New lesions versus growth of existing disease: Does it impact prognosis? ASCO Meeting Abstract

Note: this study concerns the clinical criteria for evidence of progressive/new disease 

Conclusions:

In 9,741 (patients), survival after development of new lesions as the sole reason for progression did not significantly differ from patients with other reasons of PD (progressive disease). These findings give further validation to the use of new lesions as a classifier of PD according to established criteria. (RECIST)

Background:

Clinical trials use established criteria (RECIST or WHO) to determine objective tumor behavior on therapy. Participants are labeled to have progressive disease (PD) and are taken off study if they meet specific parameters of increase in size of their known lesions, but can also be labeled as PD if they develop new lesions without meeting criteria for progression in known lesions. To determine whether there are outcome disparities among these patients, we explored survival differences by reason of progression among patients who developed PD on study using data from the phase III Intergroup trial N9741 which compared IFL, FOLFOX4, and IROX as first-line therapy in advanced colorectal cancer (Goldberg JCO 2004).