William W. Tseng, MD, an associate professor of Clinical Surgery and a sarcoma surgeon with Keck Medicine of the University of Southern California, discusses the goals of the Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) analysis in retroperitoneal sarcoma (RPS).

The exploratory TARPSWG analysis was a retrospective study, says Tseng; however, a prospective study is being planned in the near future. One goal of this research was to get as many sarcoma referral centers as possible to participate, adds Tseng. However, the primary goal of the study was to determine whether neoadjuvant systemic therapy is beneficial in patients with RPS.

Prior to surgery, patients were given systemic therapy, with investigators calculating how many achieved a complete response, partial response, or progressive disease. The goal was to have these data quantitated, concludes Tseng.

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William W. Tseng, MD, discusses the goals of the Transatlantic Australasian Retroperitoneal Sarcoma Working Group analysis in retroperitoneal sarcoma.
 

Dr. Tseng on the Goal of the TARPSWG Analysis in Retroperitoneal Sarcoma

William W. Tseng, MD, a sarcoma surgeon with Keck Medicine of the University of Southern California, discusses the significance of the Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) analysis in retroperitoneal sarcoma (RPS).

In the exploratory TARPSWG analysis, patients with ​high-risk RPS demonstrated a modest response to ​neoadjuvant systemic therapy, says Tseng. For example, partial response​s were reported in about 23% of patients, ​and56% experienced stable disease.

 Based on published literature, some controversy remains with regard to the utility of systemic therapy​, particularly chemotherapy, in the ​sarcoma space, Tseng explains. ​However, these data chemotherapy has activity in this rare sarcoma subtype.

Ultimately, additional research is needed to elucidate the role of chemotherapy in this space, Tseng concludes.

William W. Tseng, MD, discusses the significance of the Transatlantic Australasian Retroperitoneal Sarcoma Working Group analysis in retroperitoneal sarcoma.

Dr. Tseng on the Significance of the TARPSWG Analysis in Retroperitoneal Sarcoma

William W. Tseng, MD, a sarcoma surgeon with Keck Medicine of the University of Southern California, discusses the rationale for the Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) analysis in retroperitoneal sarcoma (RPS).

Although RPS is a rare cancer that occurs in the retroperitoneum, it accounts for about 20% of adult soft tissue sarcomas, says Tseng.

Historically, this disease has been a challenge to treat and is widely known as one of the largest tumors that can be found in the human body. These tumors typically weigh around 20 to 30 pounds; however, there have also been reports of tumors that weigh up to 77 pounds.

Due to its size, this tumor touches several vital structures within the abdomen, such as major blood vessels and organs. Notably, the tumor starts in the back of the abdomen and pushes its way to the front, resulting in challenging operations.

Unfortunately, recurrence rates in this patient population are high, and, in certain subtypes, there are high distant metastatic rates, Tseng explains.

As such, in the TARPSWG analysis, investigators evaluated the frequency and potential predictors of tumor response to therapy and assessed the clinical outcomes of patients with high-risk RPS who were treated with neoadjuvant systemic therapy, followed by surgery.

William W. Tseng, MD, discusses the rationale for the Transatlantic Australasian Retroperitoneal Sarcoma Working Group analysis in retroperitoneal sarcoma.

Dr. Tseng on the Rationale for the TARPSWG Analysis in Retroperitoneal Sarcoma

William W. Tseng, MD, a sarcoma surgeon with Keck Medicine of University of Southern California, discusses the potential role of neoadjuvant systemic therapy in high-risk retroperitoneal sarcoma (RPS).

In this retrospective study, investigators collected clinicopathologic data on eligible patients treated from 2008 to 2018 at 13 institutions within the Transatlantic Australasian Retroperitoneal Sarcoma Working Group.

A total of 158 patients were enrolled on the study, and they were treated with a median of 3 cycles of neoadjuvant systemic therapy; just under half, or 46%, of patients also received neoadjuvant radiation therapy. Results showed that 23% of patients experienced a partial response with this approach and 56% achieved stable disease.

Twenty-one percent of patients experienced disease progression. In terms of clinical outcomes, the most significant finding, according to Tseng, was that patients with progressive disease had worse outcomes. Specifically, these patients had 2.7-fold lower overall survival than those whose disease did not progress, adds Tseng.

The results indicate that the response to neoadjuvant systemic therapy could be used as a potential indicator of disease biology to predict outcome following surgery, explains Tseng.

The results from the study also raise the question of whether patients with progressive disease, and thus, worse survival, should receive second-line treatment. Surgery can be very challenging and the recovery can be difficult for patients. If a patient’s survival is poor, Tseng posits trying another type of therapy, but the topic is still under discussion.

William W. Tseng, MD, discusses the potential role of neoadjuvant systemic therapy in high-risk retroperitoneal sarcoma.

William W. Tseng, MD

Articles

Dr. Tseng on the Goal of the TARPSWG Analysis in Retroperitoneal Sarcoma

Dr. Tseng on the Significance of the TARPSWG Analysis in Retroperitoneal Sarcoma

Dr. Tseng on the Rationale for the TARPSWG Analysis in Retroperitoneal Sarcoma

Dr. Tseng on Role of Neoadjuvant Systemic Therapy in High-Risk Retroperitoneal Sarcoma