Prognostic Nomogram for Rectal Cancer Patients With Tumor Deposits.

Xiaohong Zhong,Lei Wang,Gang Chen,Liang Hong,Junxin Wu,Lingdong Shao,Xueqing Zhang

doi:10.3389/fonc.2022.808557

Abstract

AimTumor deposits (TDs) are an aggressive hallmark of rectal cancer, but their prognostic value has not been addressed in current staging systems. This study aimed to construct and validate a prognostic nomogram for rectal cancer patients with TDs.MethodsA total of 1,388 stage III–IV rectal cancer patients who underwent radical surgical resection from the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively analyzed to identify the clinical value of TDs. TD-positive rectal cancer patients in the SEER database were used as the training set to construct a prognostic model, which was validated by Fujian Cancer Hospital. Three models were constructed to predict the prognosis of rectal cancer patients with TDs, including the least absolute shrinkage and selection operator regression (LASSO, model 1), backward stepwise regression (BSR, model 2), and LASSO followed by BSR (model 3). A nomogram was established among the three models.ResultsIn the entire cohort, TD was also identified as an independent risk factor for overall survival (OS), even after adjusting for baseline factors, stage, other risk factors, treatments, and all the included variables in this study (all P < 0.05). Among patients with TDs, model 3 exhibited a higher C-index and area under the curves (AUCs) at 3, 4, and 5 years compared with the American Joint Committee on Cancer staging system both in the training and validation sets (all P < 0.05). The nomogram obtained from model 3 showed good consistency based on the calibration curves and excellent clinical applicability by the decision curve analysis curves. In addition, patients were divided into two subgroups with apparently different OS according to the current nomogram (both P < 0.05), and only patients in the high-risk subgroup were found to benefit from postoperative radiotherapy (P < 0.05).ConclusionWe identified a novel nomogram that could not only predict the prognosis of rectal cancer patients with TDs but also provide reliable evidence for clinical decision-making.

Highlights

Tumor deposits (TDs) were first reported in 1935 [1] and are associated with aggressive characteristics, advanced stage, and adverse prognosis of rectal cancers [2,3,4]
Three models were constructed to predict the prognosis of rectal cancer patients with TDs, including the least absolute shrinkage and selection operator regression (LASSO, model 1), backward stepwise regression (BSR, model 2), and LASSO followed by BSR
Among patients with TDs, model 3 exhibited a higher concordance index (C-index) and area under the curves (AUCs) at 3, 4, and 5 years compared with the American Joint Committee on Cancer staging system both in the training and validation sets

Summary

Introduction

Tumor deposits (TDs) were first reported in 1935 [1] and are associated with aggressive characteristics, advanced stage, and adverse prognosis of rectal cancers [2,3,4]. TDs are considered as an aggressive hallmark of rectal cancer in the absence of regional lymph node metastasis (LNM) [8, 9], and in patients with LNM [10, 11]. As an efficient anti-recurrence prophylaxis and an alternative salvage strategy for recurrent tumors, postoperative radiotherapy (RT) is only recommended for N1c patients in the European Society for Medical Oncology (ESMO) clinical practice guideline for rectal cancer [12]

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