Neoplasia & Oncogenesis

what causes cancer?

Damage to cell DNA during normal cell reproduction leads to mutations

Many accumulated mutations cause onset of uncontrolled growth

what is the suffix for a benign tumor?

-oma

what is the suffix for a malignant epithelial tissue?

-carcinoma

what is the suffix for a malignant connective tissue?

-sarcoma

benign tumors contain cells that look like normal tissue cells. May perform normal function of the tissue such as secrete hormones, however this may lead to

over secretion

a malignant neoplasm contains cells that do not look like normal adult cells. they do not perform normal functions of the tissue

■May secrete signals, enzymes, toxins. Grow rapidly

●Lack capsules, so they send 

“legs” into surrounding tissue (the word cancer means “crab” based on these legs)

in cancer, growth fraction (dividing:resting cells)

increases and doubling time decreases.

how do some cancers invade cells?

enzymes that break down proteins

what are the 2 main ways of cancer spread?

lymphatic & vasculature

bladder cancer often metastasizes to where?

bone, liver, & lungs

What is the process through which healthy cells become transformed into cancer cells?

oncogenesis

○Familial predisposition

○Exposure to carcinogens: chemicals, radiation, food

○Viruses (HPV, epsteinbar)

○Hormones

○Tumor antigens
are all examples of causes for disruption in balance between

proto-oncogenes & anti-oncogenes

what stage of carcinogenesis is when most likely irreversible DNA damage occurs?

• Does not mean cancer is inevitable, the tissue is vulnerable

• Only a few things can cause DNA damage

Initiation

what stage of carcinogenesis is when vulnerable cells have repeated

exposures to carcinogens?

• Leads to membrane changes

• At this point, it MAY be contained by immune system

promotion

what stage of carcinogenesis is when cells proliferate, encounter additional exposures and become malignant?

progression

what associated gene codes for normal cell division proteins. Growth factors, growth factor receptors, transcription factors, cell cycle proteins, apoptosis inhibitors?

proto-oncogenes

what do proto-oncogenes mutate to? Examples: ras, Philadelphia chromosome, HER-2/neu

oncogenes; insertions, deletions, translocations 🡪 increased or activated

what cancer associated genes inhibit cell division? Mutations inhibit or decrease

tumor suppressor genes

what are some local effects of tumor growth?

Compression of adjacent structures

○Hollow organs

○Blood vessels

■Bleeding, hemorrhage

○ Effusions

what are some systemic effects of tumor growth?

Anemia, Anorexia, and cachexia

○Fatigue & sleep disturbances

○Ectopic hormones or factors secreted by tumor cells

What is associated w/ certain tumor types?

•Tumor cells release substances that affect neurological function & may have hormonal effects

Paraneoplastic syndrome

what is an example of a cytologic study?

pap smear

what is an example of microarray technology?

gene chips

what is the most widely used cancer staging system?

TNM classification

what does the T in TNM classification stand for?

size of primary tumor

what does the N in TNM classification stand for?

(node) number of regional lymph nodes found to be cancerous

what does the M in TNM classification stand for?

(metastasis) if cancer has spread to other parts of the body

T is followed by X-4 based on size of primary tumor. Sizing is different for each disease site

•X=

cannot be evaluated/0=no evidence of primary tumor/1=small tumor/4=large tumor

•Tis= in situ (early cancer that has not spread to adjacent tissue)

N is followed X-3 based on # of regional lymph nodes involved

•X=cannot be evaluated/0=no involvement/1-3=

number and extent of involvement

M is followed by 0 or 1, 0=

not present/1=present

What stage of solid tumors has abnormal cells present, but have not spread to nearby tissue. Carcinoma in situ (CIS)

stage 0

what stage of solid tumors has cancer present? Higher # mean large tumors, & more spread to neighboring tissues.

Stage I-III

what stage of solid tumors where cancer has spread to distant parts of the body outside of the primary site? Metastatic disease

stage IV

what surgical tx involves removal of as much as possible if total removal damages surrounding structures?

Debulking

what type of surgery involves reducing pain & symptoms (for comfort, not cure)?

palliative

what type of surgery involves removal of tissue that is likely to become cancerous?

Prophylactic

how long can skin effects last following radiation tx?

greater than 10 yrs