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Questions and Answers
What is a known increased risk associated with Sjögren syndrome?
What is a known increased risk associated with Sjögren syndrome?
What immunodeficiency condition is notably associated with an increased risk of Kaposi sarcoma?
What immunodeficiency condition is notably associated with an increased risk of Kaposi sarcoma?
Which of the following is categorized as a precursor lesion?
Which of the following is categorized as a precursor lesion?
Which type of hyperplasia is specifically mentioned as a precursor condition?
Which type of hyperplasia is specifically mentioned as a precursor condition?
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What is crucial for normal cell surveillance in the context of immune function?
What is crucial for normal cell surveillance in the context of immune function?
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What is the second leading cause of death in adults?
What is the second leading cause of death in adults?
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What percentage risk of developing cancer do males have over their lifetime?
What percentage risk of developing cancer do males have over their lifetime?
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Which of the following cancers accounts for a significant proportion of US cancer diagnoses and deaths?
Which of the following cancers accounts for a significant proportion of US cancer diagnoses and deaths?
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In the last 20-25 years, what has contributed to the decrease in overall cancer death rates?
In the last 20-25 years, what has contributed to the decrease in overall cancer death rates?
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What characterizes a malignant tumor as opposed to a benign tumor?
What characterizes a malignant tumor as opposed to a benign tumor?
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What is the main purpose of cancer screening?
What is the main purpose of cancer screening?
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Which term refers to a malignancy of epithelial tissue?
Which term refers to a malignancy of epithelial tissue?
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Which of the following is NOT included in cancer registries or epidemiology statistics due to its prevalence?
Which of the following is NOT included in cancer registries or epidemiology statistics due to its prevalence?
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What is a defining feature of dysplasia?
What is a defining feature of dysplasia?
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Which of the following cancers has the highest incidence in adults?
Which of the following cancers has the highest incidence in adults?
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What describes a teratoma?
What describes a teratoma?
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What percentage of cancer death risk do females face over their lifetime?
What percentage of cancer death risk do females face over their lifetime?
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Which type of cells do dysplastic cells lack to become carcinogenic?
Which type of cells do dysplastic cells lack to become carcinogenic?
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What is the significance of a basement membrane in malignancy?
What is the significance of a basement membrane in malignancy?
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What is a characteristic of a hamartoma?
What is a characteristic of a hamartoma?
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Which term appropriately describes a malignancy of lymphocytes?
Which term appropriately describes a malignancy of lymphocytes?
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What distinguishes neoplasia from hyperplasia and tissue repair?
What distinguishes neoplasia from hyperplasia and tissue repair?
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What is a key feature of benign neoplasms?
What is a key feature of benign neoplasms?
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Which of the following statements is true regarding malignant neoplasms?
Which of the following statements is true regarding malignant neoplasms?
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What characteristic can sometimes mislead regarding the aggressiveness of benign neoplasms?
What characteristic can sometimes mislead regarding the aggressiveness of benign neoplasms?
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How does the growth pattern of malignant neoplasms typically differ from that of benign neoplasms?
How does the growth pattern of malignant neoplasms typically differ from that of benign neoplasms?
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Which neoplasm is characterized by clonal plasma cells expressing only one type of light chain?
Which neoplasm is characterized by clonal plasma cells expressing only one type of light chain?
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What common characteristic is generally associated with benign neoplasms in terms of appearance?
What common characteristic is generally associated with benign neoplasms in terms of appearance?
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Which of the following is a possible characteristic of malignant neoplasms?
Which of the following is a possible characteristic of malignant neoplasms?
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What does the presence of a single type of light chain in plasma cells indicate about the type of neoplasm?
What does the presence of a single type of light chain in plasma cells indicate about the type of neoplasm?
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What is a significant caveat regarding malignant neoplasms?
What is a significant caveat regarding malignant neoplasms?
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What is the main reason cancers that are detected late tend to have a poor prognosis?
What is the main reason cancers that are detected late tend to have a poor prognosis?
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Which screening method is specifically used to detect cervical dysplasia before it develops into cancer?
Which screening method is specifically used to detect cervical dysplasia before it develops into cancer?
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Which of the following factors accounts for the majority of mutations leading to human cancers?
Which of the following factors accounts for the majority of mutations leading to human cancers?
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What percentage of childhood cancers are typically curable?
What percentage of childhood cancers are typically curable?
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Which demographic is considered the primary age group for cancer occurrence?
Which demographic is considered the primary age group for cancer occurrence?
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What is the primary risk factor attributed to premature deaths related to lung cancer?
What is the primary risk factor attributed to premature deaths related to lung cancer?
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How much of cancer deaths are attributed to alcohol consumption?
How much of cancer deaths are attributed to alcohol consumption?
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Which infectious agent is known to significantly increase the risk of hepatocellular carcinoma?
Which infectious agent is known to significantly increase the risk of hepatocellular carcinoma?
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What role does chronic inflammation play in cancer risk?
What role does chronic inflammation play in cancer risk?
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What is the relationship between estrogen stimulation and breast cancer risk?
What is the relationship between estrogen stimulation and breast cancer risk?
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What is the primary method for detecting prostate carcinoma before it spreads?
What is the primary method for detecting prostate carcinoma before it spreads?
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Which cancer is primarily associated with smoking and secondhand smoke exposure?
Which cancer is primarily associated with smoking and secondhand smoke exposure?
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Which of the following cancers has a strong association with obesity?
Which of the following cancers has a strong association with obesity?
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What percentage of cancers may be preventable due to environmental influences?
What percentage of cancers may be preventable due to environmental influences?
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Study Notes
Neoplasia
- A disorder of cell growth triggered by a series of genomic alterations
- Excessive proliferation is independent of and uncontrolled by physiologic growth signals
- Alterations give neoplastic cells a survival and growth advantage
- Alterations affect a single cell and its clonal progeny
- Neoplasms are clonal: neoplastic cells derive from a single mother cell
Neoplasms: Benign and Malignant
- Benign neoplasms stay localized and do not spread/metastasize to other sites
- Benign neoplasms are usually well-circumscribed and non-infiltrative
- Benign neoplasms are possible to remove surgically
- Malignant neoplasms are cancerous
- Malignant neoplasms have invasive growth that destroys adjacent tissues
- Malignant neoplasms can spread to distant sites (metastasize)
- Approximately 30% of tumors first present as metastatic disease
- Treatment for malignant neoplasms is complicated, especially in advanced disease
- Prognosis for malignant neoplasms may be questionable
- Benign neoplasms may behave aggressively, cause significant morbidity, or be fatal
- Cancers may occasionally be quite small and require a high level of clinical skill to suspect and identify
Benign vs. Malignant: Microscopic Features
- Well-differentiated (resembling normal tissue) vs. poorly-differentiated (not resembling normal tissue)
- Typical tissue organization vs. atypical tissue structure
- Rare, normal mitoses vs. frequent, abnormal mitoses
- Histologic features of malignancy include pleomorphism (variable size and shape of cells/nuclei), high nuclear/cytoplasmic ratio of cells, and loss of identifiable differentiation
Neoplasm Nomenclature
- Beginning of the name identifies tissue of origin
- Ending of the name usually means neoplasm
- -oma usually means benign
- -carcinoma and -sarcoma are always malignant
Dysplasia
- Genetically altered cells stay within epithelium
- Basement membrane acts as a barrier between epithelium and connective tissue
- Dysplasia cannot grow aggressively or metastasize
- The patient can be cured by surgical excision
- Dysplasia is a precursor to carcinoma
- Once dysplasia invades through the basement membrane into connective tissue, it becomes carcinoma
- Carcinoma in situ: dysplasia involving full thickness of epithelium but still confined by the basement membrane; the patient can still be cured by complete surgical excision
Teratoma
- A benign tumor containing cells/tissues from more than one tissue type and more than one germ layer
- Nearly all other neoplasms consist of cells of one tissue type
- Originates from germ cells
Hamartoma
- A benign proliferation of cells/ tissues native to the involved site
- Considered a benign, highly differentiated neoplasm
Choristoma
- Benign proliferation of cells/ tissues in a non-native site
- Considered a benign, highly differentiated neoplasm
Cancer Epidemiology
- Cancer is the 2nd leading cause of death in both adults and children
- The leading causes of death in adults are (1) cardiovascular disease, (2) cancer, and (3) chronic respiratory disease
- The leading causes of death in children are (1) accidents, (2) cancer, and (3) congenital defects
- The most common cancers by incidence in adults are (1) breast/prostate, (2) lung, and (3) colorectal cancer
- The most common causes of cancer mortality in adults are (1) lung, (2) breast/prostate, and (3) colorectal cancer
- The most common cancers by incidence in adults are (1) breast/prostate, (2) lung, and (3) colorectal cancer
- The most common causes of cancer mortality in adults are (1) lung, (2) breast/prostate, and (3) colorectal cancer.
- Cardiovascular disease is the leading cause of death in the US and worldwide.
- Cancer is the second leading cause of death in the US and worldwide.
- Lifetime cancer risk: Males - Risk of developing: 40%; Risk of death: 21%
- Lifetime cancer risk: Females - Risk of developing: 39%; Risk of death: 18%
- Approximately 50% of US cancer diagnoses/deaths are accounted for by the ‘big 4’: Lung, Breast, Prostate, Colorectal
- Some cancers are more aggressive than others
Basal cell carcinoma and Squamous cell carcinoma of skin
- Most common human cancers by far
- BCC: 3-4 million cases per year in US
- SCC: 2-3 million cases per year in US
- Not included in cancer registries or epidemiology statistics
- Indolent and treatable
Cancer Screening:
- Screening seeks to catch dysplasia (precancerous change) before it becomes carcinoma
- Screening seeks to catch carcinoma before clinical symptoms arise
- Purpose of screening is to decrease cancer-specific mortality
- Cancers that do not produce symptoms until late in disease have undergone additional divisions and mutations
- Cancers detected late tend to have a poor prognosis
- Common screening methods:
- Pap smear - detects cervical dysplasia (CIN) before it becomes carcinoma
- Mammography - detects in situ breast cancer (e.g., DCIS) before it invades or invasive carcinoma before it becomes clinically palpable
- Prostate-specific antigen (PSA) and digital rectal exam - detects prostate carcinoma before it spreads
- Hemoccult test (for occult blood in stool) and colonoscopy - detect colonic adenoma before it becomes colonic carcinoma or carcinoma before it spreads
Cancer and Age
- Most cancers occur over 55 years of age
- Men aged 60-79: main cause of death
- Women aged 40-79: main cause of death
- Explained by:
- Accumulation of pathogenic genomic alterations in (stem) cells over lifetime
- Decline in immune system competence
- Cancer accounts for 10% of all childhood deaths
- 80% of childhood cancers are cured
- Most common pediatric cancers are leukemia/lymphoma and brain/CNS tumors
Carcinogenesis
- Carcinogenesis results from the accumulation of complementary genomic alterations
- Genomic (genetic and epigenetic) alterations come from three sources:
- DNA replication errors during (stem) cell division
- Approximately 65-70% of mutations in human cancers
- ~ 3 mutations and an unknown number of epigenetic alterations occur every time a normal human stem cell divides
- Environmental factors
- Inherited/hereditary genetic mutations
- 5-10% of cancers have a hereditary component
- DNA replication errors during (stem) cell division
- Stem cells in different adult tissue types undergo different numbers of cell divisions
- Strong correlation (0.8) between average number of stem cell divisions per tissue and rate/risk of cancer in that tissue
Environmental Factors
- Remarkable geographic variation in cancer incidence
- Evidence of the role of environmental carcinogens
- Environmental influences appear to be dominant risk factors for many cancers
- Approximately 20-40% of cancers may be preventable
Tobacco
- World’s single greatest preventable cause of death
- Single most important factor contributing to premature death in the US
- Implicated in 80% of 140,000 annual lung cancer deaths
- 4000-7000 due to secondhand smoke
- Also implicated in cancers of:
- Oral cavity, pharynx, larynx
- Esophagus
- Pancreas
- Colon
- Bladder
Obesity
- Strongly associated with cancer risk
- 10% of cancer deaths attributed to obesity
- Linked with > 10 cancers
- Colon
- Rectum
- Postmenopausal breast cancer
- Prostate
- More than two-thirds of Americans are overweight/obese
- 20% of children/adolescents obese
Alcohol
- Contributes to 5% of cancer deaths
- Increased risk of cancers of:
- Oral cavity, pharynx, larynx
- Esophagus
- Liver
- Colon
- Breast
- Alcohol and tobacco synergistically increase the risk of cancers in the upper aerodigestive tract
Infectious Agents
- 15% of cancers worldwide are caused by infectious agents
- 30-45% of cancers in the developing world
- Many individuals infected with hepatitis C virus (HCV) may develop hepatocellular (liver) carcinoma.
- Human papillomavirus (HPV)
- Cause of cervical carcinoma
- Cause of an increasing fraction of head and neck cancers
- Oropharynx, in particular
- Incidence of HPV-positive oropharyngeal cancer has now surpassed the incidence of cervical carcinoma
Reproductive History
- Cumulative exposure to estrogen stimulation increases the risk of breast and endometrial cancer
- ½ the risk of breast cancer if age at first full-term pregnancy < 20 years compared to > 35 years
- Postmenopausal hormone replacement therapy increases the risk of breast cancer
Other Environmental Carcinogens
- In the environment: UV rays, smog
- In the workplace: asbestos
- In diet: grilled meat, fat, alcohol
Acquired Predisposing Conditions
- Chronic inflammation (infectious or non-infectious)
- Increased cell proliferation to repair damage → increased opportunity for genetic mutations
- Presence of activated immune cells in inflamed tissue
- Produced reactive oxygen species are directly genotoxic
- Alcoholism → pancreatitis: increased risk of pancreatic carcinoma
- Inflammatory bowel disease: increased risk of colorectal carcinoma
- Autoimmune diseases, e.g. Sjögren syndrome: increased risk of MALT lymphoma
- Immunodeficiency: Intact immune system, in particular intact T-cell immunity, is critical for normal cell surveillance
- Deficits in immune function associated with increased cancer risk
- HIV/AIDS
- Chronic pharmacologic immunosuppression
- Kaposi sarcoma: seen in HIV/AIDS
- Deficits in immune function associated with increased cancer risk
- Precursor lesions:
- Metaplasia
- e.g. Barrett’s esophagus
- Hyperplasia
- e.g. endometrial hyperplasia
- Dysplasia
- Benign neoplasia
- e.g. colorectal adenoma
- Metaplasia
Genetics and Cancer
- Nevoid basal cell carcinoma syndrome (NBCCS)
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Description
This quiz covers key concepts related to neoplasia, including the characteristics of neoplastic growth, differences between benign and malignant neoplasms, and their implications for treatment and prognosis. Test your understanding of cellular alterations and tumor behavior.
