Oncology is a specialized discipline in medicine that deals with the treatment of cancer and tumors. Oncology is an interdisciplinary science of causes, factors, prevention, and general nature of occurrence and growth and the treatment of tumors. In this area are directed research in the field of several basic biological and medical sciences, such as biochemistry, genetics, physiology, immunology, endocrinology, nuclear medicine, pathology, surgery, radiation physics, and other experimental and clinical professions.

• The main approaches and pathways of tumor treatment are:
• Diagnosis of cancer (pathology);
• Therapy (eg surgery, chemotherapy, radiotherapy, and other modalities)
• Monitoring of cancer patients after successful treatment;
• Palliative care of patients with terminal malignant disease;
• Ethical issues of the environment and the care of the ill;
• Screening in: population, or germ analysis, which includes relatives of patients (in types of cancer considered to have hereditary basics, such as breast cancer.

Medical history is still an important snapshot of the circumstances: the nature of the disorder that causes the patient’s examination and the non-specific symptom (such as fatigue, weight loss, inexplicable anemia, fever of unknown origin, paraneoplastic events and other signs) can be the basis for further malignancy tests. Occasionally, the site of malignancy can be determined by physical examination. Diagnostic methods include a series of searches, such as:

• Biopsy or resection; these are methods by which the susceptible neoplastic outgrowth can be removed in part or in whole, and this is assessed by the pathologist for the detection of malignancy. This is currently the gold standard for diagnosis of cancer and the key procedure leading to the next step in the management of the procedure (active monitoring, surgery, radiation therapy, chemotherapy or a combination thereof);
• Endoscopy or upper or lower gastrointestinal tract, cystoscopy, bronchoscopy or nasendoscopy, which locate areas of suspect malignancy, followed by biopsy when necessary:
• X-rays, CT, MRI scanning, ultrasound and other radiological techniques for localization and a biopsy guide;
• Scintigraphy, single-photon emission computed tomography (SPECT), positron emission tomography (PET), and other nuclear medicine methods to identify areas of suspected malignancy.
• Blood tests, including tumor markers, which can increase suspicion of certain types of cancer.

In addition to diagnosis, these methods (especially CT imaging) are often used to determine the operability, or whether it is operable to remove the tumor as a whole. Of vital importance for the correct classification of cancer, to guide the next step in therapy is currently the diagnosis of pathology of the tissue (from a biopsy). In extremely rare cases, when this is not possible, “empirical therapy” can be undertaken (without an accurate diagnosis), based on available evidence (e.g., history of illness, X-ray and scanning).

In very rare cases, and metastatic lumbar or pathological lymph nodes are (usually in the neck) for which the primary tumor cannot be found. However, immunohistochemical markers often give a strong indicator of primary malignancy. This situation is called unknown primary malignancy, and again treatment is empirically based on previous experience of the most probable origin.