MIB1 as a possible predictor of recurrence in low-grade endometrial stromal sarcoma of the uterus

Prognostic Value of Ki-67 Index in Patients With Endometrial Stromal Sarcoma

Objective

The Ki-67 index is used to evaluate cell proliferation activity, which is related to tumor progression, metastasis, and prognosis. We aimed to explore the prognostic value of Ki-67 index in endometrial stromal sarcoma and to explore the optimal cut-off value of Ki-67 index for predicting recurrent endometrial stromal sarcoma.

Methods

A total of 82 patients with endometrial stromal sarcoma who were treated in our hospital were collected. Clinicopathological data of these patients were retrospectively analyzed. Ki-67 index was detected by the immunohistochemical method. Receiver operating characteristic curve and the Youden index were performed to determine the optimal cut-off value of Ki-67 index for predicting recurrent endometrial stromal sarcoma. The Cox regression was performed to analyze risk factors affecting prognosis of endometrial stromal sarcoma. The Kaplan–Meier method and Log-rank test were performed to analyze the survival of patients.

Results

The optimal cut-off value of Ki-67 index for predicting recurrent endometrial stromal sarcoma was 35%. The results of univariate analysis showed that high Ki-67 index (≥35%) was statistically significantly bound up with shorter progress free survival and overall survival. The results of multivariate analysis showed that Ki-67 index (P = 0.001) and ovarian preservation (P = 0.040) were independent prognostic factors of progress free survival.

Conclusions

A Ki-67 index cut-off of 35% was optimal for predicting recurrent endometrial stromal sarcoma. Ki-67 index may be a useful prognostic marker in endometrial stromal sarcoma.

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.

Ki-67 and CD100 immunohistochemical expression is associated with local recurrence and poor prognosis in soft tissue sarcomas, respectively

Soft tissue sarcomas (STSs) are a heterogeneous group of mesenchymal tumors of >50 subtypes. However, STSs represent <1% of types of cancer. Despite this low frequency, the disease is aggressive and treatment, when possible, is based on traditional chemotherapies. A number of cases of resistance to adjuvant therapies have been reported. Metastases are commonly identified in STS patients during diagnosis and the development of effective clinical parameters is crucial for correct management of the disease. The use of biological markers in cancer is a useful tool to determine patient prognosis. Ki-67 is a protein marker for proliferation of somatic cells and is widely used in prognostic studies of various types of tumor, including STSs. Cluster of differentiation 100 (CD100) is a member of the semaphorin family. The family was initially described as axon guidance molecules important for angiogenesis, organogenesis, apoptosis and neoplasia. CD100 was previously utilized as a prognostic factor in tumors and also in STSs. In the present study, protein expression of Ki-67 and CD100 was analyzed by immunohistochemistry in samples of STS patients of the Barretos Cancer Hospital (Barretos, Brazil) to establish prognostic criteria of the disease. Results demonstrate a correlation between CD100 expression and poor prognosis, consistent with a previous study. Moreover, the expression of Ki-67 was identified to correlate with presence of local or locoregional recurrence. To the best of our knowledge, no large casuistic study has revealed this correlation between Ki-67 and local recurrence in STSs. The use of Ki-67 and CD100 as markers in clinical pathological analysis may be suitable as a prognostic criterion in disease progression.

Treatment of early uterine sarcomas: disentangling adjuvant modalities

Uterine sarcomas are a rare group of neoplasms with aggressive clinical course and poor prognosis. They are classified into four main histological subtypes in order of decreasing incidence: carcinosarcomas, leiomyosarcomas, endometrial stromal sarcomas and "other" sarcomas. The pathological subtype demands a tailored approach. Surgical resection is regarded as the mainstay of treatment. Total abdominal hysterectomy and bilateral salpingo-oophorectomy represents the standard treatment of uterine sarcomas. Pelvic and para-aortic lymph node dissection in carcinosarcomas is recommended, given their high incidence of lymph node metastases, and may have a role in endometrial stromal sarcomas. Adjuvant radiation therapy has historically been of little survival value, but it appears to improve local control and may delay recurrence. Regarding adjuvant chemotherapy, there is little evidence in the literature supporting its use except for carcinosarcomas. However, more trials are needed to address these issues, especially, their sequential application. Patients with uterine sarcomas should be referred to large academic centers for participation in clinical trials.

Endometrial Stromal Sarcoma: Treatment and Patterns of Recurrence

Our objective was to investigate recurrence patterns and conduct an outcome analysis of patients with endometrial stromal sarcoma (ESS).

A retrospective review yielded 30 patients with ESS (20 low-grade, 10 high-grade) who underwent primary surgical resection from 1982 to 2005. Median follow-up was 42 months.

All patients underwent hysterectomy, whereas pelvic (P) and paraaortic (PA) lymphadenectomy were performed in 12 and 7 patients, respectively. A median of 26 pelvic lymph nodes and 9 PA lymph nodes were removed. Pelvic or PA lymphatic disease was noted in 25% and 29% of patients, respectively. Extrauterine disease was identified in 11 (45%) of 24 patients undergoing exploratory laparotomy; 6 had no residual disease after cytoreductive surgery. None of these 6 patients experienced abdominal failure, but 1 had a hematological recurrence. Thrombotic complications were noted in 13% of patients. The 5-year overall survival was 65%. Overall survival was influenced by grade (79% vs 40%, P = 0.03) and extrauterine disease (77% vs 32%, P = 0.01). No patient who underwent a systematic lymphadenectomy had a lymphatic recurrence, irrespective of nodal status. There were 7 (23%) hematological recurrences; 2 in surgical stage I ESS. Two patients with low-grade ESS remain without evidence of disease 130 and 210 months after secondary cytoreduction. In contrast, no patient with high-grade ESS survived a recurrence.

There is high prevalence of extrauterine and nodal disease in ESS. Patients are at high risk for thrombotic complications. If aggressively staged, the predominant failure risk for stage I patients is hematogenous, suggesting the need for improved systemic treatments.

Phenotypic characterization of endometrial stromal sarcoma of the uterus

Endometrial stromal sarcoma (ESS) of the uterus is a rare uterine malignancy that has not been characterized in detail. To characterize the phenotype of ESS of the uterus, we extracted RNA from ESS and the stroma of normal endometrium using a tissue microdissection system and compared the expression profiles in the two tissues. After suppression subtractive hybridization and differential screening, we detected the metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) gene as one of the major genes upregulated in ESS, and a full-length placental cDNA clone (CS0DI066YJ10) as one of the major genes downregulated. The results were confirmed by in situ hybridization in four resected specimens of ESS and 36 biopsy specimens of normal endometrial tissue. All ESS (4/4) and all cases of endometrial stromal cells in the proliferative phase (13/13) were positive for MALAT-1, but samples of normal stroma in the secretory phase and menopausal state included some that were negative or weakly positive for MALAT-1 (5/13 and 3/10, respectively). In contrast, all ESS and 12 of 13 cases of stromal cells in the proliferative phase were negative for the full-length placental cDNA clone but 10 of 13 cases of endometrial stromal cells in the secretory phase were positive for transcripts of the gene (P < 0.05). These results indicated that endometrial stromal cells have different phenotypic characteristics between proliferative and secretory phases and the tumor cells of ESS have the phenotypic character of endometrial stromal cells in the proliferative phase.

Utility of MIB-1 and estrogen and progesterone receptor in distinguishing between endometrial stromal sarcomas and endometrial stromal nodules, highly cellular leiomyomas

It is difficult to differentiate between an endometrial stromal nodule (ESN) and endometrial stromal sarcoma (ESS) in curettage specimen, and the recommended therapy of endometrial stromal neoplasm is hysterectomy. If we could discriminate ESS from ESN in curettage specimens, there would be an opportunity to treat ESN by local excision rather than by hysterectomy. We analyzed MIB-1 and estrogen and progesterone receptor (ER/PR) expression in a retrospective series of 8 ESSs, 7 ESNs, and 17 highly cellular leiomyomas obtained from hysterectomy specimens. ESSs expressed MIB-1 more frequently than ESNs (P < 0.05), and ESSs had a tendency to express ER less frequently than ESNs (P= 0.08). We observed that in spite of showing MIB-1 expression to some extent, highly cellular leiomyomas usually could not reach ESSs' level and frequency of MIB-1 expression in the current study. Although MIB-1 and ER appear to be promising markers in the differential diagnosis of ESSs, a larger study would be necessary to confirm their validity.