Recently, Jin et al. (1) reported that tumor invasion (T stage), lymphovascular invasion, and signet ring histology were significantly associated with the recurrence of gastric cancer patients with negative nodes after surgery. Although this paper has been published, several profound issues should be discussed for the correct guidance to readers.
Authors adopted the clinicopathological data from seven hospitals to set up the negative-node patient database for further statistical analysis. However, 54 of 317 negative-node patients were identified to experience disease recurrence after surgery. It is really incredible that only 54 cases of negative-node disease were statistically analyzed for about 30 variables in that study, which cannot guarantee the accuracy of results and conclusions in that study.
A total of 86 patients underwent the neoadjuvant therapy, in which those patients should be excluded in the study because of postoperative stage migration. We took notice of 30 cases underwent neoadjuvant therapy presented the recurrence after surgery. Authors should figure out which patients were diagnosed as advanced stage disease with the high risk of lymph node metastases.
Many articles have demonstrated that lymph node metastasis was positively related to the depth of tumor invasion in gastric cancer (2). The median number of nodes examined was 15 for T3 tumors and 18 for T4 tumors, which is much lower than that in Asian. More than half of negative-node patients experienced recurrence presented T3 or T4 tumor invasion, which indicated that the false negative rate of lymph node metastasis in those patients was underestimated inevitably. In my opinion, it is still controversial that whether the micrometastasis in negative nodes has impact on the survival of patients with gastric cancer.
Authors stated that all included patients had a range of lymph nodes retrieved from 1 to 54, and the median number of examined nodes for 317 negative-node disease patients was 16 (range, 9–22). Notably, the median number of examined nodes for 54 negative-node disease patients presented the recurrence was only 14 (range, 6–22), which is absolutely cannot be deemed as the basic guarantee of node dissection for gastric cancer in the current AJCC/UICC TNM classification (3). How did authors explain the lymphovascular invasion, the most intensive factor related to lymph node metastasis, has the intensive effect on the survival in that study?
Therefore, we think that Jin and colleagues cannot elucidate the elaborately potential factor in relation to the recurrence of gastric cancer. The patients included should be guaranteed with the radical lymphadenectomy (D2 and number of examined nodes more than 15). The patients who underwent neoadjuvant therapy should be excluded, owing to initial advanced stage of disease. Lastly, the quantity of patients experienced recurrence of gastric cancer need to be enlarged for accurately statistical calculation.
Provenance: This is a Guest Commentary commissioned by the Section Editor Dr. Rulin Miao (Department of Gastrointestinal Surgery, Peking University Cancer Hospital & Institute, Beijing 100142, China).
Conflicts of Interest: The authors have no conflicts of interest to declare.
- Jin LX, Moses LE, Squires MH 3rd, et al. Factors Associated With Recurrence and Survival in Lymph Node-negative Gastric Adenocarcinoma: A 7-Institution Study of the US Gastric Cancer Collaborative. Ann Surg 2015;262:999-1005. [PubMed]
- Li X, Liu Y, Cao B, et al. Metastatic lymph node ratio and prognosis of gastric cancer at different pT stages. Hepatogastroenterology 2015;62:507-11. [PubMed]
- Bilici A, Ustaalioglu BB, Gumus M, et al. Is metastatic lymph node ratio superior to the number of metastatic lymph nodes to assess outcome and survival of gastric cancer? Onkologie 2010;33:101-5. [PubMed]