C URRENT O PINION Pseudoadjuvant chemotherapy in resectable metastatic colorectal cancer Laura Polastro  , Georges El Hachem  , and Alain Hendlisz Purpose of review In this article, we focus on the potential benefits and risks of chemotherapy administration before (perioperative) or after (pseudoadjuvant) a curative resection of colorectal cancer (CRC) metastases. Recent findings In the published evidence, there is a lack of survival benefit from peri or postoperative chemotherapy in the context of resectable metastatic CRC. However, high-risk patients may have a certain benefit when receiving a postoperative cytotoxic treatment. Apart from, according to the published data, the administration of a preoperative chemotherapy has been associated with serious parenchymal liver damage and an increase in the postoperative morbidity-mortality rate. Summary Surgery is the only potentially curative treatment for metastatic CRC, but the risk of recurrence remains high. The current guidelines recommend the administration of either a perioperative or a pseudoadjuvant chemotherapy in this setting despite the absence of survival benefit. A better selection of patients who may require and gain an advantage from chemotherapy in the setting of resectable metastasis is highly needed. In this view, a prospective trial enrolling patients at high risk of recurrence is ongoing. Keywords colorectal cancer, perioperative chemotherapy, pseudoadjuvant chemotherapy, resectable liver metastases INTRODUCTION Colorectal cancer (CRC) is a major public health concern, accounting for approximately 8% of all cancer-related deaths. In about 80% of cases, the disease is localized at diagnosis [1]. Surgery remains the treatment’s cornerstone for nonmetastatic CRC, but the patients’ survival is correlated with the dis- ease’s stage with a 5-year survival of 90% in stage I, 70–80% in stage II, and 40–65% in stage III. Adju- vant 5-fluorouracil-based chemotherapy adminis- tered postoperatively during 6 months has been shown beneficial on patients survival and is cur- rently recommended for stage III and high-risk stage II colon [2,3]. The adjuvant treatment in rectal cancer remains a field of conflicting data, for which no definitive recommendation can be provided after preoperative radiochemotherapy and surgical resection [4–6]. Unfortunately, 20% of the patients with CRC present synchronous metastases at diagnosis and an additional 30% will develop metachronous metas- tases despite an adequate adjuvant treatment. The metastatic spread in CRC occurs mainly in the liver, which is the exclusive site in 30–40% of the cases [2]. Surgery is the only potentially curative option for hepatic colorectal recurrence, although only 15 – 20% of the patients are eligible for surgical resection. Most large retrospective series report a 5-year overall survival (OS) ranging from 28 to 44%, with a 10-year recurrence-free survival below 20%, underlining a recurrence rate over 75% [7,8]. The persistence of a microscopic residual disease is the most cited hypothesis behind the recurrence. Based on the hypothesis that adjuvant chemotherapy improves the prognosis of patients after resection of nonmet- astatic colon cancer, several attempts have been made to transpose this benefit into the management of patients with CRC metastatic to the liver eligible Medicine Department, Gastro-Intestinal Unit, Institut Jules Bordet, Brus- sels, Belgium Correspondence to Alain Hendlisz, MD, PhD, Gastro-enterologist, Medi- cal Oncologist, Brussels, Belgium. Tel: +003225413480; e-mail: alain.hendlisz@bordet.be  Laura Polastro and Georges El Hachem contributed equally to this article. Curr Opin Oncol 2018, 30:000–000 DOI:10.1097/CCO.0000000000000455 1040-8746 Copyright ß 2018 Wolters Kluwer Health, Inc. All rights reserved. www.co-oncology.com REVIEW Copyright © 2018 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.