Adjuvant carboplatin, paclitaxel, and vaginal cuff brachytherapy for stage III endometrial cancer: analysis of outcomes and patterns of recurrence based on pathologic characteristics

Radiotherapy and Chemotherapy Features in the Treatment for Locoregional Recurrence of Endometrial Cancer: A Systematic Review

Radiation therapy (RT) is the standard of care in patients with locoregional or isolated vaginal recurrence who never underwent irradiation. It is often associated with brachytherapy (BT), whereas chemotherapy (CT) is a rare treatment option. We systematically searched the PubMed and Scopus databases in February 2023. We included patients with relapsed endometrial cancer, describing the treatment of locoregional recurrence, and reporting at least one outcome of interest-disease-free survival (DFS), overall survival (OS), recurrence rate (RR), site of recurrence, and major complications. A total of 15 studies fulfilled the inclusion criteria. Overall, 11 evaluated RT only, 3 evaluated CT, and 1 analyzed oncological outcomes after administration with a combination of CT and RT. In total, 4.5-year OS ranged from 16% to 96%, and DFS ranged from 36.3% to 100% at 4.5 years. RR ranged from 3.7% to 98.2% during a median follow-up of 51.5 months. Overall, RT showed a 4.5-year DFS from 40% to 100%. CT revealed 36.3% DFS at 4.5 years. RT showed a 4.5-year OS ranging from 16% to 96%, whereas CT revealed a 27.7% OS rate. It would be appropriate to test multi-modality regimens to evaluate outcomes and toxicity. EBRT and BT are the most employed options to treat vaginal recurrences.

Role of brachytherapy in stage III endometrial cancer treated with adjuvant chemotherapy: Identifying factors predictive of a survival benefit

OBJECTIVES

To determine which patients with stage III endometrial cancer receiving adjuvant chemotherapy derive benefit from the addition of vaginal brachytherapy, as stage III is a highly heterogeneous population with substantial variations in practice.

METHODS

Patients with FIGO stage III endometrial carcinoma diagnosed 2004-2016 who underwent at least total hysterectomy and adjuvant multiagent chemotherapy were identified in the National Cancer Database. The primary outcome was overall survival according to receipt of brachytherapy, stratified by histologic type, pathological features, and status of pelvic external beam radiotherapy (EBRT), and analyzed using the Kaplan-Meier method and Cox multivariable regression.

RESULTS

In total, 9369 patients were identified (24% stage IIIA, 5% stage IIIB, 71% stage IIIC; 61% endometrioid, 39% nonendometrioid histology), and 28% received brachytherapy. In the endometrioid cohort, brachytherapy was associated with a 5% absolute increase in 3-year overall survival (87% vs. 82%, p < 0.0001), which persisted in multivariable analysis (adjusted hazard ratio 0.74, 95% confidence interval 0.64-0.84, p < 0.0001). The benefit of brachytherapy was greater in patients not also receiving EBRT, and in patients with vaginal/parametrial extension, grade 3 disease, lymphovascular invasion, and/or deep myometrial invasion. In the nonendometrioid cohort, brachytherapy was associated with a significant survival benefit in univariable but not multivariable analysis, regardless of EBRT status or pathological features.

CONCLUSIONS

Factors predictive of brachytherapy benefit were endometrioid histology and pathological risk factors for local recurrence. Additionally, brachytherapy appeared more beneficial in patients not already receiving pelvic EBRT. Further research is warranted to determine which stage III patients may be best served by brachytherapy, EBRT, or both.

Predictors of Survival in Women with High-Risk Endometrial Cancer and Comparisons of Sandwich versus Concurrent Adjuvant Chemotherapy and Radiotherapy

Background: to elucidate the predictors of progression-free survival (PFS) and overall survival (OS) in high-risk endometrial cancer patients. Methods: the medical records of all consecutivewomen with high-risk endometrial cancer were reviewed. Results: among 92 high-risk endometrial cancer patients, 30 women experienced recurrence, and 21 women died. The 5-year PFS and OS probabilities were 65.3% and 75.9%, respectively. Multivariable Cox regression revealed that body mass index (hazard ratio (HR) = 1.11), paraaortic lymph node metastasis (HR = 11.11), lymphovascular space invasion (HR = 5.61), and sandwich chemoradiotherapy (HR = 0.15) were independently predictors of PFS. Body mass index (HR = 1.31), paraaortic lymph node metastasis (HR = 32.74), non-endometrioid cell type (HR = 11.31), and sandwich chemoradiotherapy (HR = 0.07) were independently predictors of OS. Among 51 women who underwent sandwich (n = 35) or concurrent (n = 16) chemoradiotherapy, the use of sandwich chemoradiotherapy were associated with better PFS (adjusted HR = 0.26, 95% CI = 0.08-0.87, p = 0.03) and OS (adjusted HR = 0.11, 95% CI = 0.02-0.71, p = 0.02) compared with concurrent chemoradiotherapy. Conclusion: compared with concurrent chemoradiotherapy, sandwich chemoradiotherapy was associated with better PFS and OS in high-risk endometrial cancer patients. In addition, high body mass index, paraaortic lymph node metastasis, and non-endometrioid cell type were also predictors of poor OS in high-risk endometrial cancer patients.

Stage III uterine serous carcinoma: modern trends in multimodality treatment

Objective

To examine outcomes in a modern treatment era for stage III uterine serous carcinoma (USC).

Methods

Fifty women were retrospectively identified as 2009 International Federation of Gynecology and Obstetrics stage III USC patients who received radiotherapy (RT) at our institution between 1/2003–5/2018. The patients were divided into 2 cohorts: 20 in the early era (2003–2010) and 30 in the modern era (2011–2018). Patient characteristics were compared using χ² tests for categorical variables and t-tests for continuous variables. Recurrence free survival (RFS) and overall survival (OS) were analyzed with Kaplan-Meier estimates, the log-rank test, and Cox proportional hazards.

Results

The modern era differed from the early era in the increased use of volume-directed external beam RT (EBRT) as opposed to vaginal brachytherapy (VB) alone (33.3% vs 5.0%, p=0.048), minimally invasive surgery (56.7% vs. 25%, p=0.027), sentinel node sampling (26.7% vs. 0%, p=0.012), computed tomography imaging in the perioperative period (63.3% vs. 30%, p=0.044), and human epidermal growth factor receptor 2/neu testing (96.7% vs. 55%, p=0.001). Median follow-up for early and modern eras was 37.27 and 33.23 months, respectively. The early vs. modern 3-year RFS was 33% and 64% (p=0.039), respectively, while the 3-year OS was 55% and 90% (p=0.034). Regional nodal recurrence more common among the patients who received VB only (p=0.048).

Conclusion

Modern era treatment was associated with improved RFS and OS in patients with stage III USC. Regional nodal recurrences were significantly reduced in patients who received EBRT.

Sacituzumab govitecan, an antibody-drug conjugate targeting trophoblast cell-surface antigen 2, shows cytotoxic activity against poorly differentiated endometrial adenocarcinomas in vitro and in vivo

Endometrial cancer is the most common gynecologic malignancy in developed countries. The antibody-drug conjugate (ADC) sacituzumab govitecan (SG) targets trophoblast cell-surface antigen-2 (Trop-2) - a cell-surface glycoprotein highly expressed in many epithelial tumors - and delivers the active metabolite of irinotecan SN-38 to Trop-2-positive tumor cells. We evaluated Trop-2 expression in endometrial endometrioid carcinoma (EC) tissues and the activity of SG against primary poorly differentiated EC cell lines and xenografts. Trop-2 expression was assessed in 143 formalin-fixed-paraffin-embedded tumors and seven primary tumor cell lines by immunohistochemistry and flow cytometry, respectively. Cell viability of primary tumor cell lines was assessed following exposure to SG, or control antibodies. Antibody-dependent cell cytotoxicity (ADCC) against Trop-2-positive and Trop-2-negative EC cell lines was measured in vitro using 4-h chromium release assays. A Trop-2-positive EC xenograft model was used to determine the in vivo activity of SG. Moderate-to-strong staining was detected in 84% (120/143) of EC samples, whereas 43% (3/7) of the primary EC cell lines tested overexpressed Trop-2. EC cell lines overexpressing Trop-2 were significantly more sensitive to SG compared to control ADC (P = 0.014 and P = 0.005). Both SG and the unconjugated parental antibody hRS7 mediated high ADCC against Trop-2-positive cell lines. Moreover, SG induced significant bystander killing of Trop-2-negative tumors cocultured with Trop-2-positive tumors. In the xenograft model, intravenous administration of SG twice weekly for three weeks was well tolerated and demonstrated impressive tumor growth inhibition against poorly differentiated, chemotherapy-resistant EC xenografts (P = 0.011). In summary, SG is a novel ADC with remarkable preclinical activity against poorly differentiated EC cell lines overexpressing Trop-2. These findings warrant future clinical trials.

Patterns of FIRST recurrence of stage IIIC1 endometrial cancer with no PARAAORTIC nodal assessment

OBJECTIVE

To assess the rates and distribution of first recurrence in patients with FIGO stage IIIC1 endometrial cancer (EC) who did not undergo paraaortic dissection at surgical staging.

METHODS

We retrospectively selected all (n = 207) stage IIIC1 patients treated at a single institution from 5/1993-1/2017. Sites of first recurrence were identified, disease-free (DFS) and overall survival (OS) calculated, multivariate logistic regression performed to identify factors associated with recurrence.

RESULTS

Three-year DFS and OS were 66.5% and 85.7%, respectively. The most common histology was endometroid (64.2%). Three-year DFS was 81% (SE±3.8%) endometrioid vs. 39.5% (SE±6.6%) non-endometrioid (P < 0.001). Three-year OS was 96.9% (SE±1.8%) endometrioid vs. 65.6% (SE±6.7%) non-endometrioid (P < 0.001). Sixty-two (30.1%) patients recurred. Patterns of recurrence were: 14 (8.3%) multiple sites, 17 (8.2%) abdominal, 14 (6.8%) extra-abdominal, 17 (8.3%) isolated nodal (8 of these (3.9%) paraaortic). Patients with isolated tumor cells (ITCs) in lymph nodes only had 12/71 (17%) recurrence rate vs. 50/135 (37%) for patients with micro-/macrometastasis. On univariate analysis, grade (HR 4.67 95%CI 1.5-14.5, P = 0.008), histology (HR 4.9 95%CI 2.6-9.3, P < 0.001), myometrial invasion (HR 1.9 95%CI 1.04-3.5, P = 0.04), pelvic washing (HR 2.2 95%CI 1.1-4.5, P = 0.03), tumor volume in pelvic LNs (ITC vs. micro-/macrometastasis; HR 0.3 95%CI 0.2-0.7, P = 0.003) were associated with recurrence. On multivariate analysis, only histology was associated with recurrence (HR 7.88 95%CI 3.43-18.13, P < 0.001).

CONCLUSIONS

Isolated paraaortic recurrence in stage IIIC1 EC is uncommon. Micro-/macrometastasis were associated with twice the recurrence rate compared to ITC. These data will help clinicians counsel patients with stage IIIC1 EC regarding paraaortic assessment.

Value of combined adjuvant chemotherapy and radiation on survival for stage III uterine cancer: is less radiation equal to more?

Objective

Locally advanced endometrioid adenocarcinoma (LA-EAC) accounts for the majority of deaths for this cancer, yet there is no consensus on adjuvant treatment after surgery. Past studies suggest that combined modality treatment (CMT) may improve outcomes over treatment with chemotherapy (CT) or radiation therapy (RT, either external beam radiotherapy [EBRT] or vaginal brachytherapy [VBT]) alone. Using a large US-based population-based registry, we evaluated adjuvant CMT in LA-EAC and the relative benefit of regional EBRT compared to focused VBT.

Methods

We studied patients diagnosed with Stage III LA-EAC between 2004 and 2013 from the National Cancer Data Base (NCDB). We used Cox regression and a log-rank test to assess survival based on treatment with CT alone, EBRT alone, VBT alone, or CMT with EBRT and/or VBT. We used a χ² test to compare covariates between patients receiving CMT with EBRT or VBT.

Results

Patients who received CMT had better survival than those who received CT or EBRT/VBT alone. Compared to CMT with VBT, patients who received CMT with EBRT were slightly older and had more advanced-stage or positive nodes, and fewer had lymph node surgery. We found no survival difference between CMT with EBRT and CMT with VBT even when categorizing patients as high or low risk according to age, grade, and stage (low-risk p=0.3460; high-risk p=0.2158).

Conclusion

CMT was associated with superior survival outcomes compared to monotherapy. We observed no survival difference between radiation modalities in CMT, which highlights the effectiveness of a more focused treatment like brachytherapy.

In Vitro and In Vivo Activity of IMGN853, an Antibody-Drug Conjugate Targeting Folate Receptor Alpha Linked to DM4, in Biologically Aggressive Endometrial Cancers

Grade 3 endometrioid and uterine serous carcinomas (USC) account for the vast majority of endometrial cancer deaths. The purpose of this study was to determine folic acid receptor alpha (FRα) expression in these biologically aggressive (type II) endometrial cancers and evaluate FRα as a targetable receptor for IMGN853 (mirvetuximab soravtansine). The expression of FRα was evaluated by immunohistochemistry (IHC) and flow cytometry in 90 endometrioid and USC samples. The in vitro cytotoxic activity and bystander effect were studied in primary uterine cancer cell lines expressing differential levels of FRα. In vivo antitumor efficacy of IMGN853 was evaluated in xenograft/patient-derived xenograft (PDX) models. Semiquantitative IHC analysis indicated that 41% of the USC patients overexpress FRα. Further, overexpression of FRα (i.e., 2+) was detected via flow cytometry in 22% (2/9) of primary endometrioid and in 27% (3/11) of primary USC cell lines. Increased cytotoxicity was seen with IMGN853 treatment compared with control in 2+ expressing uterine tumor cell lines. In contrast, tumor cell lines with low FRα showed no difference when exposed to IMGN853 versus control. IMGN853 induced bystander killing of FRα = 0 tumor cells. In an endometrioid xenograft model (END(K)265), harboring 2+ FRα, IMGN853 treatment showed complete resolution of tumors (P < 0.001). Treatment with IMGN853 in the USC PDX model (BIO(K)1), expressing 2+ FRα, induced twofold increase in median survival (P < 0.001). IMGN853 shows impressive antitumor activity in biologically aggressive FRα 2+ uterine cancers. These preclinical data suggest that patients with chemotherapy resistant/recurrent endometrial cancer overexpressing FRα may benefit from this treatment. Mol Cancer Ther; 17(5); 1003-11. ©2018 AACR.

Paclitaxel, Carboplatin, and Bevacizumab in Advanced and Recurrent Endometrial Carcinoma

OBJECTIVE

The aim of this study was to evaluate the efficacy of adding bevacizumab to paclitaxel and carboplatin and as maintenance in a larger cohort of patients with advanced or recurrent endometrial carcinoma.

METHODS

We retrospectively identified endometrial cancer patients treated with paclitaxel (175 mg/m per 3 hours), carboplatin (area under the curve, 5) and bevacizumab (15 mg/kg) and maintenance bevacizumab treated in a post-protocol treatment cohort and evaluated them with our previously published phase 2 trial of this regimen.

RESULTS

Twenty-seven additional patients were identified; 19 received the regimen as first-line therapy, and 8 received the regimen as second-line therapy after prior paclitaxel and carboplatin. The 19 patients who received first-line therapy were analyzed alone and with the 15 patients enrolled on protocol. The 2 cohorts were similar with respect to risk factors. Overall survival curves were not statistically different between the protocol and the postprotocol patients (log-rank test; P > 0.1). Collectively, a total of 266 courses (median, 6 courses; range, 1-20 courses) of carboplatin, paclitaxel, and bevacizumab combination therapy and 305 courses (median, 16 courses; range, 0-45courses) of bevacizumab maintenance therapy were administered as first-line therapy. Collectively, the median progression-free survival was 20 months, and median overall survival was 56 months. Among 29 patients with measurable disease, the response rate was 82.8% (95% confidence interval, 69.0%-96.5%; 15 complete responses and 9 partial responses). Among the 8 patients who received paclitaxel and carboplatin and bevacizumab as second-line therapy after paclitaxel and carboplatin, the response rate was 87.5% (6 complete responses, 1 partial response). Their median progression-free survival and median overall survival were not reached after a median follow-up of 23.5 months.

CONCLUSIONS

Although there are inherent limitations to small retrospective studies, this second analysis confirms the high response rate, progression-free survival, and overall survival in the bevacizumab, paclitaxel, and carboplatin regimen as first-line therapy in advanced and recurrent endometrial carcinoma.

MR- versus CT-based high-dose-rate interstitial brachytherapy for vaginal recurrence of endometrial cancer

PURPOSE

To compare clinical outcomes of MR-based versus CT-based high-dose-rate interstitial brachytherapy (ISBT) for vaginal recurrence of endometrioid endometrial cancer (EC).

METHODS AND MATERIALS

We reviewed 66 patients with vaginal recurrent EC; 18 had MR-based ISBT on a prospective clinical trial and 48 had CT-based treatment. Kaplan-Meier survival modeling was used to generate estimates for local control (LC), disease-free interval (DFI), and overall survival (OS), and multivariate Cox modeling was used to assess prognostic factors. Toxicities were evaluated and compared.

RESULTS

Median followup was 33 months (CT 30 months, MR 35 months). Median cumulative equivalent dose in 2-Gy fractions was 75.5 Gy for MR-ISBT and 73.8 Gy for CT-ISBT (p = 0.58). MR patients were older (p = 0.03) and had larger tumor size (>4 cm vs. ≤ 4 cm) compared to CT patients (p = 0.04). For MR-based versus CT-based ISBT, 3-year KM rate for local control was 100% versus 78% (p = 0.04), DFI was 69% versus 55% (p = 0.1), and OS was 63% versus 75% (p = 0.81), respectively. On multivariate analysis, tumor Grade 3 was associated with worse OS (HR 3.57, 95% CI 1.25, 11.36) in a model with MR-ISBT (HR 0.56, 95% CI 0.16, 1.89). Toxicities were not significantly different between the two modalities.

CONCLUSION

Despite worse patient prognostic features, MR-ISBT was associated with a significantly better (100%) 3-year local control, comparable survival, and improved DFI rates compared to CT. Toxicities did not differ compared to CT-ISBT patients. Tumor grade contributed as the most significant predictor for survival. Larger prospective studies are needed to assess the impact of MR-ISBT on survival outcomes.

Comparative results of three short brachytherapy schedules as exclusive treatment in postoperative endometrial carcinoma

PURPOSE

To compare vaginal control and treatment toxicity of three different high-dose-rate brachytherapy schedules as exclusive treatment in postoperative endometrial carcinoma.

METHODS AND MATERIALS

From 2003 to 2015, three different schedules were used as postoperative treatment for 146 patients (p) with intermediate-risk endometrial carcinoma. Group 1 (41 p): six fractions of 4-6 Gy, 3-4 fractions per week; Group 2 (59 p): four fractions of 5-6 Gy administered daily; Group 3 (46 p): 6 Gy × 3 fractions in three consecutive days. The dose was prescribed at 5 mm of applicator surface using an active treatment length of 2.5 cm. Toxicity scores were evaluated using the Radiation Therapy Oncology Group scores for bladder and rectum and the objective criteria of late effects of normal tissues-subjective, objective, management, analytic for vagina. Statistics used were group descriptions calculating their means, medians, and ranges. Bivariate analysis was evaluated using variance models and χ² tests.

RESULTS

The mean followup was as follows: Group 1: 88 months, Group 2: 75 months, and 41 months in Group 3. No vaginal relapses were found. Late toxicity ≥ G2: rectum: 0 p in the three groups (0%). Bladder: Group 1: 1 p (2.4%), Group 2: 0%, and Group 3: 0%. Vagina: Group 1: 4 p (9.5%); Group 2: 9 p (15.3%); and Group 3:10 p (21.8%). There were no differences in late toxicity among the three groups of patients for rectum (p = 0.83), bladder (p = 0.58), and vagina (p = 0.67); the expected global risk of complications for rectum, bladder, and vagina is 0.8%, 0.8%, and 28.8%, respectively.

CONCLUSIONS

Similar results in vaginal control and complications were achieved with the three schedules. The use of three fractions of 6 Gy administered daily is the best option for patient comfort and convenience and use of resources. Nonetheless, specific studies are needed to demonstrate the best cost-efficacy regime.

Outcomes of Patients With Surgically and Pathologically Staged IIIA-IVB Pure Endometrioid-type Endometrial Cancer: A Taiwanese Gynecology Oncology Group (TGOG-2005) Retrospective Cohort Study (A STROBE-Compliant Article)

In the management of patients with advanced-stage pure endometrioid-type endometrial cancer (E-EC), such as positive lymph nodes (stage III) or stage IV, treatment options are severely limited. This article aims to investigate the outcome of women with FIGO III-IV E-EC (based on FIGO 2009 system). The retrospective cohort study, based on the Taiwanese Gynecologic Oncology Group (TGOG-2005), enrolled patients undergoing staging surgery to have a pathologically confirmed FIGO III-IV E-EC from 22-member hospitals between 1991 and 2010. This cohort included 541 patients (stage III, n = 464; stage IV, n = 77). Five-year overall survival (OS) was 70.4%. Median progression-free survival (PFS) was 43 months (range 0-258 months) and median OS was 52 months (range 1-258 months). Multivariate analysis showed that FIGO stage, >1/2 myometrial invasion (hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.12-2.09; P = 0.007), histological grade 3 (HR 2.0, 95% CI 1.47-2.75; P < 0.001), and metastases of pelvic and para-aortic lymph nodes (PLN and PALN) (HR 2.75, 95% CI 1.13-6.72; P < 0.001) were independent risk factors for PFS. FIGO stage, >1/2 myometrial invasion (HR 1.89, 95% CI 1.34-2.64; P < 0.001), and histological grade 3 (HR 2.42, 95% CI 1.75-3.35; P < 0.001) influenced OS. Complete dissection of PLN and PALN (HR 0.27, 95% CI 0.16-0.45; P < 0.001, and HR 0.14, 95% CI 0.08-0.26; P < 0.001) and the following paclitaxel-based therapy (HR 0.61, 95% CI 0.79-0.92; P = 0.017, and HR 0.48; 95% CI 0.31-0.75; P = 0.001) provided the better PFS and OS, respectively. In management of women with FIGO III-V E-EC, combination of complete staging surgery (complete dissection of PLN and PALN is included) and the following paclitaxel-based therapy could provide the better chance to survive. Patients with tumor >1/2 myometrial invasion and histological grade 3 are risky for disease-related mortality.