Validation of a Mitotic Index Cutoff as a Prognostic Marker in Undifferentiated Uterine Sarcomas

Prognostic factors in undifferentiated uterine sarcoma: a subanalysis of the SARCUT study

PURPOSE

The aim of this study was to analyze the prognostic factors related to the recurrence rate and overall survival of patients with undifferentiated uterine sarcoma.

METHODS

An international multicenter study involving 43 international centers, the SARCUT study, collected 966 uterine sarcoma cases; among them 39 cases corresponded to undifferentiated uterine sarcoma and where included in the present subanalysis. The risk factors related to the oncological outcomes where analyzed.

RESULTS

The median age of the patients was 63 (range 14-85) years. Seventeen (43.5%) patients presented FIGO stage I. The 5-year overall survival (OS) was 15.3% and 12-months disease-free survival (DFS) 41%. FIGO stage I was significantly associated with a better prognosis. In addition, patients who received adjuvant radiotherapy showed significant longer disease-free survival compared to those without adjuvant radiotherapy (20.5 vs. 4.0 months, respectively; p = 0.04) and longer overall survival (34.7 vs. 18.2 months, respectively; p = 0.05). Chemotherapy administration was associated with shorter DFS (HR 4.41, 95% CI 1.35-14.43, p = 0.014). Persistent disease after primary treatment (HR = 6.86, 95% CI 1.51-31.09, p = 0.012) and FIGO stage IV (HR 4.12, 95%CI 1.37-12.44, p = 0.011) showed significant worse prognosis for OS.

CONCLUSION

FIGO stage seems to be the most important prognostic factor in patients with undifferentiated uterine sarcoma. Adjuvant radiotherapy seems to be significantly associated also to a better disease-free and overall survival. On the contrary, the role of chemotherapy administration remains unclear since was associated to a shorted DFS.

Sarcoma of the Uterus. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/074, April 2021)

Purpose This is an official guideline, published and coordinated by the Germany Society for Gynecology and Obstetrics (Deutsche Gesellschaft für Gynäkologie und Geburtshilfe, DGGG). Because of their rarity and heterogeneous histopathology, uterine sarcomas are challenging in terms of their clinical management and therefore require a multidisciplinary approach. To our knowledge, there are currently no binding evidence-based recommendations for the appropriate management of this heterogeneous group of tumors. Methods This S2k guideline was first published in 2015. The update published here is once again the result of the consensus of a representative interdisciplinary committee of experts who were commissioned by the Guidelines Committee of the DGGG to carry out a systematic search of the literature on uterine sarcomas. Members of the participating professional societies achieved a formal consensus after a structured consensus process. Recommendations 1.1 Epidemiology, classification, staging of uterine sarcomas. 1.2 Symptoms, general diagnostic workup, general pathology or genetic predisposition to uterine sarcomas. 2. Management of leiomyosarcomas. 3. Management of low-grade endometrial stromal sarcomas. 4. Management of high-grade endometrial stromal sarcoma and undifferentiated uterine sarcomas. 5. Management of adenosarcomas. 6. Rhabdomyosarcomas of the uterus in children and adolescents. 7. Follow-up of uterine sarcomas. 8. Management of morcellated uterine sarcomas. 9. Information provided to patients.

Data Set for Reporting of Uterine Malignant and Potentially Malignant Mesenchymal Tumors: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

The International Collaboration on Cancer Reporting (ICCR) seeks to produce standardized, evidence-based protocols for the reporting of tumors with the aim of ensuring that all cancer reports generated worldwide will be of similar high quality and record the same elements. Herein, we describe the development of the data set for the reporting of uterine malignant and potentially malignant mesenchymal tumors by a panel of expert pathologists and a single clinician and provide the commentary and rationale for the inclusion of core and noncore elements. This data set, which incorporates the recent updates from the 5th edition of the World Health Organization Classification of Female Genital Tumors, addresses several subjects of debate including which mesenchymal tumors should be graded, how to document extent of invasion, mitotic counts, and the role of ancillary testing in tumor diagnosis and patient management. The inclusion of elements is evidence-based or based on consensus of the expert panel with clinical relevance being the guiding standard.

[Endometrial and other rare uterine sarcomas : Diagnostic aspects in the context of the 2020 WHO classification]

Uterine sarcomas are a heterogeneous group of rare malignancies. Mostly (40-50%), they are leiomyosarcomas, followed by endometrial stromal sarcomas (ESS), low-grade (LG) and high-grade (HG), as well as undifferentiated sarcoma of the uterus (UUS) and adenosarcomas (AS). Other, non-organ-specific tumours such as NTRK-rearranged spindle cell neoplasia, perivascular epithelioid cell tumour (PEComa) and inflammatory myofibroblastic tumour (IMT) are extremely difficult to differentiate.In the most recent WHO classification, endometrial stromal tumours are subdivided as follows: benign, expansively growing endometrial stromal nodule (ESN) with sharp demarcation, the histologically similar-looking LG-ESS with infiltrative growth, the highly malignant HG-ESS and, as a diagnosis of exclusion, the highly aggressive UUS lacking specific lines of differentiation. LG-ESS can be differentiated from HG-ESS in most cases histomorphologically and immunohistochemically, but molecular investigations are necessary in individual cases. HG-ESS can be divided into 4 subtypes (YWHAE/NUTM2 fusion low-grade component, YWHAE/NUTM2 fusion high-grade component, ZC3H7B-BCOR fusion or BCOR-ITD) on the basis of molecular findings. Prognostically unfavourable factors in AS are severe sarcomatous overgrowth, deep myometrial invasion, high-grade histology and lymphatic vessel invasion. Tumours with NTRK fusion are immunohistochemically positive for S100 and TRK. PEComas express cathepsin K and HMB45, as well as TFE3 when translocation is present. Almost every IMT shows an alteration in the ALK gene In the case of overlapping morphology and simultaneous therapeutic and prognostic relevance, it is becoming increasingly important to verify or confirm the suspected histomorphological diagnosis by immunohistochemical and possibly molecular investigations.

New Aspects of Sarcomas of Uterine Corpus-A Brief Narrative Review

Sarcomas of the uterine corpus are rare malignant neoplasms, which are further classified into mesenchymal tumors, and mixed (epithelial plus mesenchymal) tumors. The main issues concerning these neoplasms are the small number of clinical trials, insufficient data from evidence-based medicine, insignificant interest from the pharmaceutical industry, all of which close a vicious circle. The low frequency of these malignancies implies insufficient experience in the diagnosis, hence incomplete surgical and complex treatment. Additionally, the rarity of these sarcomas makes it very difficult to develop clinical practice guidelines. Preoperative diagnosis, neoadjuvant and adjuvant chemoradiation, target and hormone therapies still raise many controversies. Disagreements about the role and type of surgical treatment are also often observed in medical literature. There are still insufficient data about the role of pelvic lymph node dissection and fertility-sparing surgery. Pathologists’ experience is of paramount importance for an accurate diagnosis. Additionally, genetics examinations become part of diagnosis in some sarcomas of the uterine corpus. Some gene mutations observed in uterine sarcomas are associated with different outcomes. Therefore, a development of molecular classification of uterine sarcomas should be considered in the future. In this review, we focus on the epidemiology, pathogenesis, pathology, diagnosis and treatment of the following sarcomas of the uterine corpus: leiomyosarcoma, low- and high-grade endometrial stromal sarcomas, undifferentiated sarcoma and adenosarcoma. Uterine carcinosarcomas are excluded as they represent an epithelial tumor rather than a true sarcoma.

[Interdisciplinary S2k guidelines on the diagnosis and treatment of uterine sarcomas-recommendations for surgical pathology]

Uterine sarcomas represent a heterogeneous group of rare malignancies, derived from the myometrium, the endometrial stroma, and very rarely from the nonspecialized uterine soft tissue. The actual incidence is about 1.5 for Caucasian and 3.0 for Afro-American women. There is no grading system for leimoysarcoma defined by the WHO classification; however, if clinicians request, the FNCLCC grading can be specified in analogy to soft tissue sarcomas. Adenosarcomas must be distinguished from adenofibromas (the existence of which is questionable)-with the vast majority of these tumors being uterine adenosarcomas. Within adenosarcomas, deep myometrial invasion (>50%), sarcomatous overgrowth, and a high-grade heterologous component are associated with a higher recurrence rate and poor survival. The immunohistochemical panel represents a very helpful tool for distinguishing low-grade from high grade endometrial stromal sarcomas (ESS) and may be supplemented by molecular analyses. Steroid hormone receptor analysis should be performed for all ESS due to the possible therapeutic relevance. Undifferentiated uterine sarcomas represent a diagnosis of exclusion and have a very poor prognosis. Carcinosarcomas represent a special subtype of endometrial carcinomas and are in fact not uterine sarcomas. Uterine sarcomas may present substantial intratumoral heterogeneity and adequate embedding is mandatory. Lesions ≤2 cm in the largest dimension should be processed completely and larger tumors should be processed with one block per centimeter for the largest tumor dimension.

High-grade endometrial stromal sarcoma versus undifferentiated uterine sarcoma: a Turkish uterine sarcoma group study-001

OBJECTIVE

Prognostic factors associated with high-grade endometrial stromal sarcoma (HGESS) and undifferentiated uterine sarcoma (UUS) have not been distinctly determined due to the repetitive changes in the World Health Organization (WHO) classification. We aimed to compare clinicopathologic features and outcomes of patients with HGESS with those of patients with UUS.

METHODS

A multi-institutional, retrospective, cohort study was conducted including 71 patients, who underwent surgery at 13 centers from 2008 to 2017. An experienced gynecopathologist from each institution re-evaluated the slides of their own cases according to the WHO₂₀₁₄ classification. Factors associated with refractory/progressive disease, recurrence or death were examined using logistic regression analyses. Kaplan-Meier method and log-rank test were used for survival comparisons.

RESULTS

The median disease-free survival (DFS) for HGESS and UUS was 12 months and 6 months, respectively. While the median overall survival was not reached in HGESS group, it was 22 months in the UUS group. Kaplan-Meier analyses revealed that patients with UUS had a significantly poorer DFS than those with HGESS (p = 0.016), although OS did not differ between the groups (p = 0.135). Lymphovascular-space involvement (LVSI) was the sole significant factor associated with progression, recurrence or death for HGESS (Hazard ratio: 9.353, 95% confidence interval: 2.539-34.457, p = 0.001), whereas no significant independent factor was found for UUS.

CONCLUSIONS

UUS has a more aggressive behavior than HGESS. While no significant predictor of prognosis was found for UUS, LVSI is the sole independent prognostic factor for HGESS, with patients 9.3 times more likely to experience refractory/progressive disease, recurrence or death.

Undifferentiated and dedifferentiated neoplasms of the female genital tract

Undifferentiated neoplasms in the female gynecologic tract comprise two main groups-undifferentiated carcinoma, most common in the endometrium and ovary, and undifferentiated uterine sarcoma, although tumors with an undifferentiated appearance may occur in all gynecologic organs. Their differential diagnosis is broad and generous sampling, careful morphological evaluation, judicious use of immunohistochemistry, and in many cases, molecular testing is often essential in the diagnostic work-up. As some of these neoplasms fail to respond to conventional chemotherapy regimens and/or radiation therapy, targeted therapy may be valuable in treating these highly aggressive tumors, thus the importance of precise diagnosis. In this review we discuss the clinicopathological features of undifferentiated carcinoma, dedifferentiated carcinoma, and undifferentiated uterine sarcoma, followed by a comprehensive analysis of morphological mimickers. Finally, we briefly review ovarian and lower genital tract tumors with an undifferentiated histological appearance.

Survival outcomes and prognostic factors of endometrial stromal sarcoma and undifferentiated uterine sarcoma

PURPOSE

To review the diagnostic and therapeutic procedures of patients diagnosed with Endometrial Stromal Sarcoma (ESS) and Undifferentiated Uterine Sarcoma (USS) at our institution and investigate their clinical outcomes and factors affecting prognosis.

METHODS

We retrospectively collected demographic data, preoperative diagnostic methods and therapeutic management of patients treated for ESS and UUS between January 1995 and December 2019 at Vall d'Hebron Barcelona Hospital Campus, Spain. Overall survival and disease-free survival were calculated. Cox proportional-hazards regression models were calculated.

RESULTS

Sixty-three patients were included in the study, of which 51(81%) had a diagnosis of ESS and 12(19%) of UUS. Twenty patients (31.7%) were diagnosed after a previous non-oncologic surgery, and 12 of them (60%) suffered from tumor disruption. Cytoreductive procedures were needed in 29 patients (46%), and optimal cytoreduction was achieved in 80.9% of the patients. The median follow-up was 7.6 years (IQR = 0.99-14.31). Five-year overall survival was 57.6% (44.2-68.8) and was significantly better for low-grade ESS (LG-ESS) patients (p < 0.01). Five-year disease-free survival was 57.1% (42.8-69.1) and was also significantly higher in LG-ESS cohort (p = 0.03). After multivariate analysis histological type, age, FIGO stage, optimal surgery and mitotic index were found significantly correlated with survival. For high-grade EES (HG-ESS) and USS patients adjuvant radiotherapy also correlated with improved survival.

CONCLUSION

Overall survival and disease-free survival are significantly better in patients with LG-ESS cohort. HG-ESS and UUS show similar survival outcomes. Age, FIGO stage, optimal surgery and histological type were significantly correlated with survival in the global cohort, whilst adjuvant radiotherapy correlated with improved survival in HG-ESS and UUS patients.

Uterine mesenchymal tumours: recent advances

Almost all uterine mesenchymal tumours have been historically classified as either smooth muscle or endometrial stromal neoplasms. Recent application of molecular techniques has identified numerous lesions with distinctive genetic abnormalities and clinicopathological characteristics. Newly discovered uterine sarcoma subtypes include high-grade endometrial stromal sarcomas with BCOR genetic abnormalities, fibrosarcoma-like uterine sarcomas with NTRK rearrangements and COL1A-PDGFRB fusions, as well as undifferentiated uterine sarcomas with SMARCA4 mutations. Novel PLAG1 and PGR fusions have been identified in subsets of myxoid and epithelioid leiomyosarcomas. Some uterine tumours resembling ovarian sex-cord tumour harbour GREB1 and ESR1 rearrangements. Histological and immunophenotypical features as well as underlying genetic abnormalities defining these lesions are discussed.

Uterine Mesenchymal Tumors: Update on Classification, Staging, and Molecular Features

The spectrum of mesenchymal neoplasia in the uterus has expanded in recent years. First, the identification of prevalent, recurrent molecular alterations has led to a more biologically and clinically congruent classification of endometrial stromal tumors. Likewise, the diagnostic criteria of several rare and miscellaneous tumor types have been refined in recent case series (Perivascular Epithelioid Cell tumor, inflammatory myofibroblastic tumor). Pure mesenchymal tumors are still broadly classified based on morphology according to the tumor cell phenotype. Smooth muscle tumors predominate in frequency, followed by tumors of endometrial stromal derivation; the latter are covered in depth in this article with an emphasis on defining molecular alterations and their morphologic and clinical correlates. The remaining entities comprise a miscellaneous group in which cell derivation does not have a normal counterpart in the uterus (eg, rhabdomyosarcoma) or is obscure (eg, undifferentiated uterine sarcoma). This article discusses their clinical relevance, recent insights into their molecular biology, and the most important differential diagnoses. Regarding the latter, immunohistochemistry and (increasingly) molecular diagnostics play a role in the diagnostic workup. We conclude with a few considerations on intraoperative consultation and macroscopic examination, as well as pathologic staging and grading of uterine sarcomas as per the most recent American Joint Cancer Commission and the Fédération Internationale de Gynécologie et d'Obstétrique staging systems.

Localized high grade endometrial stromal sarcoma and localized undifferentiated uterine sarcoma: a retrospective series of the French Sarcoma Group

OBJECTIVE

High grade endometrial stromal sarcoma and undifferentiated uterine sarcomas are associated with a very poor prognosis. Although large surgical resection is the standard of care, the optimal adjuvant strategy remains unclear.

METHODS

A retrospective analysis of patients with localized high grade endometrial stromal sarcoma and undifferentiated uterine sarcomas (stages I-III) treated in 10 French Sarcoma Group centers was conducted.

RESULTS

39 patients with localized high grade endometrial stromal sarcoma and undifferentiated uterine sarcomas treated from 2008 to 2016 were included. 24/39 patients (61.5%) were stage I at diagnosis. 38/39 patients underwent surgical resection, with total hysterectomy and bilateral oophorectomy completed in 26/38 (68%). Surgeries were mostly resection complete (R0, 23/38, 60%) and microscopically incomplete resection (R1, 6/38, 16%). 22 patients (58%) underwent postoperative radiotherapy (including brachytherapy in 11 cases), and 11 (29%) underwent adjuvant chemotherapy. After a median follow-up of 33 months (range 2.6-112), 17/39 patients were alive and 21/39 (54%) had relapsed (9 local relapses and 16 metastases). The 3 year and 5 year overall survival rates were 49.8% and 31.1%, respectively, and 3 year and 5 year disease free survival rates were 42.7% and 16.0%, respectively. Median overall survival and disease free survival were 32.7 (95% CI 16.3-49.1) and 23 (4.4-41.6) months, respectively. Medians were, respectively, 46.7 months and 39.0 months among those who underwent adjuvant radiotherapy and 41.0 months and 10.3 months for those who underwent adjuvant chemotherapy. In multivariate analysis, adjuvant radiotherapy was an independent prognostic factor for overall survival (P=0.012) and disease free survival (P=0.036). Chemotherapy, International Federation of Gynecology and Obstetrics I-II stages, and Eastern Cooperative Oncology Group-performance status 0 correlated with improved overall survival (P=0.034, P=0.002, P=0.006), and absence of vascular invasion (P=0.014) was associated with better disease free survival.

CONCLUSIONS

The standard treatment of primary localized high grade endometrial stromal sarcoma and undifferentiated uterine sarcomas is total hysterectomy and bilateral oophorectomy. The current study shows that adjuvant radiotherapy and adjuvant chemotherapy appear to improve overall survival. A prospective large study is warranted to validate this therapeutic management.

Integrated Molecular Analysis of Undifferentiated Uterine Sarcomas Reveals Clinically Relevant Molecular Subtypes

PURPOSE

Undifferentiated uterine sarcomas (UUS) are rare, extremely deadly, sarcomas with no effective treatment. The goal of this study was to identify novel intrinsic molecular UUS subtypes using integrated clinical, histopathologic, and molecular evaluation of a large, fully annotated, patient cohort.

EXPERIMENTAL DESIGN

Fifty cases of UUS with full clinicopathologic annotation were analyzed for gene expression (n = 50), copy-number variation (CNV, n = 40), cell morphometry (n = 39), and protein expression (n = 22). Gene ontology and network enrichment analysis were used to relate over- and underexpressed genes to pathways and further to clinicopathologic and phenotypic findings.

RESULTS

Gene expression identified four distinct groups of tumors, which varied in their clinicopathologic parameters. Gene ontology analysis revealed differential activation of pathways related to genital tract development, extracellular matrix (ECM), muscle function, and proliferation. A multivariable, adjusted Cox proportional hazard model demonstrated that RNA group, mitotic index, and hormone receptor expression influence patient overall survival (OS). CNV arrays revealed characteristic chromosomal changes for each group. Morphometry demonstrated that the ECM group, the most aggressive, exhibited a decreased cell density and increased nuclear area. A cell density cutoff of 4,300 tumor cells per mm² could separate ECM tumors from the remaining cases with a sensitivity of 83% and a specificity of 94%. IHC staining of MMP-14, Collagens 1 and 6, and Fibronectin proteins revealed differential expression of these ECM-related proteins, identifying potential new biomarkers for this aggressive sarcoma subgroup.

CONCLUSIONS

Molecular evaluation of UUS provides novel insights into the biology, prognosis, phenotype, and possible treatment of these tumors.

Management of uterine sarcomas and prognostic indicators: real world data from a single-institution

Background

Uterine sarcomas consist a heterogeneous group of mesenchymal gynecological malignancies with unclear therapeutic recommendations and unspecific but poor prognosis, since they usually metastasize and tend to recur very often, even in early stages.

Methods

We retrospectively analyzed all female patients with uterine sarcomas treated in our institution over the last 17 years. Clinico-pathological data, treatments and outcomes were recorded. Kaplan-Meier curves were plotted and time-to-event analyses were estimated using Cox regression.

Results

Data were retrieved from 61 women with a median age of 53 (range: 27–78) years, at diagnosis. Fifty-one patients were diagnosed with leiomyosarcoma (LMS), 3 with high grade endometrial stromal sarcoma (ESS), 5 with undifferentiated uterine sarcoma (UUS), 1 with Ewing sarcoma (ES) and 1 with Rhabdomyosarcoma (RS). 24 cases had stage I, 7 stage II, 14 stage III and 16 stage IV disease. Median disease-free survival (DFS) in adjuvant approach was 18.83 months, and median overall survival (OS) 31.07 months. High mitotic count (> 15 mitoses) was significantly associated with worse OS (P < 0.001) and worse DFS (P = 0.028).

Conclusions

Mitotic count appears to be independent prognostic factor while further insights are needed to improve adjuvant and palliative treatment of uterine sarcomas.