Sociodemographic determinants of incidence of primary fallopian tube carcinoma, Finland 1953–97

Abstract

Primary fallopian tube carcinoma is very rare. In Western countries, it accounts for about 1% of all female genital malignant tumors. Its etiology remains poorly known, but high parity is considered to be protective. We studied determinants of incidence of primary fallopian tube carcinoma in Finland. Incidence rates for primary fallopian tube carcinoma, according to the population based Finnish Cancer Registry, from 1953-97 were assessed by age, year of diagnosis, and type of residential area. Standardized incidence ratios (SIRs) for the years 1971-95 were calculated by occupation and social class variables taken from the 1970 Population Census. There were 485 cases of primary fallopian tube carcinoma registered during 45 years. The age-adjusted incidence rate increased from 1.2/1,000,000 in 1953-57 to 5.4/ 1,000,000 in 1993-97. This 4.5-fold increase in incidence rate corresponds to a 7-fold increase in the number of new cases. The increase is attributable to the age group beyond 55 years, the peak incidence occurring between 60 -64 years. Although the relative increase in incidence rate has been larger in rural areas than in cities, the rate in the latter remains 2-fold. Women in the 2 highest social classes had a 1.8-fold incidence (95% CI ‫؍‬ 1.2-2.6) as compared to the lowest social class. Women in agriculture and those not working outside the home had only half the cancer incidence of those in academic or clerical occupations. The incidence of primary fallopian tube carcinoma increases in Finland. Evidently, the incidence has increased simultaneously with the affluence of urban life. Part of the variation in incidence correlates with variation in parity. © 2003 Wiley-Liss, Inc. Key words: primary fallopian tube carcinoma; incidence; social class; occupationPrimary fallopian tube carcinoma (PFTC) is a very rare but highly aggressive disease, reported to comprise 0.1-1.1% of all female genital malignancies. 1 PFTC was described for the first time by Renaud in 1847. 2 Although its etiologic factors are largely unknown, they have been considered to be similar to those of ovarian carcinoma. Histologically, most PFTCs are pure adenocarcinomas, the main type being serous adenocarcinoma. Occasional cases of endometrioid, clear cell, transitional cell, and glassy cell carcinomas have been reported. 3 Finland is an industrialized country with 5.2 million inhabitants. Most Finns live in urban communities. Finland is characterized by a relatively homogenous population and an effective nearly freeof-charge healthcare system. The nationwide population-based cancer registry allowed us to study incidence characteristics of PFTC over a period of 45 years in Finland. MATERIAL AND METHODSMore than 99% of all cancer cases have been reported to the Finnish Cancer Registry 1953. 4 In the 1990s, about 95% of the cases were microscopically confirmed, and about 1% of the cases based on death certificate only. 5 The Registry obtains information from hospitals and other institutions with inpatient beds, general practitioners, and pa...

The incidence of primary fallopian tube cancer in the United States

“…The U.S. incidence rate for PFTC (0.41 per 100,000) was similar to those reported in Denmark and Finland of 0.3 and 0.5 per 100,000, respectively [22,23]. White women in the United States had significantly higher rates of PFTC than other women, a finding consistent with ovarian cancer.…”

“…Incidence rates peaked at an older age (70-79) in our study, but most previous studies reported peak incidence occurring in the early 60s [15,22,27]. Population-based registries contributing data to these studies included cases diagnosed 10-50 years ago [15,22]; however, while our study included diagnoses from the last 4-9 years.…”

“…Nulliparity is a risk factor for ovarian cancer [25] and may explain some of the observed racial variability in risk of ovarian cancer according to a case-control study that compared differences in the obstetric experiences of white and black women [26]. Case-control studies probing PFTC and parity have yet to be published, however, a study linking registry data to census data in a Finnish population suggested that variations in PFTC incidence might be correlated with variations in parity [22]. Incidence rates were highest in urban areas and among higher social classes in Finland, and parity was low among these populations [22].…”

“…Case-control studies probing PFTC and parity have yet to be published, however, a study linking registry data to census data in a Finnish population suggested that variations in PFTC incidence might be correlated with variations in parity [22]. Incidence rates were highest in urban areas and among higher social classes in Finland, and parity was low among these populations [22]. In contrast to a previous study showing variable PFTC rates by geography [15], PFTC rates were generally similar among census regions in our study.…”

“…Population-based registries contributing data to these studies included cases diagnosed 10-50 years ago [15,22]; however, while our study included diagnoses from the last 4-9 years. The age difference observed between these studies and ours may be a reflection of the recent longer life expectancy of Americans, resulting in a greater number of cancer diagnoses among older people [28].…”