2nd lecture cancer treatment (1).pdf

CANCER TREATMENT Dr kamal marie Lecturer of Physical Therapy Ahram Canadian University  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 c...

CANCER TREATMENT Dr kamal marie Lecturer of Physical Therapy Ahram Canadian University  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 cells. 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 cells are genetically unstable Loss of normal cell architecture results in cells 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 ty site Histology (disease site) Anatomic extent (Staging) Patient’s Disease Anatomic extent (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  CLINICAL, PATHOLOGIC, COLLABORATIVE STAGING Clinical (cT, cN, cM) Before initiation of primary treatment Important in deciding primary treatment Pathologic (pT, pN, pM) From resected tissues Collaborative (CS) Clinical, pathologic staging & non anatomic (site-specific) 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 Cell Cancer) Lumping different histopathologic subtypes (Soft tissue sarcoma: multiple histologies) Dominated by anatomic pathology and histology (size, nodes, histopathology, grade) Gradually incorporating other prognostic variables  DESCRIPTORS Presence of multiple primary T pT(m)NM 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, well differentiated, Undifferentiated Lymphovascular invasion Residual tumor RX, R0 – 2 resections Site-specific factors Breast: ER, PR, Her2-neu Thyroid: Age CRC: Microsatellite instability, MMR, K-ras status Prostate: PSA, Gleason’s Score  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 locally May be curative for many tumours especially if caught early  RADIATION THERAPY Local therapy Causes DNA damage to cancer cells and leads to their death May be curative on its own RADIATION THERAPY  CHEMOTHERAPY Multitude of drugs developed to kill cancer cells 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 There are many different types of chemotherapy agents  ALKYLATING AGENTS Direct DNA damage by alkylating agents stops division of cancer cells and is efficacious in all stages of the cell cycle. Many cancers are treated with alkylating agents such as lymphoma, leukemia, multiple myeloma, Hodgkin’s disease, and sarcomas  ANTIMETABOLITES These drugs are analogs for the units of DNA and RNA, and hence by incorporation, they stop growth of DNA and RNA.  HORMONE THERAPY Advancements in the field of molecular biology in recent years clarified the role of hormones in cell growth and in the regulation of malignant cells. Nearly 25% of tumors in men and 40% in women are known to have hormonal basis. Hormonal treatment is effective to treat cancer without any cytotoxicity which is associated with chemotherapy  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