Topotecan/carboplatin regimen for refractory/recurrent rhabdomyosarcoma in children: Report from the AIEOP Soft Tissue Sarcoma Committee

Significance of fusion status, Oberlin risk factors, local and maintenance treatment in pediatric and adolescent patients with metastatic rhabdomyosarcoma: Data of the European Soft Tissue Sarcoma Registry SoTiSaR

BACKGROUND

Outcome of primary metastatic rhabdomyosarcoma (RMS) is poor. Certain risk factors as fusion status, Oberlin score, and local treatment of primary tumor are known to influence prognosis.

PROCEDURE

Patients with metastatic RMS were treated according to Cooperative Weichteilsarkom Studiengruppe (CWS) guidance with chemotherapy (CHT), radiotherapy (RT) excluding total lung irradiation (TLI), complete resection of the primary tumor, and metastasectomy if possible. Kaplan-Meier estimators and Cox proportional hazard models were used to examine event-free survival (EFS) and overall survival (OS) involving also landmark analyses.

RESULTS

In the European Soft Tissue Sarcoma Registry SoTiSaR (2009-2018), 211 patients were analyzed. Many patients had fusion-positive alveolar RMS (n = 83; 39%). Median age was 9.4 years [0.1-19.7 years]. Treatment primarily consisted of CHT with CEVAIE (carboplatin, epirubicine, vincristine, actinomycin-D, ifosfamide, etoposide: 86%, other regimens: 14%), RT (71%), resection of primary tumor (37%), metastasectomy (19%), and lymph node sampling/dissection (21%). Maintenance treatment (MT) (oral trofosfamide, idarubicin, etoposide) was added in 74% of patients. Oberlin factors, fusion status, and MT were predictive for EFS and OS. MT with O-TIE was not improving outcome when adjusting for the immortal time bias. Local treatment of the primary tumor and radical irradiation (except TLI) improved EFS, not OS, when adjusting for the Oberlin score. Patients with fusion-negative alveolar RMS (n = 9) had an excellent outcome with a 5-year EFS and OS of 100%, compared to patients with embryonal RMS (49%/62%), PAX7- (22%/47%) and PAX3/FOXO1-positive ARMS (10/13%), respectively (p < .001).

CONCLUSIONS

Prognosis of metastatic RMS primarily depends on fusion status and Oberlin score. Fusion status needs to be considered in future trials to optimize treatment outcome. The role of radical irradiation needs further investigation.

Platinum-Based Regimens Are Active in Advanced Pediatric-Type Rhabdomyosarcoma in Adults and Depending on HMGB1 Expression

Rhabdomyosarcoma (RMS) in adults is a rare and aggressive disease, which lacks standard therapies for relapsed or advanced disease. This retrospective study aimed to describe the activity of BOMP-EPI (bleomycin, vincristine, methotrexate and cisplatin alternating with etoposide, cisplatin and ifosfamide), an alternative platinum-based regimen, in adult patients with relapsed/metastatic RMS. In the study, 10 patients with RMS with a median age at diagnosis of 20.8 years and a female/male distribution of 6/4 received a mean of 2.5 cycles of BOMP-EPI. The best RECIST response was a complete response in 1/10 (10%) patients, a partial response in 5/10 (50%), stable disease in 3/10 (30%) and progression in 1/10 (10%). With a median follow-up in the alive patients from the start of therapy of 30.5 months (15.7-258), all patients progressed with a median progression-free survival of 8.47 months (95% CI 8.1-8.8), and 7/10 patients died with a median overall survival of 24.7 months (95% CI 13.7-35.6). BOMP-EPI was an active chemotherapy regimen in adults with pediatric-type metastatic RMS, with outcomes in terms of survival that seem superior to what was expected for this poor-prognosis population. Low HMGB1 expression level was identified as a predictive factor of better response to this treatment.

Application of Approved Cisplatin Derivatives in Combination Therapy against Different Cancer Diseases

The problems with anticancer therapy are resistance and toxicity. From 3000 Cisplatin derivatives tested as antitumor agents, most of them have been rejected, due to toxicity. The aim of current study is the comparison of therapeutic combinations of the currently applied in clinical practice: Cisplatin, Carboplatin, Oxaliplatin, Nedaplatin, Lobaplatin, Heptaplatin, and Satraplatin. The literature data show that the strategies for the development of platinum anticancer agents and bypassing of resistance to Cisplatin derivatives and their toxicity are: combination therapy, Pt IV prodrugs, the targeted nanocarriers. The very important strategy for the improvement of the antitumor effect against different cancers is synergistic combination of Cisplatin derivatives with: (1) anticancer agents-Fluorouracil, Gemcitabine, Cytarabine, Fludarabine, Pemetrexed, Ifosfamide, Irinotecan, Topotecan, Etoposide, Amrubicin, Doxorubicin, Epirubicin, Vinorelbine, Docetaxel, Paclitaxel, Nab-Paclitaxel; (2) modulators of resistant mechanisms; (3) signaling protein inhibitors-Erlotinib; Bortezomib; Everolimus; (4) and immunotherapeutic drugs-Atezolizumab, Avelumab, Bevacizumab, Cemiplimab, Cetuximab, Durvalumab, Erlotinib, Imatinib, Necitumumab, Nimotuzumab, Nivolumab, Onartuzumab, Panitumumab, Pembrolizumab, Rilotumumab, Trastuzumab, Tremelimumab, and Sintilimab. An important approach for overcoming the drug resistance and reduction of toxicity of Cisplatin derivatives is the application of nanocarriers (polymers and liposomes), which provide improved targeted delivery, increased intracellular penetration, selective accumulation in tumor tissue, and enhanced therapeutic efficacy. The advantages of combination therapy are maximum removal of tumor cells in different phases; prevention of resistance; inhibition of the adaptation of tumor cells and their mutations; and reduction of toxicity.

Integrating irinotecan in standard chemotherapy: A novel dose-density combination for high-risk pediatric sarcomas

BACKGROUND

Irinotecan is a drug active against pediatric sarcomas with a toxicity profile that theoretically allows for its association with more myelotoxic drugs. We examined the feasibility of a dose-density strategy integrating irinotecan in standard chemotherapy regimens for patients with high-risk sarcomas.

METHODS

Between November 2013 and January 2020, 23 patients ≤25 years old were included in the study. Eleven patients newly diagnosed with metastatic disease received nine cycles of IrIVA (irinotecan-ifosfamide-vincristine-actinomycin D; ifosfamide 3 g/m² on days 1 and 2, vincristine 1.5 mg/m² on day 1, actinomycin D 1.5 mg/m² on day 1, irinotecan 20 mg/m² for 5 consecutive days starting on day 8) as first-line therapy. Two relapsed patients received IrIVA and 10 IrVAC (irinotecan-vincristine-actinomycin D-cyclophosphamide; cyclophosphamide 1.5 g/m² on day 1 instead of ifosfamide). Feasibility was assessed in terms of toxicity and time to complete the treatment.

RESULTS

Seventeen rhabdomyosarcomas, four Ewing sarcomas, two desmoplastic small round cell tumors received a total of 181 cycles (range 2-10). Grade 4 neutropenia occurred in 62.4% of the cycles. Thirteen patients had febrile neutropenia. Diarrhea occurred in 14 cycles. The median time to complete the treatment was 195 days (range 170-231), 83.4% of cycles were administered on time or with a delay <1 week. With a median follow-up of 2.6 years (range 0.2-5.0), 12 patients are alive, nine complete remissions, three with the disease.

CONCLUSIONS

A dose-density strategy combining irinotecan with standard chemotherapy is feasible. This approach will be investigated in the next trial coordinated by the European pediatric Soft tissue sarcoma Study Group.

Relapsed Rhabdomyosarcoma

Relapsed rhabdomyosarcoma (RMS) represents a significant therapeutic challenge. Nearly one-third of patients diagnosed with localized RMS and over two-thirds of patients with metastatic RMS will experience disease recurrence following primary treatment, generally within three years. Clinical features at diagnosis, including primary site, tumor invasiveness, size, stage, and histology impact likelihood of relapse and prognosis post-relapse. Aspects of initial treatment, including extent of surgical resection, use of radiotherapy, and chemotherapy regimen, are also associated with post-relapse outcomes, as are features of the relapse itself, including time to relapse and extent of disease involvement. Although there is no standard treatment for patients with relapsed RMS, several general principles, including tissue biopsy confirmation of diagnosis, assessment of post-relapse prognosis, determination of the feasibility of additional local control measures, and discussion of patient goals, should all be part of the approach to care. Patients with features suggestive of a favorable prognosis, which include those with botryoid RMS or stage 1 or group I embryonal RMS (ERMS) who have had no prior treatment with cyclophosphamide, have the highest chance of achieving long-term cure when treated with a multiagent chemotherapy regimen at relapse. Unfortunately, patients who do not meet these criteria represent the majority and have poor outcomes when treated with such regimens. For this group, strong consideration should be given for enrollment on a clinical trial.

Recent advances in understanding and managing pediatric rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a high-grade malignant neoplasm, with a morphologic appearance mimicking that of developing skeletal muscle. Over the last 30 years, patient outcomes have improved with the incorporation of multimodal therapies, including chemotherapy, radiation therapy, and surgery. The overall cure rates exceed 70%, with patients who have low-, intermediate-, and high-risk disease experiencing long-term survival rates of >90%, 70%, and <30%, respectively. Historically, RMS was classified according to histology; however, recent advances have revealed new molecular subgroups that allow us to more accurately identify high-, intermediate-, and low-risk disease. In this review, we discuss recent advances made in understanding RMS tumor biology and propose how this understanding can drive a new classification system that can guide clinical approaches for treatment de-escalation in patients with expected favorable outcomes and escalation for those with expected poor outcomes.

Management of Refractory Pediatric Sarcoma: Current Challenges and Future Prospects

Paediatric sarcomas are a heterogeneous group of disorders constituting bone sarcoma and various soft tissue sarcomas. Almost one-third of these presents with metastasis at baseline and another one-third recur after initial curative treatment. There is a huge unmet need in this cohort in terms of curative options and/or prolongation of survival. In this review, we have discussed the current treatment options, challenges and future strategies of managing relapsed/refractory paediatric sarcomas. Upfront risk-adapted treatment with multidisciplinary management remains the main strategy to prevent future recurrence or relapse of the disease. In the case of limited local and/or systemic relapse or late relapse, initial multimodality management can be administered. In treatment-refractory cases or where cure is not feasible, the treatment options are limited to novel therapeutics, immunotherapeutic approach, targeted therapies, and metronomic therapies. A better understanding of disease biology, mechanism of treatment refractoriness, identifications of driver mutation, the discovery of novel targeted therapies, cellular vaccine and adapted therapies should be explored in relapsed/refractory cases. Close national and international collaboration for translation research is needed to fulfil the unmet need.