Oncology comes from the Greek word "onkos" which means tumor or mass and its suffix "logy" means the area of. It is a field in medicine which deals with cancer. Diagnosis, Treatment (chemotherapy and radiation therapy), and Palliative care are its associated areas.
Cancer - refers to a disease whereby cells mutate into abnormal cells, ignoring growth regulating signals in the environment surrounding the cells. This abnormal cells form a clone, spreading directly to the surrounding tissue as well as to other sites of the body.
Spread of cancer
Localized and Encapsulated
Invade and destroy surrounding tissues
Does not cause death unless localization affect vital function
Can lead to death unless interventions are taken
Poor cell differentiation
Does not Metastasize
Carcinogenesis - are factors associated with the cause of Cancer
- Tobacco - a strong correlation between smoking and lung cancer exists; other cancers associated with tobacco use are esophageal, gastric, laryngeal, oropharyngeal, pancreatic, and bladder. Chewing tobacco increases the risk of oral and esophageal cancers; long term exposure of secondhand smoke increases the risk for lung and bladder cancer.
- Age - people age 65 and above increase their risk for cancer due to hormonal changes, altered immune response, and accumulation of free radicals.
- Gender - Lung cancer occurs commonly in males. On the other hand, Breast cancer occurs mostly in females.
- Occupational Exposures - exposure to radiation and other chemical compounds may increase the risk of cancer.
- Genetics - 15% of cancer maybe attributed to a hereditary component. Cancer demonstrating familial relationship include prostate, ovarian, colon, breast, and lung.
- Viral - infection associated with cancer includes genital herpes, papiloma virus, and hepatitis
C - change in bladder function and bowel habits
A - a sore that does not heal
U - unusual bleeding or discharges
T - thickening in breast or other parts of the body
I - indigestion or difficulty swallowing
O - obvious change in wart or mole
N - nagging cough or hoarseness of voice
A - anemia
L - loss of weight
TNM System of Tumor Classification
T = primary tumor classification by depth of invasion, surface, spread and size
- To - no evidence of primary lesion
- T1 - superficial lesion confined to organ of origin
- T2 - localized lesion with deep invasion in adjacent structure
- T3 - advance lesion confined to an anatomic region of organ of origin
- T4 - Advanced lesion extending into adjacent organs
N = lymph node involvement
- No - no evidence of disease
- N1 - palpable, movable nodes limited to the primary site
- N2, N3, N4- progressive increase in size, fixation and location of palpable nodes
M = anatomic extent of metastasis
- M0- no metastasis
- M1- isolated metastasis confined to one organ or site
- M2- multiple metastasis confined to one organ or site. No functional impairment
- M3- multiple organs involved, minimal functional impairment
- M4 - multiple organ involvement, significant functional impairment
Stages of Cancer
0 = benign stage
I = spread to nearby tissue (approximately 2 cm)
II = 2 - 5 cm sometimes with lymph node involvement
III = more than 5 cm spread, advance to connective tissues
IV = Metastasis
- Radiation Therapy