hematology and oncology
Overview of Cancer Therapy
Introduction
Curing cancer requires eliminating all cells capable of causing cancer recurrence in a person's lifetime. The major modalities of therapy are Surgery for Cancer (for local and local-regional disease) Radiation Therapy for Cancer (for local and local-regional disease) Systemic Cancer Therapy (for systemic disease) Surgery is the oldest effective cancer therapy. It can be used alone or in combination with other modalities. The size, type, and location of the cancer may determine operability and outcome. The presence of metastases typically precludes surgery. Radiation therapy can cure many cancers, particularly those that are localized or that can be completely encompassed within a radiation field. Radiation therapy plus surgery (for head and neck, laryngeal, or uterine cancer) or combined with chemotherapy and surgery (for sarcomas or breast, esophageal, lung, or rectal cancers) improves cure rates and allows for more limited surgery. Systemic cancer modalities include Conventional cytotoxic therapy (eg,fluorouracil,methotrexate,daunorubicin,cyclophosphamide) Hormonal therapy (for selected cancers, eg, prostate, breast, endometrium) Immunotherapy of Cancer , including monoclonal antibodies, interferons, biologic response modifiers, tumor vaccines, and cell therapies (for many different types of cancer) Differentiating drugs such as retinoids (for Acute Myeloid Leukemia (AML) ) and isocitrate dehydrogenase-2 ( for Chronic Myeloid Leukemia (CML) ) Often, modalities are combined to create a treatment program that is appropriate for the patient, based on patient and tumor characteristics as well as patient preferences. These modalities can be combined with the primary treatment at the same time or used before or after. The primary purpose of adjuvant therapy, which is given after, and neoadjuvant therapy, which is given beforehand, is to prevent cancer recurrence and increase survival. Overall treatment should be coordinated among a radiation oncologist, surgeon, and medical oncologist, where appropriate. Choice of modalities constantly evolves, and numerous controlled research trials continue. When available and appropriate, clinical trial participation should be considered and discussed with patients. Treatment decisions should weigh the likelihood of adverse effects against the likelihood of benefit; these decisions require frank communication and possibly the involvement of a multidisciplinary cancer team. Patient preferences for how to live out the end of life (see Advance Directives ) should be established early in the course of cancer treatment despite the difficulties of discussing death at such a sensitive time. 