Cancer risks among female farmers in Sweden

Abstract

There are few studies on cancer risks among female farmers, particularly on breast cancer and cancer in female genital organs. We have conducted a cohort study of cancer risk among 50,682 women with occupations in agriculture according to the Swedish 1970 census. The cohort was followed up in the nationwide, population-based, Cancer-Environment Register from 1 January 1971 until death or until 31 December 1987. Expected number of cases was based on annual cancer incidence in five-year age groups. The standardized incidence ratio (SIR) was computed as the ratio between observed and expected number of cases. A total of 4,474 cases of cancer were observed in the cohort from 1971 until 1987 cf 5,273 expected, resulting in a significantly decreased SIR of 0.85 (95 percent confidence interval [CI] = 0.82-0.87). SIR for breast cancer was significantly decreased (0.83, CI = 0.78-0.88), as was the SIR for cervix uteri (0.40, CI = 0.31-0.50). For the other female genital organs, SIR was close to one. Other cancer sites with significantly decreased SIRs were: colon (0.90, CI = 0.81-1.00); rectum (0.86, CI = 0.74-1.00); lung (0.46, CI = 0.37-0.57); kidney (0.81, CI = 0.68-0.97); urinary organs (0.57, CI = 0.45-0.72); connective tissue and muscle (0.62, CI = 0.39-0.95); and non-Hodgkin's lymphomas (0.78, CI = 0.63-0.96).

Meta-analyses of non-Hodgkin's lymphoma and farming

“…Four studies were restricted to female farmers (57)(58)(59)(60), and 7 studies reported results for both male and female farmers (6,39,40,(61)(62)(63)(64). Four studies (20,53,65,66) lacked information about gender.…”

Etiologic clues to lip cancer from epidemiologic studies on farmers

“…One study (12) was restricted to women, and 4 studies provided data for female farmers (table 2). Nine studies provided data on malignant melanoma and nonmelanotic skin cancer (table 3).…”

Multiple myeloma: A review of the epidemiologic literature

“…64,65 Studies in the United States, Canada and Europe have reported 6-28% reductions in overall mortality and/or cancer mortality when compared to rates in the general population. 64,[66][67][68][69][70][71][72][73][74][75] The lower overall mortality rate among farmers may be attributable to healthier lifestyle practices. As an occupational group, farmers have a lower incidence of smoking-related cancers, 64,66,67,70,72,73 reflecting lower smoking rates.…”

“…[76][77][78][79] In addition, agricultural work may be considered a salubrious lifestyle, encompassing physically demanding activities that require exercise, strength and stamina, as well as dietary choices rich in fresh foods. 76 Findings from studies of farming and multiple myeloma have been mixed, however, ranging from relative risk estimates below 1.0 64,65,67,[69][70][71][72][73] to increased risks in excess of 3-fold, 70,71 either overall or for specific subgroups.…”