Adjuvant radiation therapy is associated with improved overall survival in high-intermediate risk stage I endometrial cancer: A national cancer data base analysis

Impact of adjuvant treatment on survival in patients with 2023 FIGO stage IIC endometrial cancer: a retrospective analysis from two tertiary centers in Korea and Taiwan

OBJECTIVE

In early-stage endometrial cancer, aggressive histologic types (grade 3 endometrioid, serous, clear cell, carcinosarcomas, undifferentiated, mixed, and other unusual types) are associated with an increased risk of distant metastases and worse survival. However, the optimal adjuvant treatment for these patients remains controversial. The present study investigated the outcomes of different adjuvant treatments in patients with 2023 FIGO stage IIC endometrial cancer.

METHODS

We retrospectively identified patients with 2023 FIGO stage IIC endometrial cancer who underwent surgery followed by either adjuvant treatment or observation from 2000 to 2020 at two tertiary centers in Korea and Taiwan. Recurrence-free survival (RFS) and overall survival (OS) were evaluated using Kaplan-Meier estimates and Cox proportional-hazards models. We also analyzed recurrence patterns after different adjuvant treatments.

RESULTS

A total of 272 patients were identified; 204 received adjuvant treatment postoperatively, whereas 68 only underwent observation. Adjuvant treatment was not associated with improved RFS or OS. Non-endometrioid histologic types (p=0.003) and presence of lymphovascular space invasion (LVSI, p=0.002) were associated with worse RFS, whereas only non-endometrioid histologic types impacted OS (p=0.004). In subgroup analyses, adjuvant treatment improved OS in patients with LVSI (p=0.020) and in patients with both LVSI and grade 3 endometrioid histologic type (p=0.007). We found no difference in locoregional and distant recurrence between patients undergoing adjuvant treatment or observation.

CONCLUSION

In this study, the addition of adjuvant treatment was associated with an OS benefit for patients with LVSI, especially those with grade 3 endometrioid tumors.

Practice patterns, time trends and quality of care of uterine cancer in Belgium: An analysis of the EFFECT database

OBJECTIVES

To investigate the practice patterns and quality of care for uterine cancer on a national level in Belgium, including trends in practice over the period 2012-2016.

METHODS

Quality indicators were measured using the EFFectiveness of Endometrial Cancer Treatment (EFFECT) database. Multivariable logistic mixed regression was used to test for associations between the quality indicators and year of diagnosis, adjusted for potential confounders and intra-cluster correlations.

RESULTS

The EFFECT database includes 4178 patients diagnosed with uterine cancer in the period 2012-2016. Minimally invasive surgery (laparoscopic or robotic-assisted) was applied in 61.6% of patients who had surgery for clinical stage I endometrial carcinoma (EC), increasing from 52.9% in 2012 to 66.4% in 2016. At least pelvic lymph node staging was performed in 69.0% of patients with clinical stage I, high-grade EC; and in 63.9% of patients with clinical stage I-II serous carcinoma, clear cell carcinoma or carcinosarcoma. The latter increased from 48.8% in 2012 to 77.2% in 2016. Adjuvant radiotherapy (external beam and/or brachytherapy) was offered to 33.5% of patients who had surgery without lymph node staging for pathological stage I EC at high-intermediate or high risk of recurrence. Adjuvant chemotherapy was administered to 64.4% of patients with pathological stage III-IVA EC.

CONCLUSIONS

Study results indicate an overall good quality of care for patients with uterine cancer in Belgium. Treatment areas with potential room for improvement include the use of minimally invasive surgery, comprehensive surgical staging and adjuvant therapy, which confirms the remaining controversies in uterine cancer treatment and the need for further research.

Role of adjuvant chemotherapy in patients with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma treated with surgery and post-operative radiotherapy

BACKGROUND

The optimal treatment of patients with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma remains unknown.

OBJECTIVE

To compare overall survival following treatment with a hysterectomy and adjuvant radiotherapy with or without chemotherapy in this group of patients.

METHODS

Patients diagnosed between January 2004 and January 2016 with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma treated with hysterectomy and postoperative radiotherapy with or without adjuvant concurrent chemotherapy were identified in the National Cancer Database. Overall survival was assessed with Kaplan-Meier curves. A Cox model was constructed to evaluate survival after controlling for confounding variables. A logistic regression model was used to reveal predictors of chemotherapy use.

RESULTS

A total of 2173 patients were included. The receipt of chemotherapy was associated with an increased 5-year overall survival from 67.6% to 75.6% (p=0.0313). This association trended toward statistical significance on multivariate analysis (adjusted HR (aHR) 0.80; 95% CI 0.63 to 1.01; p=0.0653). Other factors associated with improved survival were undergoing a lymphadenectomy, absence of lymphovascular space invasion, younger age, smaller tumor size, non-black race, and absence of comorbidities. Patients who underwent brachytherapy, had lymphovascular space invasion, were younger, were diagnosed in the more recent years, and were treated in higher volume centers were more likely to receive adjuvant chemotherapy.

CONCLUSION

Adjuvant chemotherapy and radiation therapy were associated with an increase in survival in patients with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma compared with those treated with adjuvant radiotherapy alone.

Outcomes of intermediate-risk to high-risk stage I endometrial cancer: 10-year clinical experiences of using in-house multi-channel applicators in a single center

BACKGROUND

There are only very few reports on clinical outcomes using multi-channel applicators (MCA) for patients with endometrial cancer (EC) in China. We aimed to evaluate the clinical experience of treating intermediate-risk (IR) to high-risk (HR) stage I EC using in-house made multi-channel applicators (IH-MCA) in a single institution.

METHODS

Three hundred and ninety patients with stage I IR to HR EC were treated with hysterectomy and adjuvant radiotherapy from 2003 to 2015. All patients received post-operative vaginal cuff brachytherapy (VBT) alone or as a boost after external beam radiotherapy (EBRT). The prescriptions were 500 cGy per fraction for a total of 5 to 6 fractions with brachytherapy alone or 400 to 600 cGy per fraction for 2 to 3 fractions if it was combined with EBRT. Two types of applicators including a traditional rigid IH-MCA and a recent model custom-made with 3 dimension printing technology were used for treatment. The Kaplan-Meier method was used to calculate survival rate.

RESULTS

Follow-up rate was 92.8% and the median follow-up time was 48 months (range 4-172 months). The 5-year overall survival (OS), progression-free survival, local recurrence, and distant metastasis rates for all patients were 96.3%, 92.1%, 2.9%, and 4.8% respectively. Two patients had isolated relapse in vagina outside the irradiated volume. The univariate and multivariate analysis showed that age and grade were the prognostic factors correlated with OS (hazard ratio: 0.368, 95% confidence interval [CI]: 0.131-1.035, P = 0.048; hazard ratio: 0.576, 95% CI: 0.347-0.958, P = 0.026,).

CONCLUSIONS

For patients with IR to HR stage I EC, adjuvant VBT alone or in combination with EBRT using IH-MCA led to excellent survival and recurrence rates. Age and grade were the prognostic factors correlated with OS.

Outcomes and relapse patterns of stage IB grade 2 or 3 endometrial cancer treated with adjuvant vaginal brachytherapy

Introduction

Risk factors for pelvic recurrence in early stage endometrial cancer are poorly understood. We sought to describe outcomes, patterns of failure, and risk factors for recurrence among patients with grade 2–3 endometrial cancer with deep myometrial invasion who were treated with vaginal brachytherapy as sole adjuvant therapy after hysterectomy and lymph node dissection.

Methods

We retrospectively reviewed the records of stage I patients with grade 2–3 endometrioid histology and ≥50% myometrial invasion treated at an academic institution from January 2005 to December 2017. Only patients with endometrioid histology were included. Mixed histologies, including papillary serous or clear cell components, were excluded. Further exclusion criteria were International Federation of Gynecology and Obstetrics stage IB grade 1 patients, follow-up time less than 3 months, receipt of pelvic irradiation or any form of systemic therapy (chemotherapy, aromatase inhibitor). Overall survival, disease-free survival, and pelvic recurrence-free survival were calculated with Kaplan–Meier methods. Multivariable Cox proportional hazards regression was used to analyze factors associated with overall survival and disease-free survival.

Results

Among 131 consecutive patients identified, 111 (85%) patients met the inclusion criteria. The majority (98.2%) underwent lymph node dissection with ≥10 lymph nodes removed in 78.9%. With a median follow-up of 36 months (IQR 12–70 months), the 3-year overall survival, disease-free survival, and pelvic recurrence-free survival were 89.6%, 90.1%, and 92.8%, respectively. Histologic grade 3, older age, and lymphovascular invasion were not associated with inferior outcomes; however, lower uterine segment involvement (p=0.031), tumor size >4 cm (p=0.024), and <10 lymph nodes removed (p=0.032) were associated with reduced disease-free survival on multivariable analysis. Pelvic recurrence occurred in 12 (11%) patients, most often in the setting of synchronous distant disease (n=9), and was significantly more likely with lower uterine segment involvement.

Conclusion

Among patients with stage IB grade 2–3 endometrial cancer treated with vaginal brachytherapy, the risk factors for recurrence (larger tumor size and lower uterine segment involvement) in conjunction with established risk factors (high grade, ≥50% myometrial invasion, and lymphovascular invasion) may identify a group of high-risk patients who might benefit from pelvic radiotherapy.

High-grade uterine corpus-confined endometrial cancer with lymphadenectomy: does adjuvant therapy improve survival?

Objective:

To evaluate the necessity of adjuvant therapy and other prognostic factors in high-grade uterine corpus-confined endometrial cancer (EC) with lymphadenectomy performed.

Materials and Methods:

This study included 120 patients who had endometrioid-type grade 3, serous-type, clear cell-type, and undifferentiated-type EC and underwent lymphadenectomy.

Results:

Patients with high-grade uterine corpus-confined EC who underwent lymphadenectomy were evaluated. The modality of adjuvant therapy performed was not a predictor for the site of recurrence. The loco-regional recurrence rate decreased from 9.5% to 3.8% in patients who received radiotherapy. However, this difference was not statistically significant (p=0.206). In addition, performing adjuvant chemotherapy did not alter the risk of extrapelvic recurrence. Only International Federation of Gynecology and Obstetrics 2009 stage was significant in the univariate analysis. On the other hand, age, tumor type, number of removed lymph nodes, presence of myometrial and lymphovascular space invasion, tumor size and adjuvant therapy modality were not related with disease-free survival.

Conclusion:

Performing adjuvant therapy and therapy modality does not improve oncologic outcomes in intermediate and high-risk patients. However, radiotherapy reduced the risk of local recurrence by more than 50%. Vaginal brachytherapy was efficient as external beam radiotherapy. Therefore, vaginal brachytherapy should be used for these patients in order to reduce loco-regional recurrence even if it is not reported to be effective on disease-free survival.

A proposal for a new classification of "unfavorable risk criteria" in patients with stage I endometrial cancer

BACKGROUND

Randomized trials describe differing sets of high-intermediate risk criteria.

OBJECTIVE

To use the National Cancer Database to compare the impact of radiation therapy in patients with stage I endometrial cancer meeting different criteria, and define a classification of "unfavorable risk."

METHODS

Patients with stage I endometrial cancer between January 2010 and December 2014 were identified in the National Cancer Database and stratified into two cohorts: (1) patients meeting Gynecologic Oncology Group (GOG)-99 criteria only for high-intermediate risk, but not Post-Operative Radiation Therapy in Endometrial Carcinoma (PORTEC)-1 criteria and (2) those meeting PORTEC-1 criteria only. High-risk stage I patients with both FIGO stage IB (under FIGO 2009 staging) and grade 3 disease were excluded. In each cohort, propensity score-matched survival analyses were performed. Based on these analyses, we propose a new classification of unfavorable risk. We then analyzed the association of adjuvant radiation with survival, stratified by this classification.

RESULTS

We identified 117,272 patients with stage I endometrial cancer. Of these, 11,207 patients met GOG-99 criteria only and 5,920 patients met PORTEC-1 criteria only. After propensity score matching, adjuvant radiation therapy improved survival (HR=0.73; 95% CI 0.60 to 0.89; p=0.002) in the GOG-99 only cohort. However, there was no benefit of adjuvant radiation (HR=0.89; 95% CI 0.69 to 1.14; p=0.355) in the PORTEC-1 only cohort. We, therefore, defined unfavorable risk stage I endometrial cancer as two or more of the following risk factors: lymphovascular invasion, age ≥70, grade 2-3 disease, and FIGO stage IB. Adjuvant radiation improved survival in stage I patients with adverse risk factors (HR=0.74; 95% CI 0.68 to 0.80; p<0.001), but not in other stage I patients (HR=1.02; 95% CI 0.91 to 1.15; p=0.710; p interaction <0.001).

CONCLUSION

Our study showed that adjuvant radiation was associated with an overall survival benefit in patients meeting GOG-99 criteria only; however, no survival benefit was seen in patients meeting PORTEC-1 criteria only. We propose a definition of unfavorable risk stage I endometrial cancer: ≥2 risk factors from among lymphovascular invasion, age ≥70, grade 2-3 disease, and FIGO stage IB disease.

Immortal Time Bias in National Cancer Database Studies

PURPOSE

In studies evaluating the benefit of adjuvant therapies, immortal time bias (ITB) can affect the results by incorrectly reporting a survival advantage. It does so by including all deceased patients who may have been planned to receive adjuvant therapy within the observation cohort. Given the increase in National Cancer Database (NCDB) analyses evaluating postoperative radiation therapy (PORT) as an adjuvant therapy, we sought to examine how often such studies accounted and adjusted for ITB.

METHODS AND MATERIALS

A systematic review was undertaken to search MEDLINE and EMBASE from January 2014 until May 2019 for NCDB studies evaluating PORT. After appropriate exclusion criteria were applied, 60 peer-reviewed manuscripts in which PORT was compared with postoperative observation or maintenance therapy were reviewed. The manuscripts were reviewed to evaluate whether ITB was accounted for, the method with which it was adjusted for, impact factor, year of publication, and whether PORT was beneficial.

RESULTS

Of the 60 publications reviewed, 23 studies (38.3%) did not include an adjustment for ITB. Most studies that did adjust for ITB employed a single landmark (LM) time (n = 31), 4 used a sequential landmark analyses, and 2 used a time-dependent Cox model. In 23 of 31 studies (74.2%) that did adjust for ITB via a single LM time, the rationale behind why the specified LM time was chosen was not clearly explained. There was no relationship between adjusting for ITB and year of publication (P = .074) or whether the study was published in a high-impact journal (P = .55).

CONCLUSIONS

Studies assessing adjuvant radiation therapy by analyzing the NCDB are susceptible to ITB, which overestimates the effect size of adjuvant therapies and can provide misleading results. Adjusting for this bias is essential for accurate data representation and to better quantify the impact of adjuvant therapies such as PORT.

Impact of different adjuvant radiotherapy modalities on women with early-stage intermediate- to high-risk endometrial cancer

OBJECTIVE

Vaginal brachytherapy was recommended for patients with intermediate-risk endometrial cancer, however, optimal radiotherapy modalities for intermediate-high- or high-risk patients remains controversial. Previous studies have mainly focused on survival outcomes and have seldom taken cost issues into consideration, especially for high-risk patients. The purpose of this study is to compare the survival outcomes and costs associated with two adjuvant radiotherapy modalities in the management of patients with early-stage, intermediate- to high-risk endometrial cancer.

METHODS

According to ESMO-ESCO-ESTRO criteria, 238 patients with stage I/II, intermediate- to high-risk endometrial cancer who underwent radiotherapy from January 2003 to December 2015 at our institution were reviewed. The vaginal brachytherapy group and external beam radiation therapy combined with the vaginal brachytherapy group were propensity score-matched at a 1:1 ratio. The Kaplan-Meier method and Cox proportional hazards regression model were used.

RESULTS

A total of 361 patients met our inclusion criteria, the median age of the patients was 58 years (range, 28-85). All were diagnosed with stage I-II endometrial cancer (324 with stage I and 37 with stage II; 350 with endometrioid adenocarcinoma; and 10 with mucinous carcinoma). The median follow-up time was 60.5 months (range, 3-177). Among 119 matched pairs, no significant differences were found in overall (10.9% vs 8.4%, P=0.51), locoregional (4.2% vs 1.7%, P=0.45), or distant recurrence rates (6.7% vs 6.7%, P=1.0) between the two groups. There were also no differences in the 5-year overall (94.8% vs 93.9%, P=0.78) or progression-free survival (90.0% vs 84.4%, P=0.23) between the two groups. The rates of acute and late toxicity were significantly higher in the external beam radiation therapy combined with vaginal brachytherapy vs the vaginal brachytherapy group (all P<0.05), except for the acute hematological toxicity rate (17.6% vs 9.2%, P=0.06). External beam radiation therapy combined with vaginal brachytherapy had a higher median cost ($2759 vs $937, P<0.001) and longer median radiotherapy duration (41 days vs 17 days, P<0.001) than vaginal brachytherapy.

CONCLUSION

Vaginal brachytherapy was associated with similar local control and long-term survival outcomes relative to the combination of external beam radiotherapy and vaginal brachytherapy and it also minimizes radiation-related complications, reduces medical costs, and shortens radiotherapy duration. Vaginal brachytherapy may be the optimal radiation modality for patients with early-stage endometrial cancer at intermediate to high risk.

Factors Predictive of Receiving Adjuvant Radiotherapy in High-Intermediate-Risk Stage I Endometrial Cancer

OBJECTIVES

Randomized trials have shown a local control benefit with adjuvant radiotherapy (RT) in high-intermediate-risk endometrial cancer patients, although not all such patients receive RT. We reviewed the National Cancer Data Base to investigate which patient/tumor-related factors are associated with delivery of adjuvant RT.

METHODS

The National Cancer Data Base was queried for patients diagnosed with International Federation of Gynecology and Obstetrics 2009 stage I endometrioid adenocarcinoma from 1998 to 2012 who underwent surgery +/- adjuvant RT. Exclusion criteria were unknown stage/grade, nonsurgical primary therapy, less than 30 days' follow-up, RT of more than 6 months after surgery, or palliative treatment. High-intermediate risk was defined based on Post Operative Radiation Therapy in Endometrial Carcinoma 2 criteria: older than 60 years with stage IA grade 3 or stage IB grade 1-2.

RESULTS

Seventeen thousand five hundred twenty-four met inclusion criteria, and the 13,651 patients with complete data were subjected to a multiple logistic regression analysis; 7814 (57.2%) received surgery alone, and 5837 (42.8%) received surgery + RT. Receipt of adjuvant RT was more likely among black women and women with higher income, Northeastern residence, diagnosis after 2010, greater than 50% myometrial invasion, and receipt of adjuvant chemotherapy (P < 0.05). Patients older than 80 years or those undergoing lymph node dissection were less likely to receive adjuvant RT (P < 0.05). Of those treated with RT, 44.0% received external beam therapy, 54.8% received vaginal cuff brachytherapy, and 0.6% received both. Among irradiated women, patients older than 80 years and those with Northeastern residence, treatment at academic facilities, diagnosis after 2004, and lymph node dissection were more likely to undergo brachytherapy over external beam radiation therapy (P < 0.05). Overall use of adjuvant RT was 28.8% between 1998 and 2004, 42.0% between 2005 and 2010, and 43.4% between 2011 and 2012; the difference between 1998-2004 and 2005-2010 was not statistically significant.

CONCLUSIONS

Fewer than half of patients with high-intermediate-risk endometrial cancer by Post Operative Radiation Therapy in Endometrial Carcinoma 2 criteria received adjuvant RT despite evidence demonstrating improved local control. Both patient- and tumor-related factors are associated with delivery of adjuvant RT and the modality selected.

Cost-effectiveness of adjuvant intravaginal brachytherapy in high-intermediate risk endometrial carcinoma

PURPOSE

We assessed the cost-effectiveness of adjuvant intravaginal brachytherapy (IVBT) vs. observation after total hysterectomy and bilateral salpingo-oophorectomy (TH/BSO) for high-intermediate risk (HIR) endometrial carcinoma.

METHODS AND MATERIALS

A Markov model was used to assess the cost-effectiveness of IVBT by comparing average cumulative costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) between patients allocated to (1) 'observation' or (2) 'IVBT' after TH/BSO. We used a prototype Post-Operative Radiation Therapy in Endometrial Carcinoma (PORTEC)-defined HIR patient in the base case analysis. We calibrated the model to match the outcomes reported in the PORTEC-1 and PORTEC-2 trials. Utilities were obtained from published estimates, and costs were calculated based on Medicare reimbursement ($5445 for IVBT). The societal willingness-to-pay threshold was set at $100,000 per QALY. The time horizon was 5 years.

RESULTS

IVBT was associated with a net increase of 0.094 QALYs (4.512 vs. 4.418) as well as an increase in mean cost ($17,453 vs. $15,620) relative to observation. The ICER for IVBT was $19,500 per QALY. On one-way sensitivity analysis, IVBT remained cost-effective when its cost was less than $12,937. If the probability of vaginal recurrence in the observation arm was increased or decreased by 25%, the ICER became $1335 per QALY and $87,925 per QALY, respectively. Probabilistic sensitivity analysis revealed that IVBT was the preferred management option in 86% of simulations.

CONCLUSIONS

IVBT is cost-effective compared with observation after TH/BSO for HIR endometrial carcinoma by commonly accepted willingness-to-pay thresholds.