Znt. J. Cancer: 5 1 , 6 2 4 6 (1992) 0 1992 Wiley-Liss, Inc.
)
Publication of the International Union Against Cancer Publication de I‘Union Internationale Contre le Cancer
DESCRIPTIVE EPIDEMIOLOGY OF MALE BREAST CANCER IN EUROPE Carlo LA VECCHIA’,~, Fabio LEVI’3334 and Franca LUCCHINI’ ’Institut universitaire de mtdecine sociale et prtventive, Bugnon 17, 1005 Lausanne, Switzerland; 21stituto di Ricerche Farmacologiche “Mario Negn’’: Via Eritrea 62, 20157 Milan, Italy; and 3Registre vaudois des tumeurs, Institut universitaire de midecine sociale et prtventive, CHUI/; Falaises 1, 101 1 Lausanne, Switzerland. Trends in death certification rates from male breast cancer over the period 1955-89 were analysed for 25 European countries (excluding the Soviet Union and a few small countries) on the basis of official data from the World Health Organization database. In the late 198O’s, about 550-600 deaths per year from male breast cancer were certified in these countries. The variation was relatively limited, most age-standardized (world standard) rates being within the range of I .5 to 3.0 per million. The highest rates were in France, Hungary, Austria and Scotland. No clear pattern of trend was observed over the last few decades, but mortality rates in the late 1980’s tended to be, for most countries, lower than those registered 3 decades earlier. Comparisonwas possible for I 8 countries, and for I I (including the largest ones, i.e. France, Germany, Italy and England and Wales), male breast cancer rates in 1985-89 were lower than in 1955-59. The pattern was similar when only truncated (from 35 to 64 years) mortality rates were consideredand, for the largest countries, upon accurate inspection of age-specific rates. In conclusion, therefore, this overview of male breast cancer trends in Europe precludes any generalized increase in mortality from the disease over recent decades and, hence, weighs against the introduction and presence of any important new cause of this rare disease.
Breast cancer in males is a rare disease, representing approximately 1% of all breast cancers, and only 1% of all cancer deaths in males. Not surprisingly, therefore, very little is known about the epidemiology of the disease. Genetic factors, as indicated by family history of the disease in male and female relatives, emerged as a risk factor in one study (Rosenblatt et al., 1991), but only scattered data are available on potential environmental factors. Among other factors (i.e., occupational history, radiation, overweight and obesity and drugs which increase prolactin or oestrogen availability) (Mabuchi et al., 1985; Olsson and Ranstam, 1988; Casagrande et al., 1988; Lenfant-Pejovic et al., 1990), it has been suggested that exposure to electromagnetic fields may be associated with increased risk of breast cancer in males (Stevens, 1987; Matanosky et al., 1991; Demers et al., 1991). If this were true, systematic rises in male breast cancer rates could be expected, since on a population level exposure to electromagnetic fields has substantially increased over the last few decades (Poole and Trichopoulos, 1991). Only scanty information, however, is available on trends in male breast cancer. Incidence data from Scandinavia (Ewertz et al., 1989) showed a significant increase of about 1 % per year over the period 1943-82 in Denmark (although the trend was not linear), but no significant time effect in other Nordic countrics. T o provide baseline documentation on dcscriptivc epidemiology of male breast cancer, we decided to examine the patterns of trends in mortality registered in various European countries over the last few decadcs.
TABLE I - LIST OF COUNTRIES AND CALENDAR YEARS FOR WHICH DATA FOR MALE BREAST CANCER WERE MISSING ACROSS THE PERIOD 195549 Countrv
Years
Belgium Bulgaria Denmark Finland France Germany, GDR Greece Ireland Italy Netherlands Norway Poland Romania Spain Sweden Yugoslavia
85,87-89
55-63 89
89 89 55-72,79 55-60,89 89 89 89
89 55-58 55-58,79,85-89 87-89 88-89 55-60,89
For the calendar period considered (1955-89), 4 different Revisions of the International Classification of Diseases (ICD) were used (WHO, 1950, 1957, 1967, 1977). Classification of deaths from male breast cancer was thus re-coded, for all calendar periods and countries, according to the 9th Revision of the International Classification of Diseases (ICD-9), i.e. the ICD code 170 for the 6th and 7th Revisions was pooled with codes 174 for the 8th and 175 for the 9th Revisions. In a few countries, data were missing for part of one or more calendar periods (Table I). When a single year was missing within a quinquennium, numerators and denominators were interpolated linearly for the previous and subsequent calendar year. No extrapolation was made for missing data at the beginning or the end of the calendar period considered, or when data for one or more quinquennia were not available. Estimates of the resident population, generally based on official Censuses, were obtained from the same W H O databank. From the matrices of certified deaths and resident populations, age-specific rates for each 5-year age-group and calendar period were computed. Age-standardized rates, at all ages as well as truncated 35-64 years, were based on the World Standard Population (Doll and Smith, 1982). RESULTS
Table I1 gives the trends in overall age-standardized death certification rates from male breast cancer in various European countries over the period 1955-89. In the late 1980’s about 550-600 deaths per year from male breast cancer were certified in the 25 countries considered. The variation was relatively limited, particularly considering the extent of ran-
MATERIAL AND METHODS
Official death certification numbers for 25 European countries (excluding the Soviet Union and a few small countries such as Andorra, Iceland and Liechtenstein) were derived from the W H O database (La Vecchia et al., 1992).
4Towhom correspondence and requests for reprints should be sent.
Received: November 1, 1991 and in revised form December 11, 1991.
63
MALE BREAST CANCER IN EUROPE TABLE I1 - TRENDS IN MORTALITY FROM MALE BREAST CANCER IN SELECTED EUROPEAN COUNTRIES Average number of deaths
Age-standardizedl death certification rateimillion males in:
Country
Austria Belgium Bulgaria Czechoslovakia Denmark Finland France Germany, GDR Germany, FRG Greece Hungary Ireland Italy Netherlands Norway Poland Portugal Romania Spain Sweden Switzerland UK, England and Wales UK, Northern Ireland UK, Scotland Yugoslavia
1955-59
1965-69
1975-79
1985-89
2.7 2.9 1.8 2.0 1.5 3.8 2.2 2.9 1.8 2.2 2.4 1.5 1.4 1.9
2.9 2.0 1.9 1.6 1.8 0.6 5.5 1.8 3.4 2.5 3.8 3.4 2.7 2.6 1.0 0.9 1.7 2.7 1.8 1.7 2.0 2.5
3.0 2.5 1.5 2.1 2.4 0.8 3.4 1.8 1.9 1.0 3.4 1.5 0.6 1.9 1.2
1.5 1.9 2.5
2.9 1.7 2.0 2.2 1.8 0.8 4.5 2.7 1.7 3.3 0.9 2.3 3.1 1.1 3.1 0.7 2.0 0.5 1.9 1.2 2.6
1.6 2.2 -
2.8 1.8 -
1.9 2.0 2.0
1.8 2.8 1.9
-
-
2.7 1.8 1.1 1.7 2.1
y6Ll!$
Percent change
1985-89
'". 1955-59
15 18 10 21 10 2 114 19 85 9 25 4 35 19 5 19 47 12
- 27
+11 - 14 17 +20 -47 - 11 - 14 + 17 - 17 -73 -21 -20 93
+
+-
10
-11
84
- 16
2 10 26
+ 13 f 27
-
'World standard population. TABLE 111 -TKENDS IS MORTAL1 I Y FKOM .M,\l.l. BKFI\SI'('.\NC'I'H I[\ SELECTED EUROPEAN COUYTRIES. Tl
)
Publication of the International Union Against Cancer Publication de I‘Union Internationale Contre le Cancer
DESCRIPTIVE EPIDEMIOLOGY OF MALE BREAST CANCER IN EUROPE Carlo LA VECCHIA’,~, Fabio LEVI’3334 and Franca LUCCHINI’ ’Institut universitaire de mtdecine sociale et prtventive, Bugnon 17, 1005 Lausanne, Switzerland; 21stituto di Ricerche Farmacologiche “Mario Negn’’: Via Eritrea 62, 20157 Milan, Italy; and 3Registre vaudois des tumeurs, Institut universitaire de midecine sociale et prtventive, CHUI/; Falaises 1, 101 1 Lausanne, Switzerland. Trends in death certification rates from male breast cancer over the period 1955-89 were analysed for 25 European countries (excluding the Soviet Union and a few small countries) on the basis of official data from the World Health Organization database. In the late 198O’s, about 550-600 deaths per year from male breast cancer were certified in these countries. The variation was relatively limited, most age-standardized (world standard) rates being within the range of I .5 to 3.0 per million. The highest rates were in France, Hungary, Austria and Scotland. No clear pattern of trend was observed over the last few decades, but mortality rates in the late 1980’s tended to be, for most countries, lower than those registered 3 decades earlier. Comparisonwas possible for I 8 countries, and for I I (including the largest ones, i.e. France, Germany, Italy and England and Wales), male breast cancer rates in 1985-89 were lower than in 1955-59. The pattern was similar when only truncated (from 35 to 64 years) mortality rates were consideredand, for the largest countries, upon accurate inspection of age-specific rates. In conclusion, therefore, this overview of male breast cancer trends in Europe precludes any generalized increase in mortality from the disease over recent decades and, hence, weighs against the introduction and presence of any important new cause of this rare disease.
Breast cancer in males is a rare disease, representing approximately 1% of all breast cancers, and only 1% of all cancer deaths in males. Not surprisingly, therefore, very little is known about the epidemiology of the disease. Genetic factors, as indicated by family history of the disease in male and female relatives, emerged as a risk factor in one study (Rosenblatt et al., 1991), but only scattered data are available on potential environmental factors. Among other factors (i.e., occupational history, radiation, overweight and obesity and drugs which increase prolactin or oestrogen availability) (Mabuchi et al., 1985; Olsson and Ranstam, 1988; Casagrande et al., 1988; Lenfant-Pejovic et al., 1990), it has been suggested that exposure to electromagnetic fields may be associated with increased risk of breast cancer in males (Stevens, 1987; Matanosky et al., 1991; Demers et al., 1991). If this were true, systematic rises in male breast cancer rates could be expected, since on a population level exposure to electromagnetic fields has substantially increased over the last few decades (Poole and Trichopoulos, 1991). Only scanty information, however, is available on trends in male breast cancer. Incidence data from Scandinavia (Ewertz et al., 1989) showed a significant increase of about 1 % per year over the period 1943-82 in Denmark (although the trend was not linear), but no significant time effect in other Nordic countrics. T o provide baseline documentation on dcscriptivc epidemiology of male breast cancer, we decided to examine the patterns of trends in mortality registered in various European countries over the last few decadcs.
TABLE I - LIST OF COUNTRIES AND CALENDAR YEARS FOR WHICH DATA FOR MALE BREAST CANCER WERE MISSING ACROSS THE PERIOD 195549 Countrv
Years
Belgium Bulgaria Denmark Finland France Germany, GDR Greece Ireland Italy Netherlands Norway Poland Romania Spain Sweden Yugoslavia
85,87-89
55-63 89
89 89 55-72,79 55-60,89 89 89 89
89 55-58 55-58,79,85-89 87-89 88-89 55-60,89
For the calendar period considered (1955-89), 4 different Revisions of the International Classification of Diseases (ICD) were used (WHO, 1950, 1957, 1967, 1977). Classification of deaths from male breast cancer was thus re-coded, for all calendar periods and countries, according to the 9th Revision of the International Classification of Diseases (ICD-9), i.e. the ICD code 170 for the 6th and 7th Revisions was pooled with codes 174 for the 8th and 175 for the 9th Revisions. In a few countries, data were missing for part of one or more calendar periods (Table I). When a single year was missing within a quinquennium, numerators and denominators were interpolated linearly for the previous and subsequent calendar year. No extrapolation was made for missing data at the beginning or the end of the calendar period considered, or when data for one or more quinquennia were not available. Estimates of the resident population, generally based on official Censuses, were obtained from the same W H O databank. From the matrices of certified deaths and resident populations, age-specific rates for each 5-year age-group and calendar period were computed. Age-standardized rates, at all ages as well as truncated 35-64 years, were based on the World Standard Population (Doll and Smith, 1982). RESULTS
Table I1 gives the trends in overall age-standardized death certification rates from male breast cancer in various European countries over the period 1955-89. In the late 1980’s about 550-600 deaths per year from male breast cancer were certified in the 25 countries considered. The variation was relatively limited, particularly considering the extent of ran-
MATERIAL AND METHODS
Official death certification numbers for 25 European countries (excluding the Soviet Union and a few small countries such as Andorra, Iceland and Liechtenstein) were derived from the W H O database (La Vecchia et al., 1992).
4Towhom correspondence and requests for reprints should be sent.
Received: November 1, 1991 and in revised form December 11, 1991.
63
MALE BREAST CANCER IN EUROPE TABLE I1 - TRENDS IN MORTALITY FROM MALE BREAST CANCER IN SELECTED EUROPEAN COUNTRIES Average number of deaths
Age-standardizedl death certification rateimillion males in:
Country
Austria Belgium Bulgaria Czechoslovakia Denmark Finland France Germany, GDR Germany, FRG Greece Hungary Ireland Italy Netherlands Norway Poland Portugal Romania Spain Sweden Switzerland UK, England and Wales UK, Northern Ireland UK, Scotland Yugoslavia
1955-59
1965-69
1975-79
1985-89
2.7 2.9 1.8 2.0 1.5 3.8 2.2 2.9 1.8 2.2 2.4 1.5 1.4 1.9
2.9 2.0 1.9 1.6 1.8 0.6 5.5 1.8 3.4 2.5 3.8 3.4 2.7 2.6 1.0 0.9 1.7 2.7 1.8 1.7 2.0 2.5
3.0 2.5 1.5 2.1 2.4 0.8 3.4 1.8 1.9 1.0 3.4 1.5 0.6 1.9 1.2
1.5 1.9 2.5
2.9 1.7 2.0 2.2 1.8 0.8 4.5 2.7 1.7 3.3 0.9 2.3 3.1 1.1 3.1 0.7 2.0 0.5 1.9 1.2 2.6
1.6 2.2 -
2.8 1.8 -
1.9 2.0 2.0
1.8 2.8 1.9
-
-
2.7 1.8 1.1 1.7 2.1
y6Ll!$
Percent change
1985-89
'". 1955-59
15 18 10 21 10 2 114 19 85 9 25 4 35 19 5 19 47 12
- 27
+11 - 14 17 +20 -47 - 11 - 14 + 17 - 17 -73 -21 -20 93
+
+-
10
-11
84
- 16
2 10 26
+ 13 f 27
-
'World standard population. TABLE 111 -TKENDS IS MORTAL1 I Y FKOM .M,\l.l. BKFI\SI'('.\NC'I'H I[\ SELECTED EUROPEAN COUYTRIES. Tl
