This clinical trial is for men and women with resectable or metastatic solid tumor malignancies. The objective of the study is to investigate whether high dose vitamin C infusion leads to pathological tumor response in resectable colorectal, pancreatic, and lung cancers.

Patients will receive high dose Vitamin C infusion for 4 days per week for 2-4 consecutive weeks prior to surgery. A tumor sample will be resected after completion of study drug (high dose vitamin C infusion) treatment to examine the effects of study drug. In addition, organoids will be grown in vitro and continue to be treated with vitamin C added in culture medium to examine tumor response.