Most recent research suggests a low dose approach to chemotherapy dosing improves outcomes for cancer patients. Conventional chemotherapy regimen are made of high-dose, intermittent use of one or two chemotherapies. In metronomic chemotherapy, low doses of several chemotherapy agents are combined in an uninterrupted fashion.

The approach challenges the conventional wisdom of delivering chemotherapy drugs every 3 weeks at the highest possible doses, coined MTD, maximal tolerated dose—a toxic treatment schedule that not only leads to hair loss, vomiting, and extreme fatigue, but also damage the immune system, leaving patients vulnerable to new and recurring disease. Conventional chemotherapy regimens consist of drugs administration in cycles near or at the maximum tolerated dose (MTD), followed by a long drug-free period to permit the patient to recover from acute toxicities. Despite this strategy is successful in controlling the cancer process at the beginning, a significant number of patients tend to recurred or progress. The repertoire of drugs directed against tumor cells has greatly increased and metronomic chemotherapy (MC) could be an effective treatment option.

Metronomic chemotherapy, on the other hand, may offer more effective tumor control as well as fewer side effects. And it has a track record of patients surpassing their projected survival rates. This novel approach is rapidly changing the cancer treatment landscape.

The Metronomic Concept

Conventional chemotherapy kills all rapidly dividing cells whether they’re healthy or not. While the MTD approach may destroy the bulk of tumor cells, it often spares a number of cancer stem cells cells, which allows new, more aggressive tumors to grow and spread.

This metronomic approach inhibits the growth of cancer stem cells in the growing vascular network of the tumor. It hits cancer at the source while also suppressing the growth of resistant cells. In addition, patients who are too weak to tolerate standard MTD chemotherapy regimens may be able to withstand a low-dose, continuous metronomic protocol. Most importantly, taking a steady, pulsed, low-dose metronomic approach to treatment not only minimizes toxicity, it also allows patients to receive multiple chemotherapy drugs simultaneously. Because of the low toxicity, multiple chemotherapy medicines can be given weekly or bi-weekly instead of every three or four weeks.

Metronomic chemotherapy increased patient outcomes and showed clinical benefit from 30 to 90 %) in most cancers, such as advanced breast cancer, recurrent ovarian cancer and advanced cancer of various tumor types. Last but not least, Metronomic chemotherapy could induce tumor response in those cases that showed acquired drug resistance after conventional MTD chemotherapies.