Six months of oxaliplatin-based chemotherapy is the standard adjuvant therapy in stage III colon cancer.
Sensory-based neurotoxicity is a troublesome dose-limiting adverse effect of oxaliplatin
that can affect a patient’s quality of life.
Since the neurotoxicity of oxaliplatin depends on the cumulative dose,
could shorter adjuvant therapy be beneficial for patients if efficacy could be maintained?
This pooled analysis of concurrent randomized phase 3 trials evaluated noninferiority in 12,834 patients
randomized to three or six months of FOLFOX, a combination of oxaliplatin, fluorouracil, and leucovorin,
or CAPOX, a combination of oxaliplatin and capecitabine.
In the overall study population, noninferiority was not confirmed,
with a 3-year disease-free survival rate of 74.6% in patients randomized to 3 months of treatment
and 75.5% in patients randomized to 6 months.
The noninferiority of 3 versus 6 months was seen for CAPOX,
but 3 months of FOLFOX was inferior to 6 months.
In exploratory subgroup analyses of combined regimens, 3 months was noninferior to 6 months
for T1 to 3N1 disease, and 6 months was superior to 3 months for T4 and N2 cancers.
The authors conclude that noninferiority was not confirmed for the overall study population,
but that disease-free survival was strongly affected by treatment regimen and risk group.
Full trial results at NEJM.org