Occupation and breast cancer mortality in a prospective cohort of US women.
The authors examined the association between main lifetime occupation and subsequent breast cancer mortality in a large prospective study of US adults. After 9 years of follow-up, 1,780 cases of fatal breast cancer were observed among 563,395 women who were cancer-free at interview in 1982. Main lifetime occupation was derived based on self-reports of current and former occupational titles and was classified into 14 broad occupational groups and 16 more narrowly defined occupational titles. Results from Cox proportional hazards models, adjusted for breast cancer risk factors, revealed little variability in breast cancer mortality by occupation. Two significant associations were observed: In comparison with housewives, women in "administrative support, including clerical" occupations were at a small increased risk (rate ratio (RR) = 1.14, 95% confidence interval (CI) 1.01-1.31), and an increased risk was seen for "executives" (RR = 1.93, 95% CI 1.03-3.62), based on 10 breast cancer deaths. No significant increases in risk were observed for teachers and librarians (RR = 0.89), nurses (RR = 0.84), managers (RR = 0.89), or women employed in sales (RR = 0.88) or service (RR = 0.84) occupations. When analyses were limited to women who had worked in their occupation for 10 or more years, the results for each occupational title were virtually unchanged. These results offer little support for an association between occupation and breast cancer mortality in general or for particular occupational titles, including teachers and nurses.
Calle
E E
EE
Department of Epidemiology and Surveillance Research, American Cancer Society, Atlanta, GA 30329-4251, USA.
Murphy
T K
TK
Rodriguez
C
C
Thun
M J
MJ
Heath
C W
CW
D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000209:etiology / Q000401:mortality*; D004522:Educational Status; D015914:Estrogen Replacement Therapy; D015444:Exercise; D005260:Female; D006801:Humans; D008875:Middle Aged; D009790:Occupations; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D013663:Teaching; D014481:United States; D014931:Women, Working / Q000145:classification