The incremental benefits of implementing effective cervical cancer screening

Cancer mortality in the Capitals and in the interior of Brazil: a four-decade analysis

OBJECTIVE:

to describe the trend of mortality from general cancer and more frequent types among men and women living in the Capitals and other municipalities of the five macro-regions of Brazil between 1978 and 2017.

METHODS:

Time series study with mortality data corrected by redistribution of ill-defined causes. Proportional cancer mortality was calculated for Brazil and regions. The annual percentage change in rates for total cancer and specific types in each segment and in the selected unit of analysis was calculated by generalized linear regression with Gaussian binding.

RESULTS:

the proportion of cancer increased progressively for both sexes from 1978 to 2017. Important differences between the Capitals and the interior of the macro-regions were seen with disaggregated data. The greatest declines occurred for stomach cancer, except in the northern and interior regions of the Northeast, and for the cervix cancer, with a generalized fall, with the exception of the interior of the northern region. Lung cancer decreased among men in the Southeast and South regions and had a generalized increase among women. Breast and prostate cancers tended to decrease in the Southeast and South regions and among residents of the Capitals but showing an increase in the interior of the North and Northeast regions. Colorectal cancer had a general tendency to increase; with stability among men in the Capitals of the South region and among women of the Southeast and Midwest regions and, since 2007, a decrease among women in the South region.

CONCLUSIONS:

Cancer mortality showed great variation among residents of capitals and the interior of the country's major regions. Clear decrease in mortality was seen for the main types in the Southeast and South regions. The North and Northeast regions have patterns compatible with cancers associated with poverty, while the large increase of the cancers related to sedentary lifestyle stand out.

A preliminary cervical cancer screening cascade for eight provinces rural Chinese women: a descriptive analysis of cervical cancer screening cases in a 3-stage framework

Background:

Cascade analysis is an effective method to analyze the processing data of an event, such as a provided service or a series of examinations. This study aimed to develop a primary cervical cancer screening cascade in China to promote the quality of the screening process.

Methods:

We designed a cervical cancer screening cascade in China according to the program flow chart. It had three stages, each with two steps and one result. Data from 117,522 women aged 35 to 64 years in the Rural Cervical Cancer Surveillance Project from January 1, 2014, to December 31, 2014, were collected to analyze the main results of the cascade. The data and proportion are used to describe the follow-up of cervical cancer and pre-cancer detection rate.

Results:

In 2014, 117,522 (80.94% of all cases reported by the Rural Cervical Cancer Surveillance Project) women aged 35 to 64 years had not received cervical cytology in the previous 3 years. The pre-cancer and cancer detection rates were 256.12/100,000 and 16.16/100,000, respectively. A total of 3031 cases failed to follow-up through the screening process, and 1189, 1555, and 287 cases were lost at cervical cytology, colposcopy, and histopathological screening stages, respectively. The estimated cases of pre-cancer and cancer cases would have been 544 and 34, respectively, and the estimated detection rates of pre-cancer and cancer would have been 462.89/100,000 and 28.93/100,000, respectively.

Conclusion:

In order to increase the detection rate of cervical cancer, cervical cancer screening staff should focus on increasing the rate of follow-up of those who are positive for cervical cancer screening (ie, those with positive cytology results), especially for the 40 to 44 years age range.

Estimating the impact of an organised screening programme on cervical cancer incidence: A 26-year study from northern Italy

The impact of the organised cervical cancer (CC) screening programmes implemented in Europe since the 1990s has been insufficiently evaluated. We investigated the changes in CC incidence following the introduction of a screening programme in the Emilia-Romagna Region (northern Italy). The study period was 1988-2013. The programme, targeting women aged 25-64 years (1,219,000 in 2018), started in 1998. The annual incidence rates that would be expected in 1998-2013 in the absence of screening were estimated, first, by analysing the annual rates in 1988-1997 with a log-linear model and, second, by analysing the annual rates in 1988-2013 with an age-period model in which the period effect was enforced to be linear. Cervical adenocarcinoma incidence trend over the entire period was used to validate both estimates. Observed annual rates were compared to the two series of expected ones with the incidence rate ratio (IRR). Incidence remained stable during 1988-1997, peaked in 1998 and then decreased until 2007, when it stabilised. The two series of expected rates were virtually coincident and their trends roughly paralleled the stable adenocarcinoma incidence trend. After 2007, the median IRR was 0.60 (95% confidence interval, 0.45-0.81) based on the log-linear model and 0.58 (95% confidence interval, 0.34-0.97) based on the age-period model. Thirty-six to seventy-five CC cases were prevented annually for an average annual frequency of 6.5 per 100,000 women in the target population. In summary, consistent circumstantial evidences were obtained that the organised screening programme brought about a 40% reduction in annual CC incidence after 10 years.

Preventable fractions of cervical cancer via effective screening in six Baltic, central, and eastern European countries 2017-40: a population-based study

BACKGROUND

Cervical cancer incidence remains high in several Baltic, central, and eastern European (BCEE) countries, mainly as a result of a historical absence of effective screening programmes. As a catalyst for action, we aimed to estimate the number of women who could be spared from cervical cancer across six countries in the region during the next 25 years, if effective screening interventions were introduced.

METHODS

In this population-based study, we applied age-period-cohort models with spline functions within a Bayesian framework to incidence data from six BCEE countries (Estonia, Latvia, Lithuania, Belarus, Bulgaria, and Russia) to develop projections of the future number of new cases of cervical cancer from 2017 to 2040 based on two future scenarios: continued absence of screening (scenario A) versus the introduction of effective screening from 2017 onwards (scenario B). The timespan of available data varied from 16 years in Bulgaria to 40 years in Estonia. Projected rates up to 2040 were obtained in scenario A by extrapolating cohort-specific trends, a marker of changing risk of human papillomavirus (HPV) infection, assuming a continued absence of effective screening in future years. Scenario B added the effect of gradual introduction of screening in each country, under the assumption period effects would be equivalent to the decreasing trend by calendar year seen in Denmark (our comparator country) since the progressive regional introduction of screening from the late 1960s.

FINDINGS

According to scenario A, projected incidence rates will continue to increase substantially in many BCEE countries. Very high age-standardised rates of cervical cancer are predicted in Lithuania, Latvia, Belarus, and Estonia (up to 88 cases per 100 000). According to scenario B, the beneficial effects of effective screening will increase progressively over time, leading to a 50-60% reduction of the projected incidence rates by around 2040, resulting in the prevention of cervical cancer in 1500 women in Estonia and more than 150 000 women in Russia. The immediate launch of effective screening programmes could prevent almost 180 000 new cervical cancer diagnoses in a 25-year period in the six BCEE countries studied.

INTERPRETATION

Based on our findings, there is a clear need to begin cervical screening in these six countries as soon as possible to reduce the high and increasing incidence of cervical cancer over the next decades.

FUNDING

None.