Chapter 11: Cancer Biology Flashcards
Final Exam
Cancer
“diseases in which abnormal cells divide without control and are able to invade other tissues.”
tumor
Generally reserved for describing a new growth, or neoplasm
Two ways to describe tumors
- Benign
- Malignant
Benign tumors are usually encapsulated with what?
Benign tumors are usually encapsulated with connective tissue
Benign tumors contain what kind of cells?
contain fairly well-differentiated cells and well-organized stroma
What kind of tissue do benign tumors usually contain? How do they interact with other structures?
They retain recognizable normal tissue structure and do not invade beyond their capsule, nor do they spread to regional lymph nodes or distant locations.
How do benign tumors spread?
they do not spread to regional lymph nodes or distant locations.
What kinds of cells are rarely present in benign tumors?
Mitotic cells are very rarely present during microscopic analysis
How are benign tumors named?
Benign tumors are generally named according to the tissues from which they arise with the suffix “-oma,”
Suffix of “oma” indicates what?
Indicates a tumor or mass
Leiomyoma
Benign tumor of smooth muscle of the uterus
Lipoma
A benign tumor of fat cells
Some tumors initially described as benign can become what?
Can progress to cancer and then are referred to as malignant tumors
How are malignant tumors distinguished from benign tumors?
malignant tumors , which are distinguished from benign tumors by more rapid growth rates and specific microscopic alterations, including loss of differentiation and absence of normal tissue organization
What is one of the microscopic hallmarks of cancer cells?
Anaplasia
Anaplasia
The loss of cellular differentiation
Pleomorphic
marked variability of size and shape
How are the size and shape of malignant cells described?
Pleomorphic
How are the nuclei of malignant tumors described?
They often have large darkly stained nuclei
What type of cells are common in malignant tumors?
Mitotic cells are common
Stroma of Malignant tumors
Malignant tumors may have a substantial amount of stroma, but it is disorganized, with loss of normal tissue structure.
How do malignant tumors grow? What do they lack?
Malignant tumors lack a capsule and grow to invade nearby blood vessels, lymphatics, and surrounding structures.
Most important and deadly characteristic of malignant tumors
their ability to spread far beyond the tissue of origin, a process known as metastasis.
Metastasis
Process in which tumors spread far beyond the tissue of origin
How are cancers named?
cancers generally are named according to the cell type from which they originate.
Carcinomas
Cancers arising in epithelial tissue
Adenocarcinomas
Cancers arising from or form a ductal or glandular structures.
Mammary adenocarcinoma
A malignant tumor arising from breast glandular tissue
Fibroadenoma
a benign breast tumor
Sarcoma suffix
Cancers arising from mesenchymal tissue (including connective tissue, muscle, bone)
Leukemias
Cancers of blood forming cells
Lymphomas
Cancers of lymphatic tissue
Carcinoma in situ (CIS)
refers to preinvasive epithelial tumors of glandular or squamous cell origin.
a group of abnormal cells that are found only in the place where they first formed in the body
Where are early stage cancers localized?
These early-stage cancers are localized to the epithelium and have not penetrated the local basement membrane or invaded the surrounding stroma.
Based on these characteristics, they are not malignant.
CIS lesions can have one of the following three fates:
- they can remain stable for a long time,
- they can progress to invasive and metastatic cancers
- they can regress and disappear.
How does CIS vary?
CIS can vary from low-grade to high-grade dysplasia
High grade CIS lesions
high-grade lesions having the highest likelihood of becoming invasive cancers.
Tumor initiation
the process that produces the initial cancer cells
Tumor initiation is dependent on what?
dependent on mutational and epigenetic changes and characteristics of the microenvironment.
Tumor promotion
the process during which the population of cancer cells expands with diversity of cancer cell phenotypes
What is tumor promotion dependent on?
is dependent on additional genetic mutations and epigenetic changes and a changing tumor microenvironment.
Tumor progression
the process leading to spread of the tumor to adjacent and distal sites (metastasis),
What is tumor progression governed by?
is governed by further genetic mutations, epigenetic aberrations, and changing microenvironments at the primary tumor and at sites of metastasis.
driver mutations
Some mutations, referred to as driver mutations , “drive” the progression of cancer.
How does a cell become cancerous?
After a critical number of driver mutations have occurred, the cell becomes cancerous.
What selective advantage does cancer cells have over others? What is it called?
its progeny can accumulate faster than its nonmutant neighbors.
This is referred to as clonal proliferation or clonal expansion
Malignant transformation
the process by which a normal cell becomes a cancer cell,
What is malignant transformation directed by?
is directed by progressive accumulation of genetic and epigenetic changes that alter the basic nature of the cell and drive it to malignancy.
Stroma
tumor microenvironment
Hallmarks of Cancer (1-5)
- Evading growth suppressors
- Enabling replicative immortality
- Tumor promoting inflammation
- Activating invasion and metastasis
- Genomic instability (mutator instability)
Hallmarks of Cancer (6-9)
- Inducing angiogenesis
- Resisting cell death
- Deregulating cellular energetics
- Sustaining proliferative signaling
- Avoiding immune destruction