Liposarcoma: patterns of tumor differentiation following induction chemotherapy

Heterogeneous in vitro effects of doxorubicin on gene expression in primary human liposarcoma cultures

BACKGROUND

Doxorubicin is considered one of the most potent established chemotherapeutics in the treatment of liposarcoma; however, the response rates usually below 30%, are still disappointing. This study was performed to identify gene expression changes in liposarcoma after doxorubicin treatment.

METHODS

Cells of 19 primary human liposarcoma were harvested intraoperatively and brought into cell culture. Cells were incubated with doxorubicin for 24 h, RNA was isolated and differential gene expression was analysed by the microarray technique.

RESULTS

A variety of genes involved in apoptosis were up and down regulated in different samples revealing a heterogeneous expression pattern of the 19 primary tumor cell cultures in response to doxorubicin treatment. However, more than 50% of the samples showed up-regulation of pro-apoptotic genes such as TRAIL Receptor2, CDKN1A, GADD45A, FAS, CD40, PAWR, NFKBIA, IER3, PSEN1, RIPK2, and CD44. The anti-apoptotic genes TNFAIP3, PEA15, Bcl2A1, NGFB, and BIRC3 were also up-regulated. The pro-apoptotic CD14, TIA1, and ITGB2 were down-regulated in more than 50% of the tumor cultures after treatment with doxorubicin, as was the antiapoptotic YWHAH.

CONCLUSION

Despite a correlation of the number of differentially regulated genes to the tumor grading and to a lesser extent histological subtype, the expression patterns varied strongly; however, especially among high grade tumors the responses of selected apoptosis genes were similar. The predescribed low clinical response rates of low grade liposarcoma to doxorubicin correspond to our results with only little changes on gene expression level and also divergent findings concerning the up- and down-regulation of single genes in the different sarcoma samples.

Liposarcoma in patients younger than or equal to 22 years of age

BACKGROUND

There have been few reported series of liposarcomas in patients younger than or equal to 22 years of age.

METHODS

A retrospective analysis of all patients presenting with liposarcoma between 1949-1990 at Memorial Sloan-Kettering Cancer Center with age at diagnosis younger than or equal to 22 years was performed. Variables evaluated for their predictive effect on survival included anatomic location of the primary, size, and completeness of surgical resection.

RESULTS

Eighteen patients were identified. Only 1 patient (6%) presented with a high-grade lesion, and in 13 patients (72%), the myxoid subtype was observed. All but one patient undergoing complete resection remain disease-free 1.3-29.1 years after treatment, while all patients with gross residual tumor have died from disease. Two of three patients with microscopic residual at resection are disease-free 2 and 11.8 years after diagnosis with the addition of external beam radiation therapy.

CONCLUSIONS

The authors conclude that complete surgical resection is crucial for survival in young patients with liposarcoma and the external beam radiation therapy may be effective against microscopic residual.

Spermatic cord liposarcoma in a young boy

We report on a spermatic cord liposarcoma arising in a 16-year-old boy. Treatment consisted of radical orchiectomy without retroperitoneal lymph node dissection, and adjuvant radiation and chemotherapy. The patient has survived 14 months without evidence of recurrence. Paratesticular localization of liposarcoma in patients less than 20 years old is rare. The tumor has no particular characteristic. Treatment consists of radical orchiectomy and the role of retroperitoneal lymphadenectomy is controversial.