Oncology chp. 1-6 english summary

Oncology notes

THE NATURE OF CANCER

Incidence  the number of new cases within a certain period

Prevalence  all persons who somewhere in time have been diagnosed with cancer and are still living at a
certain date

Mortality  number of patients who died as a result of cancer within a certain period

Survival  percentage of patients still living at a certain period after diagnosis



Cancer

 A group of diseases
 Uncontrolled cell growth
 Invasive and forming metastases
 Clonal
 Disease of the genome
o Cancer is not inheritable because almost all mutations happen in somatic cells
o You can inherit germlines that increase the chance of getting cancer


Tumor

 A heterogenous mass of cells
 Not all are invasive and metastasising
 Benign tumors  not a cancer
 Malignant tumors  cancer
o Life threatening because:
 Disturb organ function
 Cancer cells compete with normal cells for O2 and nutrients
 Growing tumors cause obstructions



Types of cancers

 Carcinomas arise from epithelia (~85% of all cancers)
o Most exposed to carcinogens as they align inside and outside of the body
 Adenocarcinomas arise from glandular tissues (e.g breast)
 Sarcomas arise from mesodermal tissues (e.g. bone, muscle)
 Lymphomas arise from (progenitors of) white blood cells



Carcinogen

 An agent causing cancer
 Causes alterations in the DNA of a cell
 Cancer cells contain many alterations in the DNA
 The accumulation of mutations in the DNA of a cell causes stepwise development of cancer




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,Main characteristics of cancer

 Have a different morphology
 Can grow at low serum concentration
 Show no/decreased contact inhibition
 Can grow without substrate for attachment
 10 Hallmarks: every hallmark is a potential target for selective therapy
 Transformation  can be used to distinguish cancer cell from non cancer cell in the lab
o The cell grows unattached to the surface




Treatment of cancer

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,  Surgery
 Radiotherapy
 Chemotherapy
 Prevention of cell division  cytostatic effect
 Killing of cancer cells  cytotoxic effect
 Therapeutic window  difference between max tolerated
dose (MTD) and the min dose needed to exert anti-cancer
activity



CANCER GENOME: MUTATIONS VS REPAIR

DNA

 Sugar + phosphate group + base
 Base
o Pyrimidine: thymine, cytosine
o Purine: adenine, guanine
o 3 bases = 1 codon = 1 amino acid
 Thymine becomes Uracil in the transcription process




Large DNA changes

 Aneuplopidy: whole chromosome gain or loss
 Deletions
 Chromosome rearrangements  translocations
 Gene amplifications



Cancer can result from (epi)genetic alteration in human cancer genes

 Stability genes (e.g. repair)  inactivation
 Oncogenes (e.g. growth factors)  activation

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