Editing Malignancy (section)

==Management==
There are various treatment forms available to help manage malignancy. Common treatments include [[chemotherapy]], [[radiation]] and [[Cancer surgery|surgical]] procedures. Photoradiation and [[hyperthermia]] are also used as treatment forms to kill or reduce malignant cells. A large portion of patients are at risk of death when diagnosed with malignancy as the disease has usually progressed for a number of years before detection.<ref name = "Donohue_2008">{{cite book | vauthors = Donohue JH | date = 2008 | chapter = Principles of cancer surgery. | veditors = Norton JA, etal | title = Surgery | pages = 1965–1984 | publisher = Springer | location = New York, NY | doi = 10.1007/978-0-387-68113-9_95 | isbn = 978-0-387-30800-5 }}</ref>

===Surgery===
Surgery can help manage or treat malignancy by either removing the tumour, localising it and/or determining whether there has been a spread to other organs.<ref name = "ASCO_Surgery">{{cite web | work = American Society of Clinical Oncology (ASCO). | title = What is cancer surgery? | date = 31 March 2011 | url = https://www.cancer.net/navigating-cancer-care/how-cancer-treated/surgery/what-cancer-surgery }}</ref><ref name = "ASCO_Surgery_How">{{cite web | work = American Society of Clinical Oncology (ASCO). | title = How Surgery Is Used for Cancer? | url = https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/surgery/how-surgery-is-used-for-cancer.html }}</ref> When undertaking surgery for malignancy, there are six major objectives which are considered.<ref name = "Donohue_2008" /> These include "prevention of cancer, diagnosis and staging of disease, disease cure, tumour debulking, symptom palliation and patient rehabilitation".<ref name = "Donohue_2008" />

Surgical prevention of cancer largely consists of removing the organ at risk of developing malignancy.<ref name = "Donohue_2008" /> This would occur if an individual is predisposed to the formation of malignant cells as a result of inherited [[genetic mutations]] and, acquired diseases.<ref name = "Donohue_2008" />

Surgical diagnosis of malignancy involves completing a [[biopsy]].<ref name = "Donohue_2008" /> This process requires a sufficient amount of tissue to make a confident diagnosis and, the handling of specimen to expand information provided from testing.<ref name = "Donohue_2008" /> Biopsies are categorised into four different processes: "fine-needle aspirate (FNA), core needle, incisional and, excisional".<ref name = "Donohue_2008" />

Curative surgery (also known as primary surgery) can be conducted when the malignant tumour has only invaded one area of the body.<ref name = "ASCO_Surgery" /><ref name = "ASCO_Surgery_How" /> The objective is to remove the entirety of the malignant cells without violating the tumour; if the tumour is violated, the risk of both tumour spillage and wound implantation would increase.<ref name = "ASCO_Surgery" /><ref name = "ASCO_Surgery_How" />

The surgical procedure of tumour debulking can be undertaken to increase the effectiveness of postoperative forms of treatment.<ref name = "Donohue_2008" /> Symptom palliation and patient rehabilitation do not play a role in controlling or reducing malignancy growth rather, they increase the patient's quality of life.<ref name = "Donohue_2008" />

===Photoradiation===
[[Hematoporphyrin|Hematoporphyrin derivative]] (HPD) is a drug which was developed to be absorbed by malignant cells and only becomes active when exposed to light.<ref>{{cite web | title = Hematoporphyrin derivative | work = NCI Dictionary of Cancer Terms. | date = 2021 | access-date = 23 April 2021 | url = https://www.cancer.gov/publications/dictionaries/cancer-terms/def/hematoporphyrin-derivative }}</ref> It is commonly used to identify and localise cancers as when it is under activation of blue light the red fluorescence of the malignant tumour (due to the HPD) can be observed easily.<ref name = "Dougherty_1978">{{cite journal | vauthors = Dougherty TJ, Kaufman JE, Goldfarb A, Weishaupt KR, Boyle D, Mittleman A | title = Photoradiation therapy for the treatment of malignant tumors. | journal = Cancer Research | date = August 1978 | volume = 38 | issue = 8 | pages = 2628–2635 | pmid = 667856 | url = https://cancerres.aacrjournals.org/content/38/8/2628.short }}</ref>

The combination of HPD with red light (photoradiation) has been used on various malignant tumours including malignant [[melanomas]] and [[carcinomas]] on a range of different organs including the breast and colon.<ref name = "Dougherty_1978" /> This form of treatment produces a [[singlet oxygen]] through the photodynamic process;<ref name = "Dougherty_1978" /> where the oxygen molecule exists in an electronically excited state.<ref>{{cite book | vauthors = Hrycay EG, Bandiera SM | title = Cytochrome P450 Function and Pharmacological Roles in Inflammation and Cancer | chapter = Involvement of Cytochrome P450 in Reactive Oxygen Species Formation and Cancer | series = Advances in Pharmacology | volume = 74 | pages = 35–84 | date = 2015 | pmid = 26233903 | doi = 10.1016/bs.apha.2015.03.003 | isbn = 9780128031193 | veditors = Hardwick JP }}</ref> The singlet oxygen is a cytotoxic agent <ref name = "Dougherty_1978" /> which holds the ability to eradicate malignant cells by preventing both [[nucleic acid]] and [[protein synthesis]].<ref>{{cite book | vauthors = Papadimitraki ED, Bertsias G, Chamilos G, Boumpas DT | chapter = Systemic Lupus Erythematosus | date = January 2011 | pages = 1083–1108 | publisher = Academic Press | doi = 10.1016/B978-0-12-374994-9.10058-0 | isbn = 9780123749949 }}</ref> The treatment process also utilises HPD's capability of accumulating at higher levels in malignant tissues compared to most other tissues.<ref name = "Dougherty_1978" />

In the case of deeply pigmented or larger tumours, a stronger course of this treatment process is required in order to be effective.<ref name = "Dougherty_1978" />

===Hyperthermia===
Malignancy can be treated through the use of hyperthermia by applying either surgical perfusion or interstitial techniques to the body.<ref name="Christophi_1998">{{cite journal | vauthors = Christophi C, Winkworth A, Muralihdaran V, Evans P | title = The treatment of malignancy by hyperthermia | journal = Surgical Oncology | volume = 7 | issue = 1–2 | pages = 83–90 | date = 1998 | pmid = 10421511 | doi = 10.1016/s0960-7404(99)00007-9 }}</ref> The use of this treatment type largely depends on the fact that malignant and normal cells have differing responses to the energy source used.<ref name="Christophi_1998" /> This dependency is due to the intracellular changes which occur during hyperthermia; as the [[nucleic acids]], [[cell membrane]] and [[cytoskeleton]] within each cell is affected indirectly and/or through multiple pathways.<ref name="Christophi_1998" /> The combination of these intracellular changes means there is no specific target of cell death in the hyperthermic process.<ref name="Christophi_1998" />

===Chemotherapy===
[[Chemotherapy]] is commonly used as either the primary treatment or in conjunction with other treatment forms such as radiotherapy or surgery.<ref name = "Nazzario_2021">{{cite web | vauthors = Nazzario B | date = 8 February 2021 | title = Chemotherapy: How it works and how you'll feel. | work = WebMD – Cancer Centre | url = https://www.webmd.com/cancer/chemotherapy-what-to-expect }}</ref> It can be administered through "injection, intra-arterial (IA), [[intraperitoneal]] (IP), [[intrathecal]] (IT), [[intravenous]] (IV), topical or oral".<ref name = "Nazzario_2021" />

The purpose of chemotherapy is to use [[cytotoxic agents]] which kill rapidly dividing cells within the body.<ref name="MacDonald_2009">{{cite journal | vauthors = MacDonald V | title = Chemotherapy: managing side effects and safe handling | journal = The Canadian Veterinary Journal | volume = 50 | issue = 6 | pages = 665–668 | date = June 2009 | pmid = 19721789 | pmc = 2684058 | doi =  }}</ref> It targets the cellular mechanisms which allow the development of malignancy throughout the body.<ref name = "Lind_2011">{{cite journal | vauthors = Lind MJ | date =2011 | title = Principles of cytotoxic chemotherapy. | journal = Medicine | volume = 39 | issue = 12 | pages = 711–716 | doi = 10.1016/j.mpmed.2011.09.009 }}</ref> There are no specific areas which are targeted and so, there is a lack of differentiation between normal and malignant cells,<ref name = "Lind_2011" /> resulting in a range of side effects. This includes [[bone marrow suppression]], [[gastrointestinal]] problems and [[alopecia]].<ref name="MacDonald_2009" /> Some side effects are specific to the anticancer drug used, the most common being bone marrow suppression as bone marrow has the ability to divide rapidly due to high growth fraction.<ref name="MacDonald_2009" /> This is because anticancer drugs have the highest activity in high growth fraction tissues.<ref name="MacDonald_2009" />

[[Alkylating agents]] are used in chemotherapy as these are chemically reactive drugs which form [[covalent bond]]s when reacting with DNA.<ref name = "Lind_2011" /> This results in breaks within DNA strands causing either inter-strand or intra-strand DNA cross-linking.<ref name = "Lind_2011" /> The sub-classes of alkylating agents are "[[nitrogen mustards]], oxazaphosphorines, alkyl alkane, sulphonates, [[nitrosoureas]], [[tetrazines]] and [[aziridines]]."<ref name = "Lind_2011" />