New Lesions versus Growth of Existing Disease: Does it impact prognosis? Axel Grothey¹, James Heun¹, Megan Branda¹, Richard M. Goldberg², Dan Sargent¹ ¹Mayo Clinic, Rochester, MN; USA ²University of North Carolina, Chapel Hill, NC; USA. Abstract ID: 2579. Results Multivariable Model 1
New Lesions versus Growth of Existing Disease: Does it impact prognosis?
Axel Grothey¹, James Heun¹, Megan Branda¹, Richard M. Goldberg², Dan Sargent¹
¹Mayo Clinic, Rochester, MN; USA
²University of North Carolina, Chapel Hill, NC; USA
Abstract ID: 2579
Multivariable Model for Evaluable Disease2
Multivariable Model for Measurable Disease3
Background: Clinical trials use established criteria (RECIST or WHO) to determine objective tumor status on therapy. Participants are defined to have progressive disease (PD) and are generally taken off study if they meet specific parameters of increase in size of their known lesions, or if they develop new lesions even without growth of known lesions. To determine whether there are outcome differences in these two mechanisms of progression, we explored post-progression survival (PPS) 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.
Methods: Patients who developed PD while receiving treatment on study were identified and reasons for progression were determined. PPS was compared among patients progressing due solely to the development of new lesions versus patients progressing for other causes (increase in known lesion size, clinical progression, ascites, pleural effusion, brain metastasis, or any combination of these).
Results: 726 patients developed PD while receiving treatment on study; reasons for progression were identified in 703 patients who were then included in this analysis. Development of new lesions was the only reason for progression in 158 patients (22.5%). Patients with progression due solely to the development of new lesions did not differ in survival compared with patients progressing for all other causes (HR 1.01, p=0.92). The lack of impact remained after controlling for length of treatment, treatment arm and baseline performance status.
Conclusions: In N9741, PPS after development of new lesions as the sole reason for progression did not significantly differ from patients with other reasons of PD. These findings give further validation to the use of new lesions as a classifier of PD according to established criteria.
Includes Brain Metastasis, Ascites and ‘Clinical Progression
1 - No Increase/No New Lesions excluded (N=27)
2 - Evaluable Increase (N=138) vs. New Evaluable Lesion (N=44)
3 - Measurable Increase (N=175) vs. New Measurable Lesion (N=112)
1- Both measurable and evaluable lesions
2- Includes brain metastasis, ascites, and “clinical progression”