A review of relative dose intensity and survival in patients with metastatic solid tumors

• Few studies analyzed the association of RDI with outcomes in metastatic disease.
• The effect of RDI on survival in metastatic or recurrent cancer remains unclear.
• Researchers are using various methods to calculate RDI.
• The methods for calculating RDI are often not clearly discussed in the publications.

Studies have shown that in the curative setting patients with cancer receiving chemotherapy at higher relative dose intensity (RDI) had better clinical outcomes than those receiving treatment at lower RDI. However, the impact of RDI in advanced/metastatic disease remains unclear. A review of the literature was performed to evaluate the relationship between RDI and survival in patients with metastatic lung, breast, or ovarian cancer receiving chemotherapy. Few studies attempted to specifically associate RDI with survival in a systematic way. Findings from studies that analyzed overall survival with a prespecified RDI threshold support the emerging perception that maintaining an RDI ≥ 85% has a favorable impact on survival. Nonetheless, these studies were limited by their retrospective nature. More studies are needed to further evaluate the impact of maintaining planned chemotherapy dose intensity on outcomes in metastatic solid tumors.