Retrospective Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jan 15, 2017; 9(1): 42-49
Published online Jan 15, 2017. doi: 10.4251/wjgo.v9.i1.42
Pre-treatment platelet counts as a prognostic and predictive factor in stage II and III rectal adenocarcinoma
Morgan Steele, Ioannis A Voutsadakis
Morgan Steele, Clinical Trials Unit, Sault Area Hospital, Sault Ste Marie, Ontario P6B 0A8, Canada
Ioannis A Voutsadakis, Division of Medical Oncology, Department of Internal Medicine, Sault Area Hospital, Sault Ste Marie, Ontario P6B 0A8, Canada
Ioannis A Voutsadakis, Division of Clinical Sciences, Northern Ontario School of Medicine, Sudbury, Ontario P3E 2C6, Canada
Author contributions: Voutsadakis IA designed research, analyzed data and wrote the paper; Steele M collected and analyzed data and wrote the paper.
Supported by the Sault Ste. Marie Academic Medical Association, Ontario, Canada to Voutsadakis IA.
Institutional review board statement: Institution Review Board approval has been obtained for this study.
Informed consent statement: Given that the study was retrospective in nature and the fact that treatments had been provided according to standards of care, no specific informed consents were needed or obtained by the individual patients. Anonymity was guaranteed.
Conflict-of-interest statement: The authors declare no conflicts of interest regarding this study.
Data sharing statement: There are no additional data available for this study.
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: Ioannis A Voutsadakis, MD, PhD, Division of Medical Oncology, Department of Internal Medicine, Sault Area Hospital, Sault Ste Marie, Sault Ste. Marie, Ontario P6B 0A8, Canada. ivoutsadakis@nosm.ca
Telephone: +1-705-7593434 Fax: +1-705-7593815
Received: June 24, 2016
Peer-review started: June 29, 2016
First decision: August 10, 2016
Revised: August 24, 2016
Accepted: November 1, 2016
Article in press: November 2, 2017
Published online: January 15, 2017
Processing time: 201 Days and 18.9 Hours
Abstract
AIM

To investigate if pre-treatment platelet counts could provide prognostic information in patients with rectal adenocarcinoma that received neo-adjuvant treatment.

METHODS

Platelet number on diagnosis of stage II and III rectal cancer was evaluated in 51 patients receiving neo-adjuvant treatment and for whom there were complete follow-up data on progression and survival, as well as pathologic outcome at the time of surgery. Pathologic responses on the surgical specimen of patients with lower platelet counts (150-300 × 109/L) were compared with these of patients with higher platelet counts (> 300 × 109/L) by the χ2 test. Overall and progression free survival Kaplan-Meier curves of the two groups were constructed and compared with the Log-Rank test.

RESULTS

A significant difference was present between the two groups in regards to pathologic response with patients with lower platelet counts being more likely to exhibit a good or complete response to neo-adjuvant treatment than patients with higher platelet counts (P = 0.015). Among other factors evaluated, there was also a significant difference between the carcinoembryonic antigen (CEA) at presentation of patients that exhibited a good or complete response and those that had no response or a minimal to moderate response. Patients with a good or complete response were more likely to present with a CEA of less than 5 μg/L (P = 0.00066). There was no significant difference in overall and progression free survival between the two platelet count groups (Log-Rank tests P = 0.42 and P = 0.35, respectively).

CONCLUSION

In this retrospective analysis of stage II and III rectal cancer patients, platelet counts at the time of diagnosis had prognostic value for neo-adjuvant treatment pathologic response. Pre-treatment CEA also held prognostic value in regards to treatment effect.

Keywords: Rectal cancer; Platelets; Prognosis; Treatment response; Neo-adjuvant; Chemoradiation

Core tip: Platelet counts may provide prognostic and treatment efficacy predictive information in various cancers. In this study, platelet number on diagnosis of stage II and III rectal cancer was evaluated in 51 patients before start of neo-adjuvant treatment. A significant difference was present between the two groups, of higher and lower platelets, regarding pathologic response to neo-adjuvant treatment. There was no significant difference in overall and progression free survival between the two platelet count groups. Pre-treatment carcinoembryonic antigen also held prognostic value in regards to treatment effect.