Midterm Flashcards
What are the most common types of cancer in Canada?
Lung, Breast, Colorectal and prostate cancer
Who’s most commonly affected?
People 50 years and older
1 in 2 Canadians expected to develop cancer during their lifetime
What is cancer?
Disease of the cell, it is a abnormal growth resulting from uncontrolled proliferation
what is a neoplasm?
abnormal growth of cells that divide more than they should. Can be malignant or benign.
Cancer biology
abnormal cell is transformed by the genetic mutation of its DNA. There are two major dysfunctions present during the process of cancer- defective cellular proliferation (the growth) and defective cellular differentiation (undifferentiation occurs).
What is cellular differentiation?
process where an unspecialized cell acquires traits that allows it to perform specialized functions. Normally a orderly process, but in cancer this process may be reversed
How can cells mutate?
Exogenous sources- pesticides, radiation, viruses, carcinogens
How does inflammation cause cancer?
Active inflammation predisposes a person to cancer. By stimulating a wound-healing response that includes proliferation and new blood vessel growth.
what are the susceptible organs that may cause chronic inflammation?
Gastrointestinal (GI) tract, pancreas
Thyroid gland
Prostate, urinary bladder
Pleura, skin
What is carcinogenesis?
Process whereby N cells are transformed into cancer cells
what are causes of cancer?
chemical carcinogens: mutagens and chemical carcinogenesis and their metabolism
Physical carcinogenesis: Radiation, UV radiation
Infectious pathogens: Human T cell leukemia, DNA virus, HPV, Epstein Barr Virus, Hep B virus
Benign Tumor?
Named according to the tissues from which they arise.
Lipoma- Fat
Neurofibroma- Nerve tumor
Leiomyoma- Smooth muscle
Malignant tumors?
Are also named according to the tissues from which they arise.
Malignant epithelial tumors: Carcinomas
Ducts or glands: Adenocarcinomas
Malignant connective tissue tumors: Sarcomas
Cancers of lymphatic tissue: Lymphomas
Cancers of blood-forming cells: Leukemias
What does in situ mean ?
Have not broken through the basement membrane or invaded the surrounding stroma.
What are the three prognosis of carcinoma in situ?
Can remain stable for a long time.
Can progress to invasive and metastatic cancers.
Can regress and disappear.
What is the other word for DCIS?
Intraductal carcinomaorstage 0 breast cancer. DCIS is a non-invasive or pre-invasive breast cancer. This means the cells that line the ducts have changed to cancer cells but they have not spread through the walls of the ducts into the nearby breast tissue
Cancer invasion and metastasis
Cancer cells secrete protease.
Proteases digest the extracellular matrix & basement membranes.
- Create pathways through which cells can move.
Metastatic cells must be able to withstand the physiologic stresses of travel in the blood and lymphatic circulation.
Metastatic cells must then survive in a new environment.
what is metastasis?
Is the spread of cancer cells from the site of the original tumor to distant tissues & organs thru the body. Is a complex process that requires cells to have many new abilities.
1. Spread
2. Survive
3. Proliferate in distant locations
4. Destination must be receptive to growth of cancer
What is invasion?
Local spread!!
Is a prerequisite for metastasis (the first step in the metastatic process).
Cancer often spreads first to regional lymph nodes thru the lymphatic system & then to distant organs thru the bloodstream.
Invasion then requires the cancer attach to specific receptors & survive in the specific environment.
Pathways that cancer may spread?
Through dissemination, and occurs thru 3 pathways.
Direct seeding of body cavities or surfaces
Occurs when a malignant neoplasm penetrates into an “open field” (i.e. peritoneal cavity, pleural space)
Often seen with ovarian cancer
Lymphatic spread
Dissemination of carcinomas by lymphatic system
Most common pathway for initial carcinoma spread
Typically involves lymphatic vessels located at the tumor margins Ex: Breast, Lung
Hematogenous spread
Dissemination by arteries and veins
Typical of sarcomas, but is also seen with carcinomas
Most often involves the lungs and liver
How are tumor classifications beneficial?
Communicate the status of the Ca to members of the health care team,
Assist in determining the most effective treatment plan,
Evaluate the treatment plan,
Predict prognosis,
Compare like groups for statistical purposes.
Staging means what?
extent of disease
Grading means what?
anatomic site and histology
Histologic classification
The appearance of abnormal cells & degree of differentiation are evaluated pathologically.
For many tumor types, four grades are used to evaluate abnormal cells based on the degree to which the cells resemble the tissue of origin.
Tumors that are poorly differentiated (undifferentiated) have a worse prognosis than those that are closer in appearance to
the N tissue
Grade 1
Cells differ slightly from N cells (mild dysplasia) and are well differentiated.
Grade 2
Cells are more abnormal (moderate dysplasia) and moderately differentiated.
Grade 3
Cells are very abnormal (severe dysplasia) and poorly differentiated.
Grade 4
Cells are immature and primitive (anaplasia) and undifferentiated; cell of origin is difficult to determine.
Clinical staging
Classifying the extent and spread of disease is termed staging.
Is completed after the diagnostic workup and determines the treatment options.
Stage 0
Cancer in situ