American Journal of Industrial Medicine 2123734376 (1992)
Renal Cell Cancer Among Architects and Allied Professionals in Sweden Joseph K. McLaughlin, PhD, Hans S.R. Malker, PhD, William J. Blot, PhD, Jan A. Weiner, PE,B.J. Stone, PhD, Jan L.E. Ericsson, MD,and Joseph F. Fraumeni, Jr., M D
The Swedish Cancer-Environment Registry was used to evaluate a recent report of a large excess risk of renal cell cancer among architects in Los Angeles. We identified 131 renal cell cancers among male Swedish architects and allied professionals during a 19-year follow-up period (1961-1979). Compared with the Swedish population, there was no significant excess of renal cell cancer among architects and allied professionals (standardized incidence ratio (SIR) = 1.15; 131 cases). Although it was not possible to estimate the risk for architects alone, the SIR was only 1.06 (16 cases) in a subset of professionals employed in architectural and engineering firms. However, a significant increase in risk (SIR = 1.38) was observed in a related group of workers employed as engineers and construction supervisors in the home construction industry. 0 1992 Wiley-Liss, Inc.
Key words: linked-registry analysis, occupational cancer, kidney cancer, construction, asbestos
INTRODUCTION Lowery and colleagues [1991] recently reported an excess of renal cell cancer among architects in Los Angeles County, California, using a proportional incidence ratio (PIR) approach. Although only 3.1 cases were expected, 13 were observed (PIR = 420; 95% confidence interval (CI) = 2.23-7.71). No proportional excesses were observed among other professionals, such as medical care and administrative personnel, as reported by others [Dubrow and Wegman, 1984; McLaughlin et al., 19871. In our earlier report using the Swedish Cancer-Environment Registry (CER), we did not present data specific to architects, but only for the broad occupational category of all professional, technical, and related workers who, as a whole, had a significant excess risk of 20% for renal cell cancer based on 995 cases [McLaughlin et al., 19871. This report attempts to evaluate the risk among architects in Sweden, using the CER, which links employment data with cancer incidence for the time period, 1961-1979. National Cancer Institute, Division of Cancer Etiology, Epidemiology and Biostatistics Program, Bethesda, MD (J.K.M., W.J.B., B.J.S., J.F.F.). National Board of Occupational Safety and Health, Solna, Sweden (H.S.R.M.,J.A.W.). National Board of Health and Welfare, Stockholm, Sweden (J.L.E.E.). Address reprint requests to Dr. J.K. McLaughlin, National Cancer Institute, Executive Plaza North, Room 415, Bethesda, MD 20892. Accepted for Publication October 28, 1991.
0 1992 Wiley-Liss, Inc.
874
McLaughlin et al.
MATERIALS AND METHODS
The CER and the statistical procedures used to calculate the standardized incidence ratios (SIR) have been described in this journal [Malker et al., 1986; Linet et al., 19881. Briefly, the CER links employment data from the 1960 national census with the Swedish National Cancer Registry for the years 1961 to 1979. All SIRS are adjusted for age in 5-year birth cohorts and for regional differences, using 24 counties and 3 metropolitan areas. Statistical significance is tested under the assumption that the observed number of renal cell cancers follows a Poisson distribution [Bailer and Ederer, 19641. The high degree of completeness of the national cancer registry [Mattson and Wallgren, 19841 and the CER [Malker, 19881 have been demonstrated in a number of studies. The category of workers examined in this paper is architects and allied professionals (occupational code 00l), which includes not only architects, but also civil engineers, technicians, construction supervisors, and related professionals. In 1960, 40% of the individuals in this occupational group were employed in the home building industry, 26% in highway construction, 20% in architectural and engineering firms, 8% in government agencies, and 2% in power plant construction. RESULTS
Among employed Swedish men, 7,405 cases of renal cell cancer occurred between 1961 and 1979, of which 131 cases were diagnosed (vs. 113.5 expected) among architects and allied professionals for a non-significant SIR of 1.15 (95% CI = 0.97-1.36). In the 1960 Swedish census there were 36,386 men in this occupational category, compared with an estimated 2,500 formally trained architects, based on records from relevant organizations and unions (L. Furusten, personal communication). Because of the heterogeneity of this occupational category, we examined risks by occupation within industry. The industry most likely to have the largest proportion of architects would be architectural and engineering firms (industry code 842), which employed about 6,000 such professionals in 1960. The SIR for occupation 001 within industry 842 was 1.06, based on 16 cases (95%CI = 0.611.72). We examined architects and allied professionals in other industries. The largest number of cases and the highest risk were associated with those in the home construction industry (SIR = 1.38; 95% CI = 1.06-1.76; 63 cases). However, most subjects in this group are engineers and construction supervisors, and not formally trained architects. Architects and allied professionals employed in other industries, such as highway construction (SIR = 0.91; 20 cases), or in government (SIR = 0.81; 7 cases) did not experience an increased risk. Architects and allied professionals employed in power plant construction had an elevated risk (SIR = 2.01), based on 3 cases. The histologic distribution of the renal cell cancers among the architects and allied professionals did not differ from other employed men in Sweden. For completeness, we also examined the occurrence of the second most common neoplasm of the kidney, renal pelvis cancer, in this occupational group and observed an SIR of 1.15, based on 14 cases (95% CI = 0.63-1.93). In the subgroup employed in architectural and
Renal Cell Cancer Among Architects
875
engineering firms, only one case of renal pelvis cancer was observed vs. 1.56 expected. DISCUSSION Our nationwide survey of 19 years of cancer incidence among Swedish architects and allied professionals did not reveal a significantly increased risk for renal cell cancer, as reported for Los Angeles architects (Lowery et al., 1991). With over 100 cases of renal cell cancer expected in the follow-up of this occupational group, we had at least 90% power to detect excess risks of 30%. The upper 95% confidence limit of 1.36 was far below the 4-fold proportional incidence ratio reported by Lowery et al. [1991]. A limitation of our study, however, is that the occupational code for architects in Sweden includes many other professionals involved in construction of homes, buildings, and other structures. In a subset of this professional group most likely to have a large percentage of architects, namely those employed in architectural and engineering firms, we found little increase in risk (SIR = 1.06) with an upper 95% confidence limit of 1.72, also far below the reported 4-fold ratio. Since architects appear to comprise less than half of these workers, an increased risk among architects might be diluted by a low SIR for the other professionals found in occupation code 001 in the architectural and engineering industry. However, the SIR of 1.06 for this more homogeneous subset compared with the SIR of 1.15 for the entire occupational group does not suggest such a relationship. Moreover, other professionals in these firms are likely to have similar activities as architects. Our negative results for renal cancer are consistent with an earlier survey of Swedish chemists and architects who graduated from one institute. No deaths from cancers of the urinary tract were noted among architects, whereas 1.5 deaths were expected [ O h and Ahlbom, 19801, In addition, a review of occupational cancer surveillance surveys revealed little evidence of an increased risk for renal cancer among architects [Dubrow and Wegman, 1983, 1984; California Department of Health Services, 1987; Milham, 1983; Petersen and Milham, 1980; Olsen and Jensen, 1987; Registrar General, 1978; Walrath et al., 19851. Further, there has been no report of an excess risk among architects in the case-control studies of renal cell cancer [McLaughlin et al., in press]. We did observe a significant 38% excess risk of renal cell cancer among occupation code 001 professionals employed in the home construction industry, but most members were engineers and construction supervisors and not architects. The reason for this elevated risk among professionals involved in home construction is unclear, but it is possible that occupational exposures, such as to asbestos [Selikoff et al., 19791 , may have played a role. Cigarette smoking may also explain some of the excess, since the cigarette smoking rate in 1963 of men 50-69 years of age for this occupation code was 3 1%, compared with 26% for Swedish men of the same age [Survey Research Institute, 19721. In summary, we found little evidence to suggest an excess risk for renal cell cancer in a Swedish professional group that included architects. However, an elevated risk was seen among engineers, construction supervisors, and others employed in home construction. Further studies of occupational determinants of renal cell cancer should be pursued in view of upward incidence trends for this tumor, particularly in the United States [Devesa et a]., 19901.
876
McLaughlin et al.
REFERENCES Bailar JC, Ederer F (1964): Significance factor for the ratio of a Poisson variable to its expectation. Biometrics 20:639-643. Devesa SS, Silverman DT, McLaughlin JK, Brown CC, Connelly RR, Fraumeni JF Jr (1990): Comparison of the descriptive epidemiology of urinary tract cancers. Cancer Causes and Control 1: 133-141. Dubrow R, Wegman DH (1983): Setting priorities for occupational cancer research and control: Synthesis of the results of occupational design surveillance studies J Natl Cancer Inst 71:1123-1142. Dubrow R, Wegman DH (1984): “Occupational Characteristics of White Male Cancer Victims in Massachusetts, 1971-1973.” Cincinnati: DHHS, PHS, CDC, NIOSH Pub No 84-109. California Department of Health Services (1987). “California Occupational Mortality, 1979-1981. ” Health and Welfare Agency, California. Linet MS, Malker HSR, McLaughlin JK, Weiner JA, Stone BF, Blot WJ, Ericsson JLE, Fraumeni JF Jr (1988): Leukemias and occupation in SweQen: A registry-based analysis. Am J Ind Med 14: 319-330. Lowery JT, Peters JM, Deapen D, London SJ (1991): Renal cell carcinoma among architects. Am J Ind Med 20:123-125. Malker HSR, McLaughlin JK, Blot WJ, Weiner JA, Malker BK, Ericsson JLE, Stone BJ (1986): Nasal cancer and occupations in Sweden, 1961-1979. Am J Ind Med 9:477-485. Malker HSR (1988): Register-epidemiology in the identification of cancer risks. Arbete Och Halsa 2 1:7-50. Mattson B, Wallgren A (1984): Completeness of the Swedish Cancer Register. Non-notified cancer cases recorded on death certificates in 1978. Acta Radio1 Oncol 23:305-313. McLaughlin JK, Malker HSR, Stone BJ, Weiner JA, Malker BK, Ericsson JLE, Blot WJ, Fraumeni JF Jr (1987): Occupational risks for renal cancer in Sweden. Br J Ind Med 44:119-123. McLaughlin JK, Blot WJ, Devesa SS, Fraumeni JF Jr (1991): Renal cancer. In Schottenfeld D, Fraumeni JF Jr (eds): “Cancer Epidemiology and Prevention.” 2nd ed. New York: Oxford University Press, (in press). Milham S (1983): “Occupational Mortality in Washington State 1950-1979.” USDHHS, PHS, CDC, NIOSH Pub1 NO 83-116. Olin GR, Ahlbom A (1980): The cancer mortality among Swedish chemists graduated during three decades: A comparison with the general population and with a cohort of architects. Environ Res 22: 154-161. Olsen JH, Jensen OM (1987): Occupation and risk of cancer in Denmark. Scand J Work Environ Health 13 (SUPPI):43-48. Petersen GR, Milham S (1980): “Occupational Mortality in the State of California, 1959-1961 .” USDHEW, PHS, CDC, NIOSH Pub1 NO 80-104. Registrar General (1978): “Occupational Mortality for England and Wales: Decennial Supplement, 1970-1972.” London: Her Majesty’s Stationery Office. Selikoff IJ, Hammond EC, Seidman H (1979): Mortality experience of insulation workers in the United States and Canada, 1943-1976. Ann N Y Acad Sci 330:91-116. Survey Research Institute (1972): “The Cigarette-A Study of Personality and Motives. ” Stockholm: National Control Bureau of Statistics (English summary only). Walrath J, Rogot E, Murray J, Blair A (1985): “Mortality Patterns Among U.S. Veterans by Occupation and Smoking Status.” USDHHS, PHS, NIH Pub1 No 85-2756.
Renal Cell Cancer Among Architects and Allied Professionals in Sweden Joseph K. McLaughlin, PhD, Hans S.R. Malker, PhD, William J. Blot, PhD, Jan A. Weiner, PE,B.J. Stone, PhD, Jan L.E. Ericsson, MD,and Joseph F. Fraumeni, Jr., M D
The Swedish Cancer-Environment Registry was used to evaluate a recent report of a large excess risk of renal cell cancer among architects in Los Angeles. We identified 131 renal cell cancers among male Swedish architects and allied professionals during a 19-year follow-up period (1961-1979). Compared with the Swedish population, there was no significant excess of renal cell cancer among architects and allied professionals (standardized incidence ratio (SIR) = 1.15; 131 cases). Although it was not possible to estimate the risk for architects alone, the SIR was only 1.06 (16 cases) in a subset of professionals employed in architectural and engineering firms. However, a significant increase in risk (SIR = 1.38) was observed in a related group of workers employed as engineers and construction supervisors in the home construction industry. 0 1992 Wiley-Liss, Inc.
Key words: linked-registry analysis, occupational cancer, kidney cancer, construction, asbestos
INTRODUCTION Lowery and colleagues [1991] recently reported an excess of renal cell cancer among architects in Los Angeles County, California, using a proportional incidence ratio (PIR) approach. Although only 3.1 cases were expected, 13 were observed (PIR = 420; 95% confidence interval (CI) = 2.23-7.71). No proportional excesses were observed among other professionals, such as medical care and administrative personnel, as reported by others [Dubrow and Wegman, 1984; McLaughlin et al., 19871. In our earlier report using the Swedish Cancer-Environment Registry (CER), we did not present data specific to architects, but only for the broad occupational category of all professional, technical, and related workers who, as a whole, had a significant excess risk of 20% for renal cell cancer based on 995 cases [McLaughlin et al., 19871. This report attempts to evaluate the risk among architects in Sweden, using the CER, which links employment data with cancer incidence for the time period, 1961-1979. National Cancer Institute, Division of Cancer Etiology, Epidemiology and Biostatistics Program, Bethesda, MD (J.K.M., W.J.B., B.J.S., J.F.F.). National Board of Occupational Safety and Health, Solna, Sweden (H.S.R.M.,J.A.W.). National Board of Health and Welfare, Stockholm, Sweden (J.L.E.E.). Address reprint requests to Dr. J.K. McLaughlin, National Cancer Institute, Executive Plaza North, Room 415, Bethesda, MD 20892. Accepted for Publication October 28, 1991.
0 1992 Wiley-Liss, Inc.
874
McLaughlin et al.
MATERIALS AND METHODS
The CER and the statistical procedures used to calculate the standardized incidence ratios (SIR) have been described in this journal [Malker et al., 1986; Linet et al., 19881. Briefly, the CER links employment data from the 1960 national census with the Swedish National Cancer Registry for the years 1961 to 1979. All SIRS are adjusted for age in 5-year birth cohorts and for regional differences, using 24 counties and 3 metropolitan areas. Statistical significance is tested under the assumption that the observed number of renal cell cancers follows a Poisson distribution [Bailer and Ederer, 19641. The high degree of completeness of the national cancer registry [Mattson and Wallgren, 19841 and the CER [Malker, 19881 have been demonstrated in a number of studies. The category of workers examined in this paper is architects and allied professionals (occupational code 00l), which includes not only architects, but also civil engineers, technicians, construction supervisors, and related professionals. In 1960, 40% of the individuals in this occupational group were employed in the home building industry, 26% in highway construction, 20% in architectural and engineering firms, 8% in government agencies, and 2% in power plant construction. RESULTS
Among employed Swedish men, 7,405 cases of renal cell cancer occurred between 1961 and 1979, of which 131 cases were diagnosed (vs. 113.5 expected) among architects and allied professionals for a non-significant SIR of 1.15 (95% CI = 0.97-1.36). In the 1960 Swedish census there were 36,386 men in this occupational category, compared with an estimated 2,500 formally trained architects, based on records from relevant organizations and unions (L. Furusten, personal communication). Because of the heterogeneity of this occupational category, we examined risks by occupation within industry. The industry most likely to have the largest proportion of architects would be architectural and engineering firms (industry code 842), which employed about 6,000 such professionals in 1960. The SIR for occupation 001 within industry 842 was 1.06, based on 16 cases (95%CI = 0.611.72). We examined architects and allied professionals in other industries. The largest number of cases and the highest risk were associated with those in the home construction industry (SIR = 1.38; 95% CI = 1.06-1.76; 63 cases). However, most subjects in this group are engineers and construction supervisors, and not formally trained architects. Architects and allied professionals employed in other industries, such as highway construction (SIR = 0.91; 20 cases), or in government (SIR = 0.81; 7 cases) did not experience an increased risk. Architects and allied professionals employed in power plant construction had an elevated risk (SIR = 2.01), based on 3 cases. The histologic distribution of the renal cell cancers among the architects and allied professionals did not differ from other employed men in Sweden. For completeness, we also examined the occurrence of the second most common neoplasm of the kidney, renal pelvis cancer, in this occupational group and observed an SIR of 1.15, based on 14 cases (95% CI = 0.63-1.93). In the subgroup employed in architectural and
Renal Cell Cancer Among Architects
875
engineering firms, only one case of renal pelvis cancer was observed vs. 1.56 expected. DISCUSSION Our nationwide survey of 19 years of cancer incidence among Swedish architects and allied professionals did not reveal a significantly increased risk for renal cell cancer, as reported for Los Angeles architects (Lowery et al., 1991). With over 100 cases of renal cell cancer expected in the follow-up of this occupational group, we had at least 90% power to detect excess risks of 30%. The upper 95% confidence limit of 1.36 was far below the 4-fold proportional incidence ratio reported by Lowery et al. [1991]. A limitation of our study, however, is that the occupational code for architects in Sweden includes many other professionals involved in construction of homes, buildings, and other structures. In a subset of this professional group most likely to have a large percentage of architects, namely those employed in architectural and engineering firms, we found little increase in risk (SIR = 1.06) with an upper 95% confidence limit of 1.72, also far below the reported 4-fold ratio. Since architects appear to comprise less than half of these workers, an increased risk among architects might be diluted by a low SIR for the other professionals found in occupation code 001 in the architectural and engineering industry. However, the SIR of 1.06 for this more homogeneous subset compared with the SIR of 1.15 for the entire occupational group does not suggest such a relationship. Moreover, other professionals in these firms are likely to have similar activities as architects. Our negative results for renal cancer are consistent with an earlier survey of Swedish chemists and architects who graduated from one institute. No deaths from cancers of the urinary tract were noted among architects, whereas 1.5 deaths were expected [ O h and Ahlbom, 19801, In addition, a review of occupational cancer surveillance surveys revealed little evidence of an increased risk for renal cancer among architects [Dubrow and Wegman, 1983, 1984; California Department of Health Services, 1987; Milham, 1983; Petersen and Milham, 1980; Olsen and Jensen, 1987; Registrar General, 1978; Walrath et al., 19851. Further, there has been no report of an excess risk among architects in the case-control studies of renal cell cancer [McLaughlin et al., in press]. We did observe a significant 38% excess risk of renal cell cancer among occupation code 001 professionals employed in the home construction industry, but most members were engineers and construction supervisors and not architects. The reason for this elevated risk among professionals involved in home construction is unclear, but it is possible that occupational exposures, such as to asbestos [Selikoff et al., 19791 , may have played a role. Cigarette smoking may also explain some of the excess, since the cigarette smoking rate in 1963 of men 50-69 years of age for this occupation code was 3 1%, compared with 26% for Swedish men of the same age [Survey Research Institute, 19721. In summary, we found little evidence to suggest an excess risk for renal cell cancer in a Swedish professional group that included architects. However, an elevated risk was seen among engineers, construction supervisors, and others employed in home construction. Further studies of occupational determinants of renal cell cancer should be pursued in view of upward incidence trends for this tumor, particularly in the United States [Devesa et a]., 19901.
876
McLaughlin et al.
REFERENCES Bailar JC, Ederer F (1964): Significance factor for the ratio of a Poisson variable to its expectation. Biometrics 20:639-643. Devesa SS, Silverman DT, McLaughlin JK, Brown CC, Connelly RR, Fraumeni JF Jr (1990): Comparison of the descriptive epidemiology of urinary tract cancers. Cancer Causes and Control 1: 133-141. Dubrow R, Wegman DH (1983): Setting priorities for occupational cancer research and control: Synthesis of the results of occupational design surveillance studies J Natl Cancer Inst 71:1123-1142. Dubrow R, Wegman DH (1984): “Occupational Characteristics of White Male Cancer Victims in Massachusetts, 1971-1973.” Cincinnati: DHHS, PHS, CDC, NIOSH Pub No 84-109. California Department of Health Services (1987). “California Occupational Mortality, 1979-1981. ” Health and Welfare Agency, California. Linet MS, Malker HSR, McLaughlin JK, Weiner JA, Stone BF, Blot WJ, Ericsson JLE, Fraumeni JF Jr (1988): Leukemias and occupation in SweQen: A registry-based analysis. Am J Ind Med 14: 319-330. Lowery JT, Peters JM, Deapen D, London SJ (1991): Renal cell carcinoma among architects. Am J Ind Med 20:123-125. Malker HSR, McLaughlin JK, Blot WJ, Weiner JA, Malker BK, Ericsson JLE, Stone BJ (1986): Nasal cancer and occupations in Sweden, 1961-1979. Am J Ind Med 9:477-485. Malker HSR (1988): Register-epidemiology in the identification of cancer risks. Arbete Och Halsa 2 1:7-50. Mattson B, Wallgren A (1984): Completeness of the Swedish Cancer Register. Non-notified cancer cases recorded on death certificates in 1978. Acta Radio1 Oncol 23:305-313. McLaughlin JK, Malker HSR, Stone BJ, Weiner JA, Malker BK, Ericsson JLE, Blot WJ, Fraumeni JF Jr (1987): Occupational risks for renal cancer in Sweden. Br J Ind Med 44:119-123. McLaughlin JK, Blot WJ, Devesa SS, Fraumeni JF Jr (1991): Renal cancer. In Schottenfeld D, Fraumeni JF Jr (eds): “Cancer Epidemiology and Prevention.” 2nd ed. New York: Oxford University Press, (in press). Milham S (1983): “Occupational Mortality in Washington State 1950-1979.” USDHHS, PHS, CDC, NIOSH Pub1 NO 83-116. Olin GR, Ahlbom A (1980): The cancer mortality among Swedish chemists graduated during three decades: A comparison with the general population and with a cohort of architects. Environ Res 22: 154-161. Olsen JH, Jensen OM (1987): Occupation and risk of cancer in Denmark. Scand J Work Environ Health 13 (SUPPI):43-48. Petersen GR, Milham S (1980): “Occupational Mortality in the State of California, 1959-1961 .” USDHEW, PHS, CDC, NIOSH Pub1 NO 80-104. Registrar General (1978): “Occupational Mortality for England and Wales: Decennial Supplement, 1970-1972.” London: Her Majesty’s Stationery Office. Selikoff IJ, Hammond EC, Seidman H (1979): Mortality experience of insulation workers in the United States and Canada, 1943-1976. Ann N Y Acad Sci 330:91-116. Survey Research Institute (1972): “The Cigarette-A Study of Personality and Motives. ” Stockholm: National Control Bureau of Statistics (English summary only). Walrath J, Rogot E, Murray J, Blair A (1985): “Mortality Patterns Among U.S. Veterans by Occupation and Smoking Status.” USDHHS, PHS, NIH Pub1 No 85-2756.
