Neoplasia Principles and Oncogenes Flashcards
What are 3 features that distinguish NEOPLASIA from hyperplasia or repair?
IRREVERSIBLE
UNREGULATED
MONOCLONAL (neoplastic cells derived from single mother cell)
How can clonality of cells be determined to differentiate between NEOPLASIA and HYPERPLASIA/REPAIR? (2) Which chromosome are these two genes on?
- G6PD ISOFORMS - Maintained 1:1 ratio in POLYCLONAL HYPERPLASIA, not maintained ratio - only 1 isoform in MONOCLONAL NEOPLASIA
- ANDROGEN RECEPTOR ISOFORM
Both present on X-chromosome
What is the Ddx of an ENLARGED LYMPH NODE (Proliferation of lymphocytes)?
- Metastatic Cancer
- Reactive Hyperplasia - Lymph node enlargement in response to an infection
- Lymphoma (only tumor of the lymph node)
Pt has an enlarged lymph node. Biopsy shows lymphocytic proliferation. Light chain study shows a Kappa:Lambda ratio of 20:1. What is my diagnosis?
STEP 1: Lymphocytic proliferation: 3 Ddx - Metastatic cancer, Reactive hyperplasia, and lymphoma
STEP 2: K:L ratio >6:1 = MONOCLONAL PROLIFERATION of B-lymphocytes
Diagnosis = LYMPHOMA
How can clonality of B-lymphocytes be determined?
Ig LIGHT CHAIN PHENOTYPE
What differentiates a POLYCLONAL HYPERPLASIA of B cells versus MONOCLONAL NEOPLASIA of B cells?
POLYCLONAL HYPERPLASIA: Normal kappa:lambda ratio - 3:1
MONOCLONAL NEOPLASIA: kappa:lambda > 6:1 (usually 20:1) OR inverted ratio (kappa:lambda = 1:3)
Which of the following neoplasias are monoclonal: BENIGN neoplasia or MALIGNANT neoplasia?
BOTH are monoclonal
What is the main distinguishing character of BENIGN tumors vs MALIGNANT tumors?
BENIGN: Absolutely do NOT metastasize
MALIGNANT: Have the POTENTIAL to metastasize
What are the most common cancers by INCIDENCE in adults?
- BREAST/PROSTATE
- LUNG
- COLORECTAL
What are the most common cancers by MORTALITY in adults?
- LUNG - Less common than breast/prostate BUT highest mortality BECAUSE of lack of early detection (NO PRACTICAL SCREENING MECHANISM) - Presents clinically LATE
- BREAST/PROSTATE
- COLORECTAL
How many divisions occur from the SINGLE MUTATED CANCER CELL (monoclonal proliferation) before clinical symptoms arise?
30 DIVISIONS
What is the difference between DYSPLASIA and CANCER?
Dysplasia: REVERSIBLE accumulation of mutations
Cancer: IRREVERSIBLE accumulation of mutations, grows unregulated and # of mutations increases with each division
What is the purpose of a PAP SMEAR?
To detect dysplastic precursor (CIN - cervical intraepithlial neoplasia I, II, III) before it becomes carcinoma
What is the purpose of a MAMMOGRAPHY?
- To detect ductal carcinoma in situ (DCIS) before it invades the BV and lymph - Calcifications often seen within DCIS
- To detect invasive carcinoma (>1cm) before it becomes clinically palpable (>2cm)
What is the purpose of a PSA and DRE?
To detect prostate carcinoma before it spreads
Prostate carcinoma arises on the POSTERIOR PERIPHERAL aspect and is thus clinically silent (unlike BPH which arises in the center and compresses on urethra)
What is the purpose of a HEMOCCULT TEST and COLONOSCOPY?
- To detect colonic adenoma before it progresses into colonic carcinoma (Adenoma-carcinoma sequence)
- To detect carcinoma before it spreads and shows clinical Sx
What is AFLATOXIN? What is the associated cancer?
AFLATOXIN = CHEMICAL TOXIN released by ASPERGILLUS that contaminated stored rice/grains
HEPATOCELLULAR CARCINOMA
Pt had chemotherapy. 5 years later, pt develops LEUKEMIA/LYMPHOMA. What is the most likely cause?
ALKYLATING AGENT DRUG
What are the 2 most common carcinogens that increase the risk of SQUAMOUS CELL CARCINOMA OF THE OROPHARYNX?
ALCOHOL
TOBACCO
ALCOHOL is a carcinogen that increases the risk of which cancers?
SQUAMOUS CELL CARCINOMA OF OROPHARYNX
SQUAMOUS CELL CARCINOMA OF UPPER ESOPHAGUS
PANCREATIC CARCINOMA [Alcoholism -> Pancreatitis]
HEPATOCELLULAR CARCINOMA [Alcoholism -> Cirrhosis]
How do you test for ARSENIC POISONING?
Clip the fingernails and sometimes remove the hair - ARSENIC can be found in the hair [HAIR and FINGERNAILS = derivatives of skin]
ARSENIC is a carcinogen that increases the risk of which 3 carcinomas?
- SQUAMOUS CELL CARCINOMA OF THE SKIN [Determine As poisoning by removing fingernails/hair - skin derivatives]
- LUNG CANCER [As - present in cigarette smoke]
- LIVER ANGIOSARCOMA
ASBESTOS exposure increases the risk of which 2 carcinomas?
- LUNG CARCINOMA
2. MESOTHELIOMA (Cancer that arises in the mesothelial cells of the pleura)
Is ASBESTOS exposure more likely to lead to LUNG CANCER or MESOTHELIOMA?
LUNG CANCER
What is the most carcinogenic component of CIGARETTE SMOKE?
POLYCYCLIC HYDROCARBONS
CIGARETTE SMOKE increases the risk of which 5 carcinomas?
SQUAMOUS CELL CARCINOMA OF OROPHARYNX SQUAMOUS CELL CARCINOMA OF ESOPHAGUS LUNG CARCINOMA RENAL CELL CARCINOMA BLADDER CARCINOMA (Urothelium - lines kidneys, ureters, bladders; cigarette smoking = most carcinogenic component enters blood, filtered, concentrated in urine and entire urothelial system is bathed in smoke)
What are NITROSAMINES? Which carcinoma does this increase the risk of?
CARCINOGEN found in smoked foods - Associated with STOMACH CARCINOMA
Responsible for high rate of stomach carcinoma in Japan
Which type of STOMACH CARCINOMA (Intestinal type OR diffuse type) are NITROSAMINES associated with?
INTESTINAL TYPE STOMACH CARCINOMA - 3 risks: Chronic h.pylori gastritis + nitrosamines + Blood type A
What is NAPHTHYLAMINE? Which carcinoma is it most associated with?
NAPHTHYLAMINE - Derived from cigarette smoke
Most associated with UROTHELIAL CARCINOMA OF BLADDER
What is the carcinogen present in PLASTIC PIPES? (History/Epidemiological Study: Occupational exposure of this carcinogen resulted in a HIGH INCIDENCE of which cancer?)
PVC - POLYVINYL CHLORIDE
LIVER ANGIOSARCOMA