Mean platelet volume (MPV) is a marker of inflammation that indicates the average size of platelets, platelet production rate and stimulation. The role of Pre-operative levels of MPV and its prognostic effect on disease free survival (DFS) and overall survival (OS) are poorly understood. This study was intended to analyze the effect of pre-operative levels of MPV on DFS and OS of stage III rectal cancer patients.
This is a retrospective study of 149 stage III rectal cancer patients who underwent surgery in our institution between 2011 and 2015. Association between pre-operative levels of MPV and clinicopathological variables were analysed. DFS and OS for 5 years were analysed, and survival analysis was done using Kaplan-Meier curve. MPV of 9.35 femto litres (fl) was chosen based on the ROC curve. The Area under curve was 0.889. Differences between survival curves were analysed for statistical significance using log-rank test.
In our study, mean 5-year OS were 91.1 and 50.36 months, for patients with MPV < 9.35 and MPV >9.35 respectively (P 0.0001). The mean DFS of MPV < 9.35 and MPV > 9.35 were 89.32 and 43.54 months respectively (P 0.0001). Univariate analysis for OS and DFS showed significance for MPV, Nodal status, Circumferential resection margin, stage and lymph node ratio. Multivariate analysis showed significance for MPV [HR 2.379 (95% CI 1.733-3.264) P .0001 for MPV>9.35] and CRM [HR 0.392 (95% CI 0.191-0.804) P 0.01) for CRM negative] for OS and DFS. Multivariate Analysis for OS & DFS
Variable OS DFS P value Hazard Ratio 95% CI P value Hazard Ratio 95% CI Lower Upper Lower Upper N Stage N1a .782 .785 .140 4.390 .824 .833 .167 4.146 N1b .119 .322 .077 1.340 .159 .389 .104 1.448 N2a .554 .715 .235 2.175 .680 .810 .297 2.209 N2b Reference Reference CRM Negative .011 .392 .191 .804 .012 .412 .207 .821 Positive Reference Reference Stage IIIA .568 .692 .196 2.447 .203 .465 .143 1.510 IIIB .474 .727 .303 1.743 .203 .607 .281 1.310 IIIC Reference Reference MPV >9.35 .0001 2.379 1.733 3.264 .0001 2.370 1.791 3.136 <9.35 Reference Reference LNR ratio >0.2 .220 3.269 .492 21.738 .059 5.756 .938 35.327 <0.2 Reference Reference
Pre-operative MPV measured one week before surgery is a convenient and inexpensive marker which has been proved to be a prognostic marker for OS and DFS in stage III rectal cancer patients.
Kidwai Memorial Institute of Oncology, Bangalore, India.
Has not received any funding.
All authors have declared no conflicts of interest.