title: Changes in trends in colorectal cancer incidence rate by anatomic site between 1978 and 2004 in Japan.
abstract: Although colorectal cancer (CRC), a major type of cancer worldwide, has shown a proximal or right-sided shift in subsite distribution in western countries, trends in subsite incidence in Asian countries remain unclear. Here, we evaluated subsite-specific trends in CRC incidence rate between 1978 and 2004 in Japan using large data from 10 population-based cancer registries. The colorectal sites (C18-C20) were categorized into three groups: proximal colon (C18.0-C18.5), distal colon (C18.6-C18.7), and rectum (C19.9 and C20.9). Trends in age-standardized incidence rates (ASRs) were characterized by joinpoint regression analysis. A total of 303 802 CRC cases were analyzed. Overall, ASRs increased remarkably until 1993, with an annual percentage change (APC) of 4.9%, and then stabilized thereafter. By subsite, however, ASRs of proximal colon significantly increased, with APCs of 7.1% (1978-1991), 3.8% (1991-1996), and 0.9% (1996-2004); distal colon showed an initial significant increase, with an APC of 7.6%, but stabilized from 1991 until the end of observation; and rectal cancer showed an initial significant increase, with APCs of 1.9% (1978-1988) and 5.6% (1988-1992), but then decreased abruptly in 1992, the year CRC screening was introduced nationwide, with an APC of -1.0%. Thus, we revealed that changes in incidence trends for the three anatomic sites apparently began to differ in the 1990s. Careful monitoring is necessary to confirm whether these trends are changing in the Japanese population.
authors.affiliation: aDivision of Epidemiology and Prevention, Aichi Cancer Center Research Institute bDepartment of Epidemiology, Nagoya University Graduate School of Medicine, Nagoya cChiba Cancer Center, Chiba dDepartment of Cancer Therapy Center, Fukui Prefectural Hospital, Fukui eDepartment of Epidemiology and Public Health, Kanazawa Medical University, Kanazawa fDepartment of Epidemiology, Radiation Effects Research Foundation, Hiroshima and Nagasaki gCenter for Cancer Control and Statistics, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Hidemi
authors.initials: H
authors.lastname: Ito
authors.forename: Satoyo
authors.initials: S
authors.lastname: Hosono
authors.forename: Isao
authors.initials: I
authors.lastname: Oze
authors.forename: Haruo
authors.initials: H
authors.lastname: Mikami
authors.forename: Masakazu
authors.initials: M
authors.lastname: Hattori
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Nishino
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sugiyama
authors.forename: Kayo
authors.initials: K
authors.lastname: Nakata
authors.forename: Hideo
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000367:Age Factors; D000368:Aged; D015179:Colorectal Neoplasms / Q000145:classification* / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012042:Registries / Q000706:statistics & numerical data*; D012737:Sex Factors; D015996:Survival Rate; D013997:Time Factors