3218- mod 2 (a)

neoplasia

a new, abnormal, and unregulated tissue grown within the body

(aka a tumour)

competes with normal cells and tissues for nutrients
when they start to grow within an area of the body, the normal tissues fail to thrive and will die

They will replace the healthy tissue

proliferation

the rapid reproduction of cells associated with neoplasia

neoplastic

can result from DNA changes in regular cells

there are many factors both external and internal that can cause this to create mutations in the genetic code 

Mutations act on the cells to alter the regulation of growth of the new cells that are produced = an overabundance of new cell growth 

these new cells are not receptive to apoptosis the way normal cells are

autonomous

one of three characteristics of neoplastic cells:

independent of growth factors / stimuli that would act on normal cells

these can grow and thrive in a very deprived environment of oxygen and nutrients

excessive

one of three characteristics of neoplastic cells:

impervious to normal regulators of cellular division

these can grow and divide on their own schedule - not regulated by the normal cell growth indicators

disorganized

one of three characteristics of neoplastic cells:

develop abnormal formations of tissue / organ and result in mutation of tissue

these tissues may share some characteristics of the original tissue but they are altered enough to change their functions

beningn

one of two classifications of neoplasia:

these are not cancerous 

the DNA is altered but not in a life-threatening way 

the tissue will remain localized and will not spread

tend to be slower growing 

most occur in the first three decades of life 
(they may still have negative consequences based on their location)

malignant

these are cancerous

have finger-like projections to help them grow out into health tissue areas

aka primary tumours

the tissue undergoes abnormal cell growth in size and rate
invades surrounding or distant tissues

can be further classified into different “omas”

sarcoma

these tumours are made of malignant cells arising from connective tusse

(all of these spread through the blood system)

carcinoma

these tumours are comprised of malignant cells arising from epithelial tissue

(most of these spread via the lymphatic system)

metastasis

the process of malignant tumour cells breaking off from their original source and travelling to other parts of the body to form new tumours 

aka secondary tumours

it is invasive in nature and only occurs with malignant tumour cells

there are three different ways in which these cells can travel (bloodstream, lymphatics, within tissue)

steps in the metastatic process

penetration, separation, dissemination, establishment, proliferation

penetration

Rampant growth at the tumour site extends through the walls of tissues/organs

Separation

These cells break off and enter into transit through the body

Dissemination

These original tumour cells are carried to one or more new sites in the body for implantation

Establishment

The cells are implanted into the new site and establish new vascular channels to provide nutrients to the cells

Proliferation

Cellular division happens and the new tumour mass grows and begins the process over again.

cancer staging

the process of determining how much cancer there is in the body and where it is located. It describes the severity of the cancer.

there are four main reasons for using a staging method to determine extent of the disease

1. Helps physicians plan a treatment for the patient

2. Informs the determination of a prognosis for the patient

3. Provides a common language with which health care workers can communicate about a patient’s case.

4. Helps identify any clinical trials that the patient may be suited for.
   there are three different types of this

cancer staging

based on knowledge of the way cancer develops 

based on four main factors: 

• Location of the primary (original) tumour

• Tumour size and number of tumours

• Lymph node involvement (whether or not the cancer has spread to the nearby lymph nodes)

• Presence or absence of metastasis (whether or not the cancer has spread to distant areas of the body)
  (cancers of the brain and spinal cord are classified according to cell type and grade. different systems are used for cancers of the blood or marrow)

clinical staging

determines how much cancer there is based on the physical exam, imaging, and biopsies

pathologic staging

this can only be done on patients who have had surgery to remove or explore the extent of the cancer

these type of staging combines the results of the clinical staging and results from the surgery

restaging

used to determine the extent of the disease if a cancer comes back after treatment

this is done to determine what the best treatment option would be at the time 

this type of staging is not common

TNM staging

this system is one of the most commonly used staging systems

the classification system was developed as a tool to stage different types of cancer based on certain standard criteria

1. The extent of the tumour (T)

2. the extent of spread to the lymph nodes (N)

3. the presence of metastasis (M)

(each system has its own letters. but once the categories are determined, an overall “stage” of I, II, III, IV can be assigned)
The stage of a cancer will not change over time

T category

describes the original (primary) tumour

N category

describes whether of not the cancer has reached nearby lymph nodes.

M category

tells whether there are distant metastases.

stage 0

tumour is in situ (undisturbed- in only one spot)

stage I

localized to one portion of the body

Stage II

early advanced state (some nodal involvement, depends on the type of cancer)

stage III

late advanced state (nodal involvement is more significant)

stage IV

Advanced, metastasized