You will be shown a paragraph from a biomedical research article. Your task is to extract all drug combinations appearing in a specific sentence within in the paragraph. Each drug combination should be assigned to one of the following three categories:

- POS: Indicates a positive interaction between the drugs in the combination; for instance, drugs that have an additive or synergistic effect.
- NEG: Indicates a negative interaction between the drugs in the combination; for instance, combining these drugs might result in adverse side effects, or might reduce their efficacy.
- COMB: Indicates that the drugs are given in combination, but the type of interaction between the drugs cannot be determined based on the provided context.

Please format your answer as a json array. Each entry in the array should itself be an array formatted as [<drug_1>, <drug_2>, ..., <drug_n>, <category>] where <category> is one of the three categories listed above and <drug_1>, ..., <drug_n> are drug names copied verbatim from the input sentence. Different combinations may involve different numbers of drugs; in other words, the `n` in <drug_n> may vary.

As an example, the following output describes two extracted drug combinations; one between two drugs, and one between three drugs:

[["artesunate", "artemether", "COMB"], ["Nifedipine", "Labetalol", "Prazosin", "POS"]]

The paragraph and specific sentence are below. You should only extract relationships expressed in the specific sentence; the paragraph is provided for context.

In your output, return only the json array and no other text. If no drug combinations appear, return an empty array `[]`.

paragraph: Advances in the treatment of gastric cancer: 2019. The aim of this study was to review studies published within the past year regarding management of gastric cancer. ### Recent Findings Laparoscopic gastrectomy achieves equivalent survival compared with open gastrectomy in early stage and locally advanced gastric cancer. Adjuvant chemotherapy with 6 months of S-1 and oxaliplatin was superior to 12 months of S-1, and the addition of postoperative radiation therapy did not improve survival. The FLOT regimen is the new standard for preoperative chemotherapy. In metastatic gastric cancer, the addition of docetaxel to S-1 and cisplatin failed to improve overall survival over two-drug chemotherapy. The addition of the immune checkpoint inhibitor pembrolizumab to chemotherapy failed to improve overall survival compared with chemotherapy alone. ### summary Laparoscopic gastrectomy is acceptable in early and locally advanced gastric cancer. Combination adjuvant chemotherapy is superior to S-1 monotherapy. Adjuvant radiation therapy after D2 gastrectomy for node-positive gastric cancer does not improve survival. Preoperative chemotherapy with FLOT ( 5-FU , leucovorin , oxaliplatin and docetaxel ) without radiation therapy is the standard treatment in the West . Two-drug chemotherapy is the optimal initial treatment in metastatic disease. Adding pembrolizumab to front-line chemotherapy did not improve survival, with use of immune checkpoint inhibitors reserved to treat chemotherapy refractory metastatic disease.

sentence: Preoperative chemotherapy with FLOT ( 5-FU , leucovorin , oxaliplatin and docetaxel ) without radiation therapy is the standard treatment in the West .
[["5-FU", "leucovorin", "oxaliplatin", "docetaxel", "POS"]]