TY - JOUR
T1 - Breast cancer survival and the timing of tumor removal during the menstrual cycle
AU - Chang, Shine
AU - Hulka, Barbara S.
AU - Baird, Donna D.
AU - Ingle, James N.
AU - Newman, Beth
AU - Graham, Mark L.
AU - Qaqish, Bahjat
AU - Donohue, John H.
AU - Melton, L. Joseph
PY - 1997
Y1 - 1997
N2 - In a retrospective cohort study of 262 premenopausal breast cancer patients treated at the Mayo Clinic between 1965 and 1985, we investigated whether survival was associated with the timing of tumor removal during the menstrual cycle. Participants were women ≤50 years old who had not used exogenous hormones, been pregnant, been lactating, or given birth within 6 months of diagnosis. The menstrual cycle day at surgery was used to assign women to group 1 (cycle days 0-7), group 2 (cycle days 8-15), or group 3 (after cycle day 15); Cox proportional hazards analysis adjusting for age at diagnosis, stage, tumor size, grade, and node involvement showed a nonsignificantly worse survival for group 2 than for group 3 [hazard ratio (HR), 1.41; 95% confidence interval (CI), 0.89-2.23]. Stratification revealed that the association between survival and timing of tumor removal during the menstrual cycle was slightly stronger among patients with stage II disease (adjusted HR, 1.56; 95% CI, 0.92-2.63). The association was the same among patients with stage II disease and node involvement (adjusted HR, 1.57; 95% CI, 0.82-3.03). Prospective studies using hormone measurements to define menstrual cycle status more accurately than the reported day of the menstrual cycle could provide further insight about the postulated association.
AB - In a retrospective cohort study of 262 premenopausal breast cancer patients treated at the Mayo Clinic between 1965 and 1985, we investigated whether survival was associated with the timing of tumor removal during the menstrual cycle. Participants were women ≤50 years old who had not used exogenous hormones, been pregnant, been lactating, or given birth within 6 months of diagnosis. The menstrual cycle day at surgery was used to assign women to group 1 (cycle days 0-7), group 2 (cycle days 8-15), or group 3 (after cycle day 15); Cox proportional hazards analysis adjusting for age at diagnosis, stage, tumor size, grade, and node involvement showed a nonsignificantly worse survival for group 2 than for group 3 [hazard ratio (HR), 1.41; 95% confidence interval (CI), 0.89-2.23]. Stratification revealed that the association between survival and timing of tumor removal during the menstrual cycle was slightly stronger among patients with stage II disease (adjusted HR, 1.56; 95% CI, 0.92-2.63). The association was the same among patients with stage II disease and node involvement (adjusted HR, 1.57; 95% CI, 0.82-3.03). Prospective studies using hormone measurements to define menstrual cycle status more accurately than the reported day of the menstrual cycle could provide further insight about the postulated association.
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M3 - Article
C2 - 9367060
AN - SCOPUS:0030727514
SN - 1055-9965
VL - 6
SP - 881
EP - 886
JO - Cancer Epidemiology Biomarkers and Prevention
JF - Cancer Epidemiology Biomarkers and Prevention
IS - 11
ER -