Prognostic factors and impact of adjuvant chemotherapy for uterine leiomyosarcoma

Molecular Approach to Uterine Leiomyosarcoma: LMP2-Deficient Mice as an Animal Model of Spontaneous Uterine Leiomyosarcoma

Uterine leiomyosarcoma (LMS) develops more often in the muscle tissue layer of the uterine body than in the uterine cervix. The development of gynecologic tumors is often correlated with female hormone secretion; however, the development of uterine LMS is not substantially correlated with hormonal conditions, and the risk factors are not yet known. Importantly, a diagnostic-biomarker which distinguishes malignant LMS from benign tumor leiomyoma (LMA) is yet to be established. Accordingly, it is necessary to analyze risk factors associated with uterine LMS, in order to establish a treatment method. LMP2-deficient mice spontaneously develop uterine LMS, with a disease prevalence of ~40% by 14 months of age. We found LMP2 expression to be absent in human LMS, but present in human LMA. Therefore, defective LMP2 expression may be one of the risk factors for LMS. LMP2 is a potential diagnostic-biomarker for uterine LMS, and may be targeted-molecule for a new therapeutic approach.

Mice-lacking LMP2, immuno-proteasome subunit, as an animal model of spontaneous uterine leiomyosarcoma

Uterine tumors are the most common type of gynecologic neoplasm. Uterine leiomyosarcoma (LMS) is rare, accounting for 2% to 5% of tumors of the uterine body. Uterine LMS develops more often in the muscle tissue layer of the uterine body than in the uterine cervix. The development of gynecologic tumors is often correlated with female hormone secretion; however, the development of uterine LMS is not substantially correlated with hormonal conditions, and the risk factors are not yet known. Radiographic evaluation combined with PET/CT can be useless in the diagnosis and surveillance of uterine LMS. Importantly, a diagnostic biomarker, which distinguishes malignant LMS and benign tumor leiomyoma (LMA) is yet to be established. Accordingly, it is necessary to analyze risk factors associated with uterine LMS in order to establish a method of treatment. LMP2-deficient mice spontaneously develop uterine LMS, with a disease prevalence of ∼40% by 14 months of age. It is therefore of interest whether human uterine LMS shows a loss of LMP2 expression. We found LMP2 expression is absent in human LMS, but present in human LMA. Therefore, defective LMP2 expression may be one of the risk factors for LMS. LMP2 is potentially a diagnostic biomarker for uterine LMS, and gene therapy with LMP2-encording DNA may be a new therapeutic approach.

Optimal management of uterine leiomyosarcoma

Uterine leiomyosarcomas (LMSs) are rare tumors, comprising 1.3% of all uterine cancers. Primary therapy for localized disease entails complete surgical resection. The majority of patients recur within 2 years of primary therapy as these tumors tend to undergo early hematogenous spread. A randomized, controlled trial showed no improvement in the overall or disease-free survival with adjuvant radiotherapy, compared with observation, following resection of early-stage uterine LMS. A Phase II study of adjuvant chemotherapy following complete surgical resection of uterine LMS reported promising results. However, in the absence of Phase III randomized data demonstrating improved outcomes, the role of post-resection chemotherapy for early-stage disease remains experimental. For metastatic or unresectable LMS, systemic chemotherapy forms the mainstay of treatment. First-line treatment options include gemcitabine-docetaxel or doxorubicin with or without ifosfamide. Novel targeted therapies are under investigation in an attempt to devise more effective treatment strategies.

Predictive value of FIGO and AJCC staging systems in patients with uterine leiomyosarcoma

BACKGROUND

Cancer staging systems aim to identify patient cohorts with different outcomes based on clinically relevant prognostic factors. Uterine leiomyosarcoma (ULMS) is classified using the FIGO staging system developed for epithelial malignancies; other sarcomas use the AJCC staging system. Neither has been validated in ULMS. We critically evaluated both systems to determine if either identified patient groups with distinct outcomes.

METHODS

We staged 230 ULMS patients by the FIGO and AJCC systems. Progression-free survival (PFS) and overall survival (OS) rates were calculated; statistical pairwise comparisons were performed.

RESULTS

The number of stages I and III patients varied by staging system. There were few stage II patients by either system. Using the FIGO system, PFS was better in stage I patients versus stage III or IV patients, and OS was better in stage I patients versus stage IV patients. Using the AJCC system, PFS and OS were better in stage I patients (low grade) versus stage II, III or IV patients, and OS was better in stage III patients versus stage IV patients. Prognosis of patients with serosal involvement (FIGO III) was similar to that of patients with metastases (FIGO IV).

CONCLUSION

Neither system classifies ULMS patients into four clinically meaningful, non-overlapping stages predictive of PFS and OS. This analysis highlights the relevance of certain factors (low grade, serosal involvement) and rarity of others (FIGO stage II, cervical invasion). Once identified, prognostic factors relevant to this malignancy should be incorporated into a new staging system in an effort to identify appropriate cohorts for different treatments.

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.

Uterine leiomyosarcoma: 14-year two-center experience of 31 cases

PURPOSE

The aim of this study was to evaluate the clinicopathological characteristics of uterine leiomyosarcoma (LMS) and possible prognostic factors.

MATERIALS AND METHODS

This study included 31 patients with histologically proven LMS at Samsung Medical Center and Ajou University Hospital between 1994 and 2007. The medical records and available histological slides were reviewed retrospectively.

RESULTS

The median age was 46 years (range, 32~63). The most common symptom was vaginal bleeding (11 patients, 35.5%). There were 23 patients with stage I, one patient with stage III, seven patients with stage IV disease. The median follow up time was 29 months (range, 1~94). The most common recurrence site was lung (5 case), followed by pelvis and upper abdomen (2 case). Nine patients died of disease with a 5-year overall survival rate of 63%. Early tumor stage and mitotic count were the prognostic factor in univariate analysis (p<0.0001 and p=0.0031, respectively), but early tumor stage only was associated with prognosis in multivariate analysis (p=0.010 vs p=0.143). Adjuvant treatment for early stage disease did not decrease the recurrence rate (p=0.1075), but high mitotic count (15>10HPF) had a trend for disease recurrence in early stage LMS (p=0.0859).

CONCLUSION

Mitotic count less than 15/HPF in early stage may be related with longer progression-free interval, but we could not reach the conclusion that adjuvant therapy in early stage LMS be effective.

Uterine leiomyosarcoma: does the primary surgical procedure matter?

BACKGROUND

Uterine leiomyosarcoma (LMS) has a poor prognosis even after early-stage diagnosis. Because there are no accurate diagnostic tools for preoperatively distinguishing LMS from uterine leiomyoma, surgeons might opt for partial surgical procedures such as myomectomy or subtotal hysterectomy. We sought to determine whether a surgical procedure that cuts through the tumor influences prognosis.

MATERIALS AND METHODS

Demographic and clinical data of consecutive patients with stage I LMS treated between 1969 and 2005 were reviewed. The study population was divided into group A: patients whose first surgical intervention was total hysterectomy (n = 21); and group B: patients who underwent procedures involving tumor injury, for example, myomectomy, laparoscopic hysterectomy with a morcellator knife, or hysteroscopic myomectomy (n = 16). Survival rates were analyzed and compared. A Cox proportional hazards model was used to assess the association between variables of interest and prognosis.

RESULTS

The median age at diagnosis was 50 years (range, 30-74 years). Median follow-up duration was 44 months. The 2 groups did not differ significantly in age at diagnosis, menopausal status, gravidity, parity, postoperative radiotherapy, or time to last follow-up. Kaplan-Meier curves showed significantly better survival rates (P = 0.04) and a significant advantage in recurrence rate (P = 0.03) for group A compared with group B. Survival in group A was 2.8-fold better than that in group B (95% confidence interval, 1.02-7.67). These estimates remained stable after adjustment for age, menopausal status, and radiotherapy.

CONCLUSIONS

In patients with stage I LMS, primary surgery involving tumor injury seems to be associated with a worse prognosis than total hysterectomy as a primary intervention.

Molecular mechanisms of uterine leiomyosarcomas: involvement of defect in LMP2 expression

Patients with uterine leiomyosarcoma (LMS) typically present with vaginal bleeding, pain, and a pelvic mass. Typical presentations with hypercalcemia or eosinophilia have been reported. Radiographic evaluation with combined positron emission tomography/computed tomography may assist in the diagnosis and surveillance of women with uterine LMS. A recently developed risk-assessment index is highly predictive of disease-specific survival. Ovarian preservation does not appear to negatively impact outcome, and the addition of adjuvant therapy after surgical treatment does not seem to improve survival. It is noteworthy that LMP2-deficient mice exhibit spontaneous development of uterine LMS with a disease prevalence of ~37% by 12 months of age. The LMP2 gene is transcribed from a promoter containing an interferon (IFN)-γ-response factor element; thus, the IFN-γ-signal strongly induces LMP2 expression. Furthermore, a recent report demonstrated the loss of ability to induce LMP2 expression, which is an interferon (IFN)-γ-inducible factor, in human uterine LMS tissues and cell lines. Analysis of human uterine LMS shows somatic mutations in the IFNγ signalling pathway, thus the loss of LMP2 induction is attributable to a defect in the earliest steps of the IFN-γ signalling pathway. The discovery of an impaired key cell-signalling pathway may provide new targets for diagnostic approaches and therapeutic intervention.

Prognostic factors and treatment outcomes of patients with uterine sarcoma: analysis of 127 patients at a single institution, 1989-2007

PURPOSE

Uterine sarcoma is a rare malignancy with the worst prognosis of all uterine cancers. This study evaluated the prognostic factors and treatment outcomes of patients with this disease.

METHODS

A retrospective analysis was performed on 127 patients with histologically verified uterine sarcoma who were treated and followed at the Asan Medical Center (Seoul, Korea) from 1989 to 2007.

RESULTS

Histological analyses revealed that 37 patients had endometrial stromal sarcoma, 44 had malignant mixed mullerian tumors and 46 had leiomyosarcoma. Surgical stages, as defined by the International Federation of Gynecology and Obstetrics (FIGO) system, were I in 82 patients, II in 6 patients, III in 18 patients and IV in 19 patients. All patients underwent surgical treatment and 72 patients received adjuvant therapy. The 10-year disease-free survival (DFS) rate was 30% and the 10-year overall survival (OS) rate was 48%, with a mean follow-up time of 38 months (ranging from 1 to 212 months). Adjuvant radiation and chemotherapy had limited impact on the outcome of early-stage disease. However, patients with advanced-stage disease who received adjuvant chemotherapy had significantly longer OS times. A multivariate analysis revealed that FIGO stage (P = 0.025), depth of myometrial invasion (P = 0.004), and complete cytoreduction (P = 0.030) were significantly associated with DFS, while menopausal status (P = 0.044), FIGO stage (P = 0.016), depth of myometrial invasion (P = 0.029), and lymph-vascular space invasion (LVSI) (P = 0.020) were significantly associated with OS.

CONCLUSIONS

This study suggests that complete cytoreduction is important and adjuvant chemotherapy can help achieve favorable prognoses in patients with advanced stage disease. However, postmenopausal status, advanced FIGO stage, deep myometrial invasion, and positive LVSI were associated with poor prognosis.

Prognostic factors and survival in 1396 patients with uterine leiomyosarcomas: emphasis on impact of lymphadenectomy and oophorectomy

BACKGROUND

The objectives of the current study were to determine the prognostic factors associated with disease-specific survival (DSS) and to analyze the role of lymphadenectomy (LND) and oophorectomy in the management of uterine leiomyosarcomas (LMS).

METHODS

Data were abstracted from the Surveillance, Epidemiology, and End Results database (1988-2003). Kaplan-Meier and Cox proportional hazards regression models were used for analyses.

RESULTS

The median age of the 1396 patients was 52 years. There were 951 patients (68.1%) with International Federation of Gynecology and Obstetrics (FIGO) stage I disease, 43 patients (3.1%) with stage II disease, 99 patients (7.1%) with stage III disease, and 303 patients (21.7%) with stage IV disease. Distribution by tumor grade included 87 patients with grade 1 tumors, 208 with grade 2, and 509 patients with grade 3 tumors. The 5-year DSS rates for patients with stage I, II, III, and IV disease were 75.8%, 60.1%, 44.9%, and 28.7%, respectively. Lymph node metastases were identified in 23 of 348 patients (6.6%) who underwent LND. The 5-year DSS rate was 26% in patients who had positive lymph nodes compared with 64.2% in patients who had negative lymph nodes (P < .001). Of 341 patients aged <50 years with stage I or II disease, 240 (70.4%) underwent oophorectomy. There was no difference in 5-year DSS based on oophorectomy. On multivariate analysis, older age at diagnosis, more recent year of diagnosis, African-American race, higher tumor grade, higher stage of disease, and lack of primary surgical treatment all were associated significantly with worse survival.

CONCLUSIONS

Independent predictors of DSS in patients with uterine LMS included age, race, stage, grade, and primary surgery. Oophorectomy was not found to have an independent impact on survival.

The management of patients with uterine sarcoma: a debated clinical challenge

Uterine sarcomas include a heterogeneous group of rare tumours that usually have an aggressive clinical behaviour and a poor prognosis. Total abdominal hysterectomy and bilateral salpingo-oophorectomy represents the standard surgical treatment. Pelvic and/or para-aortic lymphadenectomy is indicated for carcinosarcoma, but not for leiomyosarcoma and undifferentiated endometrial sarcoma. Some recent data on low numbers of patients with low-grade endometrial stromal sarcoma appear to show an incidence of nodal involvement higher than previously expected, thus suggesting a role for lymphadenectomy in this malignancy. Carcinosarcoma also requires a comprehensive surgical peritoneal staging. Postoperative treatment of uterine sarcomas has been long debated. Adjuvant pelvic radiotherapy appears to improve local control without any significant impact on overall survival. There is little evidence in the literature supporting the use of adjuvant chemotherapy in any gynaecological sarcomas except for carcinosarcomas. However, uterine sarcomas have a high tendency to develop distant recurrences, and recent data on adjuvant chemotherapy in soft tissue sarcomas are promising. As for the drugs to be used, it is worth noting that in a Swiss study, the combination of ifosfamide (IFO) and doxorubicin (DOX) obtained similar response rates in advanced gynaecological sarcomas and in advanced soft tissue sarcomas of other sites. In our decision-making scheme for early-stage disease, patients with leiomyosarcoma or undifferentiated endometrial sarcoma should receive adjuvant doxorubicin/epidoxorubicin (EPIDX)+ifosfamide, and those with carcinosarcoma should be treated with adjuvant cisplatin (CDDP)-based chemotherapy. The same drug regimens are used for the treatment of advanced disease. Sequential pelvic radiotherapy following chemotherapy could be delivered to selected cases. Recurrent disease often requires the integration of different therapeutic modalities, but no curative option is currently available with the possible exception of surgery for lung metastases and hormone therapy with or without debulking surgery for recurrent low-grade endometrial stromal sarcoma. Patients should be encouraged to enter clinical trials designed to identify new active drugs for these malignancies.