Background and Aims

Inter-ethnic differences in the clinical and pathological profile of rhabdomyosarcomas have been described, though in few limited studies. Furthermore, the relationship to recently-reclassified histological subtypes and age groups have not been studied in Asian cohorts.

We aimed to evaluate the clinical-pathological landscape, and survival outcomes of rhabdomyosarcomas in a multiracial Asian population.

Methods

We conducted a population-based 10-year (2004–2014) retrospective chart review of patients from all public tertiary institutions in Singapore which treat children and adults with rhabdomyosarcoma. Targeted sequencing for MYOD1 p.L122R point mutations, RT-PCR for PAX3/7-FOXO1 gene fusions and FISH for NCOA2 rearrangements were performed on archival formalin-fixed specimens. Histological subtypes were re-classified according to latest WHO guidelines, following central pathology review.

Results

Among 66 patients, incidence followed a tri-modal peak (0-3, 12-15, 57-63 years). There were 29 (42.0[AL1] [GYH2] %) embryonal,18 (26.1%) alveolar, 15 (21.7%) spindle-cell/sclerosing, and 4 (5.8%) pleomorphic rhabdomyosarcomas, with higher incidence of embryonal and alveolar subtypes in patients under 18 years (P=0.032). Regional nodal involvement was significantly lower in spindle-cell/sclerosing tumors (P=0.002). MYOD1 mutations occurred in 2/15 (13.3%) spindle-cell/sclerosing tumors (3.0% of all cases); none had NCOA2 rearrangements.

Overall survival –but not event-free survival– differed with stage, group and surgical resection, adjusted for age group (P=0.06, P=0.029, P=0.015, respectively). Survival outcomes did not differ significantly between histological subgroups. Relapses occurred in 5 (26.3%) embryonal tumors, 4 (36.4%) spindle-cell/sclerosing tumors, and 4 (30.8%) alveolar tumors, and was associated with significantly lower overall survival in pediatric patients but not adult patients (P=0.05 vs P=0.927, respectively). Following relapse, overall survival was higher in pediatric than adult patients (75% vs 50%).

Conclusions

Distribution of rhabdomyosarcoma histological subtypes in our population-based Asian cohort was similar to other series, though prevalence of MYOD1 mutations was lower. Established clinical risk factors and disease relapse continue to have significant prognostic value, particularly in pediatric patients.

Background and Aims

In Rhabdomyosarcoma (RMS), surgery is the mainstay of treatment, however chemotherapy and radiation are other treatment modalities. The prognosis of RMS is dependent on the site of the tumour, age of the patient, histological subtype, stage at presentation, and clinical grouping post surgery. A 78% 5-year survival has been reported in the United States of America. Currently, there is paucity of reliable data on the management approach and outcomes of RMS in South Africa. The aim of the study was to describe the management approach and outcomes of children with RMS at Chris Hani Baragwanath Academic Hospital (CHBAH).

Methods

A retrospective review of records of patients below 18 years old with RMS, who were managed by paediatric oncologists and surgeons at CHBAH, from 01 January 2008 to 31 December 2017.

Results

Fifty Eight patients presented with RMS, with a median age of 5.3 years (IQ= 7.7), 48% with a favourable primary tumour site, and 45% in an unfavourable site, 79% with an embryonal subtype, and 21% with an alveolar subtype. The overall 5-year survival was 55.0% (95% CI 68.8-41.2), a 79.3% (95% CI 94.2-64.4) survival in patients undergoing surgery, versus only 21.9% (95% CI 40.3-3.5) in those not undergoing surgery (p<0.0001). A survival of 71.2% (95% CI 89.4-53.0) with the primary tumour in a favourable site, versus 37.9% (95% CI 60.2-15.6) in an unfavourable site (p=0.03), and a 62.1% (95% CI 77.0-47.1) survival in an Embryonal subtype, versus 36.4% (95% CI 64.8-8.0) in an Alveolar subtype (p=0.18).

Conclusions

A markedly lower 5-year survival rate of 55% was observed compared to that of 78% in the USA. Survival is significantly higher if a patient qualifies for, and undergoes surgery, and when the primary tumour is in a favourable site, but there is only a weak correlation of improved outcome with the Embryonal subtype.

Background and Aims

Thoracotomy has been the classic approach for resection of pulmonary metastases (PM) in sarcomas. Recently, thoracoscopy has been proposed, for less morbidity and enhanced postoperative (PO) recovery. We analyzed our experience in the surgery of PM through an open approach to identify gaps for improvement.

Methods

Retrospective observational study. Inclusion criteria: Pediatric and adolescent patients with open resection of sarcoma PM. Study period: 2008- 2018. Demographics, pre- intra- and PO variables, pain management and complications were analyzed. Overall-survival (OS) and Event-free survival (EFS) were determined.

Results

A hundred and fourty four sarcoma diagnosis were made during the study period. 71 had PM, 31 fulfilled the inclusion criteria, with 63 surgical procedures performed (mean 2/patient, r:1-6); 16 females, mean age 12 (r:2-17). Underlying disease: Osteosarcoma 22 (70%), non-RMS 6, Ewing sarcoma 2, RMS 1. Surgical approach: unilateral thoracotomy 60 (95.2%). Nodules in preop-imaging:152; resected: 205; positive at pathology: 104. Chest tube stay: 2.73 days (1-7). Previous surgery in 21 procedures. Operative time: 186.19 min (75-360). PO pain management: intravenous in 7 (mean 2.61 days), epidural in 15 (mean 2.41 days), both 35. Mean hospital stay: 5.14 days (3-10), 2.98 days in ICU. PO mechanical ventilation needed in 1 case. Surgical complications: 13 events in 7 patients w/O2 requirement >24 hs, severe bronchospasm or ventilatory disfunction(by spirometry). They required longer chest tube stay (p=0.0002), ICU stay (p=0.0016), hospital stay (p=0.0009) and had a lower 5-year-OS (42%). Follow- up: 53.77 months. 5-yearOS: 50%; EFS: 40%. No surgery-related deaths were recorded.

Conclusions

Open operative approach allowed for identification of pulmonary nodules not found at preoperative CT scans, although impact on long term survival is not clear. Potential gaps for improvement against thoracoscopic surgery were identified related to length of stay and need for advanced pain management. Careful selection of cases in a prospective study design is recommended-