Cervical cancer in Canada: Changing patterns in incidence and mortality

Abstract

Data on incidence of cervical cancer by histologic subtype and mortality for the Canadian provinces of Ontario, Saskatchewan, and British Columbia were used to examine time trends by age, calender period, and birth cohort. Age-adjusted incidence rate of squamous cell carcinoma of the cervix decreased from 11.1 per 100,000 women in 1970-72 to 5.3 in 1994-96, while the rate for cervical adenocarcinoma increased from 1.1 per 100,000 women to 1.5 over the same period. Age-adjusted mortality rate declined from 7.9 per 100,000 women in 1953-55 to 1.9 in 1995-97. The patterns in age-specific mortality rates in 1953-72 were different from those in 1973-97; younger women experienced larger reductions in mortality during the earlier period while older women benefited to a greater extent during the latter period. Age-period-cohort modeling showed that cohort effects were responsible for the decreasing trends in incidence of squamous cell carcinoma of the cervix and increasing trends in adenocarcinoma, and both period and cohort effects account for the observed trends in mortality. The results suggest that Pap smear screening has played a significant role in the reduction in squamous cell cervical carcinoma. The causes for the increase in cervical adenocarcinoma are unclear.

Incidence and survival rate of women with cervical cancer in the Greater Amsterdam area

“…Previous studies have reported that cervical adenocarcinoma and its preinvasive stages are diagnosed less efficiently by Pap smear screening than squamous cell lesions (Mitchell et al, 1995;Stockton et al, 1997). In some countries, not only the absence of a decrease in incidence (Sigurdsson, 1993;Nieminen et al, 1995), but also increases in the incidence of cervical adenocarcinoma have been described in the presence of a screening programme (Bergstrom et al, 1999;Hemminki et al, 2001;Liu et al, 2001). One study even suggested an increase in incidence especially in younger women (Anttila et al, 1999), whereas older women were not affected by increases in the incidence rate of cervical cancer.…”

“…However, recent data suggest that the decrease in incidence is caused by a decrease of squamous cell carcinoma, while the incidence of adenocarcinoma of the cervix shows no change or sometimes even an increase (Anttila et al, 1999;Bergstrom et al, 1999;Hemminki et al, 2001;Liu et al, 2001).…”

Risk Factors for Cervical Cancer in a Sample Comprising Three Generations of Brazilian Women

“…European and North American trend studies demonstrated an increased incidence rate of cervical adenocarcinoma among women who were born between 1953 and 1957, and therefore were 30 -34 years old at the end of 70s and early 80s, compared to those who were born between 1937 and 1941. Furthermore, age cohort effect was also found in this population, revealing an increased adenocarcinoma incidence rates among young women [9] [10] [11].…”

The value of colposcopy, high risk HPV-DNA and histopathologic examination in the management of abnormal Pap smear results

“…Incidence and mortality in cervical cancer have decreased among the last 50 years with the widespread use of Papanicolaou (Pap) smear test, but not eliminated yet (2)(3)(4) . Detection of precancerous lesions has increased significantly with the use of cytological Pap smear screening; however, management of these abnormal results has raised concern.…”