 You are a biomedical researcher, and please answer the following question based on the context. 
In your answer, please first state the final answer in YES/NO/MAYBE, then include a brief explanation.

### Question: Is adjuvant therapy with streptozotocin and 5-fluorouracil useful after resection of liver metastases from digestive endocrine tumors?

### Context: 1: In patients with digestive endocrine tumors (DET) and liver metastases (LM) surgical resection is the only curative treatment. However, 5-year recurrence occurs in 50-80% of patients in the literature. The effect of adjuvant chemotherapy (CT) on relapse-free survival (RFS) and overall survival (OS) is unknown.AIM: To assess the safety and the efficacy of systemic adjuvant CT with streptozotocin and 5-fluorouracil (5-FU) following LM resection in patients with DET.
2: Between 1996 and 2006, 52 consecutive patients (23 males, median age 54 years [21-69]) underwent surgery for LM of well-differentiated DET in our center. The primary tumor was resected. After R0 resection of LM, patients were considered for adjuvant CT if the primary tumor was pancreatic, if LM was>or=10, or if the patient was<50 years old, in patients with other primary tumors. Twenty-nine patients received adjuvant CT and 23 were in the observation group. Adjuvant CT included 4 postoperative courses of i.v. streptozotocin-5-FU (500 and 400 mg/m(2), respectively, daily for 5 days every 42 days). RFS, OS and toxicity were evaluated. Log rank and chi-square analysis were used to identify prognostic factors.
3: Median post-operative follow-up was 47 months (4-162). In the adjuvant CT group, all patients except one received the 4 cycles. Two patients had grade 3-4 toxicity, including 1 febrile neutropenia resulting in death. Recurrence occurred in 43% and 65% of patients in the observation and adjuvant CT groups, respectively. RFS at 3 and 5 years was 51% and 38% in the observation group and 40% and 20% in the adjuvant CT group, respectively (P = .36). In univariate analysis, the significant prognostic factors associated with RFS were the number of LM (>or=10) and synchronous LM. Administration of adjuvant CT was not correlated with RFS. OS at 3 and 5 years was 90% and 76% in the observation group and 96% and 96% in the adjuvant CT group, respectively (P = .58).


###Response: RFS in patients receiving adjuvant CT was similar to that reported in the observation group and in historical cohorts without adjuvant CT. Thus, administration of streptozotocin-5-FU cannot be recommended in this indication.
 