Rectal gastrointestinal stromal tumor with metastasis to the penis: Case report and review of literature

Radiotherapy for Gastrointestinal Stromal Tumors

OBJECTIVE

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors of the gastrointestinal tract, which frequently cause intraabdominal metastases. The current standard of care is surgery for localized cases, and adjuvant imatinib is recommended for tumors with a high risk of recurrence. To date, radiotherapy has not been commonly accepted as a part of multimodality treatment approach other than palliation. However, recently published case reports and some small series suggest that radiotherapy is a valuable option for controlling locally progressive, drug-resistant disease. The aim of this review is to provide a viewpoint from a radiation oncologist concerning the management of GISTs, especially rectal GIST, and clarify the role and technical aspects of radiotherapy in the treatment approach.

DATA SOURCES

A comprehensive search in PubMed using the keywords "radiotherapy for rectal GIST" and "rectal GIST" was undertaken. The literature search included the related articles after 1995.

STUDY SELECTION

The main articles including rectal GIST case reports and GIST series containing rectal cases were the primary references.

RESULTS

Surgery is the mainstay of treatment. However, to date, radiotherapy is included in the multidisciplinary treatment strategy of rectal GISTs in some circumstances with palliative, adjuvant, or definitive intent using different treatment doses and fields.

CONCLUSIONS

Recently reported long-term local control rates indicate that GIST is a radiosensitive disease. This makes radiotherapy a valuable alternative in GIST management with curative intent, especially in patients who (1) cannot tolerate or are resistant to chemotherapy agents, (2) have an unresectable disease, (3) have a gross or microscopic residual disease after surgery, and (4) have a recurrent disease.

β-elemene enhances anticancer and anti-metastatic effects of osteosarcoma of ligustrazine in vitro and in vivo

The present study aimed to determine the anticancer effects of the combination of β-elemene and ligustrazine in vitro as well as in in vivo. Following evaluation using an MTT assay, β-elemene, ligustrazine and the β-elemene-ligustrazine combination treatments all exhibited the capacity to inhibit the growth of OS-732 cells, with inhibitory rates of 43.3, 54.4, and 75.0%, respectively. Using a flow cytometry assay, it was determined that the β-elemene-ligustrazine combination possessed the highest apoptotic rate (30.6%). Furthermore, β-elemene-ligustrazine combination treatment resulted in the highest downregulation of G protein-coupled receptor 124, vascular endothelial growth factor, matrix metallopeptidase (MMP)-2 and MMP-9 mRNA, and protein expression levels. In addition, the combined treatment led to an increase in the mRNA and protein expression of endostatin, TIMP metallopeptidase inhibitor (TIMP)-1 and TIMP-2 in OS-732 cells. Additionally, β-elemene-ligustrazine caused a decrease in nuclear factor-κB, interleukin-8, C-X-C motif chemokine receptor 4 and urokinase-type plasminogen activator mRNA expression, as well as an increase in caspase-3, caspase-8, and caspase-9 mRNA expression. In vivo, the β-elemene-ligustrazine combination was able to reduce the weight and the bulk of the tumor in BALB/c-nu/nu nude mice compared with any other group. All the results described above regarding changes to mRNA and protein expression were further confirmed in vivo in the tumor tissue of mice. The results of the present study have suggested that the combination of β-elemene-ligustrazine exhibits greater anticancer effects compared with β-elemene- or ligustrazine-alone treatment.