Primary tumor location and survival in colorectal cancer: A retrospective cohort study

Table 4 Overall survival sensitivity analyses

	Matched/weighted	HR (95%CI) of cetuximab vs bevacizumab, for LPTL	HR (95%CI) of cetuximab vs bevacizumab, for RPTL
	mOS (mo) for cetuximab vs bevacizumab
Main analysis with propensity score matching	27.9 vs 25.4	0.87 (0.63-1.19)	1.00 (0.68-1.46)
Planned sensitivity analyses
1:1 matching without a caliper (propensity score matching)	27.9 vs 21.7	0.76 (0.55-1.06)	0.91 (0.59-1.41)
2:1 matching without a caliper (propensity score matching)	27.9 vs 22.3	0.82 (0.61-1.11)	0.87 (0.58-1.29)
IPTW	27.9 vs 25.6	0.87 (0.63-1.19)	0.98 (0.65-1.49)
LPTL only (propensity score matching)	29.4 vs 30.5	0.88 (0.61-1.28)	NA
RPTL only (propensity score matching)	17.9 vs 20.4	NA	1.09 (0.74-1.63)
Change definition of tumor location (IPTW)
RPTL: C/A/HF; LPTL: transverse to rectum	27.9 vs 25.6	0.89 (0.66-1.20)	0.96 (0.61-1.53)
RPTL: C/A/HF to transverse; LPTL: splenic flexure to rectosigmoid	27.9 vs 26.6	0.98 (0.66-1.44)	0.98 (0.64-1.50)
RPTL: C/A/HF to transverse; LPTL: splenic flexure to descending/sigmoid	27.4 vs 25.8	0.93 (0.61-1.43)	0.98 (0.65-1.48)
RPTL: C/A/HF; LPTL: transverse to rectosigmoid	27.9 vs 26.6	1.02 (0.71-1.46)	0.95 (0.60-1.52)
RPTL: C/A/HF; LPTL: transverse to descending/sigmoid	27.4 vs 25.8	0.98 (0.67-1.45)	0.95 (0.60-1.50)
RPTL: C/A/HF; LPTL: splenic flexure to rectum	28.3 vs 25.8	0.88 (0.64-1.21)	0.96 (0.60-1.51)
RPTL: C/A/HF; LPTL: splenic flexure to rectosigmoid	28.3 vs 26.6	1.00 (0.68-1.47)	0.93 (0.59-1.48)
RPTL: C/A/HF; LPTL: splenic flexure to descending/sigmoid	28.3 vs 26.0	0.95 (0.62-1.46)	0.94 (0.60-1.47)
NRAS mutation–negative patients only (IPTW)	28.9 vs 26.0	0.77 (0.40-1.50)	1.03 (0.54-1.97)
Restricted to patients with chemotherapy backbone of FOLFIRI (IPTW)	24.6 vs 23.1	0.96 (0.64-1.44)	1.05 (0.62-1.77)
Restricted to patients with chemotherapy backbone of FOLFOX (IPTW)	Not reached vs 25.91	0.63 (0.37-1.08)	0.52 (0.23-1.17)
Change definition of index date (propensity score matching)2	27.8 vs 24.8	0.86 (0.61-1.20)	0.96 (0.64-1.44)
Restrict to stage IV patients (IPTW)	29.7 vs 29.4	0.98 (0.61-1.57)	0.99 (0.51-1.90)

¹P < 0.05.

²Index date defined as the earliest administration/non-cancelled order date of cetuximab or bevacizumab within the index line of therapy. C/A/HF: Cecum/ascending/hepatic flexure; CI: Confidence interval; FOLFIRI: 5-fluorouracil/leucovorin/irinotecan; FOLFOX: 5-fluorouracil/ leucovorin/oxaliplatin; HR: Hazard ratio; IPTW: Inverse probability of treatment weighting; LPTL: Left-sided primary tumor location; mOS: Median overall survival; NA: Not applicable; RPTL: Right-sided primary tumor location.