Tumor Biology and Precancerous Lesions

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Questions and Answers

Which type of precancerous lesion is characterized by a change in the cellular type of tissues?

Benign tumors

Dysplasia

Metaplasia (correct)

Hyperplasia

Which of the following conditions is associated with the development of osteosarcoma?

Chronic alcoholism

Cirrhosis of the liver

Paget’s disease of bone (correct)

Hepatitis B virus infection

What is primarily indicated by hyperplasia in the endometrium?

Breast cancer

Liver cancer

Endometrial carcinoma (correct)

Gastric cancer

Which method of tumor spread involves the formation of new blood vessels?

Angiogenesis Signup and view all the answers

Which viral carcinogen is linked to the development of cervical cancer?

Human papilloma virus (HPV) Signup and view all the answers

Which of the following factors is considered a co-carcinogen related to environmental exposure?

Cigarette smoking Signup and view all the answers

Which type of cancer is associated with exposure to the carcinogen aflatoxins?

Liver cancer Signup and view all the answers

What is the primary significance of tumor markers in oncology?

They help in the diagnosis and monitoring of cancer. Signup and view all the answers

Which tumor type is least likely associated with hereditary factors?

Lung cancer Signup and view all the answers

Which of the following is not considered a chemical carcinogen?

Ultraviolet rays Signup and view all the answers

Which type of tumor is classified as poorly differentiated?

Grade III Signup and view all the answers

What does the 'N' in the TNM staging system represent?

Regional lymph node involvement Signup and view all the answers

Which of the following is an example of distant spread of cancer?

Lymphatic invasion Signup and view all the answers

What does tumor marker CA-125 primarily indicate?

Ovarian cancer Signup and view all the answers

Which of the following tumors is classified as locally malignant?

Astrocytoma Signup and view all the answers

What is the role of tumor markers in cancer management?

Assessment of cancer therapy and follow-up Signup and view all the answers

What characterizes a well-differentiated tumor?

Cells closely resemble normal tissue Signup and view all the answers

Which spread mechanism involves tumor cells passing through blood vessels?

Blood spread Signup and view all the answers

Which factor is NOT a cause of death in malignant tumors?

Increased appetite Signup and view all the answers

What is NOT a characteristic of grade IV tumors?

Local spread only Signup and view all the answers

Study Notes

Intended Learning Objectives

Recall different types of precancerous lesions, carcinogens and cocarcinogens.
Define tumor grade and stage.
Describe the mechanisms of tumor invasion and metastasis, focusing on angiogenesis.
Detail the different methods of malignant tumor spread.
Define locally malignant tumors and provide examples.
Explain the definition, examples, and importance of tumor markers.
List the causes of death in malignant tumors.

Precancerous Lesions

Metaplasia: Squamous metaplasia can lead to squamous cell carcinoma.
Hyperplasia: Endometrial hyperplasia can lead to endometrial carcinoma. Mammary hyperplasia can lead to breast cancer.
Benign Tumors:
- Thyroid adenoma can transform into thyroid carcinoma.
- Transitional cell papilloma can transform into transitional cell carcinoma.
Other Precancerous Conditions:
- Liver cirrhosis leads to hepatocellular carcinoma.
- Paget's disease of bone leads to osteosarcoma.
- Cryptorchidism (undescended testes) can lead to seminoma.
- Xeroderma pigmentosa can lead to melanoma.

Co-carcinogens

Factors that promote the development of cancer.
Age: Increased exposure to carcinogens with age.
Sex: Most tumors are more common in males.
Diet: High fat diets are linked to colon cancer, and smoked fish is linked to stomach cancer.

Environmental Factors

Cigarette Smoking: Linked to cancer of the tongue, larynx, lung, kidney, and urinary bladder.
Alcoholism: Associated with cancers of the mouth and esophagus.
Excess Sun Exposure: Linked to skin cancer.

Heredity

Some cancers are inherited, including breast and colon cancer.

Chemical Carcinogens

Beta-naphthylamine (paints): Linked to bladder cancer.
Aflatoxins (aspergillus fungus): Linked to liver cancer.
Nitrosamines (preservative substance): Linked to stomach cancer.

Viral Carcinogens

Hepatitis B virus: Linked to hepatocellular carcinoma.
Human papillomavirus (HPV): Linked to cervical cancer.
Epstein-Barr virus (EBV): Linked to nasopharyngeal carcinoma and lymphoma.

Radiation Carcinogens

Ionizing radiation: Causes leukemia.
Ultraviolet rays (prolonged exposure): Causes skin cancer.
Hormones (estrogen, androgen):
- Estrogen: Linked to breast and endometrial cancer.
- Androgen: Linked to prostate cancer.

Tumor Grading (Differentiation)

Assessing the similarity between a tumor and its parent tissue.
Grades:
- Well differentiated (grade I).
- Moderately differentiated (grade II).
- Poorly differentiated (grade III).
- Undifferentiated (grade IV).

Tumor Staging (TNM System)

Assessing the degree of tumor infiltration.
Parameters:
- T (primary tumor): Tis, T1, T2, T3, T4 (varying degrees of tumor size and invasion).
- N (regional lymph nodes): N0, N1, N2, N3 (presence and extent of lymph node involvement).
- M (metastasis): M0, M1 (presence of distant metastasis).

Spread of Malignant Tumors

Local (direct) spread: Malignant cells infiltrate the surrounding extracellular matrix.
Distant spread (metastasis):
- Lymphatic spread: Tumor cells enter lymph vessels and spread to lymph nodes.
- Blood spread: Tumor cells enter blood vessels and spread to distant organs.
- Transcoelomic spread: Tumor cells cross body cavities.
Implantation: Tumor cells spread between opposing surfaces.

Locally Malignant Tumors

Malignant tumors limited to the location of origin, without spreading to distant sites.
Examples:
- Basal cell carcinoma (skin).
- Osteoclastoma (bone).
- Adamantinoma (bone).
- Astrocytoma (brain).

Tumor Markers

Substances produced by neoplastic cells, detectable in cells, serum, or body fluids.
Importance:
- Supporting diagnosis (not primary modality).
- Assessing cancer therapy.
- Monitoring treatment response (follow-up).
Examples:
- PSA (cancer prostate).
- CA-125 (cancer ovary).
- CA-15-3 (cancer breast).
- CA-19-9 (pancreatic cancer).
- Alpha-fetoprotein/Hepatitis B viral markers (hepatocellular carcinoma).
- HMB-45 (melanoma).

Causes of Death in Malignant Tumors

Tissue destruction: Brain, liver, and kidney damage.
Obstruction: Urinary tract obstruction.
Malnutrition: Interference with food intake, digestion, and absorption.
Severe anemia: Reduced red blood cell count.
Malignant cachexia: Weight loss, muscle wasting, and immune suppression.

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Description

This quiz focuses on understanding tumor biology, specifically the different types of precancerous lesions, tumor grading, and the mechanisms of invasion and metastasis. You will explore key definitions and examples such as tumor markers and locally malignant tumors, as well as the implications of various carcinogens. Test your knowledge on the causes and classifications associated with malignant tumors.