Module 10.3 - Other Cancers Flashcards
1
Q
What are the risk factors associated with lung cancer development?
A
- Tobacco smoking is the most common cause of lung cancer
- Environmental smoke exposure (second hand smoke)
- Occupation risk factors, including:
- Asbestos dust
- Arsenic, chromium, nickel dusts
- Ionizing radiation,
- Chloromethyl methyl ether (used as a solvent in the manufacture of water repellents and industrial polymers.
- Coal products
- Mustard gas- used in chemical warfare situations, such as Vietnam
- Vinyl chloride
- Genetic susceptibility
2
Q
Describe the pathogenesis of lung cancer
A
- Environmental carcinogens found in tobacco smoke and asbestos are associated with malignant transformations
- Tobacco smoke contains as many as 30 lung carcinogens
- Carcinogens, along with an inherited genetic predisposition to cancers and epigenetic mechanisms results in tumor formation and development of a microenvironment that promotes tumor progression
- Carcinogen-induced mutations occur, further tumor development is promoted by growth factors that alter cell growth and differentiation and by cells and products of inflammation that promote immune suppression, neoangiogenesis, lymphangiogenesis, remodeling of extracellular matrix, invasion and metastasis.
- Bronchial mucosa exposed to repetitive tobacco smoke, has eventual epithelial cell changes which progress from metaplasia to carcinoma in situ and finally to invasive carcinoma
- Tumor progression includes invasion of surrounding tissues and metastasis to distant sites, including brain, bone marrow and liver.
3
Q
What is the most common type of lung cancer?
A
Non-small cell lung carcinoma (NSCLC) – bronchogenic lung cancer; makes up 85% of all lung cancers.
4
Q
What are some characteristics of Squamous cell carcinoma?
A
- 30% of all bronchogenic carcinomas
- Associated with smoking and COPD
- Typically located near hila and project into bronchi
- Nonproductive cough or hemoptysis is common
- Pneumonia and atelectasis often associated with SCC
- Slow to metastasize until late in disease course
5
Q
What are some characteristics of adenocarcinomas?
A
- Tumors usually arise in the periphery of pulmonary parenchyma
- Metastasize early
- Includes bronchoalveolar cell carcinoma- which arises from terminal bronchioles and alveoli
6
Q
What are some characteristics of Large cell undifferentiated carcinoma?
A
- Constitute about 10-15% of bronchogenic carcinomas
- Transformed epithelial cells that have lost all evidence of differentiation
- Commonly arise centrally and can grow to distort trachea and cause widening of carina
- Radiation and chemotherapy has not been shown to increase survival in metastasis
7
Q
What are some characteristics of Small cell lung carcinoma (SCLC)?
A
- Most common neuroendocrine lung cancer- approx.15%
- Arise from neuroendocrine cells that contain neurosecretory granules and exist throughout tracheobronchial tree.
- Often associated with tumor-derived hormone production, with resultant signs and symptoms of paraneoplastic syndromes
- Tumors arise from central part of lung
- Most common type of lung cancer that causes signs and symptoms of SIADH
- SIADH manifestations include changes in mental status, lethargy, seizures. In some patients there are no symptoms despite very low sodium levels.
- Paraneoplastic syndrome examples include: Cushing’s syndrome, hypocalcemia, gynecomastia, carcinoid syndrome and hyponatremia
- Cell type has strongest correlation with tobacco smoking
- Metastasize early and have a rapid rate of growth
- Worst prognosis of all lung cancer types
8
Q
What are the signs and symptoms of lung cancer?
A
- Weight loss
- Chest pain
- Dyspnea
- Loss of appetite
- Cough
- Hemoptysis
- Hoarseness
- Wheezing
- Sputum production
- Recurring infections- bronchitis and pneumonia
9
Q
What laboratory/diagnostic tests are done for lung cancer?
A
- Biopsy- only definitive test, such as CT guided fine needle aspiration or bronchoscopy for sputum cytology or needle aspiration
- Pleural effusion- approx. 40-50% are malignant pleural effusions
- Chest x-ray presentation varies with cell type
- Comparison with old films is extremely valuable
10
Q
Which type of lung cancers are present in the periphery, centrally, or in the cavitation?
A
Central lesions tend to be:
- Squamous cell carcinoma
- Small cell carcinoma (SCC)
Peripheral lesions tend to be:
- Adenocarcinoma
- Large cell carcinoma
- Bronchoalveolar cell carcinoma
Cavitation tends to be:
- Squamous cell carcinoma
- Large cell carcinoma
- Early mediastinal involvement tends to be small cell carcinoma
11
Q
How do you manage a patient with small cell carcinoma?
A
- Oncology referral
- Therapy dependent on: cell type, pre-morbid conditions, underlying lung function
- Almost always treated with chemotherapy – cisplatin or carboplatin based
- RARELY treated with surgical excision (pneumonectomy)
- Commonly spreads to brain
- If extensive stage- radiation sometimes used with chemotherapy
12
Q
What are some characteristics of colorectal cancer?
A
- 3rd most common cause of cancer and cancer death in the U.S.
- Incidence declining due to successful screening programs, removal of polyps and increased use of NSAIDs
- Tends to occur in persons over age 50, rare in children
- Prevalence is highest worldwide in black population- primarily due to lack of access to screening and treatment
- Develops in individuals with an acquired or inherited genetic predisposition who are exposed to a combination of environmental risk factors
- Lifestyle modifications related to diet, alcohol, tobacco use, exercise and weight control are the most effective approaches to primary prevention of CRC
13
Q
What are some risk factors for the development of colorectal cancer?
A
-
Gene mutations may be acquired or inherited (ON TEST)
- Cells that have mutations in certain genes that are involved in correcting mistakes made when DNA is copied in a cell are termed as having a ‘mismatch repair deficiency (MMR)’. It is common in colorectal cancer (and other types of GI cancer and endometrial cancer).
- Knowing if a tumor is MMR deficient helps to plan treatment or predict how well the tumor will respond to treatment.
- Family history occurs in about 25% of all cases –
- Familial adenomatous polyposis (100% risk of developing CRC)
- Hereditary nonpolyposis colorectal cancer (HNPCC) (40% of developing CRC)
- Chronic inflammatory bowel disease increased risk of CRC after 10-15 years of disease.
- Most colorectal cancers arise from adenomatous polyps, with the exception of HNPCC, which arises from apparently normal intestinal epithelial tissue and is more rapidly spreading.
14
Q
What are tubular adenomas?
A
has a stalk projecting from intestinal wall; most prevalent type of polyp
15
Q
What are Villous adenomas?
A
has fingerlike projections of epithelium without stalks and tending to be larger than 1 cm
16
Q
What are some characteristics of adenomatous polyps?
A
- When polyps are larger than 2 cm, more numerous (> 20) and have a villous architecture, they have the most malignant potential.
- The adenomatous polyp forms in an area of epithelial cell hyper proliferation and crypt dysplasia
- When the adenoma traverses the muscularis mucosae, it becomes highly invasive and highly malignant.
- Screening colonoscopy with polypectomy is important since adenomas can be detected early and removed prior to submucosa being penetrated.
- Progression from polyps to colon cancer involves a multistep cascade of genetic mutations that occur over 10-15 years.
17
Q
What are some subjective/physical exam findings associated with colorectal cancer?
A
- Patients usually asymptomatic with polyps and early-stage tumors, making screening all important
- Symptoms of CRC dependent on location, size, shape and metastasis of lesion
- Digital rectal examination, combined with stool guaiac testing, is most important part of PE.
18
Q
What are some characteristics of right-sided colon tumors?
A
- Polypoid and extend along one wall of cecum and ascending colon
- Tumors may be silent, evolving to pain with a palpable mass in RLQ
- Fatigue, dark red or mahogany colored blood mixed with stool and anemia
- Tumors become large & bulky with necrosis and ulceration, contributing to persistent blood loss and anemia
- Obstruction uncommon since tumors do not encircle colon.
- More common in women
19
Q
What are some characteristics of left-sided colon tumors?
A
- Tumors in descending colon, small, elevated, button like masses
- Grows circumferentially, encircling entire bowel wall
- Eventually ulcerating as tumor penetrates blood supply
- Obstruction is common but occurs slowly
- CLASSIC SIGNS: change in bowel habits, stools become narrow and pencil-shaped, bright red blood on stools.
- Progressive abdominal distention and pain
- Vomiting, constipation, need for laxatives, cramps and bright red blood on the surface of stool and anemia
- More common in men
21
Q
Describe the pathophysiology associated with breast cancer
A
- The majority of breast cancers are adenocarcinomas and they arise from the ductal/lobular epithelium as carcinoma in situ (early stage, noninvasive, proliferation of epithelial cells confined to ducts and lobules)
- Breast cancer is heterogeneous- due to genetic, epigenetic, and micro environmental influences that tumor cells undergo during cancer progression
- Cellular subpopulations from different sections of the same tumor vary in many ways including growth rate, immunogenicity, and ability to metastasize and drug response, demonstrating significant heterogeneity.
- In many breast cancer cases a significant number of somatic mutations as well as a considerable number of germline mutations are found which are tumor enhancers and impose the risk of breast cancer tumorigenesis. Most of the driver mutations occur at the somatic level which a small number of mutations are passed on the lineages, which cause for 5-10% of all familial breast cancer types.
- Examples of driver genes are HER2 and MYC, PTEN and examples of tumor suppressor genes include TP53, BRCA1 and BRCA2.
26
Q
Describe the pathophysiology associated with cervical cancer
A
- Cervical cancer is almost exclusively caused by cervical HPV infection.
- Infection with high risk oncogenic types of HPV is a necessary precursor to the development of cervical dysplasia, known as precancerous cell changes that lead to invasive cancer
- Precancerous dysplasia, also termed cervical intraepithelial carcinoma (CIN) and cervical carcinoma in situ (CIS) are a more advanced form of cell changes.
- IMPORTANTLY, cervical dysplasia can be detected noninvasively through examination of cervical cells (Make sure they get their PAP smears)
- If detected early, treatment is available to prevent invasive cancer.
27
Q
What is the Transformation zone (Squamous Columnar Junction)?
A
- The line where the above 2 cell types meet.
- Very vulnerable to oncogenic effects of HPV
- Location where carcinoma in situ is most likely to develop
- In this zone, columnar epithelium is constantly being replaced by squamous epithelium in a process known as metaplasia
- Metaplasia is thought to be affected by hormonal levels
- Metaplastic cells are at increased risk of incorporating foreign or abnormal genetic material; therefore, are more prone to neoplastic changes.
35
Q
Where does prostate cancer occur?
A
- Most occur in the periphery of the prostate (peripheral zone)
- Prostatic adenocarcinoma is a heterogeneous group of tumors with a diverse spectrum of molecular and pathologic characteristics
- Biological aggressiveness related to degree of differentiation rather than size of tumor.
