oncology

Oncology is the branch of medicine that specializes in cancer, including its biology, diagnosis, treatment, and prevention. The field integrates clinical disciplines such as medical oncology, surgical oncology, and radiation oncology, along with pathology, radiology, genetics, and supportive care to manage malignant disease across the spectrum of care from screening to palliation.

Cancers arise from genetic and epigenetic alterations that disrupt normal cell growth and enable malignant behaviors such as invasion and metastasis. Research in oncology covers tumor biology, molecular profiling, and cancer epidemiology to understand disease mechanisms, risk factors, and treatment targets. Diagnosis typically combines history, physical examination, imaging, biopsy with histopathology, and increasingly molecular testing for tumor markers and mutations. Staging systems, often based on the TNM framework, assess tumor extent, node involvement, and metastasis to guide prognosis and treatment decisions.

Treatment is usually multimodal and tailored to the individual. Local therapies include surgical resection and radiotherapy to remove or control tumors. Systemic therapies encompass chemotherapy, targeted therapy, immunotherapy, and hormonal therapy. In some cases, hematopoietic stem cell transplantation or cell-based therapies are used. Palliative care, symptom management, and survivorship support are integral throughout the cancer care continuum.

Prevention and screening aim to reduce incidence and mortality through lifestyle modification, vaccination, infection control, and early detection. Common risk factors include tobacco use, unhealthy diet, obesity, and certain infections or environmental exposures. Screening programs for breast, cervical, colorectal, and other cancers improve early diagnosis and outcomes where applicable.

Advances in oncology are driven by translational and clinical research, including genomics, precision medicine, and immunotherapy. Care delivery increasingly relies on multidisciplinary teams and coordinated pathways, with attention to equity and access, clinical guidelines, and ethical considerations in trials and end-of-life care.