Ewing sarcoma is known to harbour multiple balanced translocations, and fusions involving the EWSR1 gene on chromosome 22 exist. The most common translocation is t(11;22), EWSR1-FLI1 fusion (85% of cases), causing overexpression of the FLI-1 protein. The second most common translocation is t(21;22), EWSR1-ERG fusion (5%-10% of cases). Numerous other, less common variant translocations exist. Lack of reverse transcription-polymerase chain reaction
fusion transcripts for EWSR1-FLI1 and EWSR1-ERG does not exclude the possibility of Ewing sarcoma because it does not rule out fusion transcripts that may be present below the limit of detection for the given assay (5%) [20]. It most commonly arises from bone but can develop in extra skeletal sites[21]. Ewing sarcoma of the small intestine is extremely rare based on literature [22–24].
Among the 37 cases found, 3 cases were derived from the oesophagus, 9 from the stomach, 5 were of colorectal origin and 20 arouse from small intestines. 22 cases were found to be among males and 15 among females. The age range is from 9 years old to 68 years old. FISH break-apart EWSR1 was positive in 19 cases, negative in one case and was not carried out in 17 cases[9, 18, 22, 23, 25–49]. Our patient characteristics fall within these demographic data. Till date demographic research has shown that the frequency of Ewing sarcoma is higher in United States Caucasian population than China[50].
Ewing sarcoma predominantly affects children and young adults with a peak incidence between 10 and 20 years of age. About 30% occur in adults over the age of 20 and fewer than 5% occur in adults over the age of 40 [51].
So far, the outcome of 5-year survival rate of metastatic patients is usually poor (< 30%) compared to localised ES (65%-75%), despite the use of chemotherapy[52]. Several studies have indicated that localised extra skeletal ES has a more favourable outcome than skeletal tumours[53, 54].
According to NCCN guidelines, postoperative radiation therapy should begin within 60 days of surgery and is given concurrently with consolidation chemotherapy[55]. This explains why our patient was referred to oncology department shortly after surgery for further treatments.
Intergroup Ewing’s Sarcoma Study-I and Intergroup Ewing’s Sarcoma Study-II showed that radiation therapy and chemotherapy with VACD (vincristine, adriamycin, cyclophosphamide, doxorubicin) was superior to VAC (vincristine, adriamycin, cyclophosphamide)[56]. The 5-year relapse-free survival rate was 60% and 24% for VACD and VAC, respectively (p < 0.001). The corresponding overall survival rate was 65% and 28% (p < 0.001). Womer et al[57]. reported that VACD-IE given on every 2 weeks schedule was found to be more effective and no increase in toxicity.