Cancer Management and Research (May 2018)

Tumor-infiltrating lymphocyte as a prognostic biomarker in stage IV colorectal cancer should take into account the metastatic status and operation modality

  • Xie QK,
  • He WZ,
  • Hu WM,
  • Yang L,
  • Jiang C,
  • Kong PF,
  • Yang YZ,
  • Yang Q,
  • Zhang HZ,
  • Zhang B,
  • Xia LP

Journal volume & issue
Vol. Volume 10
pp. 1365 – 1375

Abstract

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Qian-Kun Xie,1,* Wen-Zhuo He,1,* Wan-Ming Hu,2–4 Lin Yang,1 Chang Jiang,1 Peng-Fei Kong,1 Yuan-Zhong Yang,2 Qiong Yang,1,5 Hui-Zhong Zhang,2 Bei Zhang,1 Liang-Ping Xia1 1VIP Region, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; 2Department of Pathology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, SunYat-sen University Cancer Center, Guangzhou, China; 3Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China; 4Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China; 5Department of Oncology, Sun Yat-sen Memorial Hospital, Guangzhou, China *These authors contributed equally to this work Background: Although tumor-infiltrating lymphocytes (TILs) have been understood for years as a favorable prognostic factor for colorectal cancers (CRCs) after complete surgical resection, its prognostic role in metastatic CRC (mCRC) remains poorly defined, and it is largely unknown how this prognostic benefit relates to the metastatic status and operation modality. Materials and methods: After reviewing 2215 consecutive cases of surgically resected CRC, 332 patients newly diagnosed with stage IV CRC and treated at the Sun Yat-Sen University Cancer Center between 2009 and 2014 were included. H&E-stained (HES) slides from surgical specimens were evaluated for the extent of TILs. The primary end point was overall survival (OS). Cox proportional hazards regression was conducted to determine the prognostic significance of TILs. All statistical tests were 2-sided. Results: HES slides from primary tumor samples were evaluable for 302 of the 332 included cases. Among the 302 patients, 105 patients (34.8%) were classified as high TIL, the remaining 197 (65.2%) were defined as low TIL. In the univariate analysis, TILs were significantly associated with better OS (P=0.015). Multivariable analysis confirmed that high TIL strongly predicted better survival (hazard ratio =0.62, 95% CI: 0.44–0.89, P=0.008), independent of other patients’ clinicopathological characteristics. Stratified analysis revealed a prognostic benefit of high TIL for patients in the subgroup with non-oligometastatic disease (P=0.002), ≥2 metastatic organs (P=0.006), and non-metastasectomy (P=0.005). By contrast, oligometastatic disease, 1 metastatic organ, or metastasectomy fully abrogated the prognostic effect of TIL. Conclusion: Our findings indicate that the level of TILs can be used to predict the outcome for patients with mCRC; however, the operation modality and the metastatic status of patients should also be taken into account. Keywords: colorectal cancer, stage IV, tumor-infiltrating lymphocytes, metastatic status, survival

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