Invasive breast carcinoma - IARC

male population both in the USA and
the European Union (EU). A higher incidence
with a lower average age and
m o re cases in an advanced stage is
re p o rted in native Africans and Indians
{39,1281,1329,1330,2539,2985}. This is
re i n f o rced by the consistently higher
incidence rates for the black compare d
to the white male population in the US
cancer registries {2189}.
A e t i o l o g y
Some aspects of the aetiology of male
b reast cancer are similar to those of the
much more common female counterp
a rt. Thus, a direct association has
been suggested with socio-economic
class (i.e. increased risk in higher socioeconomic
classes) {607,1551,2539},
although this remains contro v e r s i a l
{1627,2906}. Likewise, it has been
re p o rted that both never married men
and Jewish men are at higher risk
{ 1 7 2 6 , 2 5 3 9 , 2 9 0 6 } .
Family history of breast cancer in
female and male first degree re l a t i v e s
has repeatedly been associated with
male breast cancer risk, although quantification
of relative and attributable
risks on a population level re m a i n s
undefined {418, 607,1185,1551,2449,
2539,2799}. It has been estimated that
t h e re is a family history in about 5% of
male breast cancer patients, but these
patients do not present at a younger
age {1210,2297}. Here d i t a ry factors
a re discussed elsewhere (see genetic
c h a p t e r ) .
Again, as for female breast cancer,
a n t h ropometric characteristics have
been investigated, and body mass
index (BMI) was directly associated with
male breast cancer risk {418,607,
1551,2539}. In a large case-contro l
study {1253}, the relative risk was 2.3
for the highest quartile of BMI. This
study also suggested an association
with height but the relative risk was only
1.5 and of borderline significance
{ 1 2 5 3 } .
P revious breast or testicular disease
and gynaecomastia have been re l a t e d
to male breast cancer, and associations
have been re p o rted with an undescended
testis {2231,2577,2906}, orc h i e c t o-
m y, orchitis, testicular injury, late puberty
and infertility {2539}.
Male breast cancer is more common
among those with Klinefelter syndro m e
{418,2539} and infertility or low fert i l i t y,
Fig. 1.166 Invasive ductal carcinoma and gynaecomastia of the male breast. Invasive carcinoma is present
in the left third of the field.
possibly as a consequence of Klinefelter
syndrome or other horm o n a l
a b n o rmalities {607,1551,2539,2906}.
Similar to the role of estrogen in female
b reast cancer {36,225,540,1128}, high
e s t rogen and prolactin levels have been
re p o rted as risk factors for male bre a s t
cancer {2539}, and several small studies
have found higher serum or urinary
e s t rogen levels in cases than in contro l s
{386,2024,2107,2363}. This is supported
by re t rospective cohort studies in
Denmark, indicating an excess occurrence
of breast cancer among men with
cirrhosis and relative hypere s t ro g e n i s m
{2755}. However, not all the results were
consistent with this pattern of horm o n a l
influence {173,3110}.
Other endocrine factors may play an
i m p o rtant role in the aetiology {815,
1253,2539}. It has been suggested that
diabetes mellitus may increase risk,
possibly through hormonal mechanisms
{815,1253,2539}.
R e p o rts on lifestyle factors have shown
in general no material association with
smoking, alcohol or coffee consumption
{1253,2231,2449}, although one study
found a significant protective effect of
smoking {2231}. A higher risk was associated
with limited physical exerc i s e
and frequent consumption of red meat,
while consumption of fruit and vegetables
was related to a decreased risk,
although the trends were not significant
{1253}. In another large study from ten
population-based cancer re g i s t r i e s
{2449}, no trends in risk were observed
with increased dietary intakes of several
foods and nutrients, and no association
was found with the use of any
d i e t a ry supplement. Dietary factors are
unlikely to be strong determinants of
b reast cancer in men {2449}, though
moderate associations, as described
for female breast cancer {1636,1639},
remain possible.
Although an association with electromagnetic
field exposure has been suggested
in the past {669,1784,2791}, the
R e p o rt of an Advisory Group on Non-
Ionising Radiation to the National Radiological
Protection Board (2001) concluded
that there is no evidence that
e l e c t romagnetic fields are related to
adult male breast cancer {2355}.
Invasive carcinoma
Clinical features
The most frequent sign is a palpable suba
reolar mass. Nipple ulceration or sanguineous
secretion is seen in 15–30%. In
25–50% of patients, there is fixation to or
ulceration of the overlying skin. A quart e r
of patients complain of pain.
Male breast cancer is usually unilateral
and occurs more frequently in the left
b reast. Synchronous bilateral tumours
a re found in less than 5% of cases.
Tumours of the male breast 111