Cancer Biology: Characteristics of Malignant Cells

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Questions and Answers

What is the primary characteristic of malignant cells?

They exhibit controlled growth.

They display uncontrolled growth. (correct)

They primarily undergo apoptosis.

They differentiate into specialized cells.

What does anaplasia refer to in neoplastic cells?

Loss of differentiation. (correct)

Formation of a benign tumor.

Normal cell structure.

Increased differentiation.

Which of the following terms describes the formation of an abnormal mass of proliferating cells?

Hyperplasia

Metaplasia

Dysplasia

Neoplasia (correct)

Which statement correctly describes dysplastic nevi?

They have irregular shapes and uneven colors. (D) Signup and view all the answers

What is the relationship between hyperplasia and cancer growth?

Hyperplasia may indicate early growth of cancer. (C) Signup and view all the answers

What mechanism is primarily disrupted in malignant disease?

Balance of cell division and apoptosis. (B) Signup and view all the answers

Which term describes the abnormality in size, shape, and organization of adult cells?

Dysplasia (C) Signup and view all the answers

What does the term 'metaplasia' specifically refer to?

The transformation of one differentiated cell type into another. (C) Signup and view all the answers

What is the first step in the process described as the androgenic switch?

Cell-cell adhesion breaks down (C) Signup and view all the answers

What is a characteristic of anchorage independent growth in cancer cells?

Cancer cells pile up on one another without inhibiting growth (D) Signup and view all the answers

What prevents normal cells from proliferating when grown in a semi-solid medium?

Contact inhibition when cells touch each other (B) Signup and view all the answers

What is the final outcome of the processes initiated by cancer cells after they leave the circulatory system?

They produce secondary metastatic tumors (A) Signup and view all the answers

What aspect of normal cells is altered in cancer cells to allow for continuous growth?

Their contact inhibition mechanisms (A) Signup and view all the answers

What is the primary characteristic that distinguishes hyperplasia from hypertrophy?

Increase in cell number (C) Signup and view all the answers

What term describes cellular enlargement that serves a purpose in response to increased workload?

Physiological hypertrophy (A) Signup and view all the answers

Which characteristic is associated with malignant cells that allows them to resist programmed cell death?

Resistance to apoptosis (A) Signup and view all the answers

In cancer cells, what role does telomerase play?

It maintains telomere length (C) Signup and view all the answers

How can sustained angiogenesis contribute to tumor growth?

By increasing blood supply (A) Signup and view all the answers

What property allows cancer cells to survive in circulation during metastasis?

Anchorage-independent growth (B) Signup and view all the answers

Which type of mutation can be caused by environmental exposure during embryonic development?

Psychotic mutations (B) Signup and view all the answers

What is a consequence of the loss of contact inhibition in cancer cells?

Cancer cells proliferate uncontrollably (C) Signup and view all the answers

Which of the following describes the ability of cancer cells to invade surrounding tissues?

Immune evasion (B) Signup and view all the answers

What is the role of growth factor signaling in cell proliferation?

It regulates gene expression for growth (B) Signup and view all the answers

What defines atrophy in the context of cell biology?

Decrease in cell size and number (A) Signup and view all the answers

Which factor is typically not a characteristic of malignant cells?

Increase in apoptosis (B) Signup and view all the answers

Which of the following is a hallmark of cancer that involves nutrient and oxygen supply?

Angiogenesis (D) Signup and view all the answers

What is the result of tumors growing beyond their blood supply limits?

Cellular necrosis (A) Signup and view all the answers

What is a characteristic of benign neoplasms compared to malignant neoplasms?

Benign neoplasms are generally encapsulated. (D) Signup and view all the answers

Which histogenetic classification is associated with connective tissue?

Sarcoma (C) Signup and view all the answers

What is a common general effect of tumors?

Fatigue (C) Signup and view all the answers

Which type of cancer is particularly associated with a high incidence of cancer cachexia?

Pancreatic cancer (A) Signup and view all the answers

What describes paraneoplastic syndromes?

They are symptoms not readily explained by local or metastatic disease. (D) Signup and view all the answers

Which of the following is a typical method used for cancer diagnosis?

Genetic testing (C) Signup and view all the answers

What is a defining feature of malignant tumors histologically?

Nuclear enlargement (D) Signup and view all the answers

What is an example of a local effect caused by tumors?

Compression of nearby structures (A) Signup and view all the answers

What role do tumor markers play in cancer management?

They assist in diagnosing and monitoring cancer. (A) Signup and view all the answers

Which of the following is a common endocrine effect associated with tumors?

Cushing's syndrome (C) Signup and view all the answers

What is the primary characteristic of cancer cachexia?

Progressive loss of skeletal muscle mass (C) Signup and view all the answers

Which test is typically performed for routine investigations in cancer diagnosis?

Blood tests (B) Signup and view all the answers

What is a limitation of PSA (prostate-specific antigen) as a tumor marker?

It may also be elevated in benign tumors. (B) Signup and view all the answers

What is the primary reason chemotherapy and radiotherapy may exacerbate cachexia?

They can induce systemic inflammation. (D) Signup and view all the answers

What is the primary consequence of somatic mutations?

They will not be passed to the next generation. (A) Signup and view all the answers

Which gene is most commonly associated with increased risk of breast and ovarian cancer?

BRCA1 (A) Signup and view all the answers

What environmental factor is specifically linked to leukemia?

Translocation of ABL and BCR genes (B) Signup and view all the answers

Which of the following is a hallmark of Xeroderma pigmentosum?

Deficiency in repairing DNA damage from UV light (A) Signup and view all the answers

What role does the p53 gene play in cancer prevention?

It functions as a tumor suppressor gene. (A) Signup and view all the answers

Which virus is primarily linked to cervical cancer?

Human papillomavirus (HPV) (B) Signup and view all the answers

How do polycyclic aromatic hydrocarbons (PAHs) pose a cancer risk?

They derive from burning fossil fuels and can cause cellular damage. (A) Signup and view all the answers

What is one of the major characteristics of an abnormal tissue microenvironment that can promote cancer?

Hypoxia (B) Signup and view all the answers

What lifestyle factor is recognized as contributing to the risk of multiple cancer types?

Tobacco use (A) Signup and view all the answers

Which type of cancer is linked to the Epstein-Barr virus?

Burkitt's lymphoma (D) Signup and view all the answers

What is a primary environmental risk factor for developing liver cancer?

Long-term infection with hepatitis B and C (A) Signup and view all the answers

What dietary component is associated with an increased risk of stomach cancer?

Red meat consumption (D) Signup and view all the answers

What is the initial step in the multi-step progression of colorectal cancer?

Acquisition of mutations (C) Signup and view all the answers

Which of the following is a known risk factor for thyroid cancer related to environmental exposure?

Radioactive exposure (D) Signup and view all the answers

What is considered a normal prostate-specific antigen (PSA) level after prostatectomy?

4.0 ng/ml or lower (C) Signup and view all the answers

Which chemotherapeutic agent is derived from the Pacific Yew tree and inhibits cancer cell proliferation?

Paclitaxel (Taxol) (A) Signup and view all the answers

What is one significant disadvantage of targeted cancer therapies?

They can also affect normal cells that express similar molecules. (C) Signup and view all the answers

Which type of therapy uses protons instead of x-rays for cancer treatment?

Proton therapy (C) Signup and view all the answers

What common side effect is associated with chemotherapy treatments?

Frequent infections (C) Signup and view all the answers

What does liquid biopsy detect in patients with cancer?

Circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) (A) Signup and view all the answers

How does hyperplasia respond to pathological conditions?

It leads to uncontrolled cell growth. (C) Signup and view all the answers

What do abnormal cells in cancer often utilize for growth and signaling?

Autocrine signaling (C) Signup and view all the answers

What is the clinical significance of telomeres in cancer cells?

Their shortening is associated with replicative senescence. (C) Signup and view all the answers

What impacts the management decision of cancer treatment?

Aggressiveness of the tumor and predictability of its spread (A) Signup and view all the answers

What kind of testing is HER2 used for in diagnosing cancer?

Breast cancer (A) Signup and view all the answers

What factor is NOT typically associated with the side effects of chemotherapy?

Increased appetite (C) Signup and view all the answers

What does the term 'molecularly targeted therapies' refer to?

Drugs that block specific molecules involved in tumor growth. (B) Signup and view all the answers

What role do factors like VEGF and FGF play in cancer?

They stimulate blood vessel formation. (C) Signup and view all the answers

Study Notes

Malignant Disease

Cancer arises from any cell type in multicellular organisms, representing a collection of distinct diseases.
The core characteristic of cancer is uncontrolled growth, disrupting the balance between cell division/differentiation and survival/apoptosis.
Invasion and metastasis are common features, often described as "crab-like" spread.

Cancer Characteristics

Loss of growth control: Cells exhibit autonomy in growth signaling and insensitivity to inhibitory signals.
Resistance to apoptosis: Cancer cells evade programmed cell death, exhibiting immortality.
Unlimited replicative potential: Telomerase activity maintains telomere length, enabling continued cell division.
Sustained angiogenesis: Cancer cells stimulate blood vessel formation for nutrient supply.
Invasion and metastasis: Cancer cells can invade surrounding tissue and spread to other parts of the body (metastasis).
Anchorage-independent growth: Cancer cells can grow without attachment to a surface.
Loss of contact inhibition: Cancer cells continue to proliferate even when in contact with other cells.

Cancer Development

Aetiology (Causes): Cancer development is linked to genetic mutations, which can be inherited or acquired.
- Mutations: Inborn (zygotic) or somatic (acquired). Acquired mutations can result from environmental factors.
- Environmental factors: Viruses, chemicals, and radiation.
- Abnormal tissue microenvironment: Hypoxia within the tissue.
- Lifestyle and other factors: Age, lifestyle choices also influence cancer risk.
Genetic mutations and increased cancer risk: Certain genetic mutations increase the likelihood of specific cancers. Examples include BRCA1/2 (breast/ovarian cancer), p53 (Li-Fraumeni syndrome), and the Philadelphia chromosome (CML).

Cancer Classification

Benign vs. Malignant: Benign tumors are localized, encapsulated, and non-invasive, while malignant tumors are invasive and may metastasize.
Histogenetic classification: Tumors are categorized based on the tissue type of origin (e.g., carcinomas from epithelial tissue, sarcomas from connective tissue).
TNM classification, staging, and grading: Systems for classifying and staging tumors based on their size, location, and spread to aid in treatment planning.

Clinical Effects of Tumors

General effects: Fatigue, weight loss, fever, nausea/vomiting, and loss of appetite.
Local effects: Compression, obstruction, ulceration, hemorrhage, rupture, perforation, and infarction due to tumor pressure.
Endocrine effects: Tumors can disrupt hormone production.
Paraneoplastic syndromes: Symptoms unrelated to tumor's direct effects, like hypercalcemia and Cushing's syndrome.

Cancer Diagnosis

Clinical signs: Identifying lumps, unusual bleeding, or changes in moles can raise suspicion for cancer.
Screening tests: Pap smears for cervical cancer.
Routine investigations: Blood tests and X-rays.
Imaging: CT scans, MRI, PET scans, ultrasounds, endoscopy, and surgical biopsies.
Genetic testing for specific genes linked to cancer susceptibility.
Tumor markers: Substances in blood, urine, or tissue associated with certain cancers (e.g., PSA for prostate cancer, HER2 for breast cancer).

Cancer Treatment

Chemotherapy: Using drugs to target rapidly dividing cells, including cancer cells.
Targeted cancer therapies: Drugs that interfere with specific molecules involved in cancer growth.
Radiation therapy: Using high-energy radiation to kill cancer cells.
Proton therapy: A form of radiation therapy that uses protons instead of x-rays.

Cancer Risk Factors

Viruses: HPV (cervical cancer), Epstein-Barr virus (Burkitt's lymphoma).
Chemicals: Polycyclic aromatic hydrocarbons (PAHs) in barbecued meats, and some occupational exposures
Radiation: UV radiation from the sun and exposure to ionizing radiation.
Lifestyle: Obesity, smoking, alcohol consumption influencing cancer risk.
Age: Risk increases with age.

Other Key Concepts

Cachexia: A severe wasting syndrome occurring in advanced stages of some cancers.
Nucleotide Excision Repair (NER): DNA repair mechanism, defects in which can increase cancer risk, like Xeroderma pigmentosum (XP).
Telomeres and telomerase: Telomeres are protective caps at the ends of chromosomes shortening with each cell division, telomerase is an enzyme which counteracts this, found in cancer cells and stem cells maintaining telomere length.
Tumor Microenvironment: The surrounding cells, extracellular matrix, and factors that influence cancer cell behavior.

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Description

Test your knowledge on the characteristics of malignant cells and the different processes involved in cancer biology. This quiz covers key concepts such as anaplasia, dysplastic nevi, and mechanisms of cancer growth. Assess your understanding of how cancer cells differ from normal cells.