Maintenance therapy and drug holiday in sarcoma patients: systematic review

Maintenance Chemotherapy for Patients with Rhabdomyosarcoma

Maintenance chemotherapy (MC) defines the administration of prolonged relatively low-intensity chemotherapy with the aim of "maintaining" tumor complete remission. This paper aims to report an update of the RMS2005 trial, which demonstrated better survival for patients with high-risk localized rhabdomyosarcoma (RMS) when MC with vinorelbine and low-dose cyclophosphamide was added to standard chemotherapy, and to discuss the published experience on MC in RMS. In the RMS2005 study, the outcome for patients receiving MC vs. those who stopped the treatment remains superior, with a 5-year disease-free survival of 78.1% vs. 70.1% (p = 0.056) and overall survival of 85.0% vs. 72.4% (p = 0.008), respectively. We found seven papers describing MC in RMS, but only one randomized trial that did not demonstrate any advantage when MC with eight courses of trofosfamide/idarubicine alternating with trofosfamide/etoposide has been employed in high-risk RMS. The use of MC showed better results in comparison to high-dose chemotherapy in non-randomized studies, including metastatic patients, and demonstrated feasibility and tolerability in relapsed RMS. Many aspects of MC in RMS need to be investigated, including the best drug combination and the optimal duration. The ongoing EpSSG trial will try to answer some of these questions.

Maintenance therapy for long-term control of high-grade endometrial stromal sarcoma

High-grade endometrial stromal sarcoma (HG-ESS) is a malignant uterine tumour with a poor prognosis. This study aimed to demonstrate the usefulness of maintenance chemotherapy with paclitaxel (PTX) and carboplatin (CBDCA) for HG-ESS recurrence, by examining a case of HG-ESS tumour progression as a result of maintenance therapy interruption because of the COVID-19 pandemic. The patient was a woman in her 60s who presented with lower abdominal pain, nausea and a pelvic tumour, which was diagnosed as HG-ESS. Chemotherapy with PTX (175 mg/m2 day 1) + CBDCA (area under the concentration-time curve 5 day 1) every 21-28 days (TC therapy) was administered for long-term maintenance of HG-ESS. After 26 cycles, chemotherapy had to be postponed because of the COVID-19 pandemic, thus leading to disease progression and eventually death. In conclusion, TC therapy can prolong survival in patients with HG-ESS, and maintenance chemotherapy should not be postponed.

Kutane Sarkome – nicht alle sind wirklich selten, die meisten „low risk“

Die biologische und morphologische Vielfalt der Weichteilmalignome, der Sarkome, ist enorm.

Diese Übersicht fokussiert deshalb auf die 5 am häufigsten vorkommenden Weichteilmalignome. Betrachtet werden soll dabei, was der Kliniker wissen muss, was neu ist und welche Fallstricke es gibt. Ziel dieses Artikels ist es dabei, eine Übersicht zu geben sowie die Konzeptbildung darüber, womit man es im Wesentlichen zu tun hat.

Hypofractionated radiation therapy for unresectable or metastatic sarcoma lesions

Purpose

Given the relative radioresistance of sarcomas and their often large size, conventional palliative radiation therapy (RT) often offers limited tumor control and symptom relief. We report on our use of hypofractionated RT (HFRT) as a strategy to promote durable local disease control and optimize palliation.

Methods and Materials

We retrospectively reviewed 73 consecutive patients with sarcoma who received >10 fractions of HFRT from 2017 to 2020. Clinical scenarios included: (1) palliative or symptomatic intent (34%), (2) an unresectable primary (27%), (3) oligometastatic disease (16%), and (4) oligoprogressive disease (23%).

Results

The HFRT target was a primary tumor in 64% of patients with a median dose of 45 Gy in 15 fractions (59% ≥45 Gy). The 1-year disease-specific survival was 59%, which was more favorable for patients receiving HFRT for oligometastatic (1-year 100%) or oligoprogressive (1-year 73%) disease (P = .001). The 1-year local control (LC) of targeted lesions was 73%. A metastatic target (1-year 95% vs 60% primary; P = .02; hazard ratio, 0.27; P = .04) and soft tissue origin (1-year 78% vs 61% bone; P = .01; hazard ratio, 0.33; P = .02) were associated with better LC. The rate of distant failure was high with a 6-month distant metastasis-free survival of only 43%. For patients not planned for adjuvant systemic therapy (n = 53), the median systemic therapy break was 9 months and notably longer in oligometastatic (13 months), oligoprogressive (12 months) or unresectable (13 months) disease. HFRT provided palliative relief in 95% of cases with symptoms. Overall, 49% of patients developed acute grade 1 to 2 RT toxicities (no grade 3-5). No late grade 2 to 5 toxicities were observed.

Conclusions

HFRT is an effective treatment strategy for patients with unresectable or metastatic sarcoma to provide durable LC, symptom relief, and systemic therapy breaks with limited toxic effects.

Gemcitabine Maintenance Therapy in Patients With Metastasized Soft Tissue Sarcomas

Background

Metastasized soft-tissue sarcomas still pose a significant therapeutic challenge given the limited efficacy of currently available multimodal treatment strategies. Recent progress in molecular characterization of sarcoma subtypes has enabled successful personalized therapy approaches in a minority of selected patients with targetable mutations. However, in the majority of patients with refractory soft tissue sarcomas, long-term survival remains poor.

Methods

We report on three adult patients with various soft tissue sarcomas subjected to Gemcitabine maintenance therapy. Tumor entities included leiomyosarcoma of the pancreas (patient 1), undifferentiated pleomorphic sarcoma of the right femur (patient 2), and peri-aortic leiomyosarcoma (patient 3). Metastatic sites encompassed liver, lung, and bones. All patients received Gemcitabine maintenance therapy until disease progression following prior salvage chemotherapy with Docetaxel and Gemcitabine. Patients were treated outside of clinical trials. Response assessment was based on radiological imaging.

Results

In response to salvage chemotherapy with Docetaxel and Gemcitabine, one patient exhibited a partial remission, and two patients showed stable disease. Patient 1 exhibited stable disease for 6 months during Gemcitabine maintenance therapy before suffering rapid progression of hepatic metastases. Patient 2 underwent 21 months of Gemcitabine maintenance therapy, which was discontinued after progressive pulmonary metastases were detected. Patient 3 is still being treated with Gemcitabine maintenance therapy. Remarkably, owing to significant chemotherapy-associated hematotoxicity, the dose of Gemcitabine dose was reduced by two-thirds. Nevertheless, stable disease with constant pulmonary metastases has been maintained in this patient for 14 months.

Conclusions

Gemcitabine maintenance therapy following prior Docetaxel and Gemcitabine chemotherapy is manageable and reveals potential benefits for patients with aggressive metastasized soft tissue sarcomas. Prospective trials evaluating Gemcitabine maintenance therapy are encouraged.

Switch maintenance therapy with anlotinib after chemotherapy in unresectable or metastatic soft tissue sarcoma: a single-center retrospective study

Background Chemotherapy is an important first-line treatment option in patients with advanced soft tissue sarcoma (STS). Whether maintenance therapy improves survival after chemotherapy is still controversial. Methods We retrospectively analyzed the data of 21 adults diagnosed with unresectable or metastatic STS between May 2018 and September 2019 in our center. They achieved an objective response or stable disease after chemotherapy and then received at least one cycle of switch maintenance therapy with anlotinib, a novel multi-targeted tyrosine kinase inhibitor. The objective response rate (ORR), disease control rate (DCR), adverse events, and median progression-free survival (PFS) after anlotinib maintenance (PFSa), and the median PFS after chemotherapy (PFSc) were analyzed. Results Nineteen patients received first-line chemotherapy and 2 received second-line chemotherapy. Five patients achieved a partial response and 16 had stable disease after chemotherapy. The median number of anlotinib maintenance cycles was five (range, 2-31). One patient achieved a complete response and two patients exhibited a partial response during anlotinib maintenance, with an ORR of 14.3%. The DCR was 81.0%. After a median follow-up of 14.0 months, the median PFSa and PFSc were 7.3 and 13.6 months, respectively. Grade 3/4 adverse events occurred in six (28.6%) patients and were managed through symptomatic treatment, dose reduction or anlotinib discontinuance. Conclusion Our results indicate that switch maintenance therapy with anlotinib is a promising strategy for the treatment of patients with unresectable or metastatic STS who have benefited from chemotherapy. Toxicities were manageable. Prospective clinical trials are needed to confirm this finding.