Efficacy of immune checkpoint inhibitors in alveolar soft-part sarcoma: results from a retrospective worldwide registry

BACKGROUND

Conventional cytotoxic drugs are not effective in alveolar soft-part sarcoma (ASPS). Immune checkpoint (programmed cell death protein 1/programmed death-ligand 1) inhibitors (ICIs) are promising drugs in ASPS. A worldwide registry explored the efficacy of ICI in ASPS.

MATERIALS AND METHODS

Data from adult patients diagnosed with ASPS and treated with ICI for advanced disease in expert sarcoma centers from Europe, Australia and North America were retrospectively collected, including demographics and data related to treatments and outcome.

RESULTS

Seventy-six ASPS patients, with a median age at diagnosis of 25 years (range 3-61 years), were registered. All patients received ICI for metastatic disease. Immunotherapy regimens consisted of monotherapy in 38 patients (50%) and combination in 38 (50%) (23 with a tyrosine kinase inhibitor). Among the 68 assessable patients, there were 3 complete responses and 34 partial responses, translating into an overall response rate of 54.4%. After a median follow-up of 36 months [95% confidence interval (CI) 32-40 months] since the start of immunotherapy, 45 (59%) patients have progressed on ICI, with a median progression-free survival (PFS) of 16.3 months (95% CI 8-25 months). Receiving ICI in first line (P = 0.042) and achieving an objective response (P = 0.043) correlated with a better PFS. Median estimated overall survival (OS) from ICI initiation has not been reached. The 12-month and 24-month OS rates were 94% and 81%, respectively.

CONCLUSIONS

This registry constitutes the largest available series of ASPS treated with ICI. Our results suggest that the ICI treatment provides long-lasting disease control and prolonged OS in patients with advanced ASPS, an ultra-rare entity with limited active therapeutic options.

[Cutaneous angiosarcoma clinically presenting as Quincke's edema]

Es wird über den Fall eines 75-jährigen Patienten mit einer Gesichtsschwellung v. a. periorbital berichtet, der unter der Verdachtsdiagnose eines Quincke-Ödems stationär aufgenommen wurde. Probebiopsien ergaben das Vorliegen eines kutanen Angiosarkoms. Bei nicht resezierbarem Befund und schwieriger Bestrahlungssituation wurde zunächst eine Chemotherapie eingeleitet. Im Verlauf erfolgte bei Befundprogress die Therapieumstellung auf Zweit- und Drittlinientherapie. Der geschilderte Fall verdeutlicht die Komplexität bei der Diagnostik und Therapie bei Patienten mit kutanem Angiosarkom.

[Imatinib and beyond-what is important for surgery?]

The treatment of gastrointestinal stromal tumors (GIST) has dramatically improved since the introduction of small molecule KIT proto-oncogene receptor tyrosine kinase inhibitors. Nevertheless, the cure of patients is still based on surgical treatment of the primary tumor. The chance of long-term tumor control by tyrosine kinase inhibitors (TKI) even in the metastatic setting also appears to be improved after achieving a surgical complete resection. The decision on which patients will most likely profit from multimodal treatment approaches is increasingly based on complex molecular predictors in addition to clinical factors and also a profound understanding of the biology of GIST that requires discussion in a multidisciplinary, highly experienced treatment team. Novel, more potent inhibitors enable a response to treatment in so far treatment-refractory GIST subtypes, such as the platelet-derived growth factor receptor (PDGFR) D842V mutated GIST subtype and also appear to show treatment benefits even in KIT mutated GIST after the failure of all approved treatments. These treatments are expected to profoundly change treatment algorithms in the near future.

HDAC3 is linked to cell cycle machinery in MiaPaCa2 cells by regulating transcription of skp2

OBJECTIVE

Histone deacetylases (HDACs) have been linked to cell cycle control in various models, involving regulation of the cyclin-dependent kinase inhibitor p27(Kip1).

RESULTS

Here, we demonstrate that HDAC inhibition by trichostatin A reduces S-phase kinase-associated protein 2 mRNA and protein abundance. Furthermore, in contrast to HDAC1, recruited to the skp2 promoter in the G(0) phase, HDAC3 is bound in early S phase. Activating function of HDAC3 towards the skp2 gene has been validated using RNA interference techniques. siRNAs, targeting HDAC3 specifically, reduced skp2 transcription.

CONCLUSION

These findings propose that the skp2 gene is a novel target of HDAC3, mediating cell cycle control and oncogenesis.