Effects of Chemotherapy-associated weight loss on pesticide burden and assessment of potential interference of pesticide exposure with the chemotherapy regimen

Over the past years, the concern over the health impact of pesticide exposure has dramatically increased. Population-based studies have reported an association between pesticide exposure and the emergence of chronic diseases such as cancer. Chemotherapy is still the most successful treatment across all cancer types next to surgical resection. For some cancer types (primarily cancers of the gastrointestinal tract as well as lung cancer), chemotherapy treatment can be accompanied by significant weight loss, often also as a consequence of the surgical intervention. As environmental pollutants such as pesticides and other persistant organic pollutants (POP) are often stored in adipose tissue, this tissue is a known source of chronic pollutant exposure. In case of significant weight loss, POP blood levels increase, their distribution within the body is altered and their detrimental effects can thereby be accentuated.
We hypothesize that the chronic pesticide burden impacts on cancer stem cell behavior and also generally influences the sensitivity of tumor cells towards chemotherapeutic drugs. These effects may become even more relevant during treatment-accompanied weight loss, as this may be associated with a acute increase of pesticide levels. For some pesticides, effects on cancer cells have previously been reported but how such affects may impact on treatment regimens remains unexplored.
In the proposed pilot study, we will recruit 20 patients suffering from different gastrointestinal cancer types (stomach, pancreas and colon cancer). Every patient will be monitored over treatment time by determining the concentration of a range of pesticides in hair and blood while additionally monitoring their body weight. In addition, we will use established patient-derived primary tumor cells (both differentiated and enriched in cancer stem cells) to address how pesticide burden and release may influence chemotherapy regimens.