The term "field cancerization" was first used in 1953 to describe an area or "field" of epithelium that has been preconditioned by (at that time) largely unknown processes so as to predispose it towards development of cancer. Since then, the terms "field cancerization" and "field defect" have been used to describe pre-malignant tissue in which new cancers are likely to arise.Field defects are important in progression to cancer. However, in most cancer research, as pointed out by Rubin “The vast majority of studies in cancer research has been done on well-defined tumors in vivo, or on discrete neoplastic foci in vitro. Yet there is evidence that more than 80% of the somatic mutations found in mutator phenotype human colorectal tumors occur before the onset of terminal clonal expansion. Similarly, Vogelstein et al. point out that more than half of somatic mutations identified in tumors occurred in a pre-neoplastic phase (in a field defect), during growth of apparently normal cells. Likewise, epigenetic alterations present in tumors may have occurred in pre-neoplastic field defects.An expanded view of field effect has been termed "etiologic field effect", which encompasses not only molecular and pathologic changes in pre-neoplastic cells but also influences of exogenous environmental factors and molecular changes in the local microenvironment on neoplastic evolution from tumor initiation to patient death.In the colon, a field defect probably arises by natural selection of a mutant or epigenetically altered cell among the stem cells at the base of one of the intestinal crypts on the inside surface of the colon.
Fluocinolone acetonide is a corticosteroid primarily used in dermatology to reduce skin inflammation and relieve itching. It is a synthetic hydrocortisone derivative. The fluorine substitution at position 9 in the steroid nucleus greatly enhances its activity. It was first synthesized in 1959 in the Research Department of Syntex Laboratories S.A. Mexico City. Preparations containing it were first marketed under the name Synalar. A typical dosage strength used in dermatology is 0.01–0.025%. One such cream is sold under the brand name Flucort-N and includes the antibiotic neomycin. Fluocinolone acetonide was also found to strongly potentiate TGF-β-associated chondrogenesis of bone marrow mesenchymal stem/progenitor cells, by increasing the levels of collagen type II by more than 100 fold compared to the widely used dexamethasone.Fluocinolone acetonide intravitreal implants have been used to treat non-infectious uveitis. A systematic review could not determine whether fluocinolone acetonide implants are superior to standard of care treatment for uveitis. A fluocinolone acetonide intravitreal implant with the brand name Iluvien is sold by biopharmaceutical company Alimera Sciences to treat diabetic macular edema (DME).It was approved for medical use in 1961. Classification
Fluocinolone is a group V (0.025%) or group VI (0.01%) corticosteroid under US classification. See also
Topical steroid
Fluocinonide
Ciprocinonide
Glucocorticoid

References
External links
"Fluocinolone acetonide". Drug Information Portal. U.S. National Library of Medicine.