CANCER▪ As per cancer research U.K it is a terrifying disease where ‘ Cells growout of control and invade , erode and destroy normal cells.▪ Cancer develops because of a complicated interaction between ourgenes, the environment and chance.
CAUSE OF CANCER▪ As genes switch on and off, they determine when and how fast the cell will growand divide, when it will stop dividing, and even when it will die▪ Cancer can result when controls over cell division are lost.▪ It is initiated by :1. Chemicals- like alcohol and tobacco.2. Diet and exercise- excessive diet, obesity and inactivity.3. Infection – Viruses like oncovirus, bacteria and parasites.4. Radiation- Ionizing radiations from medical imaging and radon gases and non-ionizingultraviolet radiation.5. Heredity- Inherited genetic defect6. Physical agents- glass wool, powdered cobalt, nickel and crystallite silica.7. Hormones- growth hormones promote cancer through cell proliferation.
CANCER SCENARIO IN INDIA
SOME TUMORS ARE CANCER, OTHERSARE NOTCells in a tissue overgrowResulting defined mass: tumorBenign, e.g., molesSlow growthExpands in the same tissue; does not spreadCells look nearly normalMalignantRapid growthInvades surrounding tissue and metastasizesCell differentiation usually poor
CANCER CELLS ARE ABNORMAL IN THEIRGROWTH AND APPEARANCE- FALSE FEET ISCOMMON FEATURE
▪ Initiation -important change introduced into cell▪ Probably through DNA alteration▪ More than one event probably needed for tumor production.▪ Reversible unless and until treated.▪ Promotion -biochemical event encourages tumorFormation and growth.▪ Genetically need both initiation and promotion▪ Initiators, promoters may be toxins OR radiation OR viruses)STEPS TO CANCER
CANCER IS A GENETIC DISEASE▪ Cancer is a genetic disease that develops in a predictablesequence of steps Carcinogenesis• Transformation of a normal cell into a cancerous cell• Step-by-step transformation
SOME MAJOR TYPES OF CANCER▪ In general, a cancer is named according to the type of tissuein which it first forms Sarcomas: cancer of connective tissue Carcinomas: cancer arising from epithelium Lymphomas: cancer of lymphoid tissue Leukemia: cancer of blood Gliomas: cancer of brain glial cells
MODALITIES OF TREATMENT:▪ local therapy:▪ -surgery.▪ -radiation therapy.▪ systemic treatment:▪ chemotherapy.▪ Hormonal therapy.▪ Monoclonal antibodies.▪ Radioactive material.
SURGERY:▪ Surgery was the first modality used successfully in the treatment of cancer.▪ It is the only curative therapy for many common solid tumors.▪ The most important determinant of a successful surgical therapy are the absence ofdistant metastases and no local infiltration.
CONT:▪ Microscopic invasion of surrounding normal tissue willnecessitate multiple frozen section.▪ Resection or sampling of regional lymph node is usuallydone.▪ Surgery may be used for palliation in patients for whomcure is not possible.▪ Has significant role in cancer prevention.
SURGERY FOR PREVENTION:▪ Patients with conditions that predispose them to certain cancers or with genetictraits associated with cancer can have normal life span with prophylactic surgery.-colectomy .-oophorectomy.-thyroidectomy.-removal of premalignant skin lesion .
RADIATION THERAPY:▪ Radiation therapy: is a local modality used in the treatment of cancer .▪ Success depend in the difference in the radio sensitivity between the tumor andnormal tissue.▪ It involves the administration of ionizing radiation in the form of x-ray or gammarays to the tumor site.▪ Method of delivery: External beam Radiotherapy(teletherapy).Internal beam therapy(Brachytherapy).Permanent brachytherapy is often performed for prostate cancer using "seeds" -small radioactive rods implanted directly into the tumor.
CONT:▪ Radiation therapy is planned and performed by a team of nurses,dosimetrists,physician and radiation oncologist.▪ A course of radiation therapy is preceded by a simulation session in which low-energy beam are used to produce radiograghic images that indicate the exact beamlocation.
CONT:▪ Radiation therapy is usually delivered in fractionated dosessuch as 180 to 300 cGy per day,five times a week for a totalcourse of 5-8 weeks.▪ Radiation therapy with curative intent is the main treatmentin limited stage Hodgkin’s disease. Also can use in palliative&emergency setting.
COMPLICATION OF RADIATION:▪ There is two types of toxicity ,acute and long term toxicity.▪ Systemic symptoms such as Fatigue,local skin reaction,GItoxicity.▪ Long-term effect may occur many months or years afterradiation therapy.▪ Radiation therapy is known to be mutagenic,carcinogenic,and teratogen,and having increased risk ofdeveloping both secondary leukemia and solid tumor.
RADIONUCLIDES:▪ For decades have been used systemically to treat malignantdisorders.▪ They are administer by specialists in nuclear medicine orradiation oncologist.▪ Radioactive iodine:in the from of 131I is effective therapy forwell differentiated thyroid ca▪ Strontium-89. Is used for the treatment of bodymetastasis.it is an alkaline earth element in the same familyas calcium
CHEMOTHERAPY:▪ Systemic chemotherapy is the main treatment available for disseminated malignantdiseases.▪ Progress in chemotherapy resulted in cure for several tumors.▪ Chemotherapy usually require multiple cycles.
CLASSIFICATION OF CYTOTOXIC DRUG:▪ Cytotoxic agent can be roughly categorized based on their activity in relation to thecell cycle.phase nonspecific. phase specificcytotoxic drug
CONT :▪ What is the difference between phase specific & phase nonspecific?…..▪ Phase non-specific:▪ The drugs generally have a linear dose-response curvePhase specific:▪ Above a certain dosage level,further increase in drugdoesn’t result in more cell killing.but you can play withduration of infusion.
COMPLICATION OF CHEMOTHERAPY:▪ Every chemotherapeutic will have some deleterious side effect on normal tissue .▪ E.G; Myelosuppression,nausea&vomiting,Stomatitis,and alopecia are the most frequently observed side effects.
CRITERIA USED TO DESCRIBERESPONSE ARE:▪ Complete response (complete remission)is thedisappearance of all detectable malignant disease.▪ Partial response :is decrease by more than 50% in the sumof the products of the perpendicular diameters of allmeasurable lesions.▪ Stable disease :no increase in size of any lesion nor theappearance of any new lesions.▪ Progressive disease :means an increase by at least 25% inthe sum of the products of the perpendicular diameters ofmeasurable lesion or the appearance of new lesions.