"Among various natural compounds, quercetin has shown great anti-cancer and anti-inflammatory properties. In vitro and in vivo experiments have revealed that quercetin possesses a cytotoxic impact on ovarian cancer cells. Despite obtaining good results both in vitro and in vivo, few clinical studies have assessed the anti-cancer effects of quercetin particularly in the ovarian cancer."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7063794/
"In the last decades, several anticancer properties of quercetin have been described, such as cell signaling, pro-apoptotic, anti-proliferative and anti-oxidant effects, growth suppression. In fact, it is now well known that quercetin has diverse biological effects, inhibiting multiple enzymes involved in cell proliferation, as well as, in signal transduction pathways. On the other hand, there are also studies reporting potential synergistic effects when combined quercetin with chemotherapeutic agents or radiotherapy."
https://pubmed.ncbi.nlm.nih.gov/26264923/
"quercetin exerts its anti-cancer effects by modulating ROS, Akt, and NF-κB pathways. Quercetin could be used as a chemopreventive option as well as in combination with chemotherapeutic drugs to improve clinical outcomes of PCa patients."
https://pubmed.ncbi.nlm.nih.gov/29898731/
Epigallocatechin Gallate (EGCG) Is the Most Effective Cancer Chemopreventive Polyphenol in Green Tea
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3509513/
"EGCG inhibits growth, invasion, angiogenesis and metastasis of pancreatic cancer"
https://pubmed.ncbi.nlm.nih.gov/17981559/
"EGCG inhibited cell proliferation under hypoxia via the downregulation of HIF-1α and its downstream target gene VEGF levels, providing a theoretical basis for the early diagnosis and treatment of gastric cancer in clinic."
https://pubmed.ncbi.nlm.nih.gov/30657557/
"New research shows that the antioxidant, known as EGCG, binds to a protein found on tumor cells and dramatically slows their growth.
Researchers say previous studies have shown that green tea helps protect against a variety of cancers, such as lung, prostate, and breast, but the mechanisms for these effects are not known."
https://www.webmd.com/food-recipes/news/20040315/green-tea-cancer-fighting