Transcript NEOPLASIA
NEOPLASIA
DR.ROOPA
Pathophysiology
Premed 3
Neoplasia
Means new growth.
Is the uncontrolled, disorderly proliferation
of cells, resulting in a benign or malignant
tumor or neoplasm.
A neoplasm , as defined by Willis , is
“an abnormal mass of tissue the growth of
which exceeds and is uncordinated with
that of the normal tissues and persists in
the same manner after the cessation of
the stimuli which evoked the change”.
Dysplasia- is a reversible change.
Often precedes malignancy.
Morphologically manifests by disorderly
maturation and spatial arrangement of
cells, marked variability in nuclear size and
shape and increased, often abnormal ,
mitosis .
nomenclature
A neoplasm is often referred to as a tumor,
and the study of tumors is called oncology.
Oncos – tumor, logos –study of
Types
Benign tumor
Malignant tumor( cancer)
Benign tumors: In
general , benign
tumors are
designated by
attaching the suffix –
oma to the cell type
from which the tumor
arises.
Eg.fibrous tissue
tumor is a fibroma.
Malignant tumors:
Mesenchymal tissue
or its derivatives are
called sarcomas.
Eg fibrosarcoma
Epithelial tissue
origuin are called
carcinoma.
Eg:adenocarcinoma
Malignant
(+) invasion: spread
to nearby structures
(+)metastasis: spread
to distant structures
(+)anaplasia :
cells are very different
from the normal cells
(poorly differentiated)
vs
Benign
(-) invasion
(+) capsule
(-)metastasis
Resemble the tissue
of origin (well
differentiated)
Tumor characteristics
Differentiation and anaplasia
Rate of growth
Local invasion
metastasis
Anaplasia
A state of complete un differentiation
Anaplastic cells show:
Pleomorphism
Hyperchromatism (dark nuclei)
Increased nuclear-cytoplasm ratio
Abnormal mitosis
Prominent nucleoli
Basic underlying cause of
cancer
4 kinds of genes are damaged:
Genes that promote growth
Genes that inhibit growth
Genes that regulate apoptosis
Genes involved in DNA repair
Cancers develop in multiple steps.
“cancer genes “cause bad
things in cells
Autonomous growth
Insensitivity to growth – inhibitory signals
Evasion of apoptosis
Limitless replication
Sustained angiogenesis
Invasion and metastasis
Forms of Malignant tumors
Carcinoma: malignant tumor of epithelial origin
1. squamous cell carcinoma
cancer of the skin
cancer of the esophagus
2. adenocarcinoma: glands
cancer of the breast
cancer of the pancreas
3. transitional cell carcinoma
cancer of the bladder
Forms of Malignant tumors
Sarcoma: of mesenchymal origin
osteosarcoma
rhabdomyosarcoma
leiomyosarcoma
liposarcoma
Teratoma: from all 3 germ layers
skin, bone, cartilage, teeth,
ovaries and testis: most common
may also be benign
teratomas consist of bits of
bone,INTESTINAL epithelium, muscle, fat,
nerve, tooth, etc.
Osteosarcoma
Liposarcoma
Teratoma
Forms of Benign tumors
Papilloma: Adenoma: glandular epithelium
-ovary, breast
Mesenchymal origin
-leiomyoma, lipoma, fibroma, chondroma
Papilloma
epithelium of skin, larynx and tongue; fingerlike
projections
Properties of Neoplasms
Monoclonality
the neoplasm comes from a single
precursor cell
Invasion
enters the blood vessels and
lymphatics
Metastases
blood vessels: sarcomas
lymphatic: carcinoma
Properties of Neoplasms
Common sites of metastases
liver, lung, brain,
adrenal glands, lymph nodes
bone marrow
Clinical signs of malignancy
Cachexia
wasting, weakness, weight loss, anemia, infection
.- Endocrine abnormalities
prolactinoma
ovarian tumors
Paraneoplastic syndrome is a disease or symptom that
is the consequence of the presence of cancer in the
body, but is not due to the local presence of cancer
cells.they commomnly presented with cancers of the
lung, breast, ovaries or lymphatic system.
eg:ectopic production of hormones
lung cancer : ACTH
summary :Risk factors
Chemical agents
Physical agents
Viruses
Activation of cancer-promoting genes
Inhibition of cancer-suppressing genes
Carcinogenesis and carcinogens
Cigarette smoking : lung CA, laryngeal CA
Excessive sun: Skin CA
Asbestos: Mesothelioma
Nitrosamines: Gastric CA
Alcohol: Esophageal CA
Low-fiber diet: Colon CA
Carcinogenesis and carcinogens
High-fat diet: Breast CA
Aniline dyes: bladder Ca
Aflatoxin: liver CA
PVC: Angiosarcoma of the liver
DES: Clear cell adenocarcinoma of the
vagina
Nickle, chromium, uranium: lung CA
Carcinogenesis and carcinogens
HTLV – 1: Adult T cell leukemia
HPV: cervical CA
EBV: Nasopharyngeal CA, Burkitts
lymphoma
HBV: Hepatocellular CA
HHV-8: Kaposi sarcoma
Helicobacter pylori: Gastric CA
Cancer suppresor genes
(anti oncogene)
p53: “ guardian of the genome” ,gatekeeper gene
mutated in 50% of all malignant tumors
causes cell cycle arrest in G1, time for DNA repair
unsuccessful repair: apoptosis
LI-FRAUMENI SYNDROME
familial cancers of the breast, soft tissue sarcomas,
brain tumors, leukemias
Cancer suppresor genes
(anti oncogene)
WT-1 and WT-2: Wilms tumor( Wilms
tumour of the kidney)
BRCA -1: breast and ovarian CA
*BRCA – 2: breast CA
RB codes for pRB protein, master brake on cell cycle
(retinoblastoma, bone, bladder, lung, and breast cancer)
Grading: degree of differentiation of the
cells
Staging: spread of the tumor or degree of
localisation
-uses the TNM system
Tumor size
Lymphonode involvement
Metastasis
CANCER TREATMENT
CHEMOTHERAPY
CYTOTOXIC DRUGS+BODY DEFENSES
SINGLE AGENT
COMBINATION CHEMOTHERAPY
_AVOIDS SINGLE AGENT RESISTANCE
CAN USE LOWER DOSE
BETTER REMISSION AND CURE RATE
RADIATION
TARGETS DNA
KILL TUMOR WITHOUT DAMAGE TO SURROUNDING
TISSUES
TUMOR MUST BE ACCESSIBLE
SURGERY
METHOD OF CHOICE,CAN REMOVE ENTIRE
TUMOR,DEBULKING
ADJUVANT CHEMOTHERAPY OR RADIATION
IMMUNOTHERAPY
.ELIMINATES CANCER CELLS ONLY
.PROVIDES PROTECTION AGAINST RECURRENCE
.T_CELL BASED OR ANTIBODY RESPONSES
.CONJUGATED ANTIBODIES
.NONSPECIFIC ENHANCEMENT OF THE IMMUNE
SYSTEM