prophylaxis and cervical screening in bulgaria- past, problems and future dr. petya kostova, phd...
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PROPHYLAXIS AND CERVICAL SCREENINGIN BULGARIA- PAST, PROBLEMS AND FUTURE
Dr. Petya Kostova, PhDGynecology Clinic,
National Oncology Hospital, Sofia; Bulgaria
Assoc. Prof. Dr V. Zlatkov, PhDGynecology Clinic,
National Transport Hospital “King Boris III”, Sofia, Bulgaria
Significance of the problem (1)
Cervical cancer is one of the most common malignant diseases in the world with annual occurrence of 500 000 cases. It is placed 5th with its share of 7.3% of the total number of localizations in both sexes.
According to the WHO, 15% of all cancers in women belong to cervical cancer, about 20% of which are found in the developed countries and 80% in the developing countries.
Significance of the problem (2)
Cancer Registry
2002
Bulgariatotal
of them women
of them
еndometrial,
cancer
cervical,
ovarian
patients
number % number %Cancer patients
216 881 127 227 58.7 32 242 25.3
New cases 29 435 14 051 47.7 3 001 21.4
Dead 15 785 6 595 41.8 895 13.8
24.6 24.3
3.94.7
5.15.47.1
9.7
7.5
7.7
0
5
10
15
20
25
30
Sites
%
Structure of cancer incidence in female Bulgaria (2001)
Primary prophylaxis
It requires control and elimination of the etiopathogenesis of the disease.
There are no effective methods for sexual behavior regulation.
Over the past years, the effectiveness of preventive vaccines against HPV infections has been discussed:
Cervarix® (GlaxoSmithKline) Gardasil® (Merck)
Secondary prophylaxis
Its aim is to detect and eliminate precancer states or early malignancies
It is performed on women with complaints and without clinical symptoms (screening).
Types of screening
• population based & selective
• organized & opportunistic
• multi-phase & one-procedure
The principles of secondary prophylaxis
The disease, object of screening, should be a medico-social problem (with high incidence and mortality);
Its clinical course should be well known, with a preclinical phase corresponding to a biologically less aggressive period of development;
The screening test should be simple to use, safe, cheap, with high sensitivity, specificity and predictive value;
The treatment of the patients, diagnosed during the screening, to be effective and to reduce mortality.
Preventive effect of cervical screening
Frequency of screening
Reduction of cumulative risk
Number of tests
1 year 93.3 % 30
2 years 92.5 % 15
3 years 91.4 % 10
5 years 83.9 % 6
10 years 64.2 % 3
Possible results
When organized screening cover 70% of the target population, it is possible to achieve the following results:
30% of cancer cases to be actively detected
30% of the advanced cancer cases can be decreased
• >15% of mortality at screening localizations can be reduced
History of the screening in Bulgaria
Since 1956, prophylactic gynecological examinations have been conducted in Bulgaria .
K.Tsanev and D.Nikolova (1970) - introduced cytological screening as a routine test.
CERVICAL
SCREENING
NOC-Sofia Regional DOZ
Women
under 30 years
Women
over 30 years
District
Ob/Gyn
Examination
PAP smear
(+) test(-) test
Colposcopy
Precancer CancerNormal finding
Cytological
laboratry
Past scheme
in Bulgaria
General principles
The screening program involves all women over 30 years of age, both married and single, and is performed once every two years.
It is conducted by district gynecologists and nurses. Diagnostic cytological tests are performed in 14 laboratories based at the district oncological centers and the National Oncological Center.
According to the screening program, 1.5 mill. women are subject to examination.
Incidence of cervical cancer in Bulgaria (1970-2002)
0
5
10
15
20
25
30
Year
105
Crude
Standardized
An increase in the crude incidence was observed (An increase in the crude incidence was observed (12.7 12.7 to to 26.26.99 % %оооооо).).The same tendency was observed for the standardized incidence from The same tendency was observed for the standardized incidence from 10.0 to 19.4 10.0 to 19.4 %%оооооо women. women.
Incidence according to age, residence and districts
Incidence (1970-1996) arise in all age groups (р<0.05), especially at 30-49 years.
Incidence (1981-1996) is higher at towns than in villages (р<0.05)
Standardized cervical cancer incidence (1991-1996 г.) varies according to districts from 6.1%ооо tо 23.1%ооо women.
Incidence of cervical cancer worldwide
Incidence
Levels Countries/regions Registries (x 10 5)
Low from 3 to 9 x 10 5 Scandinavian,USA,Canada, England, Israel
Finland (3.62), USA (4.05)
Medium from 10 to 20 x 10 5 Parts of EC, Central Europe, Japan, Australia and some in Asia
Australia (12.5) Japan (16.0) Slovenia (18.5)
High from 21 to 30 x 10 5 South-East Europe, Russia Bulgaria- (26.9)
Poland (23.8) Russia (28.6)
Very high Over 30 x 10 5 South America, Africa Zimbabwe (67.21) Brazil (64.78)
Effect of screening on incidence (Scandinavian countries)
M.Hakama, K.Louhivuori (1988)
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
1945 1950 1955 1960 1965 1970 1975 1980 1985
Years
per
105
Denmark
Norway
Iceland
Sweden
Finland
Mortality of cervical cancer in Bulgaria (1970-2002)
0
2
4
6
8
10
12
Year
105
Crude
Standardized
An increase in the crude mortality was observed, reaching from An increase in the crude mortality was observed, reaching from 3.2 3.2 ttо о 99..88 % %оооооо..The same was tendency for the standardized index-from 3.1 to 6.2 The same was tendency for the standardized index-from 3.1 to 6.2 %%оооооо women. women.
Mortality of cervical cancer worldwideCOUNTRIES Stand. mortality
(%ооо) Israel 1.42
Japan 1.98
USA 2.70
Finland 3.00
Germany 3.51
Bulgaria 6.2
Poland 8.23
Romania 10.01
Venezuela 10.51
Chile 14.87
2
3
4
5
6
7
8
9
1970 1975 1980 1985 1990 1995 2000 2005
Bulgaria
United Kingdom
EUROPE
EU average
Nordic average
Screening results Effect on mortality in Europe
19
75
19
77
19
79
19
81
19
83
19
85
19
87
19
89
19
91
19
93
19
95
19
97
19
99
20
01
0
5
10
15
20
25
30
Years
105
CaCIS
Ratio between the patients with CIS and cervical cancer in Bulgaria (1975-2002)
Ratio between the cancer in situ and invasive cancer for the studied period shows bigger frequency of invasive forms and the arisal of this ratio during the study period.
Ratio CIS / Ca (1)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
ЕС Bulgaria
CISCa
Most important is the comparison to EC countries. The ratio between CIS
and invasive cancer is 3/1 in favour of in situ forms in EC. In Bulgaria,
is the opposite. It is 5/1 due to the higher level of invasive cancer.
Ratio CIS / Ca (2)
In the USA 55-60 mill. Pap tests are completed every year,
the cost for them being $ 6 bln.
Per year
AGC-180 000
HSIL 300 000
LSIL–2 mill. women
ASCUS – 3 mill. women
Deaths - 3800
Cancer - 10300USA
Stage distribution of cervical cancer in Bulgaria (1970-2002)
0
100
200
300
400
500
600
700
800
Year
Number
stages I+II
stages III+IV
without stage
For the whole studied period we cannot observe any improvement of level of early diagnostics with stable high level of advanced cases.
Screening coverage About 1.5 mill women were screened annually until 1989, after which there was a
progressive drop and only 205 081 screening tests were reported in 1996.
0
20
40
60
80
100
120
%
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Oncological dispensaries
mean for the period
1980
1995
Legend: 1-Blagoevgrad; 2-Burgas; 3-Varna; 4-V. Тarnovо; 5-Vratsa; 6-Pleven; 7-Plovdiv; 8-Russe; 9-Sofia-city.; 10-Sofia-reg.;11-St. Zagora; 12-Shumen; 13-Haskovo; 14-Bulgaria
Share of women with biopsy The share of biopsies among the signalized women is low about 1/3, except 3 centers where it is more than 50%. This means that many women do not pass the step of precise diagnostics.
0100200
300400500600700
800900
1000
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Oncological dispensaries
Number
signalized
with biopsy
Legend: 1-Blagoevgrad; 2-Burgas; 3-Varna; 4-V. Тarnovо; 5-Vratsa; 6-Pleven; 7-Plovdiv; 8-Russe; 9-Sofia-city.; 10-Sofia-reg.;11-St. Zagora; 12-Shumen; 13-Haskovo; 14-Bulgaria
Problems of organization
They are connected with the following :
No team for management of the programme
No screening registry Lack of call and recall system No unified system for diagnostics of
signalized women No quality control on all screening levels.
Problems of test
Monitoring quality of cervical smears Adequate preparation and storage of smears at
laboratories Timely cytological answer to clinicians Registration of results in screening registry
Problems of interpretation
The need of unified
cytological classification
The introduction of internal
and external quality control
at cytological laboratories
The continuous training and
education of staff
4
3
2
1
Over the past 10 years, different teams of the Ministry of Health have initiated the development of new cervical screening programme.
One of these teams, under the guidance of prof. Chernozemski and with our participation, created “The National Strategy for Prophylactic Oncological Screening in Bulgaria for the period 2001-2006” for the three main screening localizations - breast, uterine cervix and prostate.
It was accepted by a decree of the Council of Ministers № 880 / 22.12.2000, but it could not be realized in practice.
Attempts at change
Recent situation
Selectiveopportunistic
screening
Selectiveopportunistic
screening
CashPayment
(? Women)
CashPayment
(? Women)
Population
screening
Population
screening
Secondary
prophylaxis
?
Opportunistic
screening
Opportunistic
screening
HealthInsurance
system
HealthInsurance
system
80 000 women
HealthInsurance
system
HealthInsurance
system
Gynecologist GP / GynecologistGynecologist
Necessary changes
Restoration of the organized population cervical screening as a component of the health system.
Building a structure for management and screening registry.
Introduction of unified terminological system.
Establishment of quality control at cytological laboratories.
System for continuous education.
The basic components of the future cervical screening programme
QualificationQualification
ManagementManagement
EducationEducation
Efficiency &effectiveness
Efficiency &effectiveness
Qualitycontrol
Qualitycontrol
Cervicalscreening
Target and interval
Recommended target population is 1.8 mill. women (25-60 years)
The screening interval should be 3 years.
Potential prices of cervical screening
According to world standards the mean value of one conventional screening examination is 10 €.
In our country this price is lower, around 10 leva (5 €), because of lack of realistic assessment of human labor, overheads, and equipment value.
Prices of cervical cancer treatment according to stage for one year
Cervical cancerStages
Number of cases in Bulgaria (2001)
Prices according to EU data(Andrae Bengt - 2004)
Per item Total
St. III – IV 347 30 000 € 10 410 000 €
St. I – II 670 9 000 € 6 030 000 €
CIS 275 300 € 83 500 €
Total 1292 - 16 522 500 €
Which price is better ?
If the target population (25 - 60 years) is 1.8 mill, its full coverage will cost 9 mill €.
If screening interval is 3 years, it will cost 3 mill € yearly.
Treatment of cancer cases
for one year –
about 16 mill €.