Retroperitoneal soft tissue sarcoma: low-dose neoadjuvant radiation therapy followed by surgery with or without intraoperative radiotherapy and adjuvant radiation therapy

BACKGROUND

We describe the clinical history, outcome, and toxicity of five patients with high-grade retroperitoneal soft tissue sarcoma (RSTS) who were treated with neoadjuvant low-dose radiotherapy (RT) followed by resection with or without intraoperative radiotherapy (IORT), followed by adjuvant RT. We aim to provide additional evidence for the various treatment options that exist for this rare tumor entity.

METHODS

Most patients presented with mild abdominal symptoms. Diagnosis was confirmed by biopsy. Additional imaging was done by sonography, magnetic resonance imaging (MRI), and/or positron emission tomography (PET)/computed tomography (CT). All patients were treated with neoadjuvant RT of 19.8 Gy in 1.8-Gy fractions followed by resection and postoperative RT up to 45 Gy with a median interval between resection and start of postoperative RT of 5 weeks. Two patients received additional IORT. Median follow-up was 61 months.

RESULTS

One patient developed a local recurrence that was diagnosed 30 months after the start of the first therapy. He was treated with a salvage resection and had no evidence of disease at the last follow-up. Another patient developed a right-sided RSTS on the contralateral side from the primary radiation field with pelvic bone infiltration 56 months after the start of RT. He was treated again by RT and resection and was without evidence of disease at last follow-up. Radiotherapy was well tolerated without major toxicity.

CONCLUSION

The treatment of RSTS by low-dose neoadjuvant RT, resection with IORT and adjuvant RT seems to be a feasible and effective treatment approach. Further studies comparing neoadjuvant with adjuvant RT are necessary to find the best treatment option.

Relationship between circulating tumor cells and peripheral T-cells in patients with primary breast cancer

BACKGROUND

Detection of circulating tumor cells (CTCs) in the peripheral blood of patients with primary breast cancer is associated with poor clinical outcome. Recent studies have found evidence for immunological influence on tumor cell dormancy. We therefore investigated the relationship between peripheral T-cells and CTCs, as immunological factors may contribute to the fate of CTCs.

MATERIALS AND METHODS

The peripheral blood immune status of 116 patients with primary breast cancer was analyzed by flow cytometry. Results were correlated with the presence of CTCs and clinicopathological parameters of these patients.

RESULTS

Appearance of CTCs was significantly associated with grade III tumors (p<0.05). Interestingly, CTC-positive patients presented with a significant increase of peripheral CD95(FAS)-positive T-helper cells. As immune response is regulated by CD95(APO-1/FAS)-CD95ligand interaction and tumor cells induce apoptosis via the CD95/CD95L (ligand) pathway, this might lead to tumor cell escape by apoptotic T-helper cells.

CONCLUSION

Absence of T-cell help at the time of priming may result in a loss of long-term antigen-activation of CD8 lymphocytes and could lead to an ineffective anti-tumor cell response. This might contribute to systemic immunosuppression and open the door for tumor cell dormancy.