Table 1.

Similarities, differences and lessons from the use of nanomedicines and metronomic chemotherapy to treat solid tumors.

Similarities	Differences	Recent lessons
Both nanomedicine and metronomic chemotherapy can:	Nanomedicines differ from metronomic chemotherapy in that:	The biggest lesson from nanomedicine and metronomic chemotherapy today is that:
i) maintain effective drug levels in the blood for long duration	i) nanomedicines can exhibit improved accumulation to tumor tissue (EPR effect) and target to cancer cells	i) with the use of nanomedicines the accumulation of drug is not as high as initially hoped for [4]
ii) induce vascular normalization	ii) nanomedicines are likely to have less adverse effects on normal tissues, except the liver
iii) improve tumor perfusion and oxygenation	iii) nanomedicines can exhibit limited penetration into tumor tissue owing to their large size	ii) certain chemotherapeutic agents can actually increase immune-response, while others do the opposite [28]
iv) improve drug delivery and treatment efficacy	iv) nanomedicines require less frequent dosing
v) potential to make the tumor microenvironment more immune-supportive	v) a few nanoparticles have been approved for clinical use, but metronomic therapy is not yet approved