Oncology

Oncology (also, cancerology) is the branch of medicine that studies and treats neoplasms, with special attention to malignant tumors or cancer. As a medical specialty, derived from the trunk of internal medicine, it is dedicated to the diagnosis and treatment of cancer, focused on the care of cancer patients and their treatment, among others through chemotherapy, hormonal therapy and other medications, while as a surgical specialty, it is responsible for the removal of the tumor and surrounding tissues, and radiation oncology uses radiation therapy to treat cancer.

Etymology

The term oncology derives from the ancient Greek ογκος oncos (mass or tumor) and λογος,ου -logos-ou (study). Doctors dedicated to this specialty are called oncologists.

Concept

Oncology deals with:

• The diagnosis of cancer.
• Cancer treatment (surgery and non-surgical therapies, such as chemotherapy, radiation therapy and other forms).
• Follow-up of cancer patients after treatment, including palliative care for patients with advanced disease. Request for genetic studies, especially in cases where cancer is hereditary or family type.

Subspecialties

Oncologists who care for patients are known as clinical oncologists, to distinguish them from those who do cancer-related research without direct patient contact. Surgeons oncologists are those surgeons specialized in the resection of tumors, this specialty is not recognized in many countries, including Spain.

There are countries, such as the United Kingdom, in which clinical oncologists are qualified to recommend both chemotherapy and radiotherapy, although in other countries there are subspecialties depending on the type of treatment used, which is why 2 types are distinguished from oncologists:

• Medical oncologists are those who use antineoplastic drugs, that is, chemotherapy and immunotherapy.
• Radiation oncologists, specialists who use radiation treatments, also known as radiation therapy.

We can also divide oncology into subspecialties, depending on the type of patients they care for:

• Oncologist gynecologists, specializing in the types of cancer of women.
• Pediatric oncologists, specialized in the care of children with some type of cancer.
• Oncologists. They are dedicated exclusively to the study, diagnosis and treatment of patients with bone tumors and soft parts through tumor resection and surgical reconstruction using prosthesis or bone transplants.
• Oncologists. They study the cancers that originate in the organs that form the blood. This branch is generally considered a specialty of hematology.

Concept of the tumor

Although many of the factors that favor the appearance of malignant tumors or cancer are not exactly known, information is available on certain risk factors, including the following:

• Genetics: DNA mutations.
• Biological carcinogens: some infections caused by viruses, bacteria or parasites.
• Chemical carcinogens: components of tobacco smoke, aflatoxins.
• Physical carcinogens: radiation (ultraviolet, ionizers)

Diagnosis

The medical history remains an important screening tool: the nature of the complaints and nonspecific symptoms (such as fatigue, weight loss, unexplained anemia, fever of unknown origin, paraneoplastic phenomena, and other signs) may justify a more thorough investigation of malignancy. Occasionally, a physical examination may uncover the location of a malignant neoplasm.

Diagnostic methods include:

• Biopsy or resection; these are methods by which suspicious neoplastic growths can be removed in part or in full, and evaluated by a pathologist to determine malignancy. At present, it is the golden rule for the diagnosis of cancer and is crucial to guide the next step in treatment (active surveillance, surgery, radiation therapy, chemotherapy, or a combination thereof).
• Endoscopy, either upper or lower gastrointestinal, cystoscopy, bronchoscopy or nasendoscopy; to locate suspected areas of malignity and biopsy where necessary.
• X-rays, Computed Axial Tomography (TAC), Magnetic resonance imaging, ultrasound (ultrasonide) and other radiological techniques to locate and guide the biopsy.
• Gammagraphy, CT scan of monophotonic emission (SPECT), postitron emission tomography (PET) and other nuclear medicine methods to identify suspected areas of malignancy.
• Blood tests, including tumor markers, that may increase the suspicion of certain types of cancer.

Aside from diagnosis, these modalities (especially CT imaging) are often used to determine operability, that is, whether it is surgically possible to remove a tumor in its entirety.

Currently, tissue diagnosis (from biopsy) by a pathologist is essential to correctly classify cancer and guide the next step in treatment. On very rare occasions, when this is not possible, an "empirical therapy" (without an exact diagnosis), based on available evidence (for example, history, x-rays, and scans).

Very rarely, a metastatic lump or pathologic lymph node (usually in the neck) is found for which no primary tumor can be found. However, immunohistochemical markers usually clearly indicate the primary malignancy. This situation is called "malignancy of unknown primary origin" and, again, the treatment is empirical and is based on previous experience about the most probable origin.

Therapy

Depending on the cancer identified, follow-up and palliative care will be given at this time. Certain disorders (such as ALL or AML) will require immediate admission and chemotherapy, while others will be followed with regular physical exams and blood tests.

Often, surgery is attempted to remove a tumor completely. This is only feasible when there is some degree of certainty that the tumor can be removed. When it is certain that parts will remain, curative surgery is usually impossible, for example, when there are metastases. Occasionally, when the tumor has invaded a structure that cannot be operated without endangering the life of the patient. Surgery can sometimes improve survival even though not all of the tumor tissue has been removed; the procedure is called "cytoreduction" (ie, reduction in the total amount of tumor tissue). Surgery is also used for the palliative treatment of some types of cancer, for example to relieve biliary obstruction or the problems associated with some brain tumors. The risks of surgery must be weighed against the benefits.

Chemotherapy and radiation therapy are used as radical first-line therapy in various malignancies. They are also used for adjuvant therapy, that is, when the gross tumor has already been completely surgically removed but there is a reasonable statistical risk that it will recur. Chemotherapy and radiotherapy are commonly used for palliation, when the disease is clearly incurable: in this situation, the goal is to improve quality of life and prolong it.

Hormonal manipulation is well established, especially in the treatment of breast and prostate cancer.

There is currently a rapid expansion in the use of monoclonal antibody treatments, particularly for lymphoma (Rituximab) and breast cancer (Trastuzumab).

Vaccines and other immunotherapies are the subject of intense research.

Advances in the information of occupational doctors to prevent occupational cancer

Cancer prevention requires regularly updated knowledge on the part of doctors in the field of occupational medicine. To help them do this, within the framework of the French Plan against cancer 2009-2013, the French National Cancer Institute commissioned two surveys (with more than 600 doctors) aimed at drawing up an inventory of information sources on primary prevention of work-related cancers for occupational physicians (93.5% of respondents) and highlight specific needs and lines of action, especially in the construction, public works and industry sectors, where demand of occupational doctors is more pronounced. "Archives of occupational and environmental diseases".

• More than 60% of the doctors surveyed use the press and books, and more and more internet (45%), continuous training (31%), congresses or colloquiums (20%), public agencies and agencies (25%), exchanges with colleagues (15%), personal courses and documents (10%).
• only 64% are satisfied with their opportunities to update their knowledge.
• 95 per cent would like to have access to documents resuming scientific knowledge, regularly updated information on available tools (93%, for example, the medical work record, the company's starting sheet, etc.) and would find useful recommendations for the follow-up of workers exposed to CMR (95%), as well as updates on legislation (92.5 per cent).

As a result of this work, in 2013 a documentary resource guide and a vigilance bulletin for occupational physicians and occupational health services were announced.

Palliative care

Approximately 50% of all cancer cases in the Western world can be treated into remission with radical treatment. For pediatric patients, that figure 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 from other causes. There may be ongoing problems with the control of symptoms associated with progressive cancer, and also with the treatment of the disease. These problems can include pain, nausea, anorexia, fatigue, immobility, and depression. Not all issues are strictly physical: personal dignity can be affected. Moral and spiritual issues are also important.

Although many of these problems are the province of the oncologist, palliative care has matured into a separate and closely allied specialty for addressing the problems associated with advanced disease. Palliative care is an essential part of the multidisciplinary cancer care team. Palliative care services may be less hospitable than oncology, with nurses and doctors able to visit the patient at home.

Progress and research

A lot of research is going on at all frontiers of oncology, from cancer cell biology and radiation therapy to chemotherapy treatment regimens and optimal palliative care and pain relief. In the last decade, the advent of next generation sequencing and whole genome sequencing have completely changed our understanding of cancers. The identification of new genetic/molecular markers will radically change the way we diagnose and treat cancer, paving the way for personalized medicine.

Therapeutic trials often involve patients from many different hospitals in a given region. In the UK, patients often participate in large studies coordinated by Cancer Research UK (CRUK), the Medical Research Council (MRC), the European Organization for Research and Treatment of Cancer (EORTC) or the National Cancer Research Network (NCRN).

Among the most valued companies worldwide whose leading products are in Oncology are Pfizer (United States), Roche (Switzerland), Merck (United States), AstraZeneca (United Kingdom), Novartis (Switzerland) and Bristol-Myers Squibb (United States) operating in the treatment areas Kinase inhibitors, antibodies, cancer immunotherapy and radiopharmaceuticals.

Ethical issues

There are a number of recurring ethical questions and dilemmas in oncology practice. These include:

• What information to give the patient about the extent/progression/prognosis of the disease.
• Participation in clinical trials, especially in case of terminal illness.
• Removed from active treatment.
• Orders of "not reanimate" and other issues related to the end of life.

These issues are closely related to patients' personality, religion, culture, and family life. Although these questions are complex and emotional, often the answers are obtained when the patient seeks the advice of trusted friends and personal advisors. A degree of sensitivity and very good communication is required on the part of the oncology team to adequately address these issues.