Heterogeneous oestrogen- and progesterone-receptor expression in low-grade endometrial stromal sarcomas-implications for therapy

Can proliferation biomarkers reliably predict recurrence in World Health Organization 2003 defined endometrial stromal sarcoma, low grade?

An estimated 1500–3000 invasive Endometrial Stromal Sarcomas (ESS) cases annually occur worldwide. Before 2003, ESS was divided as low and high grade ESS based on mitotic activity. In 2003 the WHO changed the names, excluded mitoses and made nuclear atypia and necrosis the essential diagnostic criteria to distinguish ESS, Low Grade (ESS-LG, recurrence-free survival >90%) and Undifferentiated Endometrial Sarcoma (UES, poor prognosis). We have evaluated in WHO2003 defined ESS-LG whether proliferation biomarkers predict recurrence. Using survival analysis, the prognostic value of classical mitosis counts (Mitotic Activity Index, MAI) in haematoxyllin-eosin (H&E) sections, and immunohistochemical proliferation biomarkers (Ki-67 and PhosphoHistone-3 (PPH3)) were examined in 24 invasive endometrial stromal sarcomas. Three of 24 (12.5%) ESS-LG recurred. The MAI, PPH3 and Ki-67 were all prognostic (P = 0.001, 0.002 and 0.03). MAI values were >3 in the recurrent cases, but never exceeded 10 (the classical threshold for low and high grade). Non-recurrent cases had 0≤MAI≤3. PPH3 and Ki67 counts can be easier to perform than MAI and therefore helpful in the diagnosis of ESS, Low Grade. In conclusion, in this small study of WHO2003 defined ESS-LG, high levels of proliferation as measured by MAI, PPH3 and Ki-67 are predictive of recurrence. Larger studies are required to confirm these results.

Expression of platelet-derived growth factor receptor in low-grade endometrial stromal sarcomas in the absence of activating mutations

AIMS

To investigate platelet-derived growth factor receptor (PDGFR)alpha and PDGFRbeta expression and a mutational analysis of PDGFRalpha (exons 11, 12, 17 and 18) and PDGFRbeta (exon 12) genes in endometrial stromal sarcomas (ESS). Gastrointestinal stromal tumours (GISTs), which have somatic mutations of the transmembrane tyrosine kinase receptor, respond to tyrosine kinase inhibitors, which act through an inhibitory effect on class 3 receptor tyrosine kinase members such as PDGFRalpha, PDGFRbeta and c-kit.

METHODS AND RESULTS

The immunohistochemical expression of PDGFRalpha and PDGFRbeta was investigated in 37 archival c-kit- ESS. Staining was scored as negative (0-10% positive tumour cells) and positive (weakly positive 11-50% positive cells; strongly positive > 50% positive cells). PDGFRalpha was expressed in 24/37 ESS [65%; strongly by 19/37 (51.5%) and weakly by 5/37 ESS (13.5%)]. ESS tumour cells were negative for PDGFRbeta, but endothelial cells stained positive. A mutational analysis of PDGFRalpha (exons 11, 12, 17 and 18) and PDGFRbeta (exon 12) genes on frozen metastatic ESS from three patients detected no mutations leading to amino acid changes in the mature protein.

CONCLUSIONS

Patients with PDGFRalpha+ ESS may benefit from treatment with tyrosine kinase inhibitors by blocking autocrine and paracrine stimulation loops, blocking neovascularization and enhancing the effects of chemotherapy.

Sarcome du chorion cytogène de bas grade

Endometrial stromal sarcoma is a rare malignant uterine tumor. We report 4 cases of low-grade endometrial stromal sarcoma, corresponding to the form with a mitotic index at less than 10 mitoses per 10 high power fields (HPF), from which we carried out a review of the literature and defined the potential interest of hormone therapy and chemotherapy by etoposide. Generally diagnosed in pre-menopause, the main clinical signs, which are not very specific, are metrorrhagia and pelvic pain. The etiologic diagnosis is established from the pathology analysis. Intravascular extension, which is observed in nearly 50% of patients, should evoke the disease. The initial treatment is mainly based open surgery, generally total hysterectomy with annexectomy. There is no effective adjuvant treatment. The potential of reccurences remains around 50% with a 34-month median. Several therapeutic options are possible after recurrence but no standard treatment has been established. We are mainly interested in three medical options but the surgery remains an alternative of choice. Chemotherapy by oral etoposide offers easy administration, good compliance and acceptable toxicity with median 20-month remission in 3 patients before progression. Hormone therapy with progestogens (hormone receptor expression of the tumor is 71% for estrogens and 95% for progesterone) is widely studied in the literature with a 46% response rate and 46% rate of disease stabilization. Hormone therapy with an anti-aromatase appears to be a promising treatment according to the bibliographic references on this subject. Overall, prognosis of low-grade endometrial sarcoma is relatively good with 100% survival at 5 years. The progression pattern is slow, requiring regular and prolonged surveillance.