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MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENSE
Medical military academy

DOAN TRONG TRUNG
RESEARCH
SOCIAL, ENVIRONMENTal FACTORS RELATING TO
CERVICAL CANCER IN SOME NORTHErN PROVINCES

Specialization: Social sanitation and health organization
Code: 62.72.73.15
SUMMARY OF MEDICAL DOCTORAL THESIS

HA NOI – 2012
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THE THESIS WAS COMPLETED:
Technical Supervisor:
1. Prof PhD. LUONG XUAN HIEN
2. Prof PhD. LE KHAC DUC
REVIEWER 1: Prof PhD. DANG DUC PHU
REVIEWER 2: Prof PhD. NGUYEN DUC VY
REVIEWER 3: Prof PhD. NGUYEN THI THU
This project will be defended at Doctoral Thesis Scoring Council
at Medical Military Academy
At: 8h30, 18 - 4 - 2012
The thesis can be found at:
- National Library
- Library of Medical Military Academy
- Medical Information Library
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RELATED PUBLISHED PROJECTS OF THE AUTHOR

of the thesis, there is no deep research analyzing model of cervical
cancer in Vietnamese women and the relevant factors including the
sterilization by Quinacrine. Only a few studies have focused on the
recognition of cervical cancer in the hospitals, or conduct research
screening cervical precancer of community in narrow areas.
Therefore, we conduct the topic "Research some social,
environmental factors related to cervical cancer in some northern
provinces" to respond above demands.
OBJECTIVES
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1) Describe the current situation of cervical cancer in 12
northern provinces in Vietnam, 2001-2006.
2) Identify some social, environmental factors related to
cervical cancer in research area.
PRACTICAL MEANING AND NEW CONTRIBUTION
OF THE PROJECT
The topic is urgent, practical, helping the health sector has new
discoveries about the characteristics of cervical cancer, an
association between cervical cancer and some factors which have not
been previously researched or insufficiently researched in Vietnam
in general and 12 mentioned provinces in particular.
The research results will be the scientific basis for policy
makers to develop policies, build up appropriate interventions and
proper health communication to prevent cervical cancer in the
community. This will contribute to improving the quality of health
care services for population in general and for women in particular.
The research results are also a scientific basis for clinical medical
staff to take as reference and put into applications in improving the
quality of care and treatment of cervical cancer.
STRUCTURE OF THE THESIS

death by this disease than other women. In addition, women who do
not have health insurance or themselves pay for medical care are at
higher risk of death from the disease.
According to research by Martinez, early sexual intercourse is
one of the factors that increases the risk of HPV infection. It was
found that cervical cancer related to external factors such as multiple
births, many abortions, STIs. The incidence of disease is detected at
high levels in women of child marriage and early birth giving,
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multiple births. Specifically, prostitutes, over 3 time married women
and women with ulcer in cervix have 7 times higher risk of getting
cancer than normal ones.
Quinacrine has been used as a contraceptive method in many
countries around the world. This method was first applied in Chile
and subsequently replicated in many countries, including Vietnam.
In Vietnam, the sterilization program for women of childbearing age
by Quinacrine has been done since 1989. By late 1993, the program
was stopped to reassess after receiving a letter from the World
Health Organization mentioned that Quinacrine can cause
gynecological cancer for users. So far this sterilization method has
not yet to be carried out again due to the above concern.
Worldwide, there have been some researches to find out the
correlation of Quinacrine with gynecological cancer issues. One of
them was the study of David C. Sokal (FHI) about the cancer risk for
women with Quinacrine sterilization in Chile by 1996. Although the
research have come up with the conclusion that there was no
possibility of Quinacrine causing cancer, but due to the sample size
of the study was not really big enough, the number of detected
cancer cases were small, so persuasiveness of the study was not
really high.

hospitals and identified through histological diagnosis or cytology.
+ Control group: Women without CC, randomly selected from
people who stay in the same villages or have same age group with
case group.
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2.3. Research Methodology
* Research Design: case – control study, in which case groups
included women with primary cervical cancer and control groups
included women without cervical cancer who lived in the same
villages / hamlets and in the same age group with responding cases
* Sample size of case group:
Calculated as following:
n=Z
2
(1-α/2)
{1/[p
1
(1-p
1
)] +1/[p
2
(1-p
2
)]
[ln(1-€)]
2
In which: p
1
is percentage of individuals exposing to risk
factors estimated for case group; p

case was conducted by histopathological examination, it is required
to diagnose the cases. In some specific situation, due to lack of
biopsy specimens, clinical diagnosis and cytology diagnosis methods
can be used.
* Handling specimens and cervical cancer diagnosis:
specimens after biopsy, surgery were fixed in formal 10%,
transferring to Citadel-2000 of Shandon. The specimen is then dyed,
read the optical microscope by the pathologist doctor with
experience at K Hospital in Hanoi. The final decision was evaluated
by the Confirm Board. The board includes three prestigious
professors of anatomy and clinical.
* Research Contents:
- Status of cervical cancer: Distribution of cervical cancer cases
in the study area (12 provinces), the type of cancer. Characteristics
of cervical cancer object on demographics, health, the use of
contraceptives, living habits, lifestyle.
- The relationship of cervical cancer with the social and
environmental factors, including demographics, health, living and
lifestyle
* The variables in the research:
The variables used in the research were divided into two
groups: Independent (The elements can be related to cervical cancer)
and the dependent variable (cervical cancer):
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The independent variables:
- Demographic and medical characteristics:
+ Age, education level, occupation, marital status…
+ The use of medical insurance card
+ Age of first pregnancy, number of living children, menstrual
status

Chart 3.2. The education level of women have cervical cancer
(n=611)
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Most cases of cervical cancer are found in women with primary
education (15.7%) and secondary education (62.2%), and a small
percentage of illiterate women (1.6%).
Chart 3.3. The occupation of women have cervical cancer (n=611)
Most of cervical cancer cases occur in farmer women (61.2%),
lowest percentage in women who had been soldiers (0.3%), the
remainder mainly worked administrative or sale field.
Table 3.1. The type of cervical cancer is detected
Type of cancer cases Number Percentage
1. Squamous cell carcinoma non keratinizing 407 66.6
2. Adenocarcinoma of cervix 73 11.9
3. Endometrioid adeno carcinoma 29 4.7
4. Adeno squamous cell carcinoma 30 4.9
5. Squamous cell carcinoma keratinizing 8 1.3
6. Mucous adenocarcinoma 28 4.6
7. Carcinoma of small cells 13 2.1
8. Clear cells carcinoma 7 1.1
9. Squamous carcinoma of crystal cells 7 1.1
10. Other 9 1.5
Total 611 100.0
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In some case of cervical cancer, Squamous cell carcinoma, non-
keratinizing account for the highest percentage (66.6%), other types
of cancer account for lower rates.
3.2. Factors associated with cervical cancer
Table 3.2. Association between education levels of women with cervical
cancer

28 92 1 -
There was no statistical difference between the groups of women
with technical intermediate education level or less and women with
college / university, with (p> 0.05).
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Table 3.3.
Association between
cigarette smoking
of women with cervical cancer

Cigarette
smoking
(>100 cigarettes)
Cancer
No
Cancer
OR
(95%CI)
p
Yes 8 17 1.42
(0.56-3.49)
>0.05
No 603 1816
Total 611 1833
There was no statistical difference in the rate of cervical cancer
among women who smoked more than 100 cigarettes in their whole
life compared to other groups.
Table 3.4.
Association between women have husband who
smoked

OR
(95%CI)
p
≥1000 cigarettes 300 520
2.49
(1.94- 3.20)
<0.05
<1000 cigarettes 120 518
Total 420 1038
The women have husband (or their partners living together) who
smoked more than 1000 cigarettes during cohabitation are at risk for
cervical cancer 2.49 times higher than the other women (p <0.05).
Table 3.6. Relationship between cervical cancer and smoke level of
their husband
The total number of
cigarettes smoked
Cance
r
No
Cancer
OR
(95%CI)
p
≥1000 cigarettes
210 380
2.15
(1.65-2.80)
<0.05
<1000 cigarettes 104 490
Total 314 890

(95%CI)
p
<22 year-old
226 535
≥22 year-old 376 1213
Never have pregnant 9 85
Total
611 1833
The women who had first-time pregnant at age less than 22 are at
risk for cervical cancer 1.36 times higher than women in other
groups (p <0.05).
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Table 3.9. Relationship between the number of partners / husbands of women
with their cervical cancer
Number of sexual
partners / husbands
Cancer
No
Cancer
OR
(95%CI)
p
≥2 sexual partners /
husbands
62 64
3.03
(2.11-4.36)
<0.05
1 sexual partners /
husbands

miscarriage
Yes
169 399
1.37
(1.11-1.69)
<0.05
No
442 1434
Number of
miscarriages
≥2 times 123 314 1.35
(0.88-2.06)
>0.05
1 time 44 83
forget 2 2
Total 169 399
Women who had miscarried are at risk for cervical cancer 1.37
times higher than other women (p <0.05). There is no finding about
the association between the number of miscarriages and cervical
cancer.
Table 3.12. Relationship between menstrual status with cervical cancer
Indicators
Canc
er
No
cancer
OR
(95%CI)
p
Age of first

OR
(95%CI)
p
Yes
316 724 1.64
(1.36-1.98)
<0.05
No
295 1109
Total 611 1833
Women with history of abortion are at risk for cervical cancer
1.64 times higher than other women (p<0.05).
OR= 2.15
CI=1.68-2.78
p<0.05
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Chart 3.5. Relationship between the number of abortions with
cervical cancer
The women with a history of more than 2 times abortion are at
risk of cervical cancer 1.34 times higher than women who aborted
only 1 times (p<0.05).
Chart 3.6. Relationship between Quinacrine sterilization with
cervical cancer
OR= 1.34
CI=1.01-1.77
p<0.05
OR= 1.34;
(CI=0.58-3.10)
p>0.05
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Yes
12 58
No
599 1775
Breast Cancer
Yes
2 5
No
609 1828
There is no statistical association between cervical cancer of
women and their other diseases: diabetes, high blood pressure,
cholelithiasis, hyperthyroidism, and breast cancer
.

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Table 3.15. The research factors associated with cervical cancer by
logistic regression analysis
Factors
(independent variables)
Beta
(SE)
OR
calibrate
P-
value
OR
crude
1. Smoking
status of their
husband

≥22 year-old - 1 -
6. < 22 year-old
0.36
(0.12)
1.34
**
(1.13-1.84)
0.003
7. History of
miscarriage
No - 1 -
8. Yes
0.26
(0.11)
1.30
*
(1.04-1.62)
0.01
9. Menstrual
Status
Menopause - 1 -
10. Menstruation
0.23
(0.10)
1.26
*
(1.02-1.55)
0.03
11. Ovaries
removed

(0.13)
1.66
***
(1.26-2.18)
0.000
17. Vaginal
douching
No - 1 -
1.93
(1.45-2.56)
Yes
0.44
(0.21)
1.56
*
(1.01-2.39)
0.04
Testing the suitability of statistical models (Hosmer& Lemeshow
test): χ
2
=1.32; df=8; p=0.99.
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*, ** and ***: Differences are statistically significant, respectively
p<0.05, p<0.01 and p<0.001
Analysis result of multivariate regression model showed that there
are associations between cervical cancer with 9 elements: smoking
status of their husband, number of sexual partners/husband, age of
first sexual intercourse, history of miscarriage , menstrual status,
ovaries removed surgery, abortion, history of genital infections and
vaginal douching (p<0.05).