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: Adjuvant cyclophosphamide, methotrexate and fluorouracil in node-negative and estrogen receptor-negative breast cancer. Updated results. Node-negative breast cancers are considered to comprise a subgroup which is amenable to cure with local-regional therapy alone. However, approximately 30% of affected patients present new disease manifestations within 10 years after surgery. To test the hypothesis that node-negative and estrogen receptor-negative breast cancer patients can benefit from adjuvant chemotherapy, a prospective randomized study was activated at the Istituto Nazionale Tumori of Milan in 1980. ### Patients And Methods The study was conducted in 90 patients operated on for unilateral breast cancer who were then assigned to receive either 12 intravenous cycles of cyclophosphamide , methotrexate and fluorouracil ( CMF ) every three weeks , or no further treatment . Adjuvant chemotherapy was administered in the outpatient clinic of the Division of Medical Oncology. Patient characteristics were fairly well balanced between the two treatment groups except for primary tumor size: 58% of those with a primary tumor measuring > 2 cm in its largest diameter were randomized in the control group compared with 38% in the CMF regimen (P = 0.06). ### results At 12 years after surgery treatment outcome was significantly superior for patients given adjuvant CMF. The relapse-free survival rate was 71% (95% confidence limits (CL): 56-86) versus 43% (95% CL: 28-58), and total survival was 80% (95% CL: 68-92) versus 50% (95% CL: 34-66), respectively. The benefit from the administration of CMF was evident in all patient subsets and was not influenced by menopausal status. ### conclusions The long-term results of this trial of adjuvant combination chemotherapy confirm our previous observations on the efficacy of adjuvant chemotherapy in node-negative breast cancer patients at high risk of early disease relapse.

sentence: The study was conducted in 90 patients operated on for unilateral breast cancer who were then assigned to receive either 12 intravenous cycles of cyclophosphamide , methotrexate and fluorouracil ( CMF ) every three weeks , or no further treatment .
[["cyclophosphamide", "methotrexate", "fluorouracil", "POS"]]