1. Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018;68(6):394-424.
2. Van Cutsem E, Nordlinger B, Cervantes A, Group EGW. Advanced colorectal cancer: ESMO Clinical Practice Guidelines for treatment. Ann Oncol. 2010;21 Suppl 5:v93-7.
3. Van Cutsem E, Nordlinger B, Adam R, Köhne CH, Pozzo C, Poston G, et al. Towards a pan-European consensus on the treatment of patients with colorectal liver metastases. Eur J Cancer. 2006;42(14):2212-21.
4. Zaydfudim VM, McMurry TL, Harrigan AM, Friel CM, Stukenborg GJ, Bauer TW, et al. Improving treatment and survival: a population‐based study of current outcomes after a hepatic resection in patients with metastatic colorectal cancer. Hpb. 2015;17(11):1019-24.
5. Cummings LC, Payes JD, Cooper GS. Survival after hepatic resection in metastatic colorectal cancer: a population-based study. Cancer. 2007;109(4):718-26.
6. National Comprehensive Cancer Network. Colon Cancer (Version 1.2020). Available at http://www.nccn.org/professionals/physician_gls/ pdf/colon.pdf. Access Dec 19, 2019.
7. Tarantino I, Warschkow R, Worni M, Cerny T, Ulrich A, Schmied BM, et al. Prognostic Relevance of Palliative Primary Tumor Removal in 37,793 Metastatic Colorectal Cancer Patients: A Population-Based, Propensity Score-Adjusted Trend Analysis. Annals of surgery. 2015;262(1):112-20.
8. ’t Lam-Boer J, Van der Geest LG, Verhoef C, Elferink ME, Koopman M, de Wilt JH. Palliative resection of the primary tumor is associated with improved overall survival in incurable stage IV colorectal cancer: A nationwide population-based propensity-score adjusted study in the Netherlands. Int J Cancer. 2016;139(9):2082-94.
9. Xu H, Xia Z, Jia X, Chen K, Li D, Dai Y, et al. Primary Tumor Resection Is Associated with Improved Survival in Stage IV Colorectal Cancer: An Instrumental Variable Analysis. Sci Rep. 2015;5:16516.
10. Mehta HB, Vargas GM, Adhikari D, Dimou F, Riall TS. Comparative effectiveness of chemotherapy vs resection of the primary tumour as the initial treatment in older patients with Stage IV colorectal cancer. Colorectal Dis. 2017;19(6):O210-O8.
11. Ahmed S, Leis A, Fields A, Chandra-Kanthan S, Haider K, Alvi R, et al. Survival impact of surgical resection of primary tumor in patients with stage IV colorectal cancer: results from a large population-based cohort study. Cancer. 2014;120(5):683-91.
12. Alawadi Z, Phatak UR, Hu CY, Bailey CE, You YN, Kao LS, et al. Comparative effectiveness of primary tumor resection in patients with stage IV colon cancer. Cancer. 2017;123(7):1124-33.
13. Kanemitsu Y, Shitara K, Mizusawa J, Hamaguchi T, Shida D, Komori K, et al. A randomized phase III trial comparing primary tumor resection plus chemotherapy with chemotherapy alone in incurable stage IV colorectal cancer: JCOG1007 study (iPACS). Journal of Clinical Oncology. 2020;38(4_suppl):7-.
14. Hu CY, Bailey CE, You YN, Skibber JM, Rodriguez-Bigas MA, Feig BW, et al. Time trend analysis of primary tumor resection for stage IV colorectal cancer: less surgery, improved survival. JAMA Surg. 2015;150(3):245-51.
15. Mik M, Berut M, Dziki L, Trzcinski R, Dziki A. Right- and left-sided colon cancer - clinical and pathological differences of the disease entity in one organ. Arch Med Sci. 2017;13(1):157-62.
16. Benedix F, Kube R, Meyer F, Schmidt U, Gastinger I, Lippert H. Comparison of 17,641 patients with right- and left-sided colon cancer: differences in epidemiology, perioperative course, histology, and survival. Dis Colon Rectum. 2010;53(1):57-64.
17. Yamauchi M, Morikawa T, Kuchiba A, Imamura Y, Qian ZR, Nishihara R, et al. Assessment of colorectal cancer molecular features along bowel subsites challenges the conception of distinct dichotomy of proximal versus distal colorectum. Gut. 2012;61(6):847-54.
18. Tejpar S, Stintzing S, Ciardiello F, Tabernero J, Van Cutsem E, Beier F, et al. Prognostic and Predictive Relevance of Primary Tumor Location in Patients With RAS Wild-Type Metastatic Colorectal Cancer: Retrospective Analyses of the CRYSTAL and FIRE-3 Trials. JAMA Oncol. 2017;3(2):194-201.
19. Price TJ, Beeke C, Ullah S, Padbury R, Maddern G, Roder D, et al. Does the primary site of colorectal cancer impact outcomes for patients with metastatic disease? Cancer. 2015;121(6):830-5.
20. Rassen JA, Schneeweiss S, Glynn RJ, Mittleman MA, Brookhart MA. Instrumental variable analysis for estimation of treatment effects with dichotomous outcomes. American journal of epidemiology. 2009;169(3):273-84 %@ 1476-6256.
21. National Cancer Institute. Surveillance epidemiology and end results. Available at http://seer.cancer.gov. Accessed Oct 10, 2019.
22. Goldstein DA, Zeichner SB, Bartnik CM, Neustadter E, Flowers CR. Metastatic Colorectal Cancer: A Systematic Review of the Value of Current Therapies. Clin Colorectal Cancer. 2016;15(1):1-6.
23. Arnold D, Lueza B, Douillard JY, Peeters M, Lenz HJ, Venook A, et al. Prognostic and predictive value of primary tumour side in patients with RAS wild-type metastatic colorectal cancer treated with chemotherapy and EGFR directed antibodies in six randomized trials. Ann Oncol. 2017;28(8):1713-29.
24. Terza JV, Bradford WD, Dismuke CE. The use of linear instrumental variables methods in health services research and health economics: a cautionary note. Health Serv Res. 2008;43(3):1102--20.
25. Terza JV, Basu A, Rathouz PJ. Two-stage residual inclusion estimation: addressing endogeneity in health econometric modeling. Journal of health economics. 2008;27(3):531-43.
26. Sheetz KH, Norton EC, Regenbogen SE, Dimick JB. An Instrumental Variable Analysis Comparing Medicare Expenditures for Laparoscopic vs Open Colectomy. JAMA surgery. 2017;152(10):921.
27. Raoof M, Haye S, Ituarte PHG, Fong Y. Liver Resection Improves Survival in Colorectal Cancer Patients: Causal-effects From Population-level Instrumental Variable Analysis. Ann Surg. 2019;270(4):692-700.
28. Newhouse JP, McClellan M. ECONOMETRICS IN OUTCOMES RESEARCH: The Use of Instrumental Variables. Annual Review of Public Health. 1998;19(1):17-34.
29. Lu-Yao GL, Albertsen PC, Moore DF, Shih W, Lin Y, DiPaola RS, et al. Fifteen-year survival outcomes following primary androgen-deprivation therapy for localized prostate cancer. JAMA internal medicine. 2014;174(9):1460-7.
30. Terza JV, Basu A, Rathouz PJ. Two-stage residual inclusion estimation: addressing endogeneity in health econometric modeling. Journal of health economics. 2008;27(3):531-43.
31. Martinez-Camblor P, Mackenzie T, Staiger DO, Goodney PP, O'Malley AJ. Adjusting for bias introduced by instrumental variable estimation in the Cox proportional hazards model. Biostatistics. 2019;20(1):80-96.
32. Missiaglia E, Jacobs B, D'Ario G, Di Narzo AF, Soneson C, Budinska E, et al. Distal and proximal colon cancers differ in terms of molecular, pathological, and clinical features. Ann Oncol. 2014;25(10):1995-2001.
33. Passiglia F, Bronte G, Bazan V, Galvano A, Vincenzi B, Russo A. Can KRAS and BRAF mutations limit the benefit of liver resection in metastatic colorectal cancer patients? A systematic review and meta-analysis. Crit Rev Oncol Hematol. 2016;99:150-7.
34. Sasaki K, Andreatos N, Margonis GA, He J, Weiss M, Johnston F, et al. The prognostic implications of primary colorectal tumor location on recurrence and overall survival in patients undergoing resection for colorectal liver metastasis. J Surg Oncol. 2016;114(7):803-9.
35. Scheer MG, Sloots CE, van der Wilt GJ, Ruers TJ. Management of patients with asymptomatic colorectal cancer and synchronous irresectable metastases. Ann Oncol. 2008;19(11):1829-35.