For example, for early stage colorectal cancer patients, surgeries such as polypectomy or colectomy are usually performed to remove the cancerous and surrounding tissues. Under the current cancer treatment guideline, the majority of stage II patients do not receive adjuvant chemotherapy even though around 27% of patients eventually develop undetected micro-metastasis and die from the cancer.
On the other hand, even though only about half of the stage III patients eventually develop micro-metastasis, nearly all of them receive adjuvant chemotherapies such as FOLFOX, meaning half of the patients still suffer from toxicity and unnecessary medical treatments and costs despite had already been cured by the surgery. According to the Annals of Oncology, “(a) difficult issue is who benefits from what? Should all stage II and III patients receive adjuvant chemotherapy, and if no which ones?” and “there is an urgent need for prognostic and predictive markers to better decide who should receive adjuvant chemotherapy”