Study type

Study type

Non-interventional study

Scope of the study

Effectiveness study (incl. comparative)
Non-interventional study

Non-interventional study design

Cohort
Other

Non-interventional study design, other

Secondary analysis of a clinical trial, incorporating observational data
Study drug and medical condition

Study drug International non-proprietary name (INN) or common name

OXALIPLATIN
FLUOROURACIL

Medical condition to be studied

Colon cancer stage II
Colon cancer stage III
Population studied

Age groups

Adults (65 to < 75 years)
Adults (75 to < 85 years)
Adults (85 years and over)

Estimated number of subjects

4500
Study design details

Main study objective

Specifically, we aim to estimate the expected effects of adjuvant chemotherapy with oxaliplatin versus 5-fluorouracil (5-FU) alone in routine care populations of older adults (age 65-75 years) diagnosed with stage II and III colon cancer.

Outcomes

All-cause mortality

Data analysis plan

We will reweight the entire MOSAIC trial population (i.e. both arms) who are aged 65-75 years at randomization to reflect the distribution of key covariates of patients aged 65-75 years with stage II and III colon cancer in the SEER-Medicare cohort initiating oxaliplatin (i.e. age at diagnosis, sex, stage of cancer (AJCC stage, substage), tumor size, (T1-4), lymph node involvement (0, 1, or 2+), differentiation (well, moderately, poor), and perforation (yes vs. no). We will then estimate the 3- and 5-year risk difference and 3- and 5-year risk ratio for all-cause mortality corresponding to the estimated “treatment effect in the treated” overall and by stage. We will use a similar weighting method to estimate a treatment effect in all patients who receive any treatment (or the estimated “treatment effect in the population”).