DOES LOCATION MATTER IN COLORECTAL CANCER: LEFT VS RIGHT? By: Dr. Dominik Modest, Medical Department III, Hospital of the University of Munich, Germany Dr. Andrea Sartore-Bianchi, Niguarda Cancer Center, Milano, Italy Dr. Sebastian Stintzing Medical Department III, Hospital of the University of Munich, Germany
RIGHT AND LEFT COLON: ANATOMY The large intestine can be divided into right and left sides. Although the anatomical limits are not standardised in the literature, the right colon comprises the caecum, ascending colon and transverse colon up to the splenic flexure; the left colorectum comprises the splenic flexure, descending colon, sigmoid colon and rectum (the rectum is sometimes included as left colorectum and sometimes considered a separate entity). Right (proximal) colon Transverse colon Hepatic flexure Ascending colon Caecum Left (distal) colorectum Splenic flexure Descending colon Sigmoid colon Rectum Lee GH, et al. Eur J Surg Oncol 2015; Li F, Lai M. J Zhejiang Univ Sci B 2009; Iacopetta B. Int J Cancer 2002
RIGHT AND LEFT COLON: ANATOMY AND GENETIC FEATURES The right colon and left colorectum have different embryonic origins and vascular supplies: the right colon originates from the midgut and blood is supplied by branches of the superior mesenteric artery and the capillary network is multi-layered; innervation derives from the vagus nerve the left colorectum originate from the hindgut and blood is supplied by tributaries from the inferior mesenteric artery and innervation is from fibres of S2 S4 Genetic profiling of normal right and left colon mucosa has confirmed major differences between colorectal sites; 351 genes have been identified as differentially expressed between the right and left colon: 157 overexpressed in the right colon and 194 in the left colon Li F, J Zhejiang Univ Sci B 2009; Missiaglia E, et al. Ann Oncol 2014
RIGHT AND LEFT COLORECTAL CANCER The site distribution of colorectal tumours is 28% (range 19 38%) for the right colon and 72% (range 63 81%) for the left colorectum In Western countries, there is evidence that the incidence of right-sided tumours has increased while that of left-sided tumours has decreased over time Symptoms associated with tumours in the right colon are often subtle, whereas those associated with tumours in the left colorectum may be more pronounced, such as rectal bleeding or changes in bowel habit Patients with right-sided tumours typically present with more advanced tumour stage than those with left-sided disease More common features of right-sided tumours compared with left include high TNM stage, large tumour size, vascular invasion, mucinous type, high grade and invasive tumour border Right-sided colon tumours appear to be more common in women than in men Lee GH, et al. Eur J Surg Oncol 2015; Riihimäki M, et al. Sci Rep 2016; Benedix F, et al. Dis Colon Rectum 2010; Brenner H, et al. Int J Cancer 2012; Li F, Lai M. J Zhejiang Univ Sci B 2009; Icopetta B. Int J Cancer 2002
RIGHT AND LEFT COLORECTAL CANCERS: DIFFERENCES IN MOLECULAR BIOMARKERS There are associations between tumour location and the frequency of gene mutations or expression levels of proteins involved in CRC signalling pathways In a retrospective analysis of data from a US cohort of mcrc patients whose tumours underwent molecular testing between 2007 and 2010 (n=431) BRAF mutations were significantly more common in the right colon (14%) than either the left colon (5%) or rectum (2%) (P < 0.001) KRAS mutations were observed at similar frequencies across the colon and rectum (P = 0.51) VEGFR2 expression levels were significantly higher in rectal tumours (1.77; range, 0.23 13.00) than left-sided colon (1.24; range, 0.18 7.66) or right-sided colon (1.10; range, 0.24 6.10) tumours (P < 0.001 for both comparisons) In another study, important signalling pathways including MAPK and ErbB were more frequently mutated in tumours from the right colon compared with the left. Analysis of genes differentially expressed between right-sided and left-sided colon tumours revealed EREG (EGF ligand) to be among the most over-expressed genes in distal carcinomas Maus MKH, et al. Pharmacogenomics J 2015;15:354 62; Missiaglia E, et al. Ann Oncol 2014;25:1995 2001
SIDENESS AND RESPONSE TO TARGETED THERAPY Given the different genetic make-up of colon arising in the left versus right side, differential outcomes have been reported with the use of EGFR- or VEGF-targeted treatments according to sideness Here we will present these data and their impact on results from phase III trials in mcrc
PROGNOSTIC IMPACT OF SIDENESS IN CRC-SEERS DATA Presented by D Schrag at ASCO 2016
Probability of PFS Probability of OS FIRE-3: RIGHT-SIDED TUMOURS AND EFFICACY OF MABS Progression-free survival Overall survival 1.0 Right-sided mcrc Cetuximab + FOLFIRI (n=38) Bevacizumab + FOLFIRI (n=50) 1.0 Right-sided mcrc Cetuximab + FOLFIRI (n=38) Bevacizumab + FOLFIRI (n=50) 0.8 HR = 1.44 (95% CI: 0.92 2.26) p = 0.11 0.8 HR = 1.31 (95% CI: 0.81 2.11) p = 0.28 0.6 0.6 cetuximab 0.4 cetuximab bevacizumab 0.4 bevacizumab 0.2 0.2 0.0 7.6 9.0 0 12 24 36 48 60 72 Months 0.0 18.3 23.0 0 12 24 36 48 60 72 Months Numbers atrisk Numbers atrisk Cetuximab + FOLFIRI 38 10 0 0 0 0 0 Bevacizumab + FOLFIRI 50 16 1 0 0 0 0 Cetuximab + FOLFIRI 38 24 10 4 1 1 0 Bevacizumab + FOLFIRI 50 37 16 7 1 0 0 Tejpar et al, JAMA Oncol 2017
Probability of PFS Probability of OS FIRE-3: LEFT-SIDED TUMOURS AND EFFICACY OF MABS Progression-free survival Overall survival A 1.0 Left-sided mcrc Cetuximab + FOLFIRI (n=157) Bevacizumab + FOLFIRI (n=149) B 1.0 Left-sided mcrc Cetuximab + FOLFIRI (n=157) Bevacizumab + FOLFIRI (n=149) 0.8 HR = 0.90 (95% CI: 0.71 1.14) p=.38 0.8 HR = 0.63 (95% CI: 0.48 0.85) p = 0.002 0.6 0.6 0.4 cetuximab 0.4 bevacizumab cetuximab bevacizumab 0.2 0.2 28.0 38.3 10.7 10.7 0.0 0 12 24 36 Months 48 60 72 0.0 0 12 24 36 48 Months 60 72 Numbers atrisk Numbers atrisk Cetuximab + FOLFIRI 157 60 17 10 6 4 0 Bevacizumab + FOLFIRI 149 56 13 7 2 0 0 Cetuximab + FOLFIRI 157 131 77 38 23 6 0 Bevacizumab + FOLFIRI 149 120 76 31 11 3 0 Tejpar et al, JAMA Oncol 2017
CALGB/SWOG 80405 [FOLFOX OR FOLFIRI +MAB]: OVERALL SURVIVAL BY BIOLOGIC (RIGHT SIDED PRIMARY) Arm N (Events) Median (95% CI) HR (95% CI) Adjusted p Bev Cetux 78 (58) 71 (56) 29.2 (22.4-36.9) 1.36 13.7 (0.93-1.99) (11.3-19.0) 0.10 Presented by Lenz et al, ESMO 2016
CALGB/SWOG 80405 [FOLFOX OR FOLFIRI +MAB]: OVERALL SURVIVAL BY BIOLOGIC (LEFT SIDED PRIMARY) Presented by Lenz et al, ESMO 2016
Kaplan-Meier estimate PRIME OS FIRST LINE EFFICACY OF PANITUMUMAB BY SIDEDNESS 100 80 60 40 Median OS (95% CI), months Pmab + FOLFOX FOLFOX HR (95% CI) Left 30.3 (25.8 36.1) 23.6 (18.2 26.9) 0.73 (0.57 0.93) Right 11.1 (8.1 25.2) 15.4 (9.1 21.7) 0.87 (0.55 1.37) 1: Pmab + FOLFOX left 2: FOLFOX left 3: Pmab + FOLFOX right 4: FOLFOX right 20 No. of subjects: 1: 2: 3: 4: 0 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 Overall survival (months) 169 159 39 49 164 151 36 42 Censor indicated by vertical bar 147 137 26 34 136 120 18 28 124 103 17 23 107 86 15 20 97 76 13 14 86 64 11 11 77 56 8 9 66 44 6 8 56 32 5 7 46 24 4 6 39 21 4 5 30 19 4 4 16 11 3 1 11 6 1 1 3 1 1 0 0 1 0 HR, hazard ratio; OS, overall survival; Pmab, panitumumab Presented by Peeters et al, ESMO 2016
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