Cancer B Pharma 2nd Semester Pathophysiology notes pdf

Cancer B Pharma 2nd Semester Pathophysiology notes pdf

Cancer B Pharma 2nd Semester Pathophysiology notes pdf

Cancer B Pharma 2nd Semester Pathophysiology notes pdf

Objective

At the end of this lecture, student will be able to

         Define the term “Tumor”

         List main characteristics of benign and malignant cancer

         Describe the nomenclature used for various types of tumors  

         Explain the mechanism of spread of tumors

CANCER

General biology of cancer

Neoplasm/ Tumour – “A mass of tissue formed as a result of abnormal, excessive, uncoordinated, autonomous and purposeless proliferation of cells

       Oncology Branch of science dealing with the study of neoplasm

       Transformation from a living normal cell into a living tumor cell

Basic features of change in neoplasia

       Change is irreversible; becomes fixed character of a transformed cell

       Acquired fixed character is heritable; tumor cell divide to give tumor cell

       Change once occurred is self-perpetuating

       Tumor cell has uncontrolled passion for continued proliferation

Classification of tumors

       Based on the nature of tumors, they are classified as

Benign tumor – Harmless and self-limited

Malignant tumor – Harmful and rapidly growing

       Names of every tumor ends with ‘oma’

       Malignant tumor of epithelial tissue – Carcinoma

       Malignant tumor of connective tissue – Sarcoma

Classification of tumor based on tissue of origin

Tissue of origin Benign Malignant
Epithelial tumors
1. Squamous  epithelium Squamous cell papilloma Squamous cell carcinoma
2. Transitional epithelium Transitional epithelium papilloma Transitional epithelium carcinoma
3. Glandular  epithelium Adenoma Adenocarcinoma
4. Hepatocytes Liver cell adenoma Hepatocellular carcinoma (Hepatoma)

 

Tissue of origin

 (Non epithelial tumors)

Benign Malignant
Adipose tissue Lipoma Liposarcoma
Fibrous tissue Fibroma Fibrosarcoma
Cartilage Chondroma Chondrosarcoma
Bone Osteoma Osteosarcoma
Blood vessels Haemangioma Angiosarcoma
Nerve cells Ganglia Neuroma Neuroblastoma

Contrasting features of benign and malignant tumor

Features Benign Malignant
Macroscopic features
  1. Boundaries
Encapsulated/ well circumscribed Irregular & poorly circumscribed
     2.  Surrounding tissues Often compressed Usually invaded
  1. Size
Usually small Often large
    4.  Secondary changes Occurs less often Occurs more often
Microscopic Features
  1. Pattern
Closely resembles the tissue of origin Poor resemblance to the tissue of origin
2.  Basal polarity Retained Lost
3.  Pleomorphism Normal  Increased
4.  Neuclio- cytoplasmic ratio Normal Increased
  1. Hyperchromatism
Absent  Present
  1. Mitosis
Always typical mitosis Atypical & abnormal mitosis
7.  Tumor giant cells May be present but with atypical nucleus Always present with atypical nucleus
8.  Cytoplasm With normal constituents Elements are reduced or lost
9.  Functions Usually well maintained Retained/ lost/ abnormal
Growth rate Usually slow Rapid
Local invasion Often compresses the surroundings; no invasion/
infiltration
Invade & infiltrate the adjacent tissue
Metastatis (Spreading) Absent Present

Structure of tumor

Tumor mass consists of:

  1. Parenchyma
  2. Stroma

Parenchyma

       Formed by proliferating tumor cells

       Parenchyma of benign tumor – organised pattern with resemblance to tissue of origin, differentiation

       Parenchyma of malignant tumor – unorganised, atypical, distorted, relation of tumor cell with basement is lost, anaplasia

Stroma

       Supporting tissue of tumor

       Consists of fibrous tissue carrying blood vessels for nourishing tumor cell

       More malignant the tumor, Cirrhous

       Carcinoma with scanty stroma – celluloid & medullary

       New blood vessels form from pre existing onesless is the fibrous tissue

       Carcinoma with extensive stroma –  with the help of a factor, “tumor angiogenesis factor”

Spread of cancer

(Two mechanism for the spread of cancer)

Spread of cancer

Routes of spread of cancer

1.      Infiltration of tissue spaces

       Tissue spaces –  preformed passages; paths of least resistance

       Most vulnerable tissues – soft tissues – adipose, muscle,

       Gamete/ compact tissues like capsule of organs, cartilage and bone (not marrow) offer greater resistance

       Tissue subjected to infiltration are destroyed  by the proteolytic enzymes & lytic substances elaborated by cancer tissue

       Tissue space invasion brings the tumor cell in direct contact with normal cells, lymphatic and blood vessels

2. Hematogenous spread:

       Carcinoma of lungs, thyroid, kidney and the prostate spread through blood vessels

Tumor cells enter blood stream by 2 ways

  1. Via thorasic duct – either by perforation of vein or by lymphatic drainage
  2. By direct invasion of blood vessels (large veins, venules & capillaries); arteries not involved due to their thick wall

3. Spread via lymphatics: Most common with carcinoma; results in both invasion & metastasis

Spread via lymphatics, Routes of spread of cancer

Spread via lymphatics

Lymphatic spread begins by lodgement of tumour cells in subcapsular sinus via afferent lymphatics entering at the convex surface of the lymph node

Spread via lymphatics

Hematogenous spread

Hematogenous spread

4. Spread via serous sacs

       Spread through peritoneal cavity; common in cancer of GIT & ovary

       Trans pleural spread –  in carcinoma of lungs and breast

       Trans pericardial spread may also occur

5. Spread along epithelium line surfaces

       Intact epithelium, mucous coat acquires resistance for penetration of  tumor

       Implantation tumor – tumor spread along the surface of epithelium

6. Spread via CSF

       Cerebrospinal cavities are affected by the escape of tumor cells from

       the malignant tumor in the brain or meninges

Summary

       A tumour is a mass of tissue formed as a result of abnormal, excessive, uncoordinated, autonomous and purposeless proliferation of cells

       Tumors are classified as benign and malignant

       Benign tumors are harmless and do not spread while malignant tumors are harmful and spread

       Tumor is made up of parenchyma and stroma

       Tumor spread by two mechanism – Haematogenous spread and lymphatic spread

Cancer FAQ

Q1: What is a tumor? A tumor is an abnormal mass of tissue that results from the uncontrolled growth of cells. Tumors can be benign (non-cancerous) or malignant (cancerous).

Q2: What are the main characteristics that distinguish benign and malignant tumors? Benign tumors are typically well-defined, slow-growing, and remain localized. They do not invade nearby tissues or metastasize. Malignant tumors, on the other hand, are fast-growing, invasive, and can spread to other parts of the body, leading to the potential for cancer.

Q3: How are tumors named, and what is the nomenclature used for various types of tumors? Tumors are named based on their tissue of origin and their characteristics. Nomenclature typically includes the type of tissue, cell type, and whether the tumor is benign or malignant. For example, “Adenocarcinoma of the lung” refers to a malignant tumor originating from glandular cells in the lung.

Q4: Can you explain the mechanism of tumor spread or metastasis? Metastasis is the process by which cancer cells spread from the primary tumor to other parts of the body. It involves several steps, including:

  • Invasion: Cancer cells break through nearby tissues.
  • Intravasation: Cancer cells enter the bloodstream or lymphatic system.
  • Circulation: Cancer cells travel to distant sites in the body.
  • Extravasation: Cancer cells exit the bloodstream or lymphatic system.
  • Colonization: Cancer cells establish new tumors at distant sites.

Q5: What are some common risk factors for the development of cancer? Common risk factors for cancer include exposure to carcinogens (such as tobacco and asbestos), genetic factors, a weakened immune system, chronic inflammation, radiation exposure, and some viral infections.

Q6: What are the most common types of cancer, and how are they typically diagnosed and treated? Common types of cancer include lung, breast, prostate, and colorectal cancer. Diagnosis often involves imaging tests, biopsies, and blood tests. Treatment options may include surgery, chemotherapy, radiation therapy, immunotherapy, targeted therapy, and palliative care.

Q7: How can cancer be prevented or early detection be promoted? Cancer prevention strategies include a healthy lifestyle (such as avoiding tobacco and limiting alcohol consumption), vaccination against cancer-related viruses (like HPV), and early screening through methods like mammography, colonoscopy, and PAP smears. Early detection is crucial for better treatment outcomes.

Q8: What are the stages of cancer, and how do they affect treatment and prognosis? Cancer staging is a way to describe the extent of cancer’s spread. It helps determine treatment options and prognosis. Stages range from 0 (in situ, localized) to IV (advanced, with distant metastases). The earlier the stage, the better the prognosis and treatment options.

Q9: What role does genetics play in cancer risk, and how can genetic testing be used to assess cancer susceptibility? Genetics can play a significant role in cancer risk. Certain genetic mutations increase susceptibility. Genetic testing can identify these mutations and help assess an individual’s risk, enabling early preventive measures and personalized treatment strategies.

Q10: What are the most promising advancements in cancer research and treatment in recent years? Recent advancements in cancer research include immunotherapy, targeted therapies, and precision medicine. These approaches aim to treat cancer more effectively while minimizing side effects.

Cancer B Pharma 2nd Semester Pathophysiology notes pdf Download

1 thought on “Cancer B Pharma 2nd Semester Pathophysiology notes pdf”

Leave a Comment