Decreasing incidence of cervical adenocarcinoma in Ontario: Is this related to improved endocervical Pap test sampling?

Abstract

In many developed countries, the incidence of cervical cancer has decreased. These reductions have been specific to squamous cell carcinoma (SCC) and have not included adenocarcinoma (AC). Incidence of AC has increased steadily over the last 20 years. The intent of this article is to examine trends in cervical adenocarcinoma incidence in Ontario over a 20-year period in relation to screening practices. All cases of cervical cancer between 1981 and 2002 were extracted from the Ontario Cancer Registry (a population-based, provincial-wide database). Age-standardized incidence rates were calculated overall, by broad age groups and by morphological type (SCC and AC). Time trends were assessed using JoinPoint methodology. In Ontario, opportunistic cervical cancer screening has been accompanied by significantly decreased rates of SCC since at least 1981. Conversely, the incidence of AC rose by 3.1% per year (95% CI: 1.6%, 4.6%) between 1981 and 1995, and subsequently declined by 4.0% per year (95% CI: 27.4%, 20.5%). From the mid-to late-1990s, instructions were distributed to clinicians, reinforcing the importance of dual specimen collection (i.e. using both spatula and endocervical brush). At the same time, laboratories routinely provided physicians with kits that included both spatula and brush. The subsequent decline in AC incidence may be due, in part, to improved specimen collection. As well, the decline may be partly due to increased awareness of AC precursors among cytopathologists and clinicians, and/or improvements in laboratory training and quality assurance. ' 2006 Wiley-Liss, Inc.

Significant decrease of adenocarcinoma in situ not reflected in cervical adenocarcinoma incidence in the Netherlands 1989–2003

“…This unchanged AC incidence contrasts with the incidence rates reported from other countries where it is rising (Zheng et al, 1996;Vizcaino et al, 1998;Bergstrom et al, 1999;Plaxe and Saltzstein, 1999;Smith et al, 2000;Liu et al, 2001;Sasieni and Adams, 2001;Visioli et al, 2004;Wang et al, 2004;Bray et al, 2005). However, a stable pattern has been reported more often (Vizcaino et al, 1998;Chan et al, 2003;Bulk et al, 2005), although a decreasing incidence has also been recorded (Vizcaino et al, 1998;Bray et al, 2005;Howlett et al, 2007). Studies covering the years after 1995 more often found a decrease in AC incidence after an earlier increase; for example, Howlett et al (2007) found an increase in AC incidence from 1981 to 1995 and a decrease in incidence from 1995 to 2001.…”

“…In a study of the screening history and risk of AC, it was concluded that AC incidence should begin to decline in the current decade among screened women (Mitchell et al, 2003). Our study included data from 1989 to 2003, the second study to incorporate years after 2000 (Howlett et al, 2007). The significant decrease of ACIS incidence in this study contrasts with two other studies describing an increase, mainly in patients under age 40 years (Plaxe and Saltzstein, 1999;Wang et al, 2004).…”

“…However, a stable pattern has been reported more often (Vizcaino et al, 1998;Chan et al, 2003;Bulk et al, 2005), although a decreasing incidence has also been recorded (Vizcaino et al, 1998;Bray et al, 2005;Howlett et al, 2007). Studies covering the years after 1995 more often found a decrease in AC incidence after an earlier increase; for example, Howlett et al (2007) found an increase in AC incidence from 1981 to 1995 and a decrease in incidence from 1995 to 2001. This was attributed to the change in the sampling device used; the endocervical brush was introduced to replace the spatula that focused only on the sampling of squamous cells.…”

Trends in the incidence of cervical cancer and severe precancerous lesions in Denmark, 1997–2012

“…& Susanne K. Kjaer susanne@cancer.dk some developed countries, including Denmark [3,[5][6][7], although not in all [8][9][10]. In the late 1960s, the Nordic countries were some of the first to introduce organized cervical cancer screening [11].…”

Incidence and mortality trend of cervical cancer in 11 cancer registries of China

“…According to Globocan2002, the estimated incidence cases in the world was 493,243 with 83.0% of new cases in the less developed countries [1] . In recent decades, the incidence rates of cervical cancer showed a decreasing trend in many countries [2][3][4] . China, as a less developed country with huge population, the incidence and mortality rate of cervical cancer there was a decreasing trend in the period of 1970-1990 [5][6] .…”