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|Subdivisions||Medical oncology, radiation oncology, surgical oncology|
|Significant tests||Tumor markers, TNM staging, CT scans, MRI|
|Hospitals, Clinics, Clinical research centers|
Oncology is a branch of medicine that deals with the study, treatment, diagnosis and prevention of tumors. A medical professional who practices oncology is an oncologist.The name's etymological origin is the Greek word ὄγκος (ónkos), meaning "tumor", "volume" or "mass". Oncology is concerned with:
Medical histories remain an important screening tool: the character of the complaints and nonspecific symptoms (such as fatigue, weight loss,unexplained anemia, fever of unknown origin, paraneoplastic phenomena and other signs) may warrant further investigation for malignancy. Occasionally, a physical examination may find the location of a malignancy.
Diagnostic methods include:
Apart from diagnoses, these modalities (especially imaging by CT scanning) are often used to determine operability, i.e. whether it is surgically possible to remove a tumor in its entirety.
Currently, a tissue diagnosis (from a biopsy) by a pathologist is essential for the proper classification of cancer and to guide the next step of treatment. On extremely rare instances when this is not possible, "empirical therapy" (without an exact diagnosis) may be considered, based on the available evidence (e.g. history, x-rays and scans.)
On very rare occasions, a metastatic lump or pathological lymph node is found (typically in the neck) for which a primary tumor cannot be found. However, immunohistochemical markers often give a strong indication of the primary malignancy. This situation is referred to as "malignacy of unknown primary", and again, treatment is empirical based on past experience of the most likely origin.
Depending upon the cancer identified, followup and palliative care will be administered at that time. Certain disorders (such as ALL or AML) will require immediate admission and chemotherapy, while others will be followed up with regular physical examination and blood tests.
Often, surgery is attempted to remove a tumor entirely. This is only feasible when there is some degree of certainty that the tumor can in fact be removed. When it is certain that parts will remain, curative surgery is often impossible, e.g. when there are metastases, Occasionally, when the tumor has invaded a structure that cannot be operated upon without risking the patient's life. Occasionally surgery can improve survival even if not all tumour tissue has been removed; the procedure is referred to as "debulking" (i.e. reducing the overall amount of tumour tissue). Surgery is also used for the palliative treatment of some of cancers, e.g. to relieve biliary obstruction, or to relieve the problems associated with some cerebral tumors. The risks of surgery must be weighed against the benefits.
Chemotherapy and radiotherapy are used as a first-line radical therapy in a number of malignancies. They are also used for adjuvant therapy, i.e. when the macroscopic tumor has already been completely removed surgically but there is a reasonable statistical risk that it will recur. Chemotherapy and radiotherapy are commonly used for palliation, where disease is clearly incurable: in this situation the aim is to improve the quality of life and to prolong it.
Hormone manipulation is well established, particularly in the treatment of breast and prostate cancer.
There is currently a rapid expansion in the use of monoclonal antibody treatments, notably for lymphoma (Rituximab) and breast cancer (Trastuzumab).
Vaccine and other immunotherapies are the subject of intensive research.
Approximately 50% of all cancer cases in the Western world can be treated to remission with radical treatment. For pediatric patients, that number is much higher. A large number of cancer patients will die from the disease, and a significant proportion of patients with incurable cancer will die of other causes. There may be ongoing issues with symptom control associated with progressive cancer, and also with the treatment of the disease. These problems may include pain, nausea, anorexia, fatigue, immobility, and depression. Not all issues are strictly physical: personal dignity may be affected. Moral and spiritual issues are also important.
While many of these problems fall within the remit of the oncologist, palliative care has matured into a separate, closely allied speciality to address the problems associated with advanced disease. Palliative care is an essential part of the multidisciplinary cancer care team. Palliative care services may be less hospital-based than oncology, with nurses and doctors who are able to visit the patient at home.
There are a number of recurring ethical questions and dilemmas in oncological practice. These include:
These issues are closely related to the patients' personality, religion, culture, and family life. Though these issues are complex and emotional, the answers are often achieved by the patient seeking counsel from trusted personal friends and advisors. It requires a degree of sensitivity and very good communication on the part of the oncology team to address these problems properly.
There is a tremendous amount of research being conducted on all frontiers of oncology, ranging from cancer cell biology, radiation therapy to chemotherapy treatment regimens and optimal palliative care and pain relief. In the past decade, the advent of next-generation sequencing and whole-genome sequencing has completely changed our understanding of cancers. Identification of novel genetic/molecular markers will dramatically change how we diagnose and treat cancer, which will pave the way for personalized medicine.
Therapeutic trials often involve patients from many different hospitals in a particular region. In the UK, patients are often enrolled in large studies coordinated by Cancer Research UK (CRUK),Medical Research Council (MRC), the European Organisation for Research and Treatment of Cancer (EORTC) or the National Cancer Research Network (NCRN).
The most valued companies worldwide whose leading products are in Oncology include Pfizer (United States), Roche (Switzerland), Merck (United States), AstraZeneca (United Kingdom), Novartis (Switzerland) and Bristol-Myers Squibb (United States) who are active in the treatment areas Kinase inhibitors, Antibodies, Immuno-oncology and Radiopharmaceuticals.
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body. It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor. Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology concerned with radiotherapy is called radiation oncology. A physician who practices in this subspecialty is a radiation oncologist.
A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secondary tumors, which most commonly have spread from tumors located outside the brain, known as brain metastasis tumors. All types of brain tumors may produce symptoms that vary depending on the size of the tumor and the part of the brain that is involved. Where symptoms exist, they may include headaches, seizures, problems with vision, vomiting and mental changes. Other symptoms may include difficulty walking, speaking, with sensations, or unconsciousness.
A radiation oncologist is a specialist physician who uses ionizing radiation in the treatment of cancer. Radiation oncology is one of the three primary specialties, the other two being surgical and medical oncology, involved in the treatment of cancer. Radiation can be given as a curative modality, either alone or in combination with surgery and/or chemotherapy. It may also be used palliatively, to relieve symptoms in patients with incurable cancers. A radiation oncologist may also use radiation to treat some benign diseases, including benign tumors. In some countries, radiotherapy and chemotherapy are controlled by a single oncologist who is a "clinical oncologist". Radiation oncologists work closely with other physicians such as surgical oncologists, interventional radiologists, internal medicine subspecialists, and medical oncologists, as well as medical physicists and technicians as part of the multi-disciplinary cancer team. Radiation oncologists undergo four years of oncology-specific training whereas oncologists who deliver chemotherapy have two years of additional training in cancer care during fellowship after internal medicine residency in the United States.
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is then fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle aspiration biopsy. Biopsies are most commonly performed for insight into possible cancerous or inflammatory conditions.
Glioblastoma, previously known as glioblastoma multiforme (GBM), is the most aggressive and most common type of cancer that originates in the brain, and has very poor prognosis for survival. Initial signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality changes, nausea, and symptoms similar to those of a stroke. Symptoms often worsen rapidly and may progress to unconsciousness.
In medicine, proton therapy, or proton radiotherapy, is a type of particle therapy that uses a beam of protons to irradiate diseased tissue, most often to treat cancer. The chief advantage of proton therapy over other types of external beam radiotherapy is that the dose of protons is deposited over a narrow range of depth; hence in minimal entry, exit, or scattered radiation dose to healthy nearby tissues.
Neuroblastoma (NB) is a type of cancer that forms in certain types of nerve tissue. It most frequently starts from one of the adrenal glands but can also develop in the neck, chest, abdomen, or spine. Symptoms may include bone pain, a lump in the abdomen, neck, or chest, or a painless bluish lump under the skin.
Adjuvant therapy, also known as adjunct therapy, adjuvant care, or augmentation therapy, is a therapy that is given in addition to the primary or initial therapy to maximize its effectiveness. The surgeries and complex treatment regimens used in cancer therapy have led the term to be used mainly to describe adjuvant cancer treatments. An example of such adjuvant therapy is the additional treatment usually given after surgery where all detectable disease has been removed, but where there remains a statistical risk of relapse due to the presence of undetected disease. If known disease is left behind following surgery, then further treatment is not technically adjuvant.
A blastoma is a type of cancer, more common in children, that is caused by malignancies in precursor cells, often called blasts. Examples are nephroblastoma, medulloblastoma, and retinoblastoma. The suffix -blastoma is used to imply a tumor of primitive, incompletely differentiated cells, e.g., chondroblastoma is composed of cells resembling the precursor of chondrocytes.
An atypical teratoid rhabdoid tumor (AT/RT) is a rare tumor usually diagnosed in childhood. Although usually a brain tumor, AT/RT can occur anywhere in the central nervous system (CNS), including the spinal cord. About 60% will be in the posterior cranial fossa. One review estimated 52% in the posterior fossa, 39% are supratentorial primitive neuroectodermal tumors (sPNET), 5% are in the pineal, 2% are spinal, and 2% are multifocal.
Bone metastasis, or osseous metastatic disease, is a category of cancer metastases that results from primary tumor invasion to bone. Bone-originating primary tumors such as osteosarcoma, chondrosarcoma, and Ewing sarcoma are rare; the most common bone tumor is a metastasis. Bone metastases can be classified as osteolytic, osteoblastic, or both. Unlike hematologic malignancies which originate in the blood and form non-solid tumors, bone metastases generally arise from epithelial tumors and form a solid mass inside the bone. Bone metastases, especially in a state of advanced disease, can cause severe pain, characterized by a dull, constant ache with periodic spikes of incident pain.
The European Society for Medical Oncology (ESMO) is the leading professional organisation for medical oncology. With more than 25,000 members representing oncology professionals from over 160 countries worldwide, ESMO was founded in 1975.
Cancer can be treated by surgery, chemotherapy, radiation therapy, hormonal therapy, targeted therapy and synthetic lethality, most commonly as a series of separate treatments. The choice of therapy depends upon the location and grade of the tumor and the stage of the disease, as well as the general state of the patient. Cancer genome sequencing helps in determining which cancer the patient exactly has for determining the best therapy for the cancer. A number of experimental cancer treatments are also under development. Under current estimates, two in five people will have cancer at some point in their lifetime.
Treatment of lung cancer refers to the use of medical therapies, such as surgery, radiation, chemotherapy, immunotherapy, percutaneous ablation, and palliative care, alone or in combination, in an attempt to cure or lessen the adverse impact of malignant neoplasms originating in lung tissue.
Gujarat Cancer & Research Institute (GCRI) is a state owned-cancer research institute in Gujarat, India. It was established in 1972. It is one of the 25 government funded Regional Cancer Centres in India.
Childhood cancer is cancer in a child. About 80% of childhood cancer cases can be successfully treated. thanks to the modern medical treatments and optimal patient care. However, only about 10% of children diagnosed with cancer reside in high-income countries where the necessary treatments and care is available. Childhood cancer represents only about 1% of all types of cancers diagnosed in children and adults. For this reason, childhood cancer is often ignored in control planning, contributing to the burden of missed opportunities for its diagnoses and management in countries that are low- and mid-income.
Interventional oncology is a subspecialty field of interventional radiology that deals with the diagnosis and treatment of cancer and cancer-related problems using targeted minimally invasive procedures performed under image guidance. Interventional oncology has developed to a separate pillar of modern oncology and it employs X-ray, ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) to help guide miniaturized instruments to allow targeted and precise treatment of solid tumours located in various organs of the human body, including but not limited to the liver, kidneys, lungs, and bones. Interventional oncology treatments are routinely carried out by interventional radiologists in appropriate settings and facilities.
A central nervous system tumor is an abnormal growth of cells from the tissues of the brain or spinal cord. CNS tumor is a generic term encompassing over 120 distinct tumor types. Common symptoms of CNS tumors include vomiting, headache, changes in vision, nausea, and seizures. A CNS tumor can be detected and classified via neurological examination, medical imaging, such as x-ray imaging, magnetic resonance imaging (MRI) or computed tomography (CT), or after analysis of a biopsy.
Metronomic therapy is a new type of chemotherapy in which anti-cancer drugs are administered in a lower dose than the maximum tolerated dose repetitively over a long period to treat cancers with fewer side effects. Metronomic therapy is shown to affect both tumor microenvironment and tumor cells to achieve its therapeutic effects. Metronomic therapy is also cost-effective as a lower dose is used compared to conventional chemotherapy. The use of metronomic therapy has been extensively investigated and can be advantageous in selected group of patients. Yet, more clinical trials are necessary to generalize the method.
Andrea A. Hayes Dixon is an American surgeon. She was the first pediatric surgeon to perform a high-risk, life-saving procedure in children with a rare form of cancer and developed the first orthotropic xenograft model of metastatic Ewing's sarcoma. In 2002, she became the first African American female pediatric surgeon board-certified in the United States.