Statistical analysis
comorbidity, colorectal Stage, cancer, colorectal and prostate, Nany, tumour, breast Stage, prostate cancer, AJCC, Cancer
RECURRENCE, CANCER, TUMOUR, REGRESSION, REGRESSION, PROSTATE CANCER, CANCER
For the breast, colorectal and prostate cohorts with a sample size of ~200 for each cohort the study was powered to estimate the baseline mean U-TXM with a precision of +/− 40 pg/mg creatinine with a 95% CI based on the U-TXM distribution of healthy individuals (mean 504 pg/mg, standard deviation 267 pg/mg) [Correlations between U-TXM levels and baseline subject demographics including age, male/female, weight as body mass index (BMI), tumour type, comorbidity, smoking status, concurrent medication, recent/ongoing cancer treatment, risk of recurrence, baseline blood counts including platelet number and inflammatory markers were explored. A higher risk of recurrence was defined for each tumour cohort based on American Joint Committee on Cancer (AJCC) TNM staging (7th edition) as follows: breast Stage III (Tany N2, T3 N1-2, T4 Nany), colorectal Stage III (Tany N1-2) or Stage IV, gastro-oesophageal Stage IIB or III and for prostate cancer D’Amico high risk as previously defined. Summary statistics and plots explored associations, then linear regression models were fitted. Regression models were based on log-transformed values of U-TXM to optimise model fit. Univariable models were fitted initially, then a multivariable model was constructed using forward stepwise procedures considering all of the covariates listed (Summary statistics were used to consider U-TXM values at the end of the run-in period (by tumour cohort) and after 3 months of randomised treatment (by treatment allocation). Participants ≥75 years were not included in the analysis of dose as they were not eligible for random allocation to the higher aspirin dose. End of run-in U-TXM (adjusted for baseline values) was considered according to baseline characteristics and previous therapy in univariable and multivariable linear models (based on log-transformed U-TXM values). U-TXM during randomised treatment is presented according to the treatment group and baseline factors, but modelling was not performed due to small numbers.