Editing Malignancy (section)

{{Short description|Tendency of a medical condition to become progressively worse}}
{{For|the band|Malignancy (band)}}
{{Redirect|Malignant}}
{{use dmy dates|date=May 2025}}
{{Infobox medical condition (new)
| name          = Malignancy
| image         = Types of tumor cells.jpg
| caption       = {{smaller|Malignant tumor (''right'') spreads uncontrollably and invades the surrounding tissues; benign tumor (''left'') remains self-contained from neighbouring tissue}}
| field         = [[Oncology]]
| synonyms      = [[Cancer]], malignant [[neoplasm]]
| pronounce     = 
| symptoms      = Fatigue, lump(s), change in skin, abnormal bleeding, prolonged cough, unexplained [[weight loss]]<ref name = "Martin_2020">{{cite web |vauthors=Martin LJ |date=2020 |title=Cancer Symptoms |publisher=[[WebMD]] |department=Cancer Centre |url=https://webmd.com/cancer/guide/understanding-cancer-symptoms}}</ref>
| complications = 
| onset         = 
| duration      = 
| causes        = 
| risks         = Smoking, sun exposure, genetics—history of malignancy, solid organ transplantation (post-transplant malignancy), [[infectious diseases]]
| diagnosis     = [[Biopsy]]
| differential  = 
| prevention    = 
| treatment     = [[Photoradiation therapy]], surgery, [[chemotherapy]], hyperthermia
| frequency     = 442.4 per 100,000 per year <ref>{{cite web |publisher=[[National Cancer Institute]] |title=Cancer Statistics |date=2015-04-02 |url=https://cancer.gov/about-cancer/understanding/statistics}}</ref>
| deaths        = {{circa|10 million}} per year<ref name = "WHO_Cancer">{{cite web |publisher=[[World Health Organization]] |title=Cancer |url=https://who.int/news-room/fact-sheets/detail/cancer |department=Factsheets |date=2021-09-21}}</ref>
}}

'''Malignancy''' ({{etymology|la|{{wikt-lang|la|male}}|badly||{{wikt-lang|la|-gnus}}|born}}) is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of [[cancer]].

A ''malignant'' tumor contrasts with a non-cancerous [[benign tumor|'''''benign''''' tumor]] in that a malignancy is not self-limited in its growth, is capable of invading into adjacent tissues, and may be capable of spreading to distant tissues.

A [[benign tumor]] has none of those properties, but may still be harmful to health. The term '''benign''' in more general medical use characterizes a condition or growth that is not cancerous, i.e. does not spread to other parts of the body or invade nearby tissue. Sometimes the term is used to suggest that a condition is not dangerous or serious.<ref>{{cite web | title=Benign Information |publisher=Mount Sinai Health System |url=https://www.mountsinai.org/health-library/special-topic/benign | access-date=23 May 2023}}</ref>

Malignancy in cancers is characterized by [[anaplasia]], invasiveness, and [[metastasis]].<ref>{{cite book | vauthors = Wilkins EM | chapter = The Patient with Cancer  |title=Clinical Practice of the Dental Hygienist Workbook |date=April 2008 |publisher=Lippincott Williams & Wilkins |isbn=978-1-58255-838-7 | pages = 858–869 }}</ref> Malignant tumors are also characterized by [[genome instability]], so that cancers, as assessed by [[whole genome sequencing]], frequently have between 10,000 and 100,000 mutations in their entire genomes.<ref name="pmid23178448">{{cite journal | vauthors = Tuna M, Amos CI | title = Genomic sequencing in cancer | journal = Cancer Letters | volume = 340 | issue = 2 | pages = 161–170 | date = November 2013 | pmid = 23178448 | pmc = 3622788 | doi = 10.1016/j.canlet.2012.11.004 }}</ref>  Cancers usually show [[tumour heterogeneity]], containing multiple subclones.<ref name="pmid23002210">{{cite journal | vauthors = Swanton C | title = Intratumor heterogeneity: evolution through space and time | journal = Cancer Research | volume = 72 | issue = 19 | pages = 4875–4882 | date = October 2012 | pmid = 23002210 | pmc = 3712191 | doi = 10.1158/0008-5472.CAN-12-2217 }}</ref> They also frequently have reduced expression of DNA repair enzymes due to [[Epigenetics#DNA repair epigenetics in cancer|epigenetic]] methylation of DNA repair genes or altered [[MicroRNA#DNA repair and cancer|microRNAs]] that control DNA repair gene expression.

Tumours can be detected through the visualisation or sensation of a lump on the body.<ref name = "Brazier_2019">{{cite web | vauthors = Brazier Y | date = 21 August 2019 | title = What are the different types of tumor? | work = Medical News Today | url = https://www.medicalnewstoday.com/articles/249141 }}</ref> In cases where there is no obvious representation of a lump, a [[Mammography|mammogram]] or an [[MRI|MRI test]] can be used to determine the presence of a tumour.<ref name = "Brazier_2019" /> In the case of an existing tumour, a [[biopsy]] would then be required to make a diagnosis and distinguish whether the tumour is malignant or benign.<ref name = "Brazier_2019" /> This involves examination of a small sample of the tissue in a laboratory.<ref name = "Brazier_2019" /> If detected as a malignant tumour, treatment is necessary; treatment during early stages is most effective.<ref name = "Brazier_2019" /> Forms of treatment include chemotherapy, surgery, photoradiation, and hyperthermia, amongst various others.