Oncology is a branch of medicine that deals with the study, treatment, diagnosis, and prevention of cancer. A medical professional who practices oncology is an oncologist.

Cancer was first found in humans in the years 3000 BCE in Egypt. The Edwin Smith papyrus described a form of cancer as "a bulging tumor of the breast." Galen, a Greek doctor who lived from 130–200 CE, was the first to use the word onkos to describe tumors, from which the words "oncologist" and "oncology" are derived.

Oncology is focused on the diagnosis of cancer in a person, therapy (e.g., surgery, chemotherapy, radiotherapy and other modalities), monitoring of people after treatment, palliative care for people with advanced-stage cancers, ethical questions surrounding cancer care, screening of people who may have cancer, and the study of cancer treatments through clinical research.

An oncologist typically focuses on a specialty area in cancer treatment, such as surgery, radiation, gynecological oncology, geriatric oncology, pediatric oncology, and various organ-specific disciplines (breast, brain, liver, among others).

Diagnosis

Medical histories are an important screening tool to assess the concerns and nonspecific symptoms in a patient (such as fatigue, weight loss, unexplained anemia, fever of unknown origin, paraneoplastic phenomena and other signs) that may require further evaluation for malignancy.

Diagnostic methods in oncology may include a biopsy or resection; these are methods used to remove suspicious neoplastic cells, which can be removed in part or in whole, and examined by a pathologist to assess for malignancy. This is essential for determining the next step in the appropriate course of management (active surveillance, surgery, radiation therapy, chemotherapy, or a combination of these).

Other diagnostic procedures may include an endoscopy, either upper or lower gastrointestinal, cystoscopy, bronchoscopy, or nasendoscopy to localize tissues suspicious for malignancy and biopsy, mammograms, X-rays, CT scanning, MRI scanning, ultrasound and other radiological techniques to localize and guide biopsy. Scintigraphy, single photon emission computed tomography (SPECT), positron emission tomography (PET) and other methods of nuclear medicine are imaging technologies used to identify areas suspicious of malignancy. Blood tests, including tumor markers, can assist diagnosis of certain types of cancers.

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.

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. In 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).

Immunohistochemical markers often give a strong indication of the primary malignancy. This situation is referred to as "malignancy of unknown primary", and again, treatment is empirically based on past experience of the most likely origin.

Therapy

Treatment or palliative care depends on the cancer. Certain disorders (such as ALL or AML) will require immediate admission and chemotherapy. Others may be followed up with regular physical examination, medical imaging, 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, is often impossible, e.g. when there are metastases, or 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 cancers, e.g. to relieve , 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 several 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.

Monoclonal antibody treatments are widely used in oncology, with established therapies such as Rituximab for lymphoma and Trastuzumab for HER2-positive breast cancer, alongside newer agents targeting various cancers. Cancer vaccines and other immunotherapies, such as checkpoint inhibitors, CAR-T cell therapy, and cytokine therapies, remain active areas of research and clinical application.

Palliative care

Although cancers can be treated to remission with radical treatment. For pediatric patients, that number is much higher. 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 specialty to address the problems associated with advanced disease. Palliative care is an essential part of the multidisciplinary cancer care team.

Progress and research

There is a tremendous amount of research being conducted, ranging from cancer cell biology, and radiation therapy to chemotherapy treatment regimens and optimal palliative care and pain relief. Next-generation sequencing and whole-genome sequencing have completely changed the understanding of cancers. Identification of novel genetic/molecular markers will change the methods of diagnosis and treatment, paving the way for personalized medicine.

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.

Specialties

See also

Organizations

Further reading

  • Watson, Ian R.; Takahashi, Koichi; Futreal, P. Andrew; Chin, Lynda (2013). . Nat Rev Genet. 14 (10): 703–718. doi:. PMC . PMID .
  • Meyerson, Matthew; Gabriel, Stacey; Getz, Gad (October 2010). "Advances in understanding cancer genomes through second-generation sequencing". Nature Reviews Genetics. 11 (10): 685–696. doi:. PMID .
  • Katsanis, Sara Huston; Katsanis, Nicholas (2013). . Nat Rev Genet. 14 (6): 415–426. doi:. PMC . PMID .
  • Mardis, Elaine R. (August 2012). "Applying next-generation sequencing to pancreatic cancer treatment". Nature Reviews Gastroenterology & Hepatology. 9 (8): 477–486. doi:. PMID .
  • Mukherjee, Siddhartha (2011). The Emperor of All Maladies: A Biography of Cancer. Fourth Estate. ISBN 978-0-00-725092-9.
  • Vickers, A. (1 March 2004). . CA: A Cancer Journal for Clinicians. 54 (2): 110–118. doi:. PMID .

External links

  • . National Cancer Institute. January 1980.
  • . National Comprehensive Cancer Network. Archived from on 2021-06-30.
  • . www.esmo.org.