Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Surgery 48 Principles of Oncology PPT-Powerpoint Presentations and lecture notes
PRINCIPLES OF ONCOLOGY
Dept. of Surgery
ETIOLOGY OF CANCER
A cancer, is thought to develop from a cell in which the
normal mechanisms for control of growth and proliferation
are altered.
Current evidence supports the concept of carcinogenesis as
a multistage process that is genetically regulated
The first step in this process is initiation, which requires
exposure of normal cells to carcinogenic substances.
Substances that may act as carcinogens or initiators include
chemical, physical, and biologic agents
Two major classes of genes are involved in carcinogenesis:
oncogenes and tumor suppressor genes
PATHOLOGY OF CANCER
Tumors may arise from any of four basic
tissue types
? Epithelial tissue
? Connective tissue (Muscle, bone, and cartilage)
? Lymphoid tissue
? Nerve tissue
Malignant cells are divided into those of epithelial
origin or the other tissue types.
? Carcinomas are malignant growths arising from epithelial
cel s.
? Sarcomas are malignant growths of muscle or connective
tissue.
? Adenocarcinoma is a malignant tumor arising from
glandular tissue.
TUMOR CHARACTERISTICS
? Invade and destroy the surrounding tissue.
? The cel s are genetical y unstable
? Loss of normal cel architecture results in cel s that are
atypical of their origin.
? Lose the ability to perform their usual functions.
? Metastasize, and consequently, recurrences are common
after removal or destruction of the primary tumor.
THE THREE AXES OF CANCER CLASSIFICATION
? Topographic site
Topographic
Histologic type
? Histology
site
(disease site)
? Anatomic extent
(Staging)
Patient'sAnatomic extent
Disease (TNM)
Staging: Why?
? To aid the clinician in planning treatment
? To give some indication of prognosis
? To assist in evaluating the results of treatment
? To facilitate the exchange of information between treatment
centers
? To contribute to continuing investigations of human
malignancies
ANATOMIC STAGING
Based on three components
T
The extent of the primary tumor
N
The absence or presence and extent of regional
lymph node metastasis
M
The absence or presence of distant metastasis
TUMOR (T): COLORECTAL CANCER
TUMOR (T): LUNG CANCER
T1 T2
T3
T4
CLINICAL, PATHOLOGIC, COLLABORATIVE STAGING
Clinical (cT, cN, cM)
Beforeinitiationofprimarytreatment
Importantindecidngprimarytreatment
Pathologic (pT, pN, pM)
Fromresctedtisues
Collaborative (CS)
Clinical,pathologicstaging&nonanatomic(site-specifc)factors
LIMITATIONS OF STAGING
Not used in hematologic malignancies
Ann Arbor Staging System
Not used in pediatric cancer
Not useful in rare diseases
Not enough cases to stratify T, N, M (Merkel Cel Cancer)
Lumping different histopathologic subtypes (Soft tissue
sarcoma: multiple histologies)
Dominated by anatomic pathology and histology (size,
nodes, histopathology, grade)
Gradual y incorporating other prognostic variables
DESCRIPTORS
Suffix
m
Presence of multiple primary T
pT(m)NM
Prefix
y
Post initial treatment (staging
ycTNM or
after preop treatment)
ypTNM
r
Recurrent tumor after a disease rTNM
free interval
a
Autopsy
aTNM
OTHER FACTORS
Histopathologic subtype
Adenocarcinoma, SCCA
Histology/Grade
Poor, mod, wel differentiated, Undifferentiated
Lymphovascular invasion
Residual tumor
RX, R0 ? 2 resections
Site-specific factors
? Breast: ER, PR, Her2-neu
? Thyroid: Age
? CRC: Microsatel ite instability, MMR, K-ras status
? Prostate: PSA, Gleason's Score
STAGING IN THE FUTURE?
Essential
TNM categories Histologic grade
Factors
Extramural venous invasion Obstruction
Quality of surgery
Additional
Grade Tumor perforation
Factors
Perineural invasion Invasion pattern
Medul ary type CEA serum level
Number of lymph nodes resected
Peritumoral lymphoid reaction
New and
Microsatel ite instability LOH 18q status
Promising
Factors
P53 DNA ploidy
VEGF, K-ras expression 20q copy number
Greene, CA Cancer J Clin
2008; 58:180-90
MANAGEMENT
? Prevention
? Screening
? Diagnosis
? Treatment
? Rehabilitation
? Follow-up care
? Palliative care
? Terminal Care
MULTIDISCIPLINARY APPROACH
FOR MANAGEMENT
Surgery
Nutrition
Radiation
Cancer
Management
Radiology
Chemotherapy
Pathology
GOALS OF CANCER TREATMENT
1- Primary goal
Cure the patient
Render him clinically and pathologically free of
disease and return their life expectancy to that of
healthy individuals of the same age and sex.
GOALS OF CANCER TREATMENT
2- The best alternative goal
To prolong survival while maintaining the
patient's functional status and quality of life.
3- The 3rd goal
Relieve symptoms such as pain for patients
in whom the likelihood of cure or prolonged
survival is very low
SURGERY
Long considered the most important aspect of cancer
treatment for solid tumours
Controls the disease local y
May be curative for many tumours especial y if caught
early
RADIATION THERAPY
? Local therapy
? Causes DNA damage to cancer cells and
leads to their death
? May be curative on its own
CHEMOTHERAPY
? Multitude of drugs developed to kil cancer cel s
? DNA damage, RNA damage, inhibit cell growth and
division, antimetabolites
? Can be used as sole modality for cure (hematologic
malignancies) or as adjunct to either surgery or radiation to
cure
? May also be given to incurable individuals to palliate
NEW PARADIGM OF TREATMENT
? Target unique proteins/genes/structures in cancer cells with novel
agents
? Differential toxicity between the tumour cell and normal tissues
? More specificity for tumours makes cancer kill greater
? Combine newer treatments with traditional strategies
? Molecular profiling
Oncogenes, protooncogenes, apoptotic markers, cytogenetics
This post was last modified on 08 April 2022