Reasons for delay in time to initiation of adjuvant chemotherapy (AC) for colon cancer (CC).

Abstract

e14553 Background: AC improves survival among patients with colon cancer. Two meta-analyses have demonstrated a decrease in survival with increasing time to AC (TTAC). Here, we examine the predominant factors leading to delay in TTAC. Methods: Individual medical records of 565 patients with CC who initiated AC Aug 2005-Nov 2010 in Eastern Ontario were reviewed to capture patient and treatment characteristics including: medical comorbidities, post-operative complications, the reason if AC was not ordered after initial medical oncology (MO) consultation, dates of surgery, referral to MO, MO consult, central venous catheter (CVC) insertion, and first cycle of AC. Patients were then categorized into two groups: (i) medical/surgical reason for delay (MSRD), defined as post-operative complications or intercurrent illness, and (ii) No MSRD. No MSRD patients were further subcategorized as post-MO delay (PMOD), defined as AC deferred at time of consultation due to patient preference or further investigations required, vs. No PMOD. A multivariate logistic regression model was used to determine factors associated with TTAC > 8 weeks (w). Results: In the No MSRD group (n= 423), 25% (n=107) were subdivided into the PMOD subgroup. On multivariate analysis, TTAC >8w was significantly associated with the presence of a MSRD [OR = 2.4 (1.6-3.9), p = <0.001] or PMOD [OR = 3.3 (1.9-5.6), p = <0.001]. No other significant associations were found, including oral vs. IV AC. Proportion of cases with TTAC >8w in the subgroups were: MSRD 76.1% (n = 108); PMOD 80.4% (n = 86); No PMOD 57.6% (n = 182). Conclusions: MSRD and PMOD are strong predictors of increased TTAC; however, the majority of patients have no MSRD or PMOD. TTAC in this group is 9 weeks. This suggests that TTAC is modifiable, and likely reflects delays in referral, consultation, and chemotherapy booking. [Table: see text]