EBRT Lowers Local Recurrence Risk in Soft Tissue Sarcoma

Markus Albertsmeier, MD

External beam radiation therapy (EBRT) lowers the risk of local recurrence in patients with either retroperitoneal or extremity sarcomas, according to a meta-analysis presented at the 2016 Connective Tissue Oncology Society (CTOS) Annual Meeting by lead study researcher Markus Albertsmeier, MD.

Among 729 patients with retroperitoneal tumors enrolled across 5 studies, there was a significant impact on local recurrence with EBRT versus no EBRT (HR, 0.42; 95% CI, 0.29-0.60; P <.00001). A separate evaluation of 3155 patients with tumors in extremities and other locations demonstrated a similar positive impact on local recurrence with EBRT (HR, 0.49; 95%, 0.31-0.77; P = .002). A third analysis of 1012 patients with extremity and trunk tumors enrolled across 8 studies showed a benefit with preoperative versus postoperative EBRT in reducing the risk of local recurrence (HR, 0.66; 95% CI, 0.49-0.01; P = 0.01).

OncLive: Can you give an overview of the effect of radiation therapy on local recurrence and overall survival in soft-tissue sarcoma?

In an interview with OncLive at the CTOS Annual Meeting, Albertsmeier, surgeon at Ludwig Maximilian University of Munich, discussed the results of the meta-analysis and the implications going forward for the treatment of patients with soft tissue sarcoma.Albertsmeier: As surgeons, we know that the only treatment available for patients with sarcoma is generally surgery. We also know that we cannot help many patients or at least we cannot cure them, so we rely on other therapies to help these patients. In sarcoma, it is very important to gain control over the tumor and we think this can, in some patients, be achieved by radiotherapy.

What were the major findings from the meta-analysis?

The problem is that the available evidence in the scientific community has never been summarized and is never so clear as to whether radiotherapy, in addition to surgery, may improve the local control and the overall survival of these patients. We did this meta-analysis to have a sound basis for future guidelines, which will also be developed at this congress. One major finding is that radiotherapy is indeed able to improve the local control of sarcoma in both the retroperitoneum, which is a frequent location, and in extremities and other locations, so it is effective in all those locations in improving local control.

Did this study confirm whether the preferred timing should be preoperative or postoperative?

Plus, we have some hints that in retroperitoneum, the overall survival might improve, while we don't see this, at least with the available evidence, for extremity sarcoma. One part of this meta-analysis was comparing studies or summarizing studies that compared those 2 points, preoperative or postoperative. We did see that there was a tendency towards better effectiveness in preoperative radiotherapy, but the quality of this evidence is rather low so we are not sure if we should believe this.

What would you say are the next steps following these results?

Plus, we also found that wound healing disorders were much more frequent in preoperative radiotherapy. The recommendation would probably be to do radiotherapy postoperative. The next steps would be performing trials that can close those gaps that we identified. Namely, doing randomized control trials examining the effectiveness of radiotherapy or the correct timing in a specific patient subgroup.

What would you like to see in the next 5 to 10 years in this treatment landscape?

What would you like the community oncologists to ultimately take away from this meta-analysis?

All of those studies that were included in those specific subgroups until now and also trials that are still ongoing, all include patients with mostly different histologies, different types of tumors, different grades, different sizes, or different tumor locations. We believe that these should be specified, which is difficult in such a rare disease but that is what needs to be done. We would like to see studies that support personalized approaches. We would like to know when a patient first comes to us, whether to offer him radical surgery or limited surgery, radiotherapy or no radiotherapy, chemotherapy, which kind of chemotherapy, and which sequence. All of these questions need to be answered for a specific patient. At the moment, most of the evidence comes from basket studies that include everything at the same time. The main message is radiotherapy appears to be effective. It probably does improve survival in retroperitoneal sarcoma. We have to be more cautious about sarcoma of the extremities and the most important thing is that we need to keep on working and generating those high-quality results.

References

Albertsmeier M, Roeder F, Gronchi A, et al. Meta-analysis of the effect of radiation therapy on local recurrence and overall survival in soft tissue sarcoma. Presented at: Connective Tissue Oncology Society Annual Meeting; Lisbon, Portugal; November 9-12, 2016. Paper 007.