cancer, Benign Tumors, Malignant Tumors, Metastasis

Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells in the body. If the spread is not controlled, it can lead to death.�Cancer can develop in almost any tissue or organ, and it often forms a mass of tissue called a tumor (though some cancers, like leukemia, do not form tumors). Tumors can be benign (non-cancerous) or malignant (cancerous).�Key features of cancer cells include:��Uncontrolled growth: Cells divide uncontrollably, ignoring normal regulatory signals.Invasion: They can invade nearby tissues.�Metastasis: They can spread to other parts of the body via the bloodstream or lymphatic system

1. cancer Presented by Priyanka Patel Guided by Dr. S.P. Nayak , Assistant Professor, Parul University.

2. Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells in the body. If the spread is not controlled, it can lead to death. Cancer can develop in almost any tissue or organ, and it often forms a mass of tissue called a tumor (though some cancers, like leukemia, do not form tumors). Tumors can be benign (non-cancerous) or malignant (cancerous). Key features of cancer cells include: Uncontrolled growth : Cells divide uncontrollably, ignoring normal regulatory signals. Invasion : They can invade nearby tissues. Metastasis : They can spread to other parts of the body via the bloodstream or lymphatic system.

3. Etiology of Cancer Cancer develops due to a combination of genetic, environmental, and lifestyle factors: Genetic Factors : Inherited mutations (e.g., BRCA1, p53) and oncogenes (e.g., HER2) can increase susceptibility. Environmental Factors : Carcinogens (e.g., tobacco, asbestos, benzene) damage DNA. Radiation (e.g., UV, ionizing radiation) causes mutations. Infections (e.g., HPV, Hepatitis B/C) increase cancer risk. Lifestyle Factors : Tobacco use , alcohol , obesity , and lack of exercise increase cancer risk. Hormonal Factors : Hormones like estrogen can promote cancers such as breast and endometrial cancer. Age : Older age increases the likelihood of accumulating mutations over time. Immune System Dysfunction : Weakened immunity (e.g., HIV, immunosuppressive drugs) increases cancer risk. Chronic Inflammation : Ongoing inflammation (e.g., Crohn’s disease) can lead to cancer development. Chemical Exposure : Long-term exposure to industrial chemicals can cause cancer (e.g., benzene, asbestos). Family History : A family history of cancer may suggest inherited risk. Epigenetic Factors : Changes in gene expression due to environmental factors can lead to cancer.

4. PATHOPHYSIOLOGY OF CANCER

5. Types of Tumors : 1. Benign Tumor 2. Malignant Tumor

6. Differences Between Benign and Malignant Tumors: Feature Benign Tumors Malignant Tumors Growth Rate Slow Rapid Invasion Do not invade nearby tissues Invade nearby tissues Metastasis Do not spread to other parts of the body Spread to distant organs (metastasis) Capsulation Usually well-capsulated, with clear boundaries Poorly defined boundaries, often non-capsulated Cell Appearance Cells resemble normal tissue (well-differentiated) Cells are abnormal and poorly differentiated Recurrence Rarely recur after removal Often recur, even after treatment Impact on Health Generally less harmful, unless in vital areas Can be life-threatening Treatment Often cured by surgical removal Requires complex treatments ( surgery, radiation, chemotherapy)

7. Diagnosis of Malignancy, Invasion, and Metastasis 1. Diagnosis of Malignancy Malignancy is typically diagnosed using a combination of clinical, radiological, and pathological methods: Clinical Diagnosis Symptoms: Unexplained weight loss, fatigue, pain, lumps, bleeding, or persistent cough. Physical Examination: Palpation of masses, lymph node enlargement, skin changes. Imaging Techniques X-ray/CT Scan/MRI: Detect masses, structural changes, and local invasion. Ultrasound: Identifies tumors in soft tissues or organs. PET Scan: Detects cancer spread by highlighting areas of high metabolic activity. Histopathological Examination Biopsy: Gold standard for diagnosis. Involves microscopic examination of tissue samples. Cytology: Examination of cells from fluids (e.g., fine-needle aspiration, Pap smear). Molecular and Genetic Testing Immunohistochemistry (IHC): Detects specific markers (e.g., HER2 in breast cancer). Genetic Testing: Identifies mutations (e.g., BRCA1/BRCA2, p53 mutations). Flow Cytometry: Analyzes cell populations in blood cancers. 7

8. 2. Invasion Invasion refers to the direct penetration and destruction of surrounding tissues by malignant cells. Key Features of Invasion: Basement Membrane Breach: Cancer cells penetrate the basement membrane, moving into surrounding connective tissue. Loss of Cell Adhesion: Decreased expression of adhesion molecules (e.g., E-cadherin). Enzymatic Degradation: Tumor cells secrete proteolytic enzymes (e.g., matrix metalloproteinases) to break down extracellular matrix. Cell Motility: Cancer cells gain the ability to migrate. Diagnostic Methods for Invasion: Histology: Identifies invasion of the basement membrane and surrounding tissues. Immunohistochemistry: Highlights invasive markers like MMPs (matrix metalloproteinases) or decreased E-cadherin.

9. 3. Metastasis 9 Metastasis refers to the spread of cancer cells from the primary site to distant organs via the bloodstream or lymphatic system. Steps in Metastasis: Local Invasion: Initial penetration into surrounding tissues. Intravasation: Entry into blood or lymphatic vessels. Survival in Circulation: Cancer cells survive immune attack and circulate in the bloodstream. Extravasation: Exit from vessels into distant tissues. Colonization: Formation of secondary tumors in new tissues. Common Sites of Metastasis: Lymph Nodes: Often the first site of spread. Liver: Common for gastrointestinal cancers. Lungs: Common for many solid tumors . Bones: Common in breast, prostate, and lung cancers. Brain: Common in lung and melanoma cancers. Diagnostic Methods for Metastasis: Imaging: CT, MRI, PET scans detect metastatic lesions. Biopsy of Metastatic Site: Confirms the same cancer type as the primary tumor . Tumor Markers: Elevated markers (e.g., CEA, CA-125, PSA) suggest metastasis. Lymph Node Biopsy: Sentinel node biopsy helps assess lymphatic spread.

10. Patterns of Cancer Spread (Metastasis) 1. Local Spread (Direct Invasion) Description: Tumor cells invade and infiltrate the surrounding tissues by breaking through natural barriers such as the basement membrane and extracellular matrix. Examples: Breast cancer invading chest wall structures. Colon cancer penetrating the intestinal wall. 2. Lymphatic Spread Description: Cancer cells travel through lymphatic vessels and lodge in nearby lymph nodes. This is common in carcinomas (epithelial cancers). Common Sites: Breast cancer spreads to axillary lymph nodes. Lung cancer spreads to mediastinal lymph nodes. Clinical Significance: Sentinel lymph node biopsy helps identify early lymphatic spread. 10

11. 3. Hematogenous (Bloodstream) Spread Description: Tumor cells invade blood vessels (especially veins) and disseminate via the circulatory system. This is common in sarcomas and certain carcinomas. Common Sites: Liver (common for gastrointestinal cancers). Lungs (common for many cancers). Bones (common in prostate and breast cancer). Brain (common in melanoma and lung cancer). 4. Transcoelomic Spread Description: Cancer cells spread across body cavities by seeding surfaces like the peritoneum, pleura, or pericardium. Examples: Ovarian cancer spreading within the peritoneal cavity. Lung cancer spreading to the pleura (pleural effusion).

12. 12 5. Perineural Invasion Description: Cancer spreads along nerve sheaths, often causing pain or neurological symptoms. Examples: Pancreatic cancer with perineural invasion causes severe back pain. Head and neck cancers frequently spread along cranial nerves. 6. Implantation Spread Description: Cancer cells are accidentally implanted in a new location during surgical procedures or biopsies. Examples: Seeding of cancer cells in surgical scars. Spread along biopsy needle tracts. 7. Vascular Spread (Angioinvasion) Description: Tumor cells invade veins, arteries, or lymphatic vessels, leading to widespread dissemination. Examples: Renal cell carcinoma invades the renal vein and can extend into the inferior vena cava.

13. 13 Breast Cancer: Lymphatic spread to axillary nodes, hematogenous spread to bones, lungs, liver, and brain. Colorectal Cancer: Lymphatic spread to mesenteric nodes, hematogenous spread to the liver. Prostate Cancer: Local spread to pelvic tissues, hematogenous spread to bones (especially the spine). Lung Cancer: Hematogenous spread to brain, liver, bones, and adrenal gland Tumor -Specific Patterns of Spread

14. 14 Distribution of Growth in Cancer Cells (Tumor Growth Patterns) 1. Expansive Growth Description: The tumor grows by expanding outward, pushing adjacent tissues without invading them. Characteristics: Well-defined, often encapsulated. Common in benign tumors. Example: Fibroadenoma of the breast. 2. Infiltrative (Invasive) Growth Description: Tumor cells invade and infiltrate surrounding tissues, breaking through natural barriers like the basement membrane. Characteristics: Poorly defined margins, no capsule. Common in malignant tumors . Example: Squamous cell carcinoma. 3. Multicentric Growth Description: Tumor originates from multiple independent sites within the same tissue or organ. Characteristics: Multiple nodules in the same organ. Can complicate surgical removal. Example: Multifocal breast cancer.

15. 4. Diffuse Growth Description: Tumor cells are widely dispersed throughout the tissue without forming a distinct mass. Characteristics: Involves extensive tissue areas. Difficult to detect early due to lack of a visible mass. Example: Diffuse large B-cell lymphoma (DLBCL). 5. Papillary Growth Description: Tumor grows in a finger-like or frond-like pattern, often projecting into a cavity or lumen. Characteristics: Covered with layers of malignant epithelial cells. May cause obstruction in hollow organs. Example: Papillary thyroid carcinoma. 15

16. 6. Nodular (Mass-forming) Growth Description: Tumor forms discrete, rounded masses or nodules. Characteristics: Clearly defined, firm masses. Can be single or multiple. Example: Hepatocellular carcinoma. 7. Scirrhous (Desmoplastic) Growth Description: Tumor is characterized by excessive fibrous tissue (desmoplasia), making it hard and firm. Characteristics: Poorly defined, highly invasive. Associated with aggressive behavior. Example: Scirrhous carcinoma of the breast. 16

17. 17

18. THANK YOU