Blue and Amber Light Exposure in Patients With Rectal and Pancreatic Cancer

This study will evaluate light therapy used in combination with standard therapies for pancreatic and rectal cancer. Participants will receive chemotherapy, radiation, and surgical treatments identical to that they had not been involved in the study. The only alteration is that some participants will be exposed additionally to either blue or amber light using commercially available seasonal affective disorder (SAD) lights that are approved for human use. Participants will use the SAD light in their own homes throughout the course of their radiation and chemotherapy treatments. They will wear goggles that filter with the desired color of light. As a comparison, another group of participants will be exposed only to their usual lighting conditions. The assignment to blue light, amber light, or usual light groups will be random. In addition to the light exposure, participants will be asked to have 10 mL of blood drawn for research purposes at 4 time points. This blood will be analyzed for markers of inflammation and circadian clock activation. Participants also will be asked to complete surveys at 3 time points. These surveys will evaluate for effects changs in sleep, pain, and quality of life. Finally, participants will be asked to wear a small clip-on light sensor and a heart rate variability monitor for 7 days. These monitors will provide information on the level of light exposure and the participant\'s physiologic response to the light. For participants going on to surgery, we will obtain a small sample of the resected pancreas or rectal tumor for research analysis. The investigators will obtain this sample only after the necessarily analysis has been performed for their clinical care.