title: Incidence of IP and risk of malignant transformation in the Swedish population 1960-2010.
abstract: The true incidence of inverted papilloma (IP) is not yet known. From hospital-based studies, its incidence has been estimated to approximately 0.5/100,000 person years. Earlier hospital case studies have shown that IP can undergo a malignant transformation in 1-53 %. The frequency of its malignant transformation on a population basis is unknown. To our knowledge, no standardised incidence ratio (SIR) has been reported for malignancies among IPs. This study aims to investigate these incidences on a population basis. Using the data from the Swedish Cancer Registry (SCR), we have identified patients with IP and patients with Squamous Cell Carcinoma (SCC) diagnosed between 1960 and 2010 in Sweden. Incidence of IP and incidence of SCC among patients with IP and SIR were analyzed. Eight hundred and fourteen patients with IP were identified. The incidence of IPs reported to the SCR increased from 1960 to 2010. In this cohort, SCC was overrepresented, as compared with the general population. The incidence of IP in the Swedish population seems to have increased.
authors.affiliation: Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden. Alexandra.elliot@karolinska.se.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Elliot
authors.affiliation: Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden.
authors.forename: Linda
authors.initials: L
authors.lastname: Marklund
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Niclas
authors.initials: N
authors.lastname: Håkansson
authors.affiliation: Institute of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Huan
authors.initials: H
authors.lastname: Song
authors.affiliation: Institute of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Weimin
authors.initials: W
authors.lastname: Ye
authors.affiliation: Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden.
authors.forename: Pär
authors.initials: P
authors.lastname: Stjärne
authors.affiliation: Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Karolinska Institutet, Karolinska University Hospital, 171 76, Stockholm, Sweden.
authors.forename: Lalle
authors.initials: L
authors.lastname: Hammarstedt-Nordenvall
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000473:pathology; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009669:Nose Neoplasms / Q000453:epidemiology* / Q000473:pathology; D018308:Papilloma, Inverted / Q000453:epidemiology* / Q000473:pathology; D012042:Registries; D017678:Sex Distribution; D013548:Sweden / Q000453:epidemiology
keywords: Incidence; Inverted papilloma; Neoplastic cell transformation; Registries; Squamous cell carcinoma