Oncology seminar

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Surgical Oncology

Transcript of Oncology seminar

Oncology Dr Shemsu.s

April 2013

Wednesday, April 12, 2023 Oncology

Out line of Presentation

• Introduction• Epidemiology• Cancer Etiology• Cancer Biology• Cancer Risk Assessment• Cancer Screening• Diagnosis• Staging• Surgical Approach to Cancer Therapy• Chemotherapy • Radiation Therapy

Wednesday, April 12, 2023 Oncology

INTRODUCTION

• Tumor - “abnormal mass of tissues the growth of which exceeds and is uncontrolled with that of normal tissues” Wills

• Cancer – ”Karanikos”

Wednesday, April 12, 2023 Oncology

Epidemiology

• In 2008 - 1.44 million new cases in US.• 565,650 – died in US

• Global Statistics on Cancer Incidence -10.9 million new cancer cases in 2002. -Lung cancer is the leading cancer in the world. - Breast cancer - the second most common

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Cancer Etiology

• Genetic disease• Somatic mutation• Germ line mutation• Hereditary cancer

Wednesday, April 12, 2023 Oncology

• factors may suggest hereditary cancer 1. Tumor development at a much younger age than

usual 2. Presence of bilateral disease 3. Presence of multiple primary malignancies 4. Presentation of a cancer in the less affected sex 5. Clustering of the same cancer type in relatives 6. Occurrence of cancer in association with other

conditions such as mental retardation or pathognomonic skin lesions

Wednesday, April 12, 2023 Oncology

• Importance of knowing hereditary cancer

– Examples• P53 and li-fraumani syndrome• RB1 Gene and Hereditary Retinoblastoma• BRCA1, BRCA2, and Hereditary Breast-Ovarian

Cancer Syndrome• APC Gene and Familial Adenomatous Polyposis

Wednesday, April 12, 2023 Oncology

Carcinogens

• Environmental factors - 60 to 90% • Three types - Chemical, Physical, or Viral

• Chemicals carcinogens • Three groups 1.genotoxins . 2. co carcinogens-potentiate genotoxins. 3.Tumor promoters.• IARC - 4 Groups• E.g. of Proven carcinogens -

aflatoxins ,tobaco ,aresnic ,benzene etc

Wednesday, April 12, 2023 Oncology

Physical Carcinogen

• Mechanism - Induction of inflammation and cell proliferation - Induce DNA damage• Radiation - Best known physical carcinogen• Ionizing -DNA break( deletion ,gene rearrangement -Direct effect -Indirect effect -Bystander effect• Non-ionizing -UV light-skin cancer

Wednesday, April 12, 2023 Oncology

Viral Carcinogens

• 15 % cancers world wide• Mechanism -Insertional mutagenesis -Expression of oncogenes -Alteration of immune system• DNA virus -Have their own Oncogen -Oncoprotiens –bind cellular genes-p53.RB -activate cellular genes-IL-5,C—MYC,H-ras -E.g.- HPV, HBV, EBV

Wednesday, April 12, 2023 Oncology

• RNA virus - Are retroiviruses -They have no their own oncogenes -Transform host proto oncogene E.G-HTLV-1

Wednesday, April 12, 2023 Oncology

Cancer Biology

Wednesday, April 12, 2023 Oncology

TUMORIOGENESIS

• Phenotipicaly • Genetically• Initiation• A single cell or clone• Field effect• Promotion• Progression– From benign lesion to CIN to invasive lesion– Accumulate genetic changes

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Tumor growth

Wednesday, April 12, 2023 Oncology

Major Classes of Genes Altered

• Oncogen• Tumor suppressor gene• Proapoptotic genes• Oncogenes -Proto-oncogenes →oncogenes -Three letter abbr - e.g. myc ,ras, prefix v or c

-Can be activated by translocation (e.g., abl), -Promoter insertion e.g., c-myc, -Mutation - e.g., ras, -Amplification (e.g., HER-2/ neu).

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Function of Oncogenes

• Promote growth– Growth factors- PDGF, FBGF.– GF receptors- e.g., HER2, HER1

• Intracellular signal transduction molecules (e.g., ras).• Nuclear transcription factors e.g., c-myc.

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Tumor Suppressor Genes

• p53, pRB.• APC• TGF-B• Function -Arrest cell cycle -Induce apoptosis -Activate other genes

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Evasion of Apoptosis

• Two path ways -Death receptor path way - Fas(CD95) -The mitochondrial Path wayStimulus - DNA damage, free radicals, withdrawal of GFs

• E.g. – Loss of CD 95 In HCC

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Cancer Invasion

• Carcinoma insitu• Invasive cancer• Steps -Loss of adhesion – cadherins -Attachemement to ECM -Degradation of ECM -locomotion

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

ANGIOGENESIS

• Proangiogenic factors- VEGF, FGF• Antiangiogenic factors- Thrombospondin 1,

Angiostatin

• Source –tumor cells-RAS,myc,HER2/NEU ,endothelial cells ,Inflammatory cellsEffect - nutrition, metastasis -Remval of Primary Tumor

Wednesday, April 12, 2023 Oncology

Metastasis

• Hematogenous • lymphatic• seeding in to body cavities.

Prerequisites -Access to circulation -survive in the circulation. -Extravasate -Initiate growth in the new tissuesOrgan specific metastasis - mechanical -Seed and soil theoryDormancy.

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Cancer Risk Assessment

• Initial evaluation of any patient• Cancer screening - genetic counseling and testing• Component -Complete history -Hx of environmental exposure -Detailed family history -Personal history -Age, race - E.g.-GAIL model for breast cancer

Wednesday, April 12, 2023 Oncology

Cancer Screenings

Early detection Criteria for screening

• The Disease -Recognizable early stage -Treatment at an early stage more effective than at a later

Stage -Prevalence

Wednesday, April 12, 2023 Oncology

• The Test - Sensitive and specific -Acceptable to the screened population -Safe -Inexpensive

• The Programme• Intensive screening

Wednesday, April 12, 2023 Oncology

Cancer Diagnosis

• The Definitive - Biopsy of the lesion - histology, grade• Open biopsy -Inscisional or Excisional -More tissue for histologic Dx• CORE Biopsy• FNAC

Wednesday, April 12, 2023 Oncology

Staging

• Anatomic extent of tumor in an individual patients• Importance - To predict prognosis - Selection of Therapy -Evaluation of Treatment -Exchange of information among Treatment

centers

Wednesday, April 12, 2023 Oncology

• TNM Staging

- Before definitive therapy

- 4 month

- Microscopically confirmed Cancer - cTNM , pTNM, aTNM, rTNM - Multiple Tumors - T2(5), T2(m) - Unknown Primary - Paired Organs - Stage Grouping

Wednesday, April 12, 2023 Oncology

• cTNM Primary tumor(T) -P/E , Imaging studies, Endoscopy -Size ,Extent, Multiplicity - Tx, T0, T is - T1, T2 , T3

• Regional LN ( N ) -Based on size -Characteristics, and location. -NX ,N0 - N1 ,N2 , N3

• M - distant metastasis - clinical examination

- M0 , M x

Wednesday, April 12, 2023 Oncology

Surgical Approach to Cancer Therapy

• Prevention• Diagnosis• Staging• Treatment• Palliation• Rehabilitation• Surgeons Role

Wednesday, April 12, 2023 Oncology

• Management of Primary Tumor -Goal of surgical mx- oncologic cure -Operable - negative surgical margin - Inoperable - positive surgical margin

• Radical vs conservative management

• Appropriate surgical margin

Wednesday, April 12, 2023 Oncology

Breast Cancer

Oncology

Surgical Management of the Regional Lymph Node Basin

• Cancers• Soft tissue sarcomas • Methods -Enbloc Removal of Primary Tumor With the LN - Separate Incision• Advantage Clinically Negative Node• Lymphatic mapping and Sentinnel LN Biopsy - Identification Rate - False Negative Rate - AdvantageWednesday, April 12, 2023

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

Surgical Management of Distant Metastases

• Mostly non curative • Curable in isolated metastasis• Survival rates depends on - Disease free interval - Natural history o f metastatic disease

• The goal is to resect the metastases with negative margins

Wednesday, April 12, 2023 Oncology

Principles of Chemotherapy

• Fractional cell kill - Constant percentage of cells killed - E.g. 1012 tumor cells, treated with a dose that result in

3 log kill 1012 → 109 cells

• Selection of chemotherapeutic agent• Conventional dose• High dose • Cyclic Therapy

Wednesday, April 12, 2023 Oncology

Wednesday, April 12, 2023 Oncology

• End Point of Drug Action - Metastatic Disease - Localized Tumors - Adjuvant Therapy -Sensitizes Tumors to radiation -As part of adjuvant therapy -Palliative therapy

• Classification -Cell-cycle phase–nonspecific agents -Cell-cycle phase–nonspecific agents

Wednesday, April 12, 2023 Oncology

• AgentsAlkylating agents - Kill cells in any phase of the cycle - MOA : cross linking the DNA strands and direct damage to

the DNA

- Three Groups –Classic ,, miscellaneous DNA Binding Agents - Classic - Cylophosphamide, Busulfan , Chlorambucil - Nitrosureas- Streptozocin ,Carmustine - miscellaneous- cisplatin, Carboplatin - Toxicity :

Wednesday, April 12, 2023 Oncology

Antimetabolites - cell-cycle–specific agents - Effective in tumors with high growth fraction -MOA : analogues of naturally occuring

metabolities involved in DNA synthesis

-Eg. - Folic acid Analogue - Methotrexate , - Pyrimidine Analogue- 5-FU - Purine Analogue - Azathioprine , Mercaptopurine

-Toxicity:

Wednesday, April 12, 2023 Oncology

• Plant Alkaloids - Derived from vinca rosea plant - Act by binding to tubulin in the S phase - Eg. - Vincristin, vinblastin - Toxicity:

• Combination therapy: - Maximizes Cell kill -Broader Range of Coverage of Resistant cell lines -Delays the emergence of Drug-Resistant cell lines

Wednesday, April 12, 2023 Oncology

Response evaluation

-Complete response -Partial response -Minimal response -Progressive disease

Wednesday, April 12, 2023 Oncology

Radiation Therapy

• Ectro magnetic Waves -Penetrate Tissues Deep• Particulate - electrons, superficial lesion

• Biologic bases -DNA breaks, cross linking - Indirectly ionizing - X-ray ,Gamma rays - Directly ionizing - Electrons, Neutrons

• Factors Influence Cell Killing -Tissue Factor - Physical Parameter of Radiation

Wednesday, April 12, 2023 Oncology

Factors influence cell killing

Wednesday, April 12, 2023 Oncology

• Radiation sentisizers - Metronidazole , misonidazole - Thymidine analogue - iododeoxy uridine. - 5 FU, actinomicin D

Wednesday, April 12, 2023 Oncology

• Planning therapy -Define Target - Shield -Homologues delivery -Fraction Dose• Conventional fractionation - 1.8-2 Gy/d,5 day /wk for 3-7

wks

• Ways of delivery -Tele Therapy -Brachy Therapy -Systemic Therapy

• Preop or post op

Wednesday, April 12, 2023 Oncology

• Indication - Component of Curative Therapy -Palliation - Prevent Development of Disease

• Toxicity- Acute and Chronic

Wednesday, April 12, 2023 Oncology

• Other Option of Therapy - Hormonal - Targeted Therapy - Gene Therapy

Wednesday, April 12, 2023 Oncology

REFFERENCE

• SCWARTZ PRINCIPLES OF SURGERY• ROBINS PHOLOGIC BASES OF DISEASE• INTERNET

THNK YOU