Occupation and cancer - European Trade Union Institute (ETUI)

Acta Oncol Downloaded from informahealthcare.com by 212.35.100.66 on 04/06/11
For personal use only.
706 E. Pukkala et al.
lowest in engine operators (0.63, 0.42 0.90) and
forestry workers (Table 39).
In women, the occupational groups with the
highest SIRs were military personnel (1.57, 1.03
2.30), dentists, journalists, physicians, administrators
and artistic workers (Table 40). The SIR was
lowest among fishermen (0.69, 0.50 0.92); followed
by forestry workers, wood workers, gardeners and
farmers.
The contrast between the highest and the lowest
SIRs was somewhat stronger for lobular cancer
(around 10% of breast cancer; http://astra.can
cer.fi/NOCCA/Incidence/breast-lobular), than for
ductal cancer (around 80% of breast cancer; http://
astra.cancer.fi/NOCCA/Incidence/breast-ductal).
The highest SIR for the lobular type was 1.79 (1.39
2.28) for journalists, followed by physicians (1.71,
1.36 2.13), dentists (1.66, 1.22 2.20) and administrators
(1.51, 1.34 1.71). The lowest SIRs were seen
for engine operators (0.43, 0.24 0.72) and woodworkers
(0.53, 0.39 0.71).
Comment. Among men, the occupations with the
highest incidence were characterised by shift- or
night work. Shift work that involves night work
(and thus circadian disruption) has been classified
by the International Agency for Cancer Research as
probably carcinogenic to humans, with the human
evidence based on breast cancer research [96]. In the
present study the results for women were less
suggestive of an association with shift or night
work. This could be related to the fact that for
women, the most important non-genetic risk factors
for breast cancer are hormonal factors, strongly
connected with reproductive behaviour [97].
Young age at first birth and an increasing number
of births are associated with lowered risk. The
/ 100 000
100
80
60
40
20
Denmark
Finland
Iceland
Norway
Sweden
Women
0
1945 1960 1975 1990 2005
Figure 29. Age standardised (World) incidence rates for breast cancer 1943 2005, by country. Modified from NORDCAN [49].
present results showed the highest SIRs in occupations
that require high education and cause women
to postpone their first childbirth. Other established
risk factors for breast cancer include ionising radiation,
lack of physical activity, high body mass index
and alcohol consumption. These factors were not
particularly reflected in the present results, except
for a tendency for occupations with high levels of
physical activity to have the lowest SIRs. The
contrasts seen between occupations were considerably
higher among men than women, which might
indicate a stronger occupationally related aetiology
among the men.
Cervical cancer
Incidence of cervical cancer has decreased in
all Nordic countries since the 1960s, except for in
Norway where the decrease started in the mid 1970s
(Figure 30). This can mainly be explained by the
introduction of organised screening programmes.
The lowest rate, in Finland, has always been less
than half of the highest rate, in Denmark.
The highest SIRs were seen among beverage
manufacture workers (SIR 2.01, 95% CI 1.51
2.61), ‘‘other construction workers’’, waiters, tobacco
manufacture workers, drivers and electrical
workers. The SIRs were lowest among the dentists
(0.48, 0.30 0.74), physicians, teachers, farmers
and nurses (Table 41).
Comment. Infection with oncogenic types of human
papilloma virus (HPV) is the main cause of cervical
cancer [98]. Tobacco has an independent role in
cervical cancer carcinogenesis.
In previous research, high rates have been found
among cleaners, food preparation workers and wait-