Third-line therapy

Therapy (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a diagnosis. In the medical field, it is usually synonymous with treatment (also abbreviated tx or Tx). Among psychologists and other mental health professionals, including psychiatrists, psychiatric nurse practitioners, counselors, and clinical social workers, the term may refer specifically to psychotherapy (sometimes dubbed 'talking therapy'). The English word therapy comes via Latin therapīa from Greek: θεραπεία and literally means 'curing' or 'healing'. Therapy (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a diagnosis. In the medical field, it is usually synonymous with treatment (also abbreviated tx or Tx). Among psychologists and other mental health professionals, including psychiatrists, psychiatric nurse practitioners, counselors, and clinical social workers, the term may refer specifically to psychotherapy (sometimes dubbed 'talking therapy'). The English word therapy comes via Latin therapīa from Greek: θεραπεία and literally means 'curing' or 'healing'. As a rule, each therapy has indications and contraindications. The words care, therapy, treatment, and intervention overlap in a semantic field, and thus they can be synonymous depending on context. Moving rightward through that order, the connotative level of holism decreases and the level of specificity (to concrete instances) increases. Thus, in health care contexts (where its senses are always noncount), the word care tends to imply a broad idea of everything done to protect or improve someone's health (for example, as in the terms preventive care and primary care, which connote ongoing action), although it sometimes implies a narrower idea (for example, in the simplest cases of wound care or postanesthesia care, a few particular steps are sufficient, and the patient's interaction with that provider is soon finished). In contrast, the word intervention tends to be specific and concrete, and thus the word is often countable; for example, one instance of cardiac catheterization is one intervention performed, and coronary care (noncount) can require a series of interventions (count). At the extreme, the piling on of such countable interventions amounts to interventionism, a flawed model of care lacking holistic circumspection—merely treating discrete problems (in billable increments) rather than maintaining health. Therapy and treatment, in the middle of the semantic field, can connote either the holism of care or the discreteness of intervention, with context conveying the intent in each use. Accordingly, they can be used in both noncount and count senses (for example, therapy for chronic kidney disease can involve several dialysis treatments per week). The words aceology and iamatology are obscure and obsolete synonyms referring to the study of therapies. Levels of care classify health care into categories of chronology, priority, or intensity, as follows: Treatment decisions often follow formal or informal algorithmic guidelines. Treatment options can often be ranked or prioritized into lines of therapy: first-line therapy, second-line therapy, third-line therapy, and so on. First-line therapy (sometimes called induction therapy, primary therapy, or front-line therapy) is the first therapy that will be tried. Its priority over other options is usually either: (1) formally recommended on the basis of clinical trial evidence for its best-available combination of efficacy, safety, and tolerability or (2) chosen based on the clinical experience of the physician. If a first-line therapy either fails to resolve the issue or produces intolerable side effects, additional (second-line) therapies may be substituted or added to the treatment regimen, followed by third-line therapies, and so on. An example of a context in which the formalization of treatment algorithms and the ranking of lines of therapy is very extensive is chemotherapy regimens. Because of the great difficulty in successfully treating some forms of cancer, one line after another may be tried. In oncology the count of therapy lines may reach 10 or even 20. Often multiple therapies may be tried simultaneously (combination therapy or polytherapy). Thus combination chemotherapy is also called polychemotherapy, whereas chemotherapy with one agent at a time is called single-agent therapy or monotherapy. Adjuvant therapy is therapy given in addition to the primary, main, or initial treatment, but simultaneously (as opposed to second-line therapy). Neoadjuvant therapy is therapy that is begun before the main therapy. Thus one can consider surgical excision of a tumor as the first-line therapy for a certain type and stage of cancer even though radiotherapy is used before it; the radiotherapy is neoadjuvant (chronologically first but not primary in the sense of the main event). Premedication is conceptually not far from this, but the words are not interchangeable; cytotoxic drugs to put a tumor 'on the ropes' before surgery delivers the 'knockout punch' are called neoadjuvant chemotherapy, not premedication, whereas things like anesthetics or prophylactic antibiotics before dental surgery are called premedication.