neoplasia Flashcards
/definition of neoplasia
new growth
why has the mortality of non-infectious diseases increased? example
due to changes in lifestyle and longer life span.
Neoplasia (cancer) is the number one worldwide killer
most common cancer types in children?
leukemia and CNs tumors
what cancers have the highest rates in males and females? name the 3 most frequent
1: prostate and breast cancers
2: lung & bronchus
3: colon & rectum
% of hereditary contribution of cancer? what contributes the most?
5%
lifestyle and environment contributes the most
what % of cancer patients are cured within 5 years?
50%
difference between benign and malignant tumors?
- benign: slow growth, not too dangerous, cells aren’t too weird, does not disseminate
- malignant: grows rapidly, causes death, invades other tissues
explain tumor nomenclature
prefix = location (ex: gland = adeno-, hemangio- = blood vessel)
suffix = benign (oma) or malignant (carcinoma)
what is the oddity in tumor nomenclature?
teratoma: mixture of different cell types
tumor cells undergo differentiation while trying to mimic what?
the structure of their parent organ, but they are a bit abnormal
describe malignant differentiation?
malignant tumors have a haphazard arrangement, little resemblance to origin cell (different size and big nucleus), abnormal function, more abnormal mitoses
What are the changes when the cells go from normal to malignant?
- Loss of contact inhibition
- Increase in growth factor secretion
- Increase in oncogene expression
- Loss of tumor suppression genes
when is cancer more easily cured?
when it is still at its site of origin (carcinoma in situ)
what is dysplasia?
abnormal growth or development of cells, not yet cancer (Indraductal hyperplasia with atypia)
what is an anaplastic tumor?
a tumor that is poorly differentiated
6 phases of cancer
- normal tissue
- intraductal hyperplasia
- carcinoma in situ
- dysplasia
- invasive cancer
- anaplastic tumor
what can benign tumors cause? give example about neuroendocrine tumors
compression and pain.
Neuroendocrine tumors (benign) can release adrenaline, thus making the patients tachycardic and have an increase in blood pressure
what is the main way how a tumor kills?
metastasis -> multiple organ failure
name other actions and consequences of malignant tumors
destroy tissue -> organ failure
erode blood vessels -> hemorrhage, anemia
obstruct lumen -> intestine, lung
facilitate infection -> local or systemic
cardiac failure -> terminal events
name the 3 systemic effects of a malignant tumor
- cachexia: total body wasting (massive loss of weight)
- paraneoplastic syndromes: biochemical, neurological, hematological derangements (also caused by compounds released by the tumor)
- immunosuppression
describe 5 common tumors
- papilloma: squamous epithelial benign tumor (wart) or carcinoma
- adenoma: glandular epithelial benign tumor (polyp) or adenocarcinoma
- liposarcoma: malignant connective tissue tumor that has pleomorphic cells with a coarse emulsion lipid / Lipoma: benign tumor where fat cells accumulate in masses
- osteogenic sarcoma: highly malignant and produces metastasis early on, malignant bone tumour
- myoma/osteoma: muscle and bone benign tumours
how does angiogenesis increases metastasis? how do tumor increase angiogenesis?
newly formed vessels are leaky which makes it easier for the tumor to invade them.
tumor secrete angiogenesis factors.
what makes metastasic prognostic worst?
increase in the distance of metastase from the original site
how do tumor cells get past basement membrane to invade blood? (steps)
- Loosening of intracellular junctions
- Attachment: Laminin receptors on the tumor bind laminin in the BM
- Degradation: cell secretes collagenase to degrade BM and ECM
- Migration: fibronectin help invasion of malignant cells
- Extravasation: then invades circulation
what often happens in the middle of a tumor
necrosis due to lack of oxygen
what surrounds metastatic tumor cells during migration to avoid immune recognition?
platelets
how does cancer get in lymphatics?
thin wall. cancer cells can increase lymph flow
what blood vessels are most susceptible to invasion?
small veins and venules because thin wall
when does retrograde venous spread happen?
lymphatic growth of tumors within a vein may cause reversal of blood flow where veins form a rich plexus and don’t have valves
4 main sites of metastasis + 1 extra
liver, lung, brain and bones.
also lymph nodes
where to breast and lung cancer tend to metastasise?
to the adrenal glands
why is metastasis hard to treat?
The properties of the metastasis may be different from the primary tumor; you may be able to treat tumour cells in one location, that will not be an effective treatment for tumour cells in another location
what is TNM system?
Tumor, Nodes, Metastasis: Survival is related to each of these features.
4 stages for tumor and nodes states, only 2 stages for metastasis. stage 2 metastasis automatically = stage 4 cancer
the more undifferentiated a tumor is, the ____ the prognosis
the worst the prognosis
what is immunohistochemistry used for?
allows a better visualization of
certain markers thus helping the prognosis and treatment
what cancer has the #1 death rate in developed world?
lung
why does lung cancer take so long to develop?
accumulation of sequential mutations in normal cells caused by carcinogens
describe the steps of lung cancer progression
- activation by carcinogens
- squamous metaplasia: Squamous cells replace normal ciliated epithelial cells in response to irritation & start multiplying
- mild dysplasia: Cells looking different from normal cells – appearance & characteristics differ
- moderate dysplasia
- severe dysplasia: combine with different cells
- Carcinoma in situ/anaplasia: accumulated enough mutations to have malignancy, still to small to be detected in situ, basal cells start to multiply
- invasion: cells erode through BM
- metastasis
basically whats the normal steps of lung/bronchus carcinoma?
metaplasia -> dysplasia -> anaplasia (CIS) -> invasion -> metastasis
what are the 4 major subtypes of lung cancers?
- Squamous cell carcinoma (30% of all lung cancers in the US)
- Small cell (oat cell) carcinoma (15% of all lung cancers in the US)
- Large cell (undifferentiated) carcinoma (15% of all lung cancers in the US)
- Adenocarcinoma (in the glands of the lung) (40% of all lung cancers in the US)
what is special about small cell carcinoma?
small cells have different reactions to therapy & higher likeliness of metastasis
where does squamous cell carcinoma originate from? what is a characteristic of it?
from basal cells that form squamous cells. often have necrosis in the center
what type of lung cancers form centrally vs peripherally?
central = small and squamous cell carcinomas
periphary = large cell carcinoma (usually spreads to lymph nodes)
what are the survival rates of small vs non-small cell lung cancer? and squamous
small = low survival rate
non-small = better survival rate. grows very slowly
squamous = grow very slowly
what are the 3 methods of diagnosis for lung cancer?
- chest X-ray
- bronchoscopy: inserting fiber optic tube into main bronchus to observe the airways
- cytology of sputum: detect shedded tumor cells
what is staging of lung cancer based on?
T location, N number of lymph nodes involved, M metastasis
what is the % of survival depending of stage of detection?
stage 1 = 71%
stage 4 = 5%
what are the 4 types of lung resectomy?
wedge resection
segment resection
lobectomy
pneumonectomy
are all lung cancers the same?
very much not they’re all so different
what is personalized molecular oncology?
Study the abnormalities in that patient’s tumor (molecular signature) to be able to effectively choose the most useful therapy for that particular patient
how does immunotherapy work for lung cancer?
create a complex hystological analysis of the tumor and the host and choose the right drig
what is an effective treatment for small cell carcinoma?
radiotherapy (mostly relieves the symptoms, not a cure)
what is immunotherapy trying to understand?
how lung cancer evades immune system
how do we think malignant cells escape immune response?
inactivate T cells once they accumulated enough mutations
how to cancer cells inhibit T cell killing?
tumor cell has PD-L1 ligand that binds to PD-1 t cell receptor
what is pembrolizumab?
anti-PD-1 drug/ab (?) that increased lung cancer survival
what are the local symptoms of lung cancer? what physical symptoms do these local symptoms cause?
- bronchiectasis: expansion of the airway caused by occlusion causing pleural effusion
- haemoptysis: coughing up of blood filled with malignant cell
- causes cough, chest pain, shortness of breath, chest infection, hoarseness, weight loss, infection
what is pleural effusion?
infection/inflammation cause by obstructive pneumonia
what are the distal symptoms of lung cancer?
compounds released by tumor cause:
- metastasis to brain/bone
- abnormal hormone release
- finger clubbing
- cachexia
what can be caused by tumor growth outside of the lung in thoracic cavity?
- Tracheal obstruction.
- Esophageal compression
- Hoarseness because of compression on laryngeal nerve.
- Lymphatic obstruction, pleural effusion.
- Obstruction of vena cava
- heart failure
how can lung cancer spread?
through circulation, through PLEURAL SPACE,
- lung metastasis usually -> blood, brain, proximal bone, liver (sometimes adrenal gland and spine)
what is the time gap between when you start smoking until when you are dead?
20 years (10 years of a cell accumulating mutations, 10 years for it to divide enough to start metastasis)
what happens if many different mutations happen in different cells
many different tumors can arise
can you cure lung cancer by stopping smoking?
no you can just decrease the risks
what % of lung cancers are due to cigarette smoking?
86%
lung cancer risks can arise from what workplaces?
- asbestos can cause lung cancer and mesothelioma cancer and hardening and scarring of lung
- arsenic, chromium
- radon (carcinogenic product of uranium)
what is mesothelioma?
cancer of the pleural coverings
how does colorectal carcinoma arise?
a single cell multiplies and fill the crypt of the large intestine
describe a benign vs malignant colorectal tumor
benign = grows into the lumen and forms an adenoma / adenomatous polyp that can be removed
malignat = grows down through intestinal wall causing sub-growth malignant cells
what is the progression of colorectal cancer? how long can the whole process take?
Normal colonic epithelia → small adenoma → large adenoma → pre- malignant changes → colorectal carcinoma
- can take 10-15 years
where is colorectal cancer most common?
distal part of colon: sigmoid and rectum (easier to detect)
ascending colon (harder to detect)
why is colorectal cancer easier to detect?
it has a well-established pathway of mutations including APC (adenomatous polyposis coli) mutations
what is adenomatous polyposis coli?
a tumor suppressor gene mutated in colorectal cancer
mutations of APC can come from what 2 origins?
inherited or acquired
what is staging of colorectal cancer based on?
how far the tumor has penetrated through the intestine wall
what does stage 4 cancer mean for any type of cancer?
metastases to other organs