The secret of the care of the patient is in caring for the patient.
Surgery is one of the treatment options available to some patients with cancer. It involves the removal of the tumour and the surrounding tissue by operating surgically on the patient. Surgery can either be performed in cancer patients to make a tissue diagnosis of cancer, where a small portion of the tumour is removed, or a complete excision of the malignant tumour is done when the diagnosis is unequivocal. Tumour removal may be curative when small in size, but mostly, surgery is combined with other treatment modalities such as radiation and/or chemotherapy.
Conventional surgery involves making a large incision, mostly through the skin and muscle, but sometimes through the bone, to remove the tumour. Less invasive methods are more popular now. They are offered to patients because of the advancement in imaging techniques which provide a complete picture, including the extent of tumour prior to surgery, and are associated with earlier recovery. De- bulking surgery is done to remove as much of the tumour as possible—without causing too much damage to the surrounding normal tissue—in patients where the surgeon is unable to remove the entire cancer. At times, when the tumour is extensive, chemotherapy or radiation is given prior to the surgery to shrink the lesion.
Palliative surgery is used to relieve side-effects caused by the growing cancer in cases that are otherwise inoperable due to the stage and extent of local spread. This is done in cases where there is a blockage of the bowel; for relieving pressure on the spinal cord which has caused severe pain; or to insert a feeding tube in a patient of oesophageal on cancer
Other forms of surgery performed on cancer patients include reconstruction surgery, to colon, and in women with strong family history of cancer restore the body's appearance in case of head or neck surgery for cancers of the mouth, or breast reconstruction after mastectomy. Prevention surgery is done for pre-cancerous polyps of the in the breast and ovary, to eliminate their risk of developing the disease in the future. Laparoscopic surgery is a minimally invasive procedure performed through small incisions and often robotically assisted in tumours of the chest, prostate, uterus, and ovary. Laser surgery focuses high intensity light to cut through the cancer tissue in a precise manner in eye lesions. Cryosurgery uses liquid nitrogen to freeze and destroy tumours, particularly in skin and cervical cancers. Supportive surgery prepares the patient for chemotherapy by inserting a port through which medication is administered.Chemotherapy
Chemotherapy is the systemic use of drugs for the treatment of cancer. The main goals of such forms of therapy vary from cure achieved by killing all tumour cells, controlling the growth of cancer cells, thereby causing remission, or palliative care to reduce symptoms and making the patient more comfortable.
Most forms of chemotherapy are administered intravenously. This allows the tumour to rapidly take up the drug, resulting in quick action against the cancer cells which can be present anywhere in the body-be it the site of origin of the tumour or on tumour cells that have spread to distant sites. A single drug, or more frequently, combinations of several drugs that act differently are used to destroy the malignant tumour. Using a combination of drugs reduces the dose of each drug, which is better tolerated by the patient owing to the decreases in their toxic effects. Drug combinations also reduce the chances of developing drug resistance early on (see p. 40 in Drug Resistance”).
Chemotherapy that is administered before surgery in order to reduce the tumour size is called neo-adjuvant chemotherapy. After surgery, it is designated as adjuvant chemotherapy. The dose of the drug is calculated accurately for each patient, based on either their body weight measured in kilograms or determined by the body surface calculated using the height and weight of the individual.
This form of medication is given in cycles—a dose of the drug followed by several days or weeks without treatment; or it is given for a certain number of days followed by a period of rest; or it is administered every other day for a set number of days, followed by complete rest. The period of no medication gives the body enough time to recuperate from the side-effects on the normal tissues of the body. Some drugs work better when given continuously, while others require three weekly cycles. The schedule for each drug is such that it maximizes the anti-cancer action and minimizes the side-effects. At times, the patient may develop serious side-effects, requiring a change in the chemotherapy plan or even stopping the drug.The Cell Cycle in Chemotherapy and Radiation
An overview of the cell cycle brings clarity to the way the drugs used in chemotherapy and radiation work, and their effects. The cell cycle is the normal life cycle of a cell.13 It comprises five phases, out of which GO is the resting phase. GO Phase: Most cells in adults are resting or quiescent, and do not undergo active cell division. To re-enter the cell cycle, the cells must be stimulated by signals. These signals push the cells out of GO (this phase lasts from a few hours o a few years) into the next phase of the cycle.
G1 Phase: In this phase (lasting 18–30 hours) the cells begin to grow and become larger in size by manufacturing more proteins.
S Phase: In this phase, the DNA content of the nucleus doubles and the chromosomes replicate to form two copies. This ensures that the daughter cells formed on completion of cell division have matching DNA. It lasts for about 18–24 hours.
G2 Phase: In this phase, further growth of the cell takes place and the DNA is ready to split into two identical cells. It lasts 2-10 hours.
M Phase (mitosis): In this phase, the cells split into two daughter cells. It lasts only 30 to 60 minutes.
An understanding of the cell cycle enables the oncologist to decide which drug, or combination of drugs, are best suited to curtail and destroy the tumour. Most chemotherapeutic drugs work only on cells that are actively dividing. Some drugs specifically attack cells in a particular phase of the cell cycle, either the S phase or the M phase. Cells in the resting phase, or GO, are not targeted by chemotherapy. Based on these facts, the oncologist can plan how often the dose of each drug should be administered for optimizing the beneficial effect of treatment.
Most chemotherapeutic agents, besides being cell-cycle specifichave a dose-related plateau in their cell-killing ability. Therefore, to increase the cell kill, there is a need to increase the duration of exposure, rather than increasing the dose of the drug. As some drugs are phase-specifico attempts have been made time drug administration in such a way that the cells are synchronized into a phase of the cell cycle that renders them especially sensitive to the cytotoxic agent.
The Shorter the ceni cycle, and the larger the fraction of cells in the cell cycle at a given time the more susceptible is the cancer to chemotherapy. Cancer cells grow more rapidly when the tumour is small, and the blood supply can keep pace with its growth. Once the malignant cells Outgrow the blood supply, they undergo necrosis or cell death. Dead tissue bas poor Or no vascular supply- thus any remaining viable cancer cells in the necrotic area are likely escape being targeted. Chemotherapy,therefore, is most effective in sma11, rapidly growing tumours.
The drugs used in chemotherapy act in two ways: ones attacking rapidly dividing cells and interrupting the cancer cell cycle by preventing mitosis or cell division; two, by inducing cancer cells to undergo programmed cell death. Drugs used for chemotherapy do not differentiate between normal cells and cancer cells. They target al cells that are in the dividing phase of the cell cycle. In other words, there is collateral damage Some normal cells.Targeted Tberap
Targeted therapy is a form of chemotherapy given to some patients with cancer. The principle behind targeted therapy is that cells have triggers (molecular targets) On their Surface function which receive signals that control their and determine their These triggers growth and proliferation TO Targeted about 2 Ce focus of in cancer some types of identified cells. have been molecular therapy is sometimes referred to as Precision therapy. It Uses information medicine” or precision not only for diagnosis, the genes and proteins of a tumours but also the current it. These to treat therapies new anti-cancer treatments.
There are of agents Used in targeted e directed against the tumour cells, and the other against the supporting tissue of the tumour. Monoclonal antibodies act against specific triggers on the tumour cells and are an example of the former Small molecule (anti-angiogenesis) drugs which block the formation Of new blood vessels resulting in starvation Of the cancer cells is the mode of action of the latter-TARGETED THERAPY VS REGULAR CHEMOTHERAPY
Targeted therapy blOCKS the specific trigger receptors on the cell surface of the cancer cell, that no signal is received by them. These signals essential for the growth of these cancer cells.
Malignant cells Without the specific triggers are unaffected, therefore, it has Little impact on Normal cells.
chemotherapy. On the other hand, acts in a non-Specific. way on all rapidly dividing cells, normal or cancerous, in cycle and not on any specific target.
Targeted therapies are designed to specific triggers and are interact with not chosen for kill rapidly their ability proliferating cells.
Toxicity resulting from targeted related problems therapy includes skin- Like dryness Wound healing, clotting and rashes, delayed disorders. and hypertension.Targeted Therapy in some Carcers
Breast Cancer: Tissue removed by excision biopsy of the breast is tested for a trigger called Human Epithelial Growth Factor Receptor 2 protein (HIER2). When HIER2 expression is high On the Surface of some breast cancers, targeted therapies can be used to destroy these cells. When malignant cells are negative for HIER 2, targeted therapy has role play.
Melanoma: Some melanomas produce altered proteins that drive cancer progression. The cell growth signalling protein, BRAF (an oncogene) is targeted in its altered form to Contain the spread of this form of skin cancer.
Lung Cancer: Drugs that block the Epithelial Growth Factor Receptor (EGFR) can stop SloW the Progression of lung cancer Positive for EGFR.
Leukaemia: Some chromosomal abnormalities present in leukaemic cells result in the formation of fusion genes, the products of which produce fusion proteins. Fusion Proteins targeted in this form of treatment.
Hormone Therapy: Certain thrive in the presence of hormones. Blocking the hormone receptors stops or slows the growth of hormone-sensitive tumours. Hormone therapy is used in the treatment of breast and prostate cancerRadiation Therapy
Radiation therapy is another important localized modality used in the treatment of cancer. It can be used in combination in with Surgery chemotherapy and/or chemotherapy or in isolation- depending on tumour type. About 50 Percent of patients with cancer receive radiotherapy It may be prior to or after .It is a low-cost alternative in Cencer treatment.How It Works
The basis of radiation therapy is the interaction of ionizing particles with the tissue at the molecular level. The ionizing particles could be x-rays, gamma rays or electrons. This interaction depends on the energy created by the production of the secondary charged particles, usually electrons, which break the chemical bonds within the nucleus and cause irreversible cellular injury and death of the cell.
There are two ways to deliver radiation therapy: external beam radiation or external radiotherapy, along with interstitial implants which require placing radioactive material in the body near the cancer cells, or even a combination of the two. The Linear Accelerator Imaging technology has made radiation therapy extremely targeted and highly effective-permitting delivery of the radiation beam with sub-millimetre precision. The direction and strength of the beam can be individualized for each patient, thereby minimizing the exposure of healthy tissue and related side-effects.
The goal of radiation therapy is to maximize the dose to the abnormal cells while minimizing the exposure of normal tissue. The effects of radiation therapy are not immediate, they generally occur over a period of time. Tumours with rapidly dividing cells respond more quickly to radiation than slowly growing ones. Radiation is painless and does not make the patient radioactive. It may be administered either before or after surgery. When given prior to surgery, it shrinks the tumour and makes removal easier. When given after surgery, it targets any remaining malignant cells at the local site, thus preventing recurrence. There are three situations wherein radiation therapy is given: as treatment to destroy the tumour and cure the disease, for prophylaxis--to prevent tumours from developing and spreading, as palliative care to relieve symptoms like pain, or for preventing seizures in brain tumours.Hoze Radiation Kids Cancer Cells
Radiation form Of localized treatment given the Where the located. It kills the cells that actively dividing, but it is less effective against cells in the resting phase of the cell cycle (GO cells), or against slowly dividing tumours. The term radio-sensitivity describes the susceptibility cells damage by radiation.