CERVICAL CANCER- THE NEED FOR A COORDINATED NATIONAL
PREVENTION PROGRAMME.
Cervical cancer is caused by the sexually transmitted Human
Papilloma virus (HPV) which is the most common viral infection of the
reproductive tract. The majority of HPV infections resolve spontaneously and do
not cause symptoms or disease. However, long standing infection with specific
types of HPV (especially types 16 and 18) may lead to precancerous lesions
which may progress to cervical cancer if untreated [1].
About 275,000 women die every year from cervical cancer and
about 500,000 new cases are reported worldwide. It is an entirely preventable disease but the second largest
cancer killer of women in low and middle-income countries [2]. In the
United States, an estimated 12,200 women were expected to be diagnosed with the
disease in 2010, with about 4210 deaths [3]. This is a sharp contrast to most
developing nations which account for more than 85% of the global burden of the
disease. In these countries, it accounts for 13% of all female cancers with the
highest risk in regions of Eastern and Western Africa [4]. According to WHO
cervical cancer crisis global card of mortality attributable to cervical
cancer, Nigeria has the 10th highest rate with 22.9/100,000 [2].
The
main thrust of a comprehensive approach to cervical cancer prevention and
control involves using the natural history of the disease to identify
opportunities in relevant age groups so that effective interventions can be
delivered. The WHO has evolved four components of cervical cancer control key
to the development of cervical cancer prevention protocol. These components
include: primary prevention, early detection (through increased awareness and
organised screening programmes), diagnosis and treatment and palliative care
for advanced disease. The Nigerian national cancer control program which began in 2008
is scheduled to end in 2013 and with just over 1,400 girls vaccinated, the
program cannot be said to have reached most of the intended participants.
The WHO protocol most suitable and easily adaptable to
developing countries is that linked with the life course of the disease [2].
This method classifies the preventive strategies into primary, secondary and
tertiary prevention. The primary prevention aims at girls between the ages of
9-13 years, the secondary prevention aims at women older than 30 years and the
tertiary prevention is for all ages of women already diagnosed with cervical
cancer (i.e. therapeutic). The components of these prevention strategies can be
seen in Table 1.
Table 1:
|
1.
|
Primary prevention
|
·
HPV vaccination
·
Sexuality education tailored to age and culture
·
Condom promotion/provision
·
Male circumcision
|
|
2.
|
Secondary Prevention
|
·
Screening and treatment
·
HPV testing (types 16 and 18)
|
|
3.
|
Tertiary Prevention
|
·
Treatment of invasive cancer at any stage ( Ablative surgery,
radiotherapy, chemotherapy)
|
HPV
vaccination for girls between the ages of 9 to 13 years in developing countries
has not achieved the desired penetration. The factors affecting the effective
distribution of these vaccines in Nigeria include cost of vaccines,
availability of vaccines, acceptance by the local community and lack of
adequate monitoring and evaluation. The cost of a HPV vaccine ranges from $100
to $10 and this excludes the logistics cost of delivery. The cost of the
vaccines has been subsidized by GAVI (Global Alliance for Vaccines and
Immunisation) but is still out of the reach of families who spend less than
$1/day. The government and the philanthropic private sector need to further
subsidise the cost of these vaccines if the goal of reaching the target
population is to be met. These vaccines need to be given three times over 6 months
which is tasking for both health workers and vaccine recipients, and it could hamper
the availability of these vaccines if not regularly sourced from its country of
production. This could be solved by adequate remuneration for the vaccine
givers, incentives such as cash rewards, free school books, free food items and
so on for the girls and/or their parents when they enrol to receive the vaccine
and when they return to get the follow up doses. The immunization program could
be school based and targeted at the cluster of girls in each school especially
in areas where school enrolment is high. This method is encouraged because it
is less likely to miss any participant, the girls and boys are taught about
safe sexual practices together and the girls could form social groups to
encourage one another to finish their HPV vaccination.
Cultural
acceptance by the recipient community is important to the success of the
immunization program. These girls are underage and consent will have to be
sought from their parents for the immunization. Adequate enlightenment of the
parents/guardians is essential, not only for consent but because they also play
a huge role in counselling the girl child about her sexual behaviour and will
encourage her to complete her immunization. The use of mass public
enlightenment programmes, the support of community heads, religious leaders and
traditional rulers cannot be over emphasized here.
The
government has to ensure the safety and efficacy of the vaccines as well as
monitor its distribution. It is advocated that girls who have received the
vaccine be logged into a national database along with the girl’s age and the
vaccine dose number [5]. Where the infrastructure to do this is lacking, each
girl vaccinated can be given a card which is manually registered and ticked for
each dose given. Regular re-evaluation of the areas covered and mop up
vaccinations (if necessary) also need to be done.
The
secondary prevention methods are hinged on screening and treatment of
pre-cancerous lesions [5]. Screening is a public health intervention used on a
population at risk, or target population. Screening is not undertaken to
diagnose a disease, but to identify individuals with a high probability of
having or of developing a disease. Women targeted for screening may actually
feel very healthy and see no need to visit a health centre. Early detection and
treatment of precancerous lesions can prevent the majority of cervical cancers.
Screening programs should aim at high coverage (80%) of the population at risk
of the disease, appropriate follow up and management for those who test
positive on screening and accurate documentation to link programme components (
from screening to diagnosis to treatment).
Screening
programmes could be of the organised type or the opportunistic type. In the
organised type, the existing resources are targeted to reach the highest
possible number of women at the greatest risk of cervical cancer. It requires
national/regional planning and should specify the target population, screening
intervals, coverage goals, means of getting women to attend screening services,
the screening tests to be used, strategies to ensure that all women found
positive on screening are informed of their result, and ways of evaluating the
effectiveness of the screening programme. Opportunistic screening, on the other
hand, is done independently of an organised or population based programme on
women who visit health centres for other reasons. The test may be recommended
by the health care giver or requested by a woman. It is generally accepted that
organised screening is more cost-effective than opportunistic screening, makes
better use of available resources and ensures that the greatest number of women
benefit. However, both methods may be combined for optimal benefit.
Although
decisions on target age group and frequency of screening are usually made at
national/regional levels based on local prevalence/incidence of cervical
cancer, the WHO recommends that the 25-49 years age group be targeted. This is
because although HPV infection is common in younger women, most infections are
transient and it may take up to 10 years for a precancerous lesion to develop
into an invasive cancer. Screening every three years is nearly as effective as
yearly screening especially in resource-limited environments. Screening even
once between the ages of 35 and 45 years will significantly reduce deaths from
cervical cancer.
How
can this be effectively integrated into the Nigerian healthcare policy so as to
ensure effective use of allocated resources and adequate follow up? There must
be serious political will and support from the government with the provision of
resources alongside interested donor contributions. Activities that bring a
large cluster of this age group together e.g. National Youth Service Corps
(NYSC) camps, religious programmes/retreats and year-end women meetings should
be targeted for enlightenment and screening programmes. The Pap smear is still
the most widely accepted method for mass screening programmes. It is easy to
use, cost-effective, reproducible and convenient for the patient. Women with
positive test results are counselled and referred to accredited health care
centres for management which may include a biopsy or testing for high risk HPV.
It is important for records purposes that a national database be created to
accurately document the number of women who have been screened and to effectively
track their follow up. Each screened woman could be given a data card/data
number stating the year of present screening, the result of the test and the
time/year for the next scheduled screening.
Training
and re-training of health care staff involved in the counselling, screening and
treatment of women should be done regularly to ensure that the quality of the
screening and follow up process is not compromised.
In
conclusion, the following will serve as basic tenets for developing an
effective cervical cancer prevention programme in Nigeria:
·
Provision of free HPV vaccines for girls between 9-13 years of age.
·
Public enlightenment for boys and girls, men and women about safe
sexual practices via religious institutions and community oriented outreach.
·
An effective, coordinated cervical cancer screening programme
using pap smears aimed at a target population and planned for periods of
maximal impact.
·
Proper record keeping and detailed documentation of girls who have
been vaccinated and women who have been screened for effective and coordinated
follow up.
·
Training and retraining of health care staff involved in this
programme.
REFERENCES.
1.
.WHO
guidance note: comprehensive cervical cancer prevention and control: a
healthier future for girls and women. WHO 2013. http://apps.who.int/iris/bitstream/10665/78128/3/9789241505147_eng.pdf
2.
Cervical cancer global crisis card. http://www.cervicalcancerfreecoalition.org/wp-content/uploads/Cervical-Cancer-Global-Crisis-Card_2013.pdf
3.
McCune S, Teng N, Trimble CL, Valea F, Morgan S,
Reynolds RK et al. Cervical cancer screening. J Natl Compr Canc Netw 2010; 8:
1358-1386.
4.
Ferlay J, Shin HR, Bray F, Forman D, Mathers C,
Parkin DM. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. Int
J Cancer 2010; 127: 2893-2917.
5.
Comprehensive cancer control: a guide to
essential practice. WHO 2006. http://whqlibdoc.who.int/publications/2006/9241547006_eng.pdf
