Tumour Deposits as an independent prognostic factor for Colorectal Cancer
Session type: Poster / e-Poster / Silent Theatre session
It is known that the presence of tumour deposits (TD) is a prognostic indicator for Colorectal cancer patients, although there is limited research into the extent which tumour deposits can be relied upon as a prognostic indicator in patients with Lymph Node metastasis. Current staging systems acknowledge the presence of tumour deposits only in the absence of lymph node metastasis. Further analysis of patient outcomes based on the newest TD definitions as published in the 8th edition TNM Classification (published 2017) is required, to assess the impact that tumour deposits has, independent of lymph node metastasis. The aim of this study is to investigate the significance of TD as an independent prognostic factor. Investigate the clinicopathological factors associated with incidence of TD and assess the Recurrence Free Survival of colorectal cancer patients that have TD.
A single centre study comprising 233 patients with stage II/III colorectal cancer (all underwent surgical resection between January 2009 and December 2011) were assessed for TD and lymph node metastasis using histopathology slides stained with Haemotoxylin and Eosin. The TD status is compared against their recurrence free survival (RFS), obtained from regular follow-up appointments after surgery.
25% of patients had positive TD status. Left sided and rectal tumours, lymphatic invasion and lymph node metastasis were associated with TD incidence. RFS for both stage II and III patients with TD positive status were significantly lower than the same staging groups without TD negative status. Patients with TD presence had significantly worse RFS irrespective of any lymph node metastasis.
Tumour deposits are a significant prognostic indicator for patients with stage II/III colorectal cancer, independent of lymph node metastasis. The ability of tumour deposits to separate the two groups of mixed stage II and III patients exhibits that in this study, the tumour deposit status of the patients may have provided more accurate prognostic information than lymph node metastasis. Based on these results, we propose revision of the AJCC TNM staging system to include documentation of TD as part of cancer staging, even in the presence of lymph node metastasis.