Background
to the
Research
- Cancer is a major cause of illness and
premature death in Northern Ireland. One in three people will get cancer
and one in four will die from it.
- Until recently, cancer research, the
planning and evaluation of cancer services and epidemiological data
on cancer in NI have been inhibited by a lack of accurate and up to
date information. The NI Cancer Registry was set up in May 1994 and
replaced the DHSS Registry which began in 1959. The new registry is
funded by the DHSS and the Ulster Cancer Foundation.
Research
Approach
- The computer systems of HPSS hold much
of the data needed for cancer registration in Northern Ireland. The
new Registry collates and analyses data from this and a variety of sources
in NI. These include the 13 hospitals Patient Administration systems,
the Registrar General's Office, the 8 Radiology sites, the Central Services
Agency's GP records of deceased patients, various disease specific registries
and the 5 pathology laboratories.
Main Findings
All
Cancers (1993-1995)
- Over the period, on average 8,500
cancers per year were registered, with males having a higher overall
rate than females. Lung, prostate and colorectal cancers were the most
common cancers in men and non-melanoma skin cancers, breast, colon and
lung cancer were the most common cancers in women. Non-melanoma skin
cancer accounted for 25% (2,260) of all cancers diagnosed per year -
these are easily treatable and rarely cause death.
- Belfast, Newry & Mourne and Derry had
higher than expected numbers of cancer in males. Higher than expected
numbers were found in females in Limavady and Derry. Over half (51%)
of all cancers diagnosed yearly were female, however, adjusting for
differentials in age distribution, women are less likely to get cancer.
The mortality rate amongst men is higher - males have a 1 in 6 chance
of dying of cancer and females a 1 in 8 chance. Cancers are more common
in younger females than males, male cancers occur mostly in old age
- over two-thirds in those aged over 65 years. In sex specific cancers,
the rates were highest in the oldest age group (85+ years). Female rates
were higher in the 20-60 year age group reflecting the influence of
sex specific cancers, especially breast and cervical cancers.
Cancer
of the Head and Neck
- On average, 111 cancers of the
lip and mouth were registered annually, mouth cancers were twice as
common in men as women. Survival for mouth cancer generally is poor,
with incidence increasing with age; over 80% of cases occur in those
over 50 year of age. On average, 48 cancers of the pharynx were registered
per year and 80% of cases occurred in people over 50. Males from the
Western Board area had a higher than expected rate of lip and mouth
cancers and men in the Southern Board area had higher than expected
rates of pharyngeal cancers.
- Comment - In approximately 79-90%
of cases cancer of the lip, mouth and pharynx is linked to tobacco use
and excessive alcohol intake. An added risk factor is inadequate amounts
of vitamin A and C in the diet. UV radiation has also been linked to
lip cancer.
- Specific Health Policies - The
population should be encouraged to have regular dental check-ups, especially
older people.
Cancer
of the Oesophagus
- On average, 171 cancers were registered
per annum, and this form of cancer was almost twice as common in males
as in females. There was no significant geographical variation. The
median age at diagnosis was 67 for men and 73 for women and the rate
for men is increasing. Survival rates are relatively poor.
- Comment - Alcohol consumption (especially
spirits) and cigarette smoking are the main risk factors in this form
of cancer - where both are used together the cumulative risk is greater.
Survival rates are poor but symptoms can be well managed.
- Specific Health Policies - A diet
rich in fruit and vegetables can protect against oesophical cancer and
may be responsible for slowing down death rates in the rest of Europe.
- Recommendations - The increased level of oesophical cancer
in young men needs further investigation and initiatives need to be
established to encourage reduced alcohol consumption.
Cancer
of the Stomach
- On average, 260 cancers were registered
per year and men were 2.5 times more at risk than women. There was no
significant geographical variation. Men over 69 years and women over
75 years accounted for half of all cases. Mortality is quite high and
is associated with late diagnosis in most patients.
- Comment - Stomach cancer rates
are linked to social class, with those in the lower socio-economic groups
having a higher rate. Possible risk factors include infection by the
bacterium Helicobacter pylori (bacteria found in the stomach in particularly
high rates in Northern Ireland) and low consumption of fruit and vegetables.
- Specific Health Initiatives -
Further research into and the prevention of Helicobacter pylori infection
should be encouraged.
Cancer of the Colon
- On average 624 cancers of the colon were
registered per year, 52% in women and 48% in men. Half of cases were
in men aged over 71 years and in women aged over 73 years. There was
a lower than expected incidence in females from the Eastern Board area
and a higher than expected incidence in females in Ballymoney District
Council area. Survival rates were modest, with twice as many cases diagnosed
as deaths recorded.
- Comment - The causes of colonic
cancer are not fully understood but three factors are broadly agreed
on, genetic factors, added risk from chronic diseases - especially ulcerative
colitis, and dietary factors - a high fat intake and low fruit and vegetable
intake.
- Specific Health Initiatives - Awareness
of the need to have changes in bowel habit, weight loss or passing blood
investigated should be heightened.
- Those with a family history of colonic
cancer - especially those with a young relative with the disease - should
contact specialists for the advisability on regular surveillance.
- Recommendations - Further research
into the aetiology of colon cancer and the role of diet should be carried
out in Northern Ireland.
- The assignment of site within the colon
should be as precise as possible.
Cancer
of the Rectum
- On average 309 cancers were registered
per year and it is slightly more common in men than women. The average
age for diagnosis for women was 73 years and for men 69 years. There
was a higher than expected number of women in Ards with cancer of the
rectum.
- Comment - NI has a relatively high
rate of rectal cancer compared to the rest of the British Isles. Given
that the causes of rectal cancer are very similar to those for colon
cancer, dietary habits account for much of the higher incidence of the
disease.
- Recommendations - Further research
into the aetiology of rectal (and colon) cancers and the role of diet
should be carried out in NI.
Cancer
of the Lung
- On average 895 cancerss were registered
per year and this is the most common form of cancer in men and the third
most common in women (excluding skin cancer). There were higher than
expected numbers in the Eastern Board area, lower than expected numbers
in the Southern Board area for men and women and higher than expected
levels in Belfast and Derry District Council areas for men and women.
The number of deaths was about 90% of the number of cases, indicating
the poor survival rate.
- Comment - Over 90% of lung cancers
are caused by smoking. Exposure to radon-gas must also be considered
among the risk factors.
- There is an established link between
smoking and lower socio-economic status; this pattern is replicated
in NI where smoking levels rise in areas of deprivation.
- Certain occupations where workers are
exposed to carcinogens carry an increased risk of lung cancer as does
'passive smoking' in the environment.
- Specific Health Initiatives
- Reduction of smoking levels holds the best chance of reducing
lung cancer rates. The numbers starting to smoke could be reduced by
a ban on advertising, increased taxation, reduction of availability
of tobacco products and enhanced heath education. Help should be given
to those who want to stop smoking and measures taken to control 'passive
smoking'.
- People with a persistent cough, pain,
etc. should be encouraged to seek medical advice.
Malignant
Melanoma of Skin
- On average 160 melanomas of the skin were
registered per annum, and this form of cancer is twice as common in
women as men. However, the number and rates of melanoma increased in
males and fell significantly in females in the period 1993-1995.
- There were higher than expected numbers
in the Southern Boards area for females, and in North Down for males.
- Comment - The incidence of malignant
melanoma has increased rapidly over the past 25 years in NI from an
average of 48 cases per year (1974-1978) to 160 per year.
- Specific Health Initiatives - The public should be encouraged to
avoid the sun between 11 am-3pm and seek shade, cover up with a hat,
T-shirt and sunglasses and use a minimum factor 15 sunscreen.
- The public must be encouraged to become
aware of skin changes which could indicate skin cancer.
- Professionals should ensure a fast track
approach to the diagnosis of suspicious lesions.
Cancer
of the Female Breast
- On average 820 female breast cancers were
registered per year, breast cancer accounts for 19% of all new cancers
diagnosed in women. Four-fifths of these occur in post menopausal women.
- Higher than expected levels were found
in the District Council areas of Limavady and Moyle. This may be due
to higher levels of disease surveillance.
- Comment - Breast cancer is the
most common cause of cancer death in women in Northern Ireland. Studies
have shown that breast cancer is more common in women who consume a
diet which is high in saturated fat, those groups/societies who have
a low fat diet show particularly low levels of breast cancer.
- The Breast Cancer Screening Programme
was fully operational in Northern Ireland by 1993. Women aged between
50 and 64 years are routinely invited every 3 years for a breast x-ray
(mammogram). Women over the age of 65 may attend, although not specifically
invited.
- Specific Health Initiatives - Women should ensure they eat a healthy
diet and not exceed the recommended levels of fat intake.
- Women between the ages of 50 and 64 should
attend screening when invited.
- Those with a strong family history should
seek advice on the value of a mammogram at an earlier age.
- Women should be encouraged to seek advice
for symptoms of breast cancer.
- Recommendations - Women with suspected
breast cancer should have their disease stage, including lymph node
status, assessed at diagnosis.
Cancer
of the Cervix Uteri
- On average 78 cases of invasive cervical
cancer were registered per year, half of these occurred in women under
the age of 49.
- There were higher than expected numbers
in the Eastern Board area.
- Comments - The major risk factor
for development of pre-invasive or invasive cancer of the cervix is
human papilloma virus infection. This overshadows the other known risk
factors such as high number of children, number of sexual partners,
smoking history and socio-economic class - cervical cancer is more common
in the lower socio-economic groups.
- Over 90% of cervical cancers can be detected
early by the PAP smear which allows examination of cells from the cervix.
In 1988 the community cervical screening programme (which began in 1965)
was replaced by the population based screening programme which invites
women aged between 20 and 64 years to have a smear taken every five
years. A regional audit indicates that half of these cancers occur in
the 30% of women who have never had a smear.
- Specific Health Initiatives - All eligible women should be encouraged
to attend for a cervical smear.
- Measures to reduce smoking among women
should be promoted.
Cancer
of the Ovaries
- On average 164 cases of cancer of the
ovary were registered per annum, half of the cases were aged over 62
years.
- There were lower than expected numbers
in the Western Board area.
- Comment - Ovarian cancer occurs
most frequently in white affluent countries - there is a reduced risk
among Japanese women. The causes of ovarian cancer are poorly understood,
a slight familial risk is shown and environmental factors are thought
to be important.
- Two protective factors have been demonstrated,
the number of pregnancies (especially two or more) and the use of the
combined oral contraceptive (use for as long as five years may reduce
the risk by about half).
- Specific Health Initiatives -
Ensure symptoms are investigated as soon as possible, as the disease
is often asymptomatic in the early stages.
Cancer
of the Prostate
- On average 450 cancers were registered
per year, half were diagnosed in men over 75 years.
- This is the second most commonly diagnosed
cancer in men, and a higher than expected number were registered in
the Southern Health Board area.
- Comment - The cause of prostate
cancer is poorly understood, endocrine/hormonal factors may play a significant
part and it is much less common in the Asian population.
- Specific Health Initiative - General
health programmes should encompass a focus on male health, especially
the importance of early investigation of symptoms.
Cancer
of the Testis
- On average 47 cases of the disease
were registered per year, and the survival rate under treatment is excellent.
There were no significant geographic variations.
- It is a disease of young males, half
of cases occurred in men under 33 years of age.
- It is the most common form of cancer in
men between the ages of 25 and 34.
- Comment - Most western populations
have recorded an increase in incidence, partly due to better detection
rates.
- Specific Health Initiatives - Men
should be encouraged to carry out regular self-examination to detect
any testicular change.
Cancer
of the Bladder
- On average 203 cases were registered per
year and 2 in every 3 cases were male. There were no significant geographic
variations.
- Comment - Cigarette smoking is
a recognised risk factor in bladder cancer.
- Specific Health Initiative - Increased
awareness among the population of the importance of early investigation
into the symptoms.
- A clear distinction should be made between
invasive and non-invasive bladder tumours.
Cancer
of the Kidney
- On average 174 cancers of the kidney
were registered per year, and 2 in 3 cases occurred in men. Half of
the cases occurred in people over the age of 68 years.
- There were lower than expected numbers
of men in the Western Board area and higher than expected numbers in
the Southern Board area.
- Comment - Over a third of kidney
cancers are associated with tobacco smoking.
Childhood
Cancers
- On average 52 childhood cancers were registered
per year, there were higher rates in boys and the 0-4 year age group
were at greater risk. Generally prognosis was good for the majority
of cases.
- Leukaemia and brain tumours accounted
for half the childhood cancers.
- Comment - Cancer in children is
extremely rare, although the emotional and psychological consequences
for patients and their families are profound.
- The causes are largely unknown, the effects
of power lines and pylons is still under investigation - the bulk of
the evidence showing little or no effect.
Summary of Recommendations
General
recommendation for all forms of cancer
- People should be encouraged to stop smoking.
- The population should be encouraged to
eat a diet rich in fresh fruit and vegetables - at least five potions
a day. The population should be encouraged to reduce their intake of
saturated fat.
- Tobacco use must be addressed in line
with the Government White Paper on tobacco control, as tobacco use is
responsible for the majority of preventable cancers.
- Increased awareness among the population
of the importance of early investigation of symptoms.
- Participation in clinical trials, which
can advise on the best outcomes, should be enhanced.
- The organisation of services should be
such as to ensure that those with the disease have as good an outcome
as possible.
- The full range of palliative care services
should be available for those with established disease.
- Recommendation to enhance the Registry:
- The recording of stage diagnosis for all
tumours should be enhanced.
- A Unique Patient Client Identifier should
be introduced to improve identification of individuals and prevent duplication.
- Pathologically diagnosed CIN III (severe
dysplasia) tumours should be consistently coded as SNOMED code M80772.
- A clear distinction should be made between
invasive and non-invasive bladder tumours.
- Address information should conform to
the British Standard BS6667.
- Pathology systems should try to improve
completeness of address information, especially post codes.
- Haematology bone marrow records should
be computerised.
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