Preserving quality of life as a key treatment goal in advanced soft tissue sarcomas

INTRODUCTION

Health-related quality of life (HRQoL) is a patient-reported outcome that addresses patients' perceptions of symptoms across physical, emotional, cognitive and social domains. As HRQoL is currently rarely measured outside clinical trials in oncology, it must be inferred from patients' everyday performance during treatment. To gain insight into the HRQoL of advanced STS patients receiving palliative treatment in clinical practice, three case studies of patients treated with trabectedin are examined. Areas covered: The patient in Case 1 has maintained complete remission for more than 8 years after receiving nine cycles of second-line trabectedin followed by secondary surgery for recurrent myxoid liposarcoma, and was able to resume normal activities during trabectedin treatment. Case 2 describes 10 years' follow-up of a patient with myxoid liposarcoma who remains well after many lines of chemotherapy including extended use of trabectedin in the second line. The third case illustrates the feasibility of extending survival time in an elderly patient with metastatic leiomyosarcoma who was able to maintain a busy and active lifestyle while receiving second-line trabectedin. Expert commentary: Owing to its relatively benign safety profile, trabectedin frequently permits prolonged therapy and is generally well tolerated, often allowing patients to carry on with normal daily activities.

Treatment of advanced, metastatic soft tissue sarcoma: latest evidence and clinical considerations

Soft tissue sarcoma (STS) is a biologically heterogeneous malignancy with over 50 subtypes. Historically, there have been few systemic treatment options for this relatively rare disease. Traditional cytotoxic agents, such as anthracyclines, alkylating agents, and taxanes have limited clinical benefit beyond the first-line setting; across all high-grade STS subtypes, median overall survival remains approximately 12-18 months for advanced metastatic disease. The development of targeted therapies has led to recent US Food and Drug Administration approval of four new treatments for high-grade STS in the advanced metastatic setting. Among these, olaratumab is most notable for its improvement in overall survival for patients with anthracycline-naïve disease. Further progress in STS management will rely on novel trial design, subtype-specific therapies and validation of biomarkers to tailor therapy. Immunotherapy has shown promise as a new, but yet undiscovered frontier in the management of STS.

Complete response after rechallenge with trabectedin in a patient with previously responding high-grade undifferentiated sarcoma

Evidence supporting rechallenge in patients responding to first exposure to trabectedin is limited. We report on a 39-year-old woman with advanced high-grade undifferentiated sarcoma (US) retreated twice with trabectedin after first response. The patient presented in June 2006 with an abdominal mass originating from the rear fascia of the rectus abdominis. Staging examinations did not indicate metastases and she underwent surgery; pathology showed a high-grade (FNCLCC G3) US. Subsequently, the patient received five cycles of adjuvant chemotherapy with epirubicin and ifosfamide. In February 2009 a computed tomography (CT) scan showed an abdominal mass involving the transverse mesocolon. R0 surgery was performed. In September 2009, peritoneal lesions appeared. Trabectedin was initiated at a dose of 1.5 mg/m² by a 24 h intravenous infusion every 3 weeks, without relevant toxicity. After six cycles (March 2010), CT and PET-CT scans showed complete disappearance of metastases. In February 2012, new secondary lesions in the subdiaphragmatic region and a peritoneal lesion appeared. We rechallenged the patient with the same schedule of trabectedin; a complete response was achieved after two cycles. In October 2013, new secondary lesions in the subdiaphragmatic region and a retroperitoneal lesion were found. We rechallenged with the same schedule of trabectedin; PET-CT scans after two cycles showed complete response on the subdiaphragmatic lesion. Radiotherapy on the retroperitoneal lesion was performed. The patient underwent a total of 18 cycles and remains free from radiologically detectable disease. We report complete radiological remission after two rechallenges with trabectedin in a patient with previously responding high-grade US.

The intriguing patterns of tumor response to trabectedin

Among soft tissue sarcomas, myxoid liposarcomas are exceedingly sensitive to trabectedin. Obvious tumor shrinkage is seen in some patients, whereas nondimensional changes in tumor tissue are seen in others especially after the first cycles of therapy. These patterns of tumor response are reminiscent of the way in which solid tumors respond to targeted therapies. The finding of trabectedin's ability to target the FUS-CHOP-mediated transcriptional block, restoring adipogenic differentiation within the tumor in myxoid liposarcomas, confirmed a 'targeted' activity that differs from its well-known atypical alkylating mechanism of action. Uterine leiomyosarcoma may show similar patterns of dimensional and nondimensional responses to trabectedin. Unusual cases of delayed response are occasionally seen and suggest other mechanisms of action, including activity on the tumor microenvironment which has recently been reported. An intriguing question is whether the different patterns of response have clinically or therapeutically meaningful correlations.