Neoplasia 2 [Compatibility Mode]
-
Upload
dr-suvarna-nalapat -
Category
Documents
-
view
217 -
download
0
Transcript of Neoplasia 2 [Compatibility Mode]
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
1/16
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
2/16
Immunology of
NeoplasiaPersons with congenital immunodeficiencies -increased risk (200 times normal) formalignancies, Immune surveillance must playsome role in preventing neoplasia.
Viral and chemical-induced cancers in
animals associated with "tumor-specificantigens" This is equivocal in humans. Suchantigens could evoke host defenses in theform of sensitized cytotoxic T lymphcytes,natural killer (NK) cells, macrophages. Such
antigens evoke humoral immunity (antibodyformation), but could "block" antigens andprevent recognition and attack throughcellular immunity.
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
3/16
Diagnostic Methods for
NeoplasiaHistory and Physical Examination
What the health care worker learns from
talking to the patient and through directexamination may give clues to the
presence of a neoplasm. Signs and
symptoms such as weight loss, fatigue,
and pain may be present. A mass maybe palpable or visible.
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
4/16
Radiographic
TechniquesThe use of plain films (x-rays),computed tomography (CT), magneticresonance imaging (MRI),mammography, and ultrasonography(US) may be very helpful to detect thepresence and location of mass lesions.The findings from these methods may
aid in staging and determination oftherapy.
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
5/16
Laboratory AnalysesGeneral findings such as anemia, enzymeabnormalities (increased alkalinephosphatase), hematuria or positive stooloccult blood helpful to suggest further
workup. More specific testing, such asmeasurement of p sa levels, may help todetermine the presence of specificneoplasms, but such tests are not perfectscreening tools in a general population.
Detection of specific genes (such as BRCA-1for breast cancer) suggest an increased riskfor some malignancies
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
6/16
Diagnosis of Neoplasia
Cytology: fastest and simplest with leastmorbidtity, but yield few cells. Techniquesinclude fine needle aspiration, brushings
through endoscope, tapping of fluidcollections through needle, direct scrapingssuch as pap smear.
Biopsy: take a bite of tissue, either a smallpiece through endoscope or larger piece as
excision. more preparation and skill required,the potential for complications greater, butmore diagnostic tissue obtained.
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
7/16
Cytology
Methods that sample cells can besimple and cost-effective and minimallyinvasive. A good example is the Papsmear for diagnosis of cervicaldysplasias and neoplasms. Cellsexfoliated into body fluids may also beexamined. Fine needle aspiration (FNA)
can be used to sample a variety ofmass lesions
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
8/16
Tissue Biopsy and
SurgeryMethods that sample small pieces of tissue(biopsy) from a particular site, often viaendoscopic techniques (such as
colonoscopy, upper endoscopy, orbronchoscopy) can often yield a specificdiagnosis of malignancy. At surgery, portionsof an organ or tissue can be sampled, or thediseased tissue(s) removed and examined in
surgical pathology to determine the stage andgrade of the neoplasm
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
9/16
Autopsy
Sometimes neoplasms are not detected orcompletely diagnosed during life. Theautopsy serves as a means of quality
assurance for clinical diagnostic methods, asa way of confirming diagnoses helpful inestablishing risks for family members, as ameans for gathering statistics for decisionmaking about how to approach diagnosis and
treatment of neoplasms, and to providematerial for future research
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
10/16
Autopsy: some neoplasms are
discovered only at autopsy, either
because they had not yet manifested aneffect, because diagnostic techniques
did not work, or because the patient
died before a diagnosis could be
obtained
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
11/16
Limitations of diagnosis:
Sampling error: not all neoplasms areuniform, material obtained may be thedesmoplastic reaction, area of necrosis,
inflammation around neoplasm, or notrepresentative of the neoplasm.
Improper handling: allowing the sample todry, crushing material, using wrong fixative,delay in sending to laboratory.
Lack of correlation betweeen histologicappearance and actual biologic behavior ofthe neoplasm
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
12/16
Adjuncts to histologic
diagnosis:Flow cytometry: more aneuploid tumorsworse prognosis, still an experimentaltechnique.
DNA probes recognize oncogenes or clonalgene rearrangements
. Immunohistochemistry identify tumor-specific products or markers (such as p s a,common leukocyte antigen, keratin).
Tumor markers in serum carcinoembryonicantigen (CEA), alpha-fetoprotein (AFP),human chorionic gonadotropin (HCG),
rostatic acid hos hatase PAP .
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
13/16
They are not all that specific or
sensitive, particularly when applied as
screening tests to a general population
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
14/16
Treatment for NeoplasiaSurgery: the most effective method, but not all
primary sites are accessible or resectablewith a clear margin. Once metastasis hasoccurred, surgery is no longer primary
curative therapy.Radiation: effectiveness depends uponradiosensitivty of tumor and the body's abilityto tolerate the dose without serious sequelaefrom necrosis, fibrosis, or radiation sickness.
Chemotherapy: effectiveness depends uponability of the drug to selectively poison theneoplastic cells and not normal cells.
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
15/16
om nat on
chemotherapy
(multiple drugs)allows lower doses of each drug withpotentially less tumor resistance. Someneoplasms -hormonal therapy (estrogensinhibit prostatic adenocarcinoma,antiestrogen therapy inhibits breastadenocarcinoma).
Immunotherapy: either tries to promote thebody's own immune surveillance (activating T
lymphocytes) or tries to direct antibodiesagainst tumor antigens.
Physical agents: hyperthermia ,cryotherapyattempt to selectively kill more thermally
-
7/31/2019 Neoplasia 2 [Compatibility Mode]
16/16
The problem with all treatments other than
surgery is that they are never 100%
selective for the neoplastic cells, and
normal cells are injured.
Patients with a positive attitude or who
have something to live for and have
emotional support from family, friends, or a
caring physician will tend to do better withtreatment and/or live longer.