ESMO Asia Virtual Congress 2020

Abstract 94P

Background

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.

Methods

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.

Results

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 Table: 94P

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

Conclusions

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.