world cancer report - iarc

invasive malignant. Malignant germ cell
tumours are uncommon.
A majority of familial ovarian cancer seems to
be due to mutations in the BRCA1 and
BRCA2 genes, which are also associated with
a predisposition for breast cancer (Genetic
susceptibility, p71), (although BRCA1 is also
mutated in a minority of sporadic tumours
[18]). Familial syndromes linked to increased
risk of ovarian cancer include breast-ovarian
cancer syndrome, rare families who present
with ovarian cancers only and Lynch type II
syndrome, which is characterized by inheri-
MULTICULTURAL ISSUES
Although incidence of cancer is often
recorded with reference to national or otherwise
large populations, the disease burden
is rarely distributed uniformly across
such groupings. This becomes apparent
when consideration is given to specific
minority groups within a wider community.
A number of variables may contribute
to such an outcome. One such variable,
genetic make-up, is not amenable to intervention
but nonetheless may have an
impact. For example, there are large
racial/ethnic differences in prostate cancer
risk, with high rates of incidence in
African-Americans, which may be partly
related to genetic differences in hormone
metabolism (Farkas A et al., Ethn Dis, 10:
69-75, 2000). However, mutations which
confer susceptibility to cancer may be carried
by individuals from any and all ethnic
groups (Neuhausen SL, Cancer, 86: 2575-
82, 1999).
In many instances, there are clear indications
that in some ethnic minorities, immigrant
populations and the poor and disadvantaged,
the burden of cancer is greater
than that of the general population (e.g.
Kogevinas M et al., Social inequalities and
cancer, Lyon, IARCPress, 1997). In the
USA, for example, whilst incidence and
mortality rates for some cancers have
decreased in the population overall, rates
have increased in some ethnic minority
groups. The mortality rate for cancer at all
tance of nonpolyposis colorectal cancer
(Colorectal cancer, p198), endometrial cancer
and ovarian cancer and is linked to mutations
in DNA mismatch repair genes MSH2,
MLH1, PMS1 and PMS2 (Carcinogen activation
and DNA repair, p89)[18,19]. Prophylactic
oophorectomy is a potential option for genetically
high-risk women.
The ERBB2 (HER-2/neu) oncogene is overexpressed
in about 30% of ovarian tumours, as is
C-MYC [21]. KRAS mutational activation is also
implicated in ovarian cancer. p53 mutations
have been found in 50% of cases.
sites in white people in 1990-96 was 167.5
per 100,000 whilst in the black population it
was 223.4. The reasons for such differences
are likely to be complex and multifactorial.
Environmental/behavioural factors may differ
between ethnic/cultural groups. For
instance, the diet to which some migrant
populations are accustomed (e.g. small
quantities of red meat, large quantities of
fruit and vegetables) may be protective in
relation to risk of colorectal cancer, but risk
increases with the adoption of a Western
diet (e.g. Santani DL, J Assoc Acad Minor
Phys, 10: 68-76, 1999).
Timely visits to a medical practitioner and
participation in screening programmes are
critical for early detection and initiation of
treatment. Language may be a barrier to
understanding health issues. Women from
certain ethnic and racial minorities are less
likely to take up invitations to participate in
breast or cervical screening programmes.
This may be partly attributable to the novelty
of the concept of preventive health, unfamiliarity
with the disease, or with the health
system, as well as modesty and
religious/cultural barriers. Women of lower
socioeconomic status tend to present with
a more advanced stage of breast cancer
than women of higher socioeconomic status.
African-American, Hispanic, American
Indian and Hawaiian women also tend to
present with a more advanced stage of
breast cancer than white women (e.g.
Hunter CP, Cancer, 88: 1193-202, 2000). In
Fig. 5.70 Histopathology of a well-differentiated,
mucus-secreting, endometrial-like adenocarcinoma
of the ovary.
the USA, women who do not subscribe to
private health insurance are less likely to
undergo screening for breast, cervical and
colorectal cancers (Hsia J et al., Prev Med,
31: 261-70, 2000). Such differences involving
increased incidence provide an opportunity
for strategic action.
Treatment and its outcome may also be
affected by ethnic and social differences.
For example, the way that pain is perceived
and dealt with is influenced by the
ethnocultural background of the patient
(Gordon C, Nurse Pract Forum, 8: 5-13,
1997). Ethical dilemmas can develop in
multicultural settings due to differing cultural
beliefs and practices. More research
into the relationship between ethnicity
and accessibility of medical care, patient
support, survival, and quality of life is
needed (Meyerowitz BE, Psychol Bull, 123:
47-70, 1998).
Recognition of multicultural issues is
becoming more widespread. The NCI has
launched an initiative to investigate the
reasons for disparities in cancer in minority
populations (the “Special Populations
Networks for Cancer Awareness Research
and Training”, Mitka M, JAMA, 283: 2092-
3, 2000). Many areas have units designed
to improve equality of access to health
care (e.g. NSW Health Multicultural
Health Communication Service,
http://www.health.nsw.gov.au).
Cancers of the female reproductive tract
221