733 Oncology Basic Principles

tumor/neoplasm

abnormal growths of new tissues that serve no useful purpose and may harm the host organism by competing for blood supply and nutrients. May be benign or malignant

benign tumor

localized, slow growing, usually encapsulated; not invasive however, can become larger enough to disband, compress, or obstruct normal tissues and to impair normal body functions

malignant tumor

invasive, rapid growth giving rise to metastasis; can be life threatening

dysplasia

a general category that suggests a disorganization of cells in which an adult cell varies from its normal size, shape, or organization

differentiation

the process by which normal cells undergo physical and structural changes, as they develop to form different tissues of the body

metaplasia

the first level of dysplasia- a reversible benign but abnormal change in which one adult cell changes from one type to another

hyperplasia

an increase in the number of cells in tissue, resulting in increased tissue mass

metastasis

movement of cancer cells from one body part to another; spread is by lymphatic system or bloodstream

characteristics of benign tumors

• slow growing

• cells stay differentiated (look like normal cells)

• surgical removal is effective

• typically stay localized

• -oma

characteristics of malignant tumors

• rapid growth rate

• poor differentiation (looks disorganized)

• can infiltrate surrounding tissue

• could metastasize to other body regions

• does not die on own

• -carcinoma or -sarcoma

cellular and genomic basis of neoplasms

• cell hypertrophy

• cell dysplasia

• cell hyperplasia

• cell metaplasia

cell hypertrophy

enlargement of cells

cell hyperplasia

excessive cell division, results in a crowding

cell dysplasia

reversion of a cell to its more mature form, lacks clear identity

cell metaplasia

abnormal cell reprogramming such that a cell appears and functions like a different type of cell

germline mutation

inherited gene mutations

somatic mutations

gene mutations acquired during one’s life

types of DNA damage

• DNA repair mechanism

• Proto-oncogenes

• Tumor suppressing genes

DNA repair mechanism

loss of the DNA repair mechanism is a common foundation of genomic foundations of neoplasms

proto-oncogenes

genes that exist to regulate normal cell division that may mutate and become “oncogenes” and allow for uncontrolled cell division and growth, potentially leading to the development of tumors

tumor suppressing genes

We all have these genes normally to suppress neoplastic/tumor growth in our bodies. When these genes mutate or are deleted during replication process, our cells may no longer be able to suppress tumor growth

why do genome changes occur?

• hereditary factors

• environmental factors

• viruses

• failure of the immune system

hereditary factors

inherited genomic changes

enviornmental factors

exposure to carcinogens

viruses- genome changes

for example, chronic hepatitis can lead to liver cancer, and HPV can lead to cervical cancer

failure of the immune system

is unable to fight and eliminate faulty cells

self sufficiency in growth signals

tumor cells will grow even though they are not getting a message to grow

insensitivity to anti-growth signals

a cancer cell will ignore messages telling it to stop growing

evading apoptosis

a cancer cell will ignore a signal that is informing the cell that it is time to die

limitless replicative potential

all cancer cells maintain the ability to replicate and eventually pick up more mutations

sustained angiogenesis

cells need nutrients to survive so they initiate the formation of new blood vessels that will provide for their growth via the process of “sustained angiogenesis”

tissue invasion and metastasis

cancer cells invade nearby tissues or distant organs by leaving their original site to form new colonies and secondary tumors

histologic type cancer classification

indicating the type of cell that the cancer originated from

tissue type cancer classification

indicating the type of tissue the cancer originated from

lymphoma

neoplasm originating in the lymphoid tissues/lymphatic system (glands and nodes)

carcinoma

originating in the epithelial tissues, eg, skin, stomach, colon, breast, and rectum

epithelial cancer statistics

80-90% of all cancer cases

two subtypes of carcinoma

1. adenocarcinoma

2. squamous cell carcinoma

adenocarcinoma

typically found in secreting organs and glands; common sites are breast, lung, colon, prostate

sarcoma

originating in connective and supportive tissues

leukemias

liquid cancer originating in the blood and blood forming organs (bone marrow)

myeloma

cancer originating in the plasma cells of bone marrow

mixed type

cross over between cancer types or within the same histologic type

bone tissue examples of tumors

benign: osteoma

malignant: osteosarcoma

cartilage tissue examples of tumors

benign: chondroma

malignant: chondrosarcoma

blood vessel tissue examples of tumors

benign: hemangioma

malignant: hemangiosarcoma

muscle tissue examples of tumors

benign: leiomyoma (smooth) or rhadbomyoma (striated)

malignant: leiomyosarcoma (smooth) or rhabdomyosarcoma (striated)

glandular epithelium tissue examples of tumors

benign: adenoma

malignant: adenocarcinoma

general signs and symptoms of cancer

• unexplained and/or rapid weight loss

• fever

• fatigue

• pain

• skin changes

• night sweats

early warning signs for cancer- C

change in bowel or bladder habits

early warning signs for cancer- A

a sore that does not heal in 6 weeks

early warning signs for cancer- U

unusual bleeding or discharge

early warning signs for cancer- T

thickening or lump in breast or elsewhere

early warning signs for cancer- I

indigestion or difficulty in swallowing

early warning signs for cancer- O

obvious change in a wart or mole

early warning signs for cancer- N

nagging cough or hoarseness

early warning signs for cancer- S

supplemental signs and symptoms

modifiable risk factors for cancer

• tobacco usage

• BMI

• poor nutrition

• excessive alcohol consumption

• viral infections

• occupational exposures

• UV radiation exposure

non-modifiable risk factors for cancer

• age

• genetic make up

• sex

• racial/ethnic groups

needle biopsy

hollow needle used to remove samples

endoscopic biopsy

uses an endoscope to guide instruments into orifices of the body to get tissue samples

surgical (open) biopsy

may remove all or part of a suspicious area

liquid biopsy

blood sample that is tested for circulating cancer cells, circulating tumor DNA, and protein from cancer cells

endoscopy

procedures in which a tube with a camera on the end is inserted into the body

cancer staging

a way to describe how aggressive and/or how widespread a cancer has become

T

tumor size

TX

primary tumor cannot be evaluated

T0

no evidence of primary tumor

Tis

carcinoma in situ (early cancer/pre-cancer cells that have not spread to neighboring tissue)

T1-T4

relates to size and/or extent of the primary tumor (higher number = larger tumor)

N

lymph node involvement

NX

regional lymph nodes cannot be evaluated

N0

no regional lymph node involvement (no cancer found in lymph nodes)

N1-N3

involvement of regional lymph nodes (number and/or extend of spread higher number indicates greater involvement)

M

metastasis to distant tissues

M0

no distant metastasis

M1

distant metastasis

Stage 0

abnormal cells are present but have not spread to nearby tissue. Often called “carcinoma in situ.” This is sometimes pre-cancerous stage

Stage I

cancer is limited to the tissue or origin, with no lymph node involvement or metastasis

Stage II

cancer is in the adjacent tissues or in more of the original tissue; lymph nodes may have micrometastasis

Stage III

cancer has spread to adjacent tissue, may be fixated to the deeper tissues, lymph nodes likely involved

Stage IV

cancer has metastasized beyond the primary site

transcoelomic metastasis

malignant cells penetrate peritoneal surfaces which allows the spread between organs that are connected by the peritoneum

hematogenous metastasis

cancer cells invade the blood vessels, use in the circulation to travel to new areas

lymphatic metastasis

cancer cells invade lymph nodes, use the lymphatic system to travel to new areas

most common sites of metastasis

bone, brain, liver, lung

breast cancer screening reccomendations

mammogram by age 40 every year

prostate cancer screening reccomendations

prostate specific antigen (PSA) blood test and digital rectal exam annually beginning age 50

cervical cancer screening reccomendations

PAP and HPV testing every 5 years, beginning at age 25

PAP testing every 3 years form ages 21-29 and then PAP+HPV every 3 years from ages 30-65

colorectal cancer screening reccomendations

structural testing (colonoscopy, sigmoidoscopy, or CT colography) every 10 years beginning at age 50 through age 75

lung cancer screening reccomendations

screening done yearly via low dose CT only in those age 55-74 that have a smoking history