Multi-institutional Analysis of Vaginal Brachytherapy Alone for Women With Stage II Endometrial Carcinoma

The Prognostic Significance of the Depth of Cervical Stromal Invasion in Women With FIGO Stage II Uterine Endometrioid Carcinoma

OBJECTIVE

The objective of this study was to investigate the prognostic significance of the depth of cervical stromal invasion (CSI) in women with FIGO stage II uterine endometrioid adenocarcinoma (EC).

METHODS

Our database of women with EC was quired for patients with stage II EC. Pathologic slides were retrieved and reviewed by gynecologic pathologists to determine cervical stromal thickness and depth of CSI as a percentage of stromal thickness (%CSI). Kaplan-Meier, univariate, and multivariate analyses were used to compare recurrence-free, disease-specific (DSS), and overall survival (OS) between women who had<50% versus ≥50% CSI. Univariate and multivariate analyses were used to assess other prognostic variables associated with survival endpoints.

RESULTS

A total of 117 patients were included in our study who had hysterectomy between 1/1990 and 8/2021. Seventy-nine patients (68%) with <50% and 38 (32w%) with ≥50% CSI. After a median follow-up of 131 months, 5-year DSS was significantly worse for women with ≥50% CSI (78% vs. 91%; P =0.04). However, %CSI was not an independent predictor for any of the studied survival endpoints. Independent predictors of worse 5-year recurrence-free survival and DSS included FIGO grade 3 tumors ( P =0.02) and the presence of lymphovascular space invasion ( P =0.03). Grade 3 tumors were the only independent predictor of worse 5-year OS ( P =0.02).

CONCLUSIONS

Our results suggest that deep CSI is not an independent prognostic factor for survival endpoints in women with stage II uterine endometroid adenocarcinoma. The lack of independent prognostic significance of the depth CSI needs to be validated in a multi-institutional analysis.

Adjuvant Radiotherapy in Stage II Endometrial Cancer: Selective De-intensification of Adjuvant Treatment

AIMS

Risk stratification, including nodal assessment, allows for selective de-intensification of adjuvant radiotherapy in stage II endometrial cancer. Patterns of treatment and clinical outcomes, including the use of reduced volume 'mini-pelvis' radiotherapy fields, were evaluated in a population-based study.

MATERIALS AND METHODS

All patients diagnosed with pathological stage II endometrial cancer between 2000 and 2014, and received adjuvant radiotherapy in a regional healthcare jurisdiction were reviewed. Registry data were supplemented by a comprehensive review of patient demographics, disease characteristics and treatment details. The Charlson Comorbidity Score was calculated. Survival and recurrence data were analysed.

RESULTS

In total, 264 patients met the inclusion criteria. Most patients had endometrioid histology (83%); 41% of patients had International Federation of Gynecologists and Obstetricians grade 1 disease. Half (49%) had surgical nodal evaluation; 11% received chemotherapy. Most patients (59%) were treated with full pelvic radiotherapy fields ± brachytherapy. Seventeen per cent of patients received mini-pelvis radiotherapy ± brachytherapy, whereas 24% received brachytherapy alone. Five-year recurrence-free survival was 87% for the entire cohort, with no significant difference by adjuvant radiotherapy approach. Only one patient receiving mini-pelvis radiotherapy ± brachytherapy recurred in the pelvis but outside of the mini-pelvis field. Recorded late toxicity rates were highest for full pelvis radiotherapy + brachytherapy.

CONCLUSION

Risk stratification in a real-world setting allowed for selective de-intensification of adjuvant radiation with equivalent outcomes for stage II endometrial cancer. Mini-pelvis radiotherapy combined with brachytherapy is effective in highly selected patients, with the potential to decrease toxicity without compromising local control. Brachytherapy should be considered in low-risk stage II patients.

Radiation Therapy for Endometrial Cancer: An American Society for Radiation Oncology Clinical Practice Guideline

PURPOSE

With the results of several recently published clinical trials, this guideline informs on the use of adjuvant radiation therapy (RT) and systemic therapy in the treatment of endometrial cancer. Updated evidence-based recommendations provide indications for adjuvant RT and the associated techniques, the utilization and sequencing of adjuvant systemic therapies, and the effect of surgical staging techniques and molecular tumor profiling.

METHODS

The American Society for Radiation Oncology convened a multidisciplinary task force to address 6 key questions that focused on the adjuvant management of patients with endometrial cancer. The key questions emphasized the (1) indications for adjuvant RT, (2) RT techniques, target volumes, dose fractionation, and treatment planning aims, (3) indications for systemic therapy, (4) sequencing of systemic therapy with RT, (5) effect of lymph node assessment on utilization of adjuvant therapy, and (6) effect of molecular tumor profiling on utilization of adjuvant therapy. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for quality of evidence grading and strength of recommendation.

RESULTS

The task force recommends RT (either vaginal brachytherapy or external beam RT) be given based on the patient's clinical-pathologic risk factors to reduce risk of vaginal and/or pelvic recurrence. When external beam RT is delivered, intensity modulated RT with daily image guided RT is recommended to reduce acute and late toxicity. Chemotherapy is recommended for patients with International Federation of Gynecology and Obstetrics (FIGO) stage I to II with high-risk histologies and those with FIGO stage III to IVA with any histology. When sequencing chemotherapy and RT, there is no prospective data to support an optimal sequence. Sentinel lymph node mapping is recommended over pelvic lymphadenectomy for surgical nodal staging. Data on sentinel lymph node pathologic ultrastaging status supports that patients with isolated tumor cells be treated as node negative and adjuvant therapy based on uterine risk factors and patients with micrometastases be treated as node positive. The available data on molecular characterization of endometrial cancer are compelling and should be increasingly considered when making recommendations for adjuvant therapy.

CONCLUSIONS

These recommendations guide evidence-based best clinical practices on the use of adjuvant therapy for endometrial cancer.

A population-based study of outcomes in adjuvant radiotherapy for stage II endometrial carcinoma

OBJECTIVE

Our study aimed to analyze recurrence and survival outcomes in stage II endometrial cancer patients treated with adjuvant radiotherapy at CancerCare Manitoba, a Canadian provincial cancer program.

METHODS

This retrospective population-based cohort study identified all International Federation of Gynecology and Obstetrics (FIGO) 2009 stage II endometrioid type endometrial carcinoma diagnosed between January 1995 and December 2019. All patients underwent surgery followed by vaginal vault brachytherapy alone or external beam pelvic radiotherapy plus vaginal vault brachytherapy. We used Kaplan-Meier curves to describe overall survival and recurrence-free survival, and cumulative incidence to describe recurrence. Cox regression was used to predict overall survival and recurrence-free survival competing risk regression to predict recurrence.

RESULTS

A total of 121 patients were included (78 vaginal brachytherapy alone and 43 external beam pelvic radiotherapy plus vaginal brachytherapy) with a median age of 62 (range 24-85). The median follow-up was 55.2 months (range 7.1-147.9) in the vaginal brachytherapy group and 41.9 months (range 7.4-127.0) in the pelvic radiotherapy group. Lymph node dissection was performed in 79 (65.3%) patients. There were 14 (17.9%) recurrences (8 vaginal vault, 3 pelvic, 3 distant) with vaginal brachytherapy and 7 (16.3%) recurrences (3 vaginal vault, 2 pelvic, 2 distant) with external beam pelvic radiotherapy. The 5 year overall survival was 73.1% with vaginal vault brachytherapy vs 73.7% with external beam pelvic radiotherapy plus vaginal brachytherapy (p=0.31), the 5 year recurrence-free survival was 65.0% vs 68.2% (p=0.61), and the 5 year recurrence risk was 20.3% vs 19.4% (p=0.94). On univariable and multivariable analysis, only age was a statistically significant predictor for overall survival and recurrence-free survival (p<0.05), but not lymphovascular space invasion (HR, 2.97; 95% CI, 0.99 to 8.93 for overall survival, p=0.15). The type of adjuvant radiotherapy did not predict for recurrence (p=0.94).

CONCLUSIONS

There was no significant difference in overall survival, recurrence-free survival, and recurrence risk between vaginal vault brachytherapy vs external beam pelvic radiotherapy plus vaginal vault brachytherapy in patients with stage II endometrial cancer.

Vaginal brachytherapy management of stage I and II endometrial cancer

Adjuvant radiotherapy is an important component of post-operative therapy for patients with early-stage endometrial cancer. In the past decades, many trials have been conducted to determine the optimal adjuvant treatment strategy, pelvic external beam radiotherapy or vaginal brachytherapy. As a result, vaginal brachytherapy became the treatment of choice for patients with early-stage endometrial cancer at high-intermediate risk, based on clinicopathological risk factors. Vaginal brachytherapy maximizes local control and has only mild side effects with limited impact on quality of life, in comparison with pelvic external beam radiotherapy. The most frequently used treatment schedule is the one which was used in the PORTEC-2 trial (21 Gy in three fractions specified at 5 mm depth) and, whenever available, image-guided brachytherapy should be used. However, the most convenient and effective treatment schedule remains to be established. More recently, the discovery and integration of four molecular classes in the risk assessment of endometrial cancer patients has created new opportunities to prevent over- and undertreatment. The 2021 endometrial cancer guideline of the European Society of Gynaecological Oncology (ESGO), European Society for Radiotherapy and Oncology (ESTRO), and the European Society of Pathology (ESP) now proposes an integrated risk stratification, in which both clinicopathologic and molecular factors are combined, to direct adjuvant therapy. This rationale is now investigated in multiple prospective trials. This review provides an overview of the rationale and currently recommended and new strategies for vaginal brachytherapy in patients with stage I and II endometrial cancer.

Substantial lymphovascular space invasion predicts worse outcomes in early-stage endometrioid endometrial cancer

INTRODUCTION

Substantial as opposed to focal or no lymphovascular space invasion (LVSI) is proposed as an independent adverse prognostic factor in patients with early-stage endometrioid endometrial cancer (EEC). We reviewed outcomes of patients treated with adjuvant vaginal brachytherapy (VB) alone in a single institution, stratified by LVSI extent.

METHODS AND MATERIALS

Retrospective review identified Stage I-II EEC patients receiving VB alone from 2010 to 2017. Extent of LVSI was reported as none, focal, or substantial. Kaplan-Meier estimates and Log-Rank test were used to determine significance between variables. Cox proportional hazards model was used for multivariate analyses.

RESULTS

In total, 325 patients were identified with a median follow-up of 35 (23-48) months. LVSI was found in 112 patients with extent reported in 78, 45 (58%) had focal, and 33 (42%) substantial LVSI. Estimated disease-free survival for those with substantial LVSI was 73 (57-94)%, focal LVSI 89 (79-100)%, and no LVSI 94 (90-98)% at 48 months (p = 0.012). On multivariate analyses substantial LVSI was the only risk factor predictive of pelvic [HR substantial vs no: 7.2 (1.0-51.6); p = 0.048] and distant failure [HR substantial vs no: 4.4 (1.2-16.3); p = 0.027]. Both high-grade disease [HR 3 vs 1: 5.5 (1.2-25.6); p = 0.031] and extent of LVSI [HR substantial vs no: 4.4 (1.7-11.4); p = 0.002] predicted for worse disease-free survival.

DISCUSSION

Substantial LVSI was the strongest adverse prognostic factor for pelvic and distant failure in this cohort of EEC patients receiving adjuvant VB alone, suggesting this subset may benefit from additional adjuvant therapy. This study underscores the importance of quantifying LVSI extent in EEC.

Neoadjuvant radiotherapy and brachytherapy in endometrial cancer with gross cervical involvement: a CHIRENDO research group study

BACKGROUND

Historically, radical hysterectomy followed by adjuvant radiotherapy has been offered to patients with endometrial cancer who have gross cervical involvement; however, this approach is known to carry considerable morbidity. Neoadjuvant radiotherapy followed by extra-fascial hysterectomy has been proposed as an alternative treatment but has been poorly studied to date.

OBJECTIVE

To evaluate the locoregional control rate associated with neoadjuvant radiotherapy followed by extra-fascial hysterectomy.

METHODS

A retrospective cohort study of 30 patients with endometrial cancer with gross cervical involvement treated between May 2006 and January 2016 was performed. Eligible patients were those aged >18 years with non-metastatic endometrial adenocarcinoma and gross cervical disease treated with curative intent at the Centre hospitalier de l'Université de Montréal. Treatment protocol consisted of pelvic neoadjuvant radiotherapy and high-dose rate brachytherapy followed by extra-fascial hysterectomy. Kaplan-Meier curves were used for survival analysis.

RESULTS

The median age was 60 (range 37-82) and median body mass index was 32 kg/m² (range 16-55). Twenty-four (80%) patients were diagnosed with a positive cervical/endocervical biopsy. Clinical staging confirmed 36.7% (n=11) as stage II, 20% (n=6) stage IIIB, 30% (n=9) stage IIIC1, and 13.3% (n=4) stage IIIC2. Seventy-seven per cent (n=23) of patients had an endometrioid histology. Locally advanced disease was identified by imaging alone in six patients. Rates of parametrial, adnexal, vaginal, and nodal invasion were 10% (n=3), 6.7% (n=2), 13.3% (n=4), and 43.3% (n=13) at diagnosis, respectively. All patients completed pelvic radiotherapy (13.3% extended field) and 90% received brachytherapy. Twenty per cent (n=6) of surgeries were performed using minimal invasive technique. On surgical specimen, 63.3% (n=19) had complete cervical response, 90% (n=27) had negative margins, and 10% (n=3) had residual nodal involvement. Median follow-up time was 62 months (range 1-120). Six recurrences were identified; all except one involved distant failure, and two with locoregional failure. Five-year locoregional control rate, disease-free, overall, and disease-specific survival were 90.5%, 78.5%, 92.6%, and 96.2%, respectively. Two patients (6.7%) had grade 3+ acute radiation-related complications (all grade 3). Grade 3+ post-operative morbidity was noted in 2 (6.7%) patients.

CONCLUSIONS

Neoadjuvant radiotherapy followed by extra-fascial hysterectomy offers good locoregional control with low treatment-related morbidity in patients with endometrial cancer with overt cervical involvement.

Adjuvant radiotherapy for endometrial cancer with cervical stromal involvement: A patterns of practice survey in Australia and New Zealand

INTRODUCTION

The purpose of this study is to describe the patterns of practice in Australia and New Zealand for post-operative radiotherapy in endometrial cancer with cervical stromal involvement.

METHODS

A ten-item survey including five clinical case scenarios in endometrial cancer with cervical stromal invasion was emailed to Royal Australian and New Zealand College of Radiologists (RANZCR) radiation oncologists in 2018. Responses were analysed to determine relative frequency distributions and preferred adjuvant treatment modalities for the clinical case scenarios.

RESULTS

A total of 65 respondents initiated the survey with 27 respondents treating more than 11 endometrial cancer cases annually. Only 31 respondents answered all five clinical case scenarios. Preferred adjuvant radiotherapy modalities varied for the Stage II cases between vault brachytherapy (VB), pelvic external beam radiotherapy (EBRT) or a combination. For the stage IIIA and IIIC1 cases, the majority recommended pelvic EBRT with or without VB boost (79% and 77%), and of these, most combined with chemotherapy (61% and 88%). For 4 of the 5 case scenarios, when pelvic EBRT was offered, most recommended a VB boost.

CONCLUSION

This patterns of practice survey suggests variability in adjuvant radiotherapy recommendations in endometrial cancer with cervical involvement, particularly in cases where there is lack of randomised data and discrepancies in consensus guidelines.

Radiation therapy for gynecologic malignancies during the COVID-19 pandemic: International expert consensus recommendations

OBJECTIVE

To develop expert consensus recommendations regarding radiation therapy for gynecologic malignancies during the COVID-19 pandemic.

METHODS

An international committee of ten experts in gynecologic radiation oncology convened to provide consensus recommendations for patients with gynecologic malignancies referred for radiation therapy. Treatment priority groups were established. A review of the relevant literature was performed and different clinical scenarios were categorized into three priority groups. For each stage and clinical scenario in cervical, endometrial, vulvar, vaginal and ovarian cancer, specific recommendations regarding dose, technique, and timing were provided by the panel.

RESULTS

Expert review and discussion generated consensus recommendations to guide radiation oncologists treating gynecologic malignancies during the COVID-19 pandemic. Priority scales for cervical, endometrial, vulvar, vaginal, and ovarian cancers are presented. Both radical and palliative treatments are discussed. Management of COVID-19 positive patients is considered. Hypofractionated radiation therapy should be used when feasible and recommendations regarding radiation dose, timing, and technique have been provided for external beam and brachytherapy treatments. Concurrent chemotherapy may be limited in some countries, and consideration of radiation alone is recommended.

CONCLUSIONS

The expert consensus recommendations provide guidance for delivering radiation therapy during the COVID-19 pandemic. Specific recommendations have been provided for common clinical scenarios encountered in gynecologic radiation oncology with a focus on strategies to reduce patient and staff exposure to COVID-19.

Outcomes of minimally invasive surgery for patients with endometrial carcinoma involving the cervix

OBJECTIVE

Most studies evaluating the oncologic safety of minimally invasive surgery for endometrial cancer focus on patients with stage I disease. The aim of this study was to investigate the outcomes of minimally invasive surgery for patients with endometrial carcinoma involving the cervix.

METHODS

Patients diagnosed between January 2010 and December 2015, with clinical stage II endometrial carcinoma, who underwent hysterectomy with lymphadenectomy, were drawn from the National Cancer Database. Inclusion criteria were clinical International Federation of Gynecology and Obstetrics (FIGO 2009) stage II, patients who underwent hysterectomy with lymphadenectomy, and known route of surgery (open or minimally invasive). Patients who received radiation therapy prior to surgery, those who had subtotal/supracervical hysterectomy, or unknown type of hysterectomy were excluded. The exposure of interest was performance of minimally invasive surgery either laparoscopic or robotic-assisted. Overall survival (primary endpoint) was assessed for patients diagnosed between January 2010 and December 2014 following generation of Kaplan-Meier curves and compared with the log-rank test. A Cox model was constructed to control for confounders.

RESULTS

A total of 2175 patients were identified and 1282 (58.9%) had minimally invasive surgery. Of these, 339 and 943 patients had laparoscopic or robotic-assisted laparoscopic hysterectomy, respectively. Minimally invasive surgery was converted to open surgery in 74 (5.8%) patients. Those undergoing minimally invasive surgery had shorter hospital stay (median 1 vs 3 days, p<0.001), lower unplanned readmission rate (2.7% vs 4.7%, p=0.014), and 90-day mortality (0.8% vs 1.8%, p=0.05). Patients who had open surgery (n=796) had worse overall survival compared with those who had minimally invasive surgery (n=1048, p=0.003); 3-year overall survival rates were 76.8% and 83.6%, respectively. After controlling for patient age, race, type of insurance, presence of co-morbidities, performance of extensive lymphadenectomy, presence of positive lymph nodes, tumor histology, presence of lymphovascular space invasion, tumor size, and administration of radiotherapy, performance of minimally invasive surgery was not associated with worse survival (HR 0.90, 95% CI 0.73 to 1.11).

CONCLUSIONS

In this retrospective analysis, minimally invasive surgery in patients with stage II endometrial carcinoma was associated with superior short-term peri-operative outcomes and improved 3-year overall survival.

External beam radiotherapy versus vaginal brachytherapy in patients with stage II endometrial cancer: a systematic review and meta-analysis

Objective

The choice of adjuvant treatment for women with stage II endometrial cancer is challenging, given the known increase in morbidity with external beam radiation compared with vaginal brachytherapy, and the lack of consensus on its benefits. We summarized the evidence on survival and recurrence for stage II endometrial cancer, defined as cervical stromal invasion, after adjuvant postoperative external beam radiotherapy and vaginal brachytherapy.

Methods

We searched the MEDLINE, EMBASE, CENTRAL, and Scopus databases from inception to January 2019 to identify studies that compared adjuvant postoperative external beam radiotherapy with or without vaginal brachytherapy and vaginal brachytherapy alone in stage II endometrial cancer. Our primary outcome was the locoregional recurrence rate, defined as recurrence in the pelvis or vagina. Secondary outcomes included the rate of recurrence at any site, distant recurrence rate, vaginal recurrence rate, pelvic recurrence rate, and 5 year overall survival. Study selection, assessment, and data abstraction were performed by an independent set of reviewers. Random effects models were used to synthesize quantitative data.

Results

We included 15 cohort studies reporting data on 1070 women. Most women with stage II endometrial cancer (848/1070, 79.3%) were treated with external beam radiotherapy with or without vaginal brachytherapy. Subgroup analysis was stratified by whether >90% of the women included underwent pelvic lymph node assessment (sampling or full dissection). Locoregional recurrence (pelvic and vaginal recurrence) was significantly reduced with external beam radiotherapy with or without vaginal brachytherapy compared with vaginal brachytherapy alone (14 studies (n=1057); odds ratio (OR) 0.33 (95% confidence interval (CI) 0.16 to 0.68); I2=5%) regardless of pelvic lymph node assessment. Most women (81.8%) who recurred locoregionally had a least one uterine risk factor (grade 3 tumor, myometrial invasion >50%, or lymphovascular invasion). There was no difference in overall survival with external beam radiotherapy with or without vaginal brachytherapy compared with vaginal brachytherapy alone (five studies (n=463); OR 0.78 (95% CI 0.34 to 1.80); I2=48%).

Conclusions

External beam radiotherapy with or without vaginal brachytherapy decreased the locoregional recurrence threefold for stage II endometrial cancer, regardless of pelvic lymph node assessment. Most women who suffered recurrence locoregionally had a least one high risk factor. Vaginal brachytherapy alone may be sufficient therapy for node negative stage II endometrial cancer without uterine risk factors, while those with uterine risk factors should be considered for external beam radiotherapy with or without vaginal brachytherapy to improve locoregional control.

Survival benefit of radiation in high-risk, early-stage endometrioid carcinoma

OBJECTIVE

To better delineate optimal management of high-risk, early-stage endometrial cancer, as national guidelines permit substantial practice variations.

METHODS

Patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB grade 3 and stage II endometrioid carcinoma who underwent at least total hysterectomy were identified in SEER-Medicare. Adjuvant treatments were brachytherapy (BT), external beam radiation therapy (EBRT), and chemotherapy. Death from endometrial cancer (cancer-specific mortality [CSM]) and local recurrence were analyzed using Gray's test and Fine-Gray regression.

RESULTS

In total, 1,095 patients were identified: 52% received BT, 56% received EBRT, 16% received chemotherapy, and 29% received no adjuvant treatment. Survival outcomes were significantly worse for stage IB grade 3 and stage II grade 3 relative to stage II grades 1-2 (5-year CSM: 18% and 23% vs. 10%; p<0.001 and p=0.003, respectively), while there was no difference between stage IB grade 3 and stage II grade 3 (p=0.618). BT had a local control benefit across all patients (p<0.001) that translated into a survival benefit in stage IB grade 3 (adjusted hazard ratio [HR] for CSM=0.47, p=0.003). EBRT had a survival benefit in stage II grade 3 (adjusted HR for CSM=0.36; p=0.031), as did lymph node dissection (p=0.015). Chemotherapy was not significantly correlated with CSM.

CONCLUSIONS

High-risk, early-stage endometrioid carcinoma is a heterogeneous population. BT was associated with a survival benefit in stage IB grade 3, whereas regional treatment with EBRT and lymphadenectomy was associated with a survival benefit in stage II grade 3.

Low-Dose Adjuvant Cylinder Brachytherapy for Endometrioid Endometrial Cancer

PURPOSE

Our purpose was to evaluate outcomes and sites of failure for women with early stage endometrial adenocarcinoma treated with adjuvant high-dose-rate (HDR) vaginal brachytherapy (VB) with a low dose scheme.

METHODS AND MATERIALS

Retrospective review identified 318 patients with International Federation of Gynecology and Obstetrics (FIGO) stage I-II endometrioid endometrial cancer who received adjuvant HDR VB to a dose of 24 Gray (Gy) in 6 fractions from 2005 to 2017. Patients with <6 months follow-up were excluded. Dose was prescribed to cylinder surface and computerized tomography (CT) imaging was performed before each fraction to assess cylinder placement. Rates of vaginal relapse (VR), pelvic nodal relapse, distant metastasis, recurrence-free survival, and overall survival were calculated by Kaplan-Meier method. Univariate analysis was performed by log rank test or Cox proportional hazards. Pretreatment CT images were analyzed for patients with VR.

RESULTS

Median follow-up was 42 months for 243 patients. The 3-year rates of VR, pelvic nodal relapse, distant metastasis, recurrence-free survival, and overall survival were 1.9%, 1.5%, 4.3%, 94.1%, and 98.9%, respectively. The 3-year VR rates by Gynecologic Oncology (GOG)-99 risk groups were 0%, 1.4%, and 3.2% for low risk, low-intermediate risk, and high-intermediate risk (HIR) disease (P = .5). By Post-operative Radiation Therapy in Endometrial Carcinoma (PORTEC) risk stratification, 3-year VR rate was 1.3% for HIR disease. On review of pretreatment CT images of the 6 patients with VR, 3 patients had relapse at the introitus outside of the treated vaginal length, and 3 had in-field recurrence at the vaginal apex. Higher body mass index (BMI) was associated with VR, with a 14% increase in risk per BMI unit (kg/m², P = .02). There were no reported grade 2 GI or any grade 3 toxicities.

CONCLUSIONS

Adjuvant HDR VB with a low-dose regimen results in excellent clinical outcomes for patients with early stage endometrioid endometrial cancer. Patients with higher BMI may be at increased risk of VR, and additional study is needed to optimize brachytherapy treatment parameters.

The vaginal cylinder: Misunderstood, misused, or trivial? An in-depth dosimetric and multiinstitutional outcome investigation

PURPOSE

The purpose of the study was to investigate the impact on dose distribution and radiobiological metrics of common high-dose-rate vaginal brachytherapy treatment parameters and to analyze multiinstitutional data for clinically significant impact on outcomes in early-stage endometrial cancer.

METHODS AND MATERIALS

Treatment plans were created for all combinations of prescription parameters and used to quantify the dosimetric impact of each parameter and to estimate the dose delivered using common voxel-integrated radiobiological metrics. A rating system, based on risk grouping from GOG and PORTEC trials, was used to consolidate staging information into a cancer "aggressiveness" measure. Correlations between the rating, toxicity, disease recurrence, and plan parameters were investigated.

RESULTS

When prescribing to 5 mm depth, the variation caused by the diameter was very large across all dose metrics, ranging from 51% to 175% increase with the most divergence in BED_max. For surface prescription, changing the cylinder diameter from 4 cm to 2 cm caused the dose metrics of BED_min, D_min, and gBEUD (a = -3) to increase by 117%, 67%, and 52%, respectively. Prescription to 5-mm depth caused changes across all dose metrics of 260% compared with surface prescription for a 2-cm cylinder. Deeper prescription point (p = 0.005) and longer treatment length (p = 0.01) were correlated with increased stenosis rates. No correlation between recurrence and any plan parameter was found.

CONCLUSIONS

Dramatic differences in dose distributions arise by small variations of plan parameters, with large impact on rates of vaginal stenosis, but no clear relation with local recurrence. To help radiation oncologists interpret the magnitude of these effects for their patients, we created a tool that allows comparison between dose and fractionation parameters.

Do vaginal recurrence rates differ among adjuvant vaginal brachytherapy regimens in early-stage endometrial cancer?

PURPOSE

We sought to retrospectively examine clinical outcomes for three adjuvant vaginal high-dose-rate (HDR) brachytherapy regimens after hysterectomy for early-stage endometrial cancer.

METHODS

Included were women of all ages from two independent hospital systems diagnosed with Stage I-II endometrial cancer of any grade between 2000 and 2016 who underwent hysterectomy followed by adjuvant vaginal cylinder HDR brachytherapy with either 7.0 Gy × 3 fractions prescribed to 0.5 cm vaginal depth, 6.5 Gy × 3 fractions prescribed to 0.5 cm vaginal depth, or 6.0 Gy × 5 fractions prescribed to the vaginal surface. Outcomes included vaginal recurrence (VR), pelvic recurrence, distant recurrence, locoregional recurrence, recurrence-free survival, and overall survival.

RESULTS

Of the 348 women, 45 (13%) received 7.0 Gy × 3 fractions, 259 (74%) received 6.5 Gy × 3 fractions, and 44 (13%) received 6.0 Gy × 5 fractions. Women receiving 5-fraction brachytherapy were more likely to be younger with a higher performance status. At a median follow-up of 4.5 years, VR rates were 2.2%, 0.8%, and 4.5%, respectively. Multivariate analysis revealed no significant differences in the risks for VR among brachytherapy regimens. Risks for VR, pelvic recurrence, distant recurrence, locoregional recurrence, recurrence-free survival, and overall survival did not differ between propensity score-matched five- and 3-fraction brachytherapy cohorts.

CONCLUSIONS

VR rates after hysterectomy and adjuvant vaginal brachytherapy for early-stage endometrial cancer were low and not significantly different by HDR dose fractionation.

Expression and potential role of SNF5 in endometrial carcinoma

Background

SNF5 is a key protein in regulating cell proliferation and apoptosis in various cancers. However, the physiological roles of SNF5 in Endometrial carcinoma (EC), which is one of the most frequent malignancies of the female reproduction worldwide, remains unclear. This study aims to investigate the role of SNF5 and its correlation with clinicopathologic characteristics in EC.

Methods

We performed immunohistochemistry to detect the SNF5 expression in 46 endometrial carcinomas and 20 normal endometrium (non-EC) specimens, as well as analyzed the correlations between SNF5 expression and clinicopathologic features of patients using a statistics software (GraphPad Prism V6.0). Western blotting had been used to confirm the protein level of SNF5 in endometrial tissues. In addition, we evaluated the correlations between SNF5 and p21 in EC.

Results

The positive immunostaining rate for SNF5 in EC and non-EC specimens were 65% (30/46) and 25% (5/20) respectively, and the expression of SNF5 was dramatically increased in EC compared with the normal endometrium (P < 0.01). The overexpression of SNF5 was associated with the PR levels, but not with age, FIGO stage, grade, lymphatic metastasis, myometrial invasion or ER status. Knockdown of SNF5 inhibits the expression of p21.

Conclusions

Our results indicate that SNF5 plays an important role of promoting oncogenesis in EC. These findings open up the possibility for various novel and effective combination therapies targeting SNF5 in the EC.