Megestrol Acetate With or Without Pterostilbene in Treating Patients With Endometrial Cancer Undergoing Hysterectomy

Inclusion Criteria: * Documented informed consent of the participant and/or legally authorized representative * Willing to undergo an intraoperative biopsy/or standard of care tissue collection during surgery, following completion of treatment with MA +/- PTE * Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 * Histologically confirmed EC or complex atypical hyperplasia of the endometrium * Candidate for a total hysterectomy with or without bilateral salpingo-oophorectomy * About to initiate preoperative window period, with planned hysterectomy scheduled * Platelets \>= 100,000/mm\^3 * NOTE: Platelet transfusions are not permitted within 14 days of platelet assessment unless cytopenia is secondary to disease involvement * Total bilirubin =\< 1.5 X upper limit of normal (ULN) * Aspartate aminotransferase (AST) =\< 1.5 x ULN * Alanine aminotransferase (ALT) =\< 1.5 x ULN * Creatinine clearance of \>= 60 mL/min per 24 hour urine test or the Cockcroft-Gault formula * Women of childbearing potential: negative urine or serum pregnancy test in premenopausal women. Postmenopausal women do not need to undergo a pregnancy test. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required Exclusion Criteria: * Pterostilbene supplements within 30 days prior to day 1 of protocol therapy * Any of the following phytochemical-based supplements within 30 days prior to day 1 of protocol therapy: resveratrol, genistein, and q…