Role of organochlorine compounds in the etiology of pancreatic cancer: A proposal to develop methodological standards

Studies on the possible role of organochlorine compounds in the etiology of pancreatic and other cancers face a set of methodologic and logistic issue s that stem from the lipophilic nature of most organochlorines, and from th e fact that tumor-induced lipid mobilization. weight loss, and metabolic ch anges can be profound before diagnosis. The question thus arises: do the xe nobiotic concentrations in blood and adipose tissue result, in Dart, from s uch pathophysiologic changes! To assess and control potential selection and information biases, a flexible framework is warranted. It could be based o n indicators such as time elapsed between the first symptom of cancer and b lood or fat sample extraction; signs, symptoms and clinical status at the t ime of extraction; cholesterol and triglycerides levels; other laboratory f indings; tumor stage at diagnosis; diagnostic procedures; treatment type an d timing; clinical complications; and survival. Before adopting qualitative criteria and quantitative standards, their impact upon causal estimators s hould be assessed empirically.