Japanese Gastric Cancer Treatment Guidelines 2021 (6th edition)

Abstract

The sixth edition of the Japanese Gastric Cancer Treatment Guidelines was completed in July 2021, incorporating new evidence that emerged after publication of the previous edition. It consists of a text-based "Treatments" part and a "Clinical Questions" part including recommendations and explanations for clinical questions. The treatments parts include a comprehensive description regarding surgery, endoscopic resection and chemotherapy for gastric cancer. The clinical question part is based on the literature search and evaluation by an independent systematic review team. Consequently, not only evidence for each therapeutic recommendation was clearly shown, but it also identified the research fields that require further evaluation to provide appropriate recommendations.

Keywords: Chemotherapy; Endoscopic resection; Evidence based; Surgery; Treatment guidelines.

Fig. 1

Algorithm of standard treatments. T/N/M and Stage are used in conjunction with the Japanese Classification of Gastric Carcinoma 15th edition [1] and TNM classification 8th edition [2]

Fig. 2

Lymph node dissection in total gastrectomy. Lymph node stations in blue need to be dissected in D1 dissection. In addition, lymph node stations in orange need to be dissected in D1 + dissection and lymph node stations in red as well in D2 dissection

Fig. 3

Lymph node dissection in distal gastrectomy. Lymph node stations in blue need to be dissected in D1 dissection. In addition, lymph node stations in orange need to be dissected in D1 + dissection and lymph node stations in red as well in D2 dissection

Fig. 4

Lymph node dissection in pylorus-preserving gastrectomy. Lymph node stations in blue need to be dissected in D1 dissection. In addition, lymph node stations in orange need to be dissected in D1+ dissection

Fig. 5

Lymph node dissection in proximal gastrectomy. Lymph node stations in blue need to be dissected in D1 dissection. In addition, lymph node stations in orange need to be dissected in D1+ dissection and lymph node stations in red as well in D2 dissection

Fig. 6

Algorithm of the surgical approach and lymph node dissection for esophagogastric junctional carcinoma

Fig. 7

Algorithm showing curability decision and additional treatments for patients who have undergone endoscopic resection

Fig. 8

Recommended regimens for the first-, second-, third-, fourth-, or later-line treatments. Only the “Recommended regimens” as defined in the text are included. These regimens are recommended for patients who are in sufficiently good general condition to be eligible for the clinical trials from which the evidence in support of these regimens was generated. 1: Risk–benefit balance of chemotherapy alone and combination with nivolumab should be considered according to the patient’s condition, and either treatment can be selected with the patient’s informed consent. 2: Pembrolizumab in second-line for MSI-High AGC is not recommended when nivolumab was administered in first-line treatment. Weekly paclitaxel plus ramucirumab should be considered in third- or later-line treatment. 3: Nivolumab in third- or later-line treatment is not recommended when pembrolizumab or nivolumab was administered in previous treatment

Fig. 9

Conditionally recommended regimens shown in alphabetical order. Even when using the Conditionally recommended regimens, refer to Fig. 8 for the basic strategy and attempt to use drugs from all of the following seven categories during the course of the treatment: fluoropyrimidines, platinum, taxanes, irinotecan, ramucirumab, nivolumab, and FTD/TPI. However, it is important to note that continuation of any of the drugs cannot be recommended beyond progression

Fig. 10

Postoperative follow-up for Stage I gastric cancer patients

Fig. 11

Postoperative follow-up for Stage II–III gastric cancer patients