Organochlorine insecticides DDT and chlordane in relation to survival following breast cancer

Abstract

Organochlorine insecticides have been studied extensively in relation to breast cancer incidence and results from two meta-analyses have been null for late-life residues, possibly due to measurement error. Whether these compounds influence survival remains to be fully explored. We examined associations between organochlorine insecticides (p,p’-DDT, its primary metabolite, p,p’-DDE, and chlordane) assessed shortly after diagnosis and survival among women with breast cancer. A population-based sample of women diagnosed with a first primary invasive or in situ breast cancer in 1996–1997 and with available organochlorine blood measures (n=633) were followed for vital status through 2011. After follow-up of 5 and 15 years, we identified 55 and 189 deaths, of which 36 and 74, respectively, were breast cancer-related. Using Cox regression models, we estimated the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for lipid-adjusted organochlorine concentrations with all-cause and breast cancer-specific mortality. At 5 years after diagnosis, the highest tertile of DDT concentration was associated with all-cause (HR=2.19; 95%CI: 1.02, 4.67) and breast cancer-specific (HR=2.72; 95%CI: 1.04, 7.13) mortality. At 15 years, middle tertile concentrations of DDT (HR=1.42; CI 0.99, 2.06) and chlordane (HR=1.42; 95%CI: 0.94, 2.12) were modestly associated with all-cause and breast cancer-specific mortality. Third tertile DDE concentrations were inversely associated with 15-year all-cause mortality (HR=0.66; 95%CI: 0.44, 0.99). This is the first population-based study in the United States to show that DDT may adversely impact survival following breast cancer diagnosis. Further studies are warranted given the high breast cancer burden and the ubiquity of these chemicals.

Organochlorine pesticide residues in human breast tissue and their relationships with clinical and pathological characteristics of breast cancer

“…However, a recent study of 633 women diagnosed with invasive or in situ breast cancer found that organochlorines may adversely impact survival. The highest tertile of lipid‐adjusted p,p′ ‐DDT concentration in serum, but not p,p′ ‐DDE concentration, was associated with all‐cause (hazard ratio, 2.19; 95% CI, 1.02–4.67) and breast cancer‐specific (hazard ratio, 2.72; 95% CI, 1.04–7.13) mortality at five years after diagnosis, supporting the adverse health effects of pesticide exposure …”

Toxic Effects of Organochlorine Pesticides: A Review

“…On subsequent poor healing, scarring and contracture formation occurs on skin [13]. Organochlorines may also have carcinogenic effects [14][15][16][17][18][19][20]. Respiratory depressions may also occur.…”

Genetic polymorphisms of diabetes‐related genes, their interaction with diabetes status, and breast cancer incidence and mortality: The Long Island Breast Cancer Study Project

“…Details of the LIBCSP follow‐up design and ascertainment of vital status have also been previously reported . In brief, the National Death Index (NDI), a centralized database of death record information maintained by the National Center for Health Statistics, was used to ascertain date and cause of death for the women with BC.…”