Case Report
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World Journal of Clinical Cases. Nov 16, 2017; 5(11): 390-396
Published online Nov 16, 2017. doi: 10.12998/wjcc.v5.i11.390
Natural killer cells activity in a metastatic colorectal cancer patient with complete and long lasting response to therapy
Alessandro Ottaiano, Maria Napolitano, Monica Capozzi, Salvatore Tafuto, Antonio Avallone, Stefania Scala
Alessandro Ottaiano, Monica Capozzi, Salvatore Tafuto, Antonio Avallone, Department of Abdominal Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori “Fondazione Giovanni Pascale” - I.R.C.C.S., Naples 80131, Italy
Maria Napolitano, Stefania Scala, Immunology Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori “Fondazione Giovanni Pascale” - I.R.C.C.S., Naples 80131, Italy
Author contributions: Ottaiano A contributed in planning, analysis, discussing and writing of the manuscript; Napolitano M, Avallone A and Scala S contributed in planningdesigning and performing experiments and discussing of the manuscript; Capozzi M and Tafuto S contributed in planning and writing of the manuscript.
Institutional review board statement: This case report was exempt from the Institutional Review Board standards at I.R.C.C.S.
Informed consent statement: The patient involved in this study gave her written informed consent authorizing use and disclosure of his protected health information.
Conflict-of-interest statement: We declare no conflict of interest.
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. Alessandro Ottaiano, Department of Abdominal Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori “Fondazione Giovanni Pascale” - I.R.C.C.S., via M. Semmola, Naples 80131, Italy. ale.otto@libero.it
Telephone: +39-81-5903510 Fax: +39-81-7714224
Received: December 16, 2016
Peer-review started: December 19, 2016
First decision: March 28, 2017
Revised: May 24, 2017
Accepted: June 12, 2017
Article in press: June 13, 2017
Published online: November 16, 2017
Processing time: 336 Days and 3.3 Hours
Abstract

Here we report a case of a 70-year-old man who received adjuvant chemotherapy with fluorouracile, folinic acid and oxaliplatin after a left hemicolectomy for a stage IIIb adenocarcinoma in May 2009. During follow-up he de-veloped abdominal lymphnodes metastases evidenced by positron emission tomography- computed tomography (PET-CT) scan and increase of carcinoembryonic antigen (CEA) level. Chemotherapy with capecitabine, oxaliplatin and bevacizumab was started in April 2012. Restaging showed a complete response and normalization of CEA. The patient received maintenance therapy with bevacizumab which was stopped in December 2013 for patient choice. In October 2014, a new increase in CEA was documented and PET-CT scan showed lung metastases. Analysis of RAS status revealed the absence of mutations, then the patient started a second-line chemotherapy with fluorouracile, folinic acid, irinotecan (folfiri) and panitumumab achieving, in January 2015, a complete response and normalization of CEA. Thereafter, folfiri was discontinued for toxicity; furthermore, upon the third occurrence of a grade 3 dermatologic toxicity, panitumumab was continued from June 2015 at 60% of the original dose and it was administered every three weeks. Until presentation of this case, the patient maintains a complete response, has no symptoms of disease and CEA is normal. Interestingly, this patient presented a high proportion of circulating natural killer (NK) cells (35.1%) with high cytotoxic activity against tumor cells. Study on the role of NK in patients with advanced colorectal cancer are ongoing.

Keywords: Colorectal cancer; Panitumumab; Natural killers; Regulatory cells; Chemotherapy

Core tip: The case presented here shows a patients with metastatic colorectal cancer (mCRC) and long-lasting responses to different treatments including chemotherapies and targeted therapies; in particular, the patient had a long-lasting complete response to panitumumab. Additionally, he presented a high proportion of circulating natural killer (NK) cells displaying high cytotoxic activity against tumor cells in vitro. Interestingly, we previously reported that patients affected by mCRC with high NK-cell cytotoxicity showed a significantly higher response rate and a longer progression-free survival compared with patients with low NK-cell cytotoxicity. Study on the role of NK in patients with mCRC should be improved.