Margaret M Lee1, Andrew MacKinlay2, Christine Semira3, Christine Schieber2, Antonio Jose Jimeno Yepes2, Belinda Lee4, Rachel Wong5, Chathurika K H Hettiarachchige2, Natalie Gunn2, Jeanne Tie6, Hui-Li Wong3, Iain Skinner7, Ian T Jones8, James Keck9, Suzanne Kosmider10, Ben Tran11, Kathryn Field12, Peter Gibbs6. 1. Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Medical Oncology, Western Health, Footscray, VIC, Australia; Medical Oncology, Eastern Health, Box Hill, VIC, Australia. Electronic address: Margaret.lee@monash.edu. 2. IBM Research, Australia Research Laboratory, Melbourne, VIC, Australia. 3. Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia. 4. Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Department of Medicine, University of Melbourne, Parkville, VIC, Australia. 5. Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Medical Oncology, Eastern Health, Box Hill, VIC, Australia. 6. Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Medical Oncology, Western Health, Footscray, VIC, Australia; Medical Oncology, Peter MacCallum Cancer Centre, Parkville, VIC, Australia. 7. Department of Surgery, University of Melbourne and Colorectal Surgery Unit, Western Health, Footscray, VIC, Australia. 8. Department of Surgery, University of Melbourne and Colorectal Surgery Unit, Royal Melbourne Hospital, Parkville, VIC, Australia. 9. Department of Surgery, Eastern Health, Box Hill, VIC, Australia. 10. Medical Oncology, Western Health, Footscray, VIC, Australia. 11. Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia; Medical Oncology, Peter MacCallum Cancer Centre, Parkville, VIC, Australia. 12. Department of Medicine, University of Melbourne, Parkville, VIC, Australia; Medical Oncology, Peter MacCallum Cancer Centre, Parkville, VIC, Australia.
Abstract
BACKGROUND: Multiple studies have defined the prognostic and potential predictive significance of the primary tumor side in metastatic colorectal cancer (CRC). However, the currently available data for early-stage disease are limited and inconsistent. MATERIALS AND METHODS: We explored the clinicopathologic, treatment, and outcome data from a multisite Australian CRC registry from 2003 to 2016. Tumors at and distal to the splenic flexure were considered a left primary (LP). RESULTS: For the 6547 patients identified, the median age at diagnosis was 69 years, 55% were men, and most (63%) had a LP. Comparing the outcomes for right primary (RP) versus LP, time-to-recurrence was similar for stage I and III disease, but longer for those with a stage II RP (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.52-0.90; P < .01). Adjuvant chemotherapy provided a consistent benefit in stage III disease, regardless of the tumor side. Overall survival (OS) was similar for those with stage I and II disease between LP and RP patients; however, those with stage III RP disease had poorer OS (HR, 1.30; 95% CI, 1.04-1.62; P < .05) and cancer-specific survival (HR, 1.55; 95% CI, 1.19-2.03; P < .01). Patients with stage IV RP, whether de novo metastatic (HR, 1.15; 95% CI, 0.95-1.39) or relapsed post-early-stage disease (HR, 1.35; 95% CI, 1.11-1.65; P < .01), had poorer OS. CONCLUSION: In early-stage CRC, the association of tumor side and effect on the time-to-recurrence and OS varies by stage. In stage III patients with an RP, poorer OS and cancer-specific survival outcomes are, in part, driven by inferior survival after recurrence, and tumor side did not influence adjuvant chemotherapy benefit. Crown
BACKGROUND: Multiple studies have defined the prognostic and potential predictive significance of the primary tumor side in metastatic colorectal cancer (CRC). However, the currently available data for early-stage disease are limited and inconsistent. MATERIALS AND METHODS: We explored the clinicopathologic, treatment, and outcome data from a multisite Australian CRC registry from 2003 to 2016. Tumors at and distal to the splenic flexure were considered a left primary (LP). RESULTS: For the 6547 patients identified, the median age at diagnosis was 69 years, 55% were men, and most (63%) had a LP. Comparing the outcomes for right primary (RP) versus LP, time-to-recurrence was similar for stage I and III disease, but longer for those with a stage II RP (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.52-0.90; P < .01). Adjuvant chemotherapy provided a consistent benefit in stage III disease, regardless of the tumor side. Overall survival (OS) was similar for those with stage I and II disease between LP and RP patients; however, those with stage III RP disease had poorer OS (HR, 1.30; 95% CI, 1.04-1.62; P < .05) and cancer-specific survival (HR, 1.55; 95% CI, 1.19-2.03; P < .01). Patients with stage IV RP, whether de novo metastatic (HR, 1.15; 95% CI, 0.95-1.39) or relapsed post-early-stage disease (HR, 1.35; 95% CI, 1.11-1.65; P < .01), had poorer OS. CONCLUSION: In early-stage CRC, the association of tumor side and effect on the time-to-recurrence and OS varies by stage. In stage III patients with an RP, poorer OS and cancer-specific survival outcomes are, in part, driven by inferior survival after recurrence, and tumor side did not influence adjuvant chemotherapy benefit. Crown