Systematic Reviews
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Dec 15, 2015; 7(12): 513-523
Published online Dec 15, 2015. doi: 10.4251/wjgo.v7.i12.513
Management of asymptomatic primary tumours in stage IV colorectal cancer: Review of outcomes
Kate Jessica Wilkinson, Wei Chua, Weng Ng, Aflah Roohullah
Kate Jessica Wilkinson, Wei Chua, Weng Ng, Aflah Roohullah, Liverpool Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW 2170, Australia
Author contributions: Wilkinson KJ and Roohullah A designed the research; Wilkinson KJ performed the research; Wilkinson KJ, Roohullah A, Chua W and Ng W analyzed the data and wrote the paper.
Conflict-of-interest statement: No conflicts of interest are declared by the authors.
Data sharing statement: All data referred to in this review is taken directly from the outcome data from the original cited papers. No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Kate Jessica Wilkinson, MBChB, Medical Oncology Advanced Trainee, Liverpool Cancer Therapy Centre, Liverpool Hospital, Corner of Elizabeth and Goulburn Streets, Liverpool, NSW 2170, Australia. kate.wilkinson@sswahs.nsw.gov.au
Telephone: +61-2-87389744 Fax: +61-2-87389811
Received: April 26, 2015
Peer-review started: April 28, 2015
First decision: September 8, 2015
Revised: September 23, 2015
Accepted: November 3, 2015
Article in press: November 4, 2015
Published online: December 15, 2015
Processing time: 232 Days and 2.1 Hours
Abstract

AIM: To compare outcomes for patients presenting with stage IV colorectal cancer and an asymptomatic primary tumour, undergoing primary tumour resection (PTR) plus palliative chemotherapy vs primary chemotherapy up-front.

METHODS: A literature search was conducted using MEDLINE and EMBASE. The primary outcome was overall survival. Secondary outcomes included perioperative mortality, morbidity and delayed surgical intervention rates in patients undergoing PTR and subsequent complication rates in patients with an un-resected primary tumour. Tertiary outcomes included impact on systemic treatment and identification of prognostic factors relevant for survival in this cohort.

RESULTS: Twenty non-randomised studies met the inclusion criteria. Eleven studies included comparative overall survival data. Three studies showed an overall survival advantage for PTR, 7 studies showed no statistically significant advantage, and 1 study showed a significant worsening in survival in the surgical group. The perioperative mortality rate ranged from 0% to 8.5%, and post-operative morbidity rate from 10% to 35%, mainly minor complications that did not preclude subsequent chemotherapy. The rate of delayed primary-tumour related symptoms, most commonly obstruction, in patients with an un-resected primary tumour ranged from 3% to 46%. The strongest independent poor prognostic factor was extensive hepatic metastases, in addition to poor performance status, M1b stage and non-use of modern chemotherapy agents.

CONCLUSION: Based on the current literature, both PTR and up front chemotherapy appear appropriate initial management strategies, with a trend towards an overall survival advantage with PTR. The procedure has a low post-operative mortality, and most complications are transient and minor. The results of recruiting randomised trials are eagerly anticipated.

Keywords: Colorectal cancer; Resection; Primary tumour; Asymptomatic; Unresectable metastases; Chemotherapy; Complications

Core tip: The management of asymptomatic primary tumours in stage IV colorectal cancer is under debate. A literature review was performed focusing on this cohort, with patients undergoing primary tumour resection (PTR) vs up front chemotherapy. Survival appears equivalent with both management strategies, with a trend to an advantage in PTR. Surgical mortality is low and most morbidity transient. Most studies are retrospective, small and non-randomised. Larger randomised controlled trials are awaited.