24 Questions
What is the primary characteristic of a benign tumor's growth rate?
Slow and steady
Which of the following is a characteristic of malignant tumors?
Invading locally and metastasizing
What is the term for the spread of a tumor to distant sites of the body?
Metastasis
Which of the following is a method of metastasis?
All of the above
What is the term for the original site where a tumor has started?
Primary site
Which of the following is a factor that affects the rate of growth of a tumor?
All of the above
What is the term for the growth of neoplastic cells at a distant site from the primary tumor?
Secondary site
Which of the following types of tumors is more likely to spread through the lymphatic system?
Carcinoma
What is the primary source of evidence for the causal association between cigarette smoking and lung cancer?
Epidemiologic studies
What does cancer incidence refer to?
The number of new cancer cases registered in a population over a specific period
What is cancer prevalence?
The number of all cancer cases, both new and existing, in a population at a given point in time
According to the World Health Organization (WHO), how many deaths were attributed to cancer in 2012?
12 million
What percentage of cancer deaths occur in low-income countries?
70%
What is the estimated probability of developing cancer, according to CRUK?
1 in 3 people
What is the proportion of deaths attributable to cancer, according to CRUK?
1 in 6 deaths
What does epidemiology provide insight into?
The magnitude of the cancer problem
What is the purpose of a sentinel lymph node biopsy?
To assess for metastatic deposits and plan surgical treatment
Which of the following is a characteristic of malignant tumors?
Infiltrate surrounding tissue
What is the most common site of metastasis?
Liver and Lungs
What is the purpose of epidemiologic studies in cancer research?
To relate environmental and genetic influences to cancer occurrence
What is a characteristic of benign tumors?
Encapsulated
What is the term for the spread of cancer cells through the bloodstream?
Metastasis via embolism
Why is the liver a common site of metastasis?
All portal area drainage flows to the liver
What is the term for the first lymph node in a regional lymphatic basin that receives lymph flow from the primary tumor?
Sentinel lymph node
Study Notes
Characteristics of Benign vs Malignant Tumors
- Benign tumors grow slowly, while malignant tumors grow faster
- Rate of growth correlates with the level of differentiation; poorly differentiated tumors tend to grow faster
- Growth is also affected by hormones and blood supply
Local Invasion
- Benign tumors remain localized and do not invade, whereas malignant tumors invade locally and metastasize
- Local invasiveness is a reliable feature to distinguish malignant from benign tumors
Metastasis
- Spread of the tumor to distant sites of the body
- Primary site: where the tumor has started; secondary site: where neoplastic cells migrate and grow as a separate tumor
- The more anaplastic, rapidly growing, and larger the primary tumor, the more likely is metastatic spread
- Metastasis marks a tumor as malignant
- Methods of metastasis:
- Seeding of body cavities and surfaces
- Lymphatic spread (more typical of Carcinoma)
- Hematogenous spread (more typical of Sarcoma)
Clinical Significance of Metastasis
- Sentinel Lymph Node: first lymph node in regional lymphatic basin that receives lymph flow from the primary tumor
- Biopsy from the sentinel lymph node is used to assess for the presence or absence of metastatic deposits
- Metastasis via embolism: liver and lungs are the most frequent sites of metastasis
Comparison of Benign and Malignant Tumors
- Benign tumors:
- Compress surrounding tissue
- Encapsulated
- Uniform population
- No anaplasia
- No invasion/infiltration
- Malignant tumors:
- Infiltrate surrounding tissue
- Have indiscrete borders
- Individual cells infiltrate surrounding tissue
- Can display anaplasia
- Can show lack of differentiation
- Numerous mitosis
- Boundaries ill-defined
- Chromosomal aberrations
Epidemiology of Cancer
- Relates environmental, racial, and cultural influences to the occurrence of specific neoplasms
- Provides insight into the magnitude of the cancer problem by studying cancer incidence, prevalence, mortality, age, sex, and geographic differences
- Cancer incidence: number of new cases of specific cancer registered over a specific period in a defined population
- Cancer mortality: number of deaths from a given form of cancer during a specified period of time
- Cancer prevalence: number of all cases of cancer, both new and registered, within a defined population at a given point in time
- Cancers are among the leading causes of morbidity and mortality worldwide
Distinguish between benign and malignant tumors based on four fundamental rules: differentiation, rate of growth, local invasion, and metastasis. Learn how to identify the characteristics of each type of tumor.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
