manage symptoms like fatigue, nausea, and hair loss. Teach breast self-exams regularly for early detection. When to Perform BSE: 1. For Menstruating Individuals: ○ Perform the BSE 7 to 10 days after the start of your menstrual period when breasts are least likely to be swollen or tender. 2. For Postmenopausal Individuals or Those Who Have Had a Hysterectomy: ○ Choose a specific day of the month and perform BSE on that same day each month to maintain consistency. Lung Cancer Lung cancer: Uncontrolled cell growth in the lungs, often metastatic. There are two main types: small cells and non-small cells. Risk Factors: Inhaled Irritants: Chronic exposure to irritants that damage lung tissue increases the risk of lung cancer. Major inhaled irritants include: ○ Cigarette Smoke: The primary cause of lung cancer, linked to both direct and secondhand smoke exposure. ○ Occupational Exposures: Certain industries expose workers to harmful chemicals, including asbestos, radon, and heavy metals. ○ Air Pollution: Pollutants such as benzopyrenes and hydrocarbons (often found in vehicle exhaust and industrial emissions) elevate risk. Types of Lung Cancer: Lung cancers are classified broadly into two main types, based on their growth rates, patterns, and tendencies to spread (metastasize). 1. Small Cell Lung Cancer (SCLC): ➔ Oat Cell Carcinoma: Known for its rapid growth rate and early spread to distant organs. 2. Non-Small Cell Lung Cancer (NSCLC): ➔ Adenocarcinoma: A common type of NSCLC with a moderate growth rate and early metastasis. Often found in the outer regions of the lung, this type is frequently diagnosed in non-smokers. ➔ Squamous Cell Carcinoma: This slow-growing cancer has a later metastasis compared to other types. It typically starts in the central part of the lungs and is more associated with a history of smoking. ➔ Large Cell Carcinoma: Characterized by fast growth and early spread, making it challenging to treat. Large cell tumors may appear anywhere in the lung and often grow aggressively. Liver Cancer Liver Cancer: Liver cancer is a disease where malignant cells form in the liver's tissues. The liver, located in the upper right abdomen, is responsible for detoxifying blood, aiding digestion, and storing energy. Types of Liver Cancer: 1. Hepatocellular Carcinoma (HCC): The most common form, starting in hepatocytes (the main liver cells). 2. Intrahepatic Cholangiocarcinoma: A less common form that begins in the bile ducts within the liver. 3. Hepatoblastoma: Rare and generally found in young children. Risk Factors: Several factors increase the risk of developing liver cancer, including: Chronic Hepatitis B or C Infections: Persistent infections damage the liver and increase cancer risk. Liver Cirrhosis: Scarring from cirrhosis, often due to alcohol or hepatitis, makes cancer more likely. Inherited Liver Diseases: Conditions like hemochromatosis (excess iron) and Wilson's disease (copper buildup) raise risk. Diabetes and Nonalcoholic Fatty Liver Disease (NAFLD): Can contribute to liver cell damage over time. Exposure to Aflatoxins: These toxins, from molds found on crops like peanuts, are linked to liver cancer. Excessive Alcohol Consumption: Long-term heavy drinking can cause cirrhosis, increasing the likelihood of cancer. Pathophysiology of Liver Cancer: Liver cancer occurs due to mutations in liver cells' DNA. DNA is the blueprint for cell function, and when mutations alter this blueprint, cells may grow uncontrollably, forming tumors. Chronic hepatitis infections are known to trigger this process, though in some cases, the cause remains unknown. Care and Complications for Liver Cancer Patients Complications: Acute Graft Rejection: In cases where a liver transplant is necessary, the body may reject the new liver. Liver or Kidney Failure: Liver cancer can lead to liver failure, and impaired blood flow may also cause kidney failure, worsening the patient’s condition Stomach Cancer Stomach cancer, or gastric cancer, often begins in the mucus-producing cells that line the stomach. This specific type is known as adenocarcinoma. In recent decades, the rate of cancer occurring in the main part of the stomach has declined globally. However, cancer has become more common in the gastroesophageal junction—the area where the top part of the stomach (cardia) meets the lower end of the esophagus. Risk Factors for Stomach Cancer Several factors increase the risk of stomach cancer, especially in the stomach body: Dietary Habits: High intake of salty and smoked foods; low intake of fruits and vegetables. Family History: Having relatives with stomach cancer. Helicobacter pylori Infection: Chronic infection with this bacterium is a major risk factor. Long-term Stomach Inflammation: Ongoing stomach inflammation can lead to changes in stomach lining cells. Pernicious Anemia: A condition affecting stomach lining and B12 absorption. Smoking: Increases risk, particularly with prolonged exposure. Stomach Polyps: Certain types of polyps raise the risk of developing cancer. Stages of Stomach Cancer Adenocarcinoma of the stomach or gastroesophageal junction cancer is categorized into stages based on tumor size, spread depth, and lymph node involvement.  Stage I: Cancer is confined to the top layer of tissue lining the esophagus or stomach, potentially with minimal lymph node involvement. Stage II: The tumor has grown into the deeper muscle layers of the esophagus or stomach and may affect more lymph nodes. Stage III: Cancer has spread through all layers of the stomach or esophagus, reaching nearby structures or lymph nodes. Stage IV: Cancer has metastasized to distant parts of the body. Nursing Diagnoses for Stomach Cancer Patients: 1. Risk for infection 2. Impaired gas exchange (problems with air circulation in the lungs) 3. Acute pain 4. Altered nutrition (not getting enough food) 5. Risk for ineffective management of treatment 6. Risk for skin damage 7. Anticipatory grieving (emotional stress about the future) Care of Patients with Stomach Cancer Pathophysiology of Stomach Cancer Stomach cancer generally begins with a mutation in a cell's DNA, causing the cell to grow and divide uncontrollably. Unlike normal cells, these mutated cells do not die when they should, leading to an accumulation of cancerous cells that form a tumor. This tumor can invade nearby structures and spread to other parts of the body. For gastroesophageal junction cancer, there are specific associated risk factors: Gastroesophageal Reflux Disease (GERD): Chronic backflow of stomach acid into the esophagus damages the lining, increasing cancer risk. Obesity and Smoking: Both are linked, though less strongly than GERD, to increased risk of gastroesophageal cancer. Colon Cancer  Colon cancer begins in the large intestine, the last part of the digestive tract. It often starts as benign polyps inside the colon, which can gradually develop into cancer. Since polyps may be asymptomatic, regular screening is recommended to detect and remove them before they become cancerous. If colon cancer does develop, treatments include surgery, radiation, chemotherapy, targeted therapy, and immunotherapy. The most common type of colon cancer is adenocarcinoma, which often spreads to the liver through the lymphatic or circulatory system. Pathophysiology: Colon cancer begins in the large intestine, often starting from small growths called polyps. These can become cancerous over time. Colon cancer often doesn’t cause symptoms early on, which is why doctors recommend screenings to detect polyps before they turn into cancer. Risk Factors: Older age (usually over 50) African-American race History of inflammatory intestinal conditions Family history of colon cancer Poor diet, diabetes, obesity, smoking, and alcohol use Duke’s Classification for Colon Cancer: Stage A: Limited to the bowel lining, 80-90% survival in 5 years Stage B: Cancer has spread into the muscle wall Stage C: Cancer has spread to lymph nodes Stage D: Cancer has spread to other organs (like the liver), with less than 5% survival in 5 years Nursing Diagnoses for Colon Cancer Patients: 1. Risk for infection 2. Impaired gas exchange (related to lung function) 3. Acute pain 4. Altered nutrition (not enough food) 5. Risk for ineffective treatment management 6. Risk for skin damage 7. Anticipatory grieving Care of Patients with Ovarian Cancer Ovarian cancer begins in the ovaries, small organs in the female reproductive system that produce eggs and hormones like estrogen and progesterone. Often undetected in early stages, ovarian cancer may not be diagnosed until it has spread to the pelvis or abdomen, making it more challenging to treat. Surgery and chemotherapy are the primary treatments. Risk Factors: Older age (most common in women aged 50–60) Family history and inherited gene mutations (e.g., BRCA1 and BRCA2) Long-term estrogen hormone replacement therapy Early menstruation or late menopause Types of Ovarian Cancer: 1. Epithelial tumors: The most common type, affecting the tissue covering the ovaries. (About 90 percent) 2. Stromal tumors: Begin in hormone-producing ovarian tissue, usually diagnosed earlier. (About 7 percent) 3. Germ cell tumors: Rare, occur in egg-producing cells, mainly in younger women. Pathophysiology: It's not clear what causes ovarian cancer, though doctors have identified factors that can increase the risk of the disease. Ovarian cancer begins in the ovaries, which produce eggs and hormones. It often goes undetected until it spreads. Early detection leads to better treatment outcomes. Most cases are treated with surgery and chemotherapy. Nursing Diagnoses for Ovarian Cancer Patients: 1. Risk for airway problems (ineffective airway clearance) 2. Risk for infection 3. Acute pain 4. Skin damage from surgery or radiation 5. Altered nutrition (not enough food) 6. Anticipatory grieving 7. Low self-esteem related to changes in appearance after surgery Care of Patients with Cervical and Uterine Cancer Cervical Cancer Cervical cancer arises in the cells of the cervix, the lower part of the uterus that connects to the vagina. Most cases are linked to certain strains of the human papillomavirus (HPV), a common sexually transmitted infection. The immune system generally clears HPV, but in some cases, the virus persists and may cause cell changes that lead to cancer. Screening tests and the HPV vaccine are effective preventative measures. Types of Cervical Cancer 1. Squamous Cell Carcinoma: The most common type, originating in the squamous cells lining the outer cervix. 2. Adenocarcinoma: Starts in the glandular cells of the cervical canal. 3. Mixed Carcinomas: Rare cases where both cell types are involved. Risk Factors Multiple Sexual Partners: Increases HPV exposure risk. Early Sexual Activity: Higher risk for HPV infection. Other STIs: STIs such as chlamydia, gonorrhea, syphilis, and HIV/AIDS increase the likelihood of HPV. Weakened Immune System: A compromised immune system heightens the risk. Smoking: Linked to squamous cell cervical cancer. Diethylstilbestrol (DES): Exposure to this drug during pregnancy can elevate risk Pathophysiology: Cervical cancer develops when healthy cervical cells undergo mutations in their DNA. DNA contains the essential instructions for cell growth, function, and programmed cell death. In normal cells: Cells grow, divide, and die in a controlled manner. DNA mutations cause cervical cells to grow uncontrollably and avoid programmed death, leading to an accumulation of abnormal cells that form a tumor. These cancerous cells: Invade nearby tissues in the cervix. May break off from the primary tumor, spreading to other parts of the body (a process known as metastasis). Leukemia Leukemia is a neoplastic disorder involving the uncontrolled proliferation of white blood cells (WBCs), leading to leukocytosis (increased WBC count). Hematopoiesis in leukemia is marked by rapid turnover of cells. This uncontrolled growth of WBCs in the bone marrow (BM) is a key feature of leukemia. Incidence of Leukemia 2004: An estimated 33,440 new leukemia cases were diagnosed. Adult onset: Leukemia is 10x more likely to occur in adults than children. Sex distribution: More common in men than women. Age distribution: More frequent in older adults (over 50 years). CML (Chronic Myelogenous Leukemia) is more common in adults. ALL (Acute Lymphocytic Leukemia) is rare in adults but commonly seen in children. Risk Factors Ionizing radiation and diagnostic radiation. Cigarette smoke. Electromagnetic fields (high power lines). Alkylating agents (associated with secondary AML). Viruses, such as those causing T and B cell lymphoma. Types of Leukemia 1. Acute Leukemia: ○ Abrupt onset, progresses quickly within a few weeks. ○ WBC development halts at the blast phase. ○ Without treatment, death occurs within weeks to months. 2. Chronic Leukemia: ○ Develops over months or years. ○ Predominantly mature WBCs. ○ Progresses slowly, and survival can extend for years. Acute Myeloid Leukemia (AML) AML results from a defect in hematopoietic stem cells that differentiate into myeloid cells (monocytes and granulocytes). It primarily affects adults, with a peak incidence at age 60. Poor prognosis is linked to older age and undifferentiated forms. - Patient survive an average of less than 1 year with treatment - Death usually a result of infection or hemorrhage Clinical Manifestations: Fever, infection, weakness, fatigue. Bleeding tendencies (ecchymosis, petechiae). Bone pain from marrow expansion. Assessment Findings: Decreased erythrocytes and platelets leading to bleeding. Common bleeding sites: GI, pulmonary, intracranial. Medical Management: Induction therapy: Aggressive chemotherapy (daunorubicin, cytarabine). Consolidation therapy: Eliminate residual leukemic cells. Bone Marrow Transplant (BMT) and Peripheral Blood Stem Cell Transplant (PBSCT) for high-risk patients or relapse. Recent advancements: Anti-CD33 antibody therapy (gemtuzumab ozogamicin). Complications: Tumor lysis syndrome: Elevated uric acid levels. Chronic Myeloid Leukemia (CML) CML arises from the mutation of myeloid stem cells, with a significant chromosomal translocation involving chromosome 22 (BCR-ABL). It is rare in patients younger than 20 and most common in adults with a median age of 40-50 years. The median life expectancy is 3-5 years. Clinical Manifestations: WBC count >100,000/mm³. Enlarged, tender spleen, malaise, weight loss. Breathlessness, confusion. Medical Management: Imatinib mesylate (Gleevec): A tyrosine kinase inhibitor that blocks signals within leukemic cells. Chemotherapy (hydroxyurea, busulfan). BMT/PBSCT for advanced disease. Acute Lymphocytic Leukemia (ALL) ALL involves uncontrolled proliferation of immature lymphoid cells (lymphoblasts), primarily affecting children, with a peak incidence around age 4. Boys are affected more than girls. Clinical Manifestations: Enlarged liver or spleen, fever, paleness, bruising, ulcerated lips/mouth, headache, vomiting (due to meningeal involvement). Medical Management: Complete remission: Goal of treatment. Chemotherapy (including intrathecal chemotherapy for meningeal involvement). Corticosteroids and supportive care. Chronic Lymphocytic Leukemia (CLL) CLL is common in older adults (typically over 60). The average survival time varies, ranging from 14 years in early stages to 2.5 years in later stages. Clinical Manifestations: Often incidentally diagnosed during routine physical exams. Lymphadenopathy, splenomegaly, fever, infection, unintentional weight loss. Medical Management: Early stages: No treatment required. Later stages: Chemotherapy with chlorambucil, rituximab, or alemtuzumab (targeting CD52 antigen). Nursing Management for Leukemia Mucositis care. Improving nutrition and pain management. Managing fatigue, fluid and electrolyte balance. Providing emotional support (anxiety, grief, spiritual well-being).