Optimal Lymph Node Yield for Survival Prediction in Rectal Cancer Patients After Neoadjuvant Therapy

Abstract

Yu-Min Lin,1 Chia-Lin Chou,2,3 Yu-Hsuan Kuo,4,5 Hung-Chang Wu,4,6 Chia-Jen Tsai,7 Chung-Han Ho,8,9 Yi-Chen Chen,8 Ching-Chieh Yang,6,7,* Cheng‐Wei Lin10– 12,* 1Division of Hepatogastroenterology, Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan; 2Division of Colorectal Surgery, Department of Surgery, Chi Mei Medical Center, Tainan, Taiwan; 3Department of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan, Taiwan; 4Division of Hematology and Oncology, Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan; 5Department of Cosmetic Science, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan; 6Department of Pharmacy, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan; 7Department of Radiation Oncology, Chi Mei Medical Center, Tainan, Taiwan; 8Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan; 9Department of Information Management, Southern Taiwan University of Science and Technology, Tainan, Taiwan; 10Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; 11Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; 12Cell Physiology and Molecular Image Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan*These authors contributed equally to this workCorrespondence: Ching-Chieh YangDepartment of Radiation Oncology Chi-Mei Medical Center, No. 901, Zhonghua Road, Yung Kang District, Tainan City, 701, Taiwan, Republic of ChinaTel [phone]Email [email protected]‐Wei LinDepartment of Biochemistry and Molecular Biology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wu ‐ Xing Street, Taipei, 11031, Taiwan, Republic of ChinaEmail [email protected]: A lymph node (LN) yield ≥ 12 is required to for accurate determination of nodal status for colorectal cancer but cannot always be achieved after neoadjuvant therapy. This study aims to determine the difference in LN yield from rectal cancer patients treated with and without neoadjuvant therapy and the effects of specific LN yields on survival.Patients and Methods: The study cohort included a total of 4344 rectal cancer patients treated between January 2007 and December 2015, 2260 (52.03%) of whom received neoadjuvant therapy. Data were retrieved from the Taiwan nationwide cancer registry database. The minimum acceptable LN yield below 12 was investigated using the maximum area under the ROC curve.Results: The median LN yield was 12 (8– 17) for patients who received neoadjuvant therapy and 17 (13– 24) for those who did not. The recommended LN yield ≥ 12 was achieved in 82.73% of patients without and 57.96% of those with neoadjuvant therapy (p < 0.0001). Patients with LN yield ≥ 12 had a higher OS probability than did those with LN < 12 (OR, 1.33; 95% CI, 1.06– 1.66; p = 0.0124). However, the predictive accuracy for survival was greater for LN yield ≥ 10 (AUC, 0.7767) than cut-offs of 12, 8, or 6, especially in patients with pathologically-negative nodes (AUC, 0.7660).Conclusion: Neoadjuvant therapy significantly reduces the LN yield in subsequent surgery. A lower yield (LN ≥ 10) may be adequate for nodal evaluation in rectal cancer patients after neoadjuvant therapy.Keywords: rectal cancer, neoadjuvant therapy, lymph node yield, quality, survival

Keywords

• rectal cancer
• neoadjuvant therapy
• lymph node yield
• quality
• survival