Multiple Computed Tomography Robust Optimization to Account for Random Anatomic Density Variations During Intensity Modulated Proton Therapy

Purpose

To propose a method of optimizing intensity modulated proton therapy (IMPT) plans robust against dosimetric degradation caused by random anatomic variations during treatment.

Methods and Materials

Fifteen patients with prostate cancer treated with IMPT to the pelvic targets were nonrandomly selected. On the repeated quality assurance computed tomography (QACTs) for some patients, bowel density changes were observed and caused dose degradation because the treated plans were not robustly optimized (non-RO). To mitigate this effect, we developed a robust planning method based on 3 CT images, including the native planning CT and its 2 copies, with the bowel structures being assigned to air and tissue, respectively. The RO settings included 5 mm setup uncertainty and 3.5% range uncertainty on 3 CTs. This method is called pseudomultiple-CT RO (pMCT-RO). Plans were also generated using RO on the native CT only, with the same setup and range uncertainties. This method is referred to as single-CT RO (SCT-RO). Doses on the QACTs and the nominal planning CT were compared for the 3 planning methods.

Results

All 3 plan methods provided sufficient clinical target volumes D95% and V95% on the QACTs. For pMCT-RO plans, the normal tissue D_max on QACTs of all patients was at maximum 109.1%, compared with 144.4% and 116.9% for non-RO and SCT-RO plans, respectively. On the nominal plans, the rectum and bladder doses were similar among all 3 plans; however, the volume of normal tissue (excluding the rectum and bladder) receiving the prescription dose or higher is substantially reduced in either pMCT-RO plans or SCT-RO plans, compared with the non-RO plans.

Conclusions

We developed a robust optimization method to further mitigate undesired dose heterogeneity caused by random anatomic changes in pelvic IMPT treatment. This method does not require additional patient CT scans. The pMCT-RO planning method has been implemented clinically since 2017 in our center.

Perceptions and Patterns in Academic Publishing: A Survey of United States Residents in Radiation Oncology

Purpose

We aimed to assess perceptions of, and training regarding, the publishing process among US radiation oncology (RO) residents, focusing on awareness and understanding of criteria for selecting appropriate and legitimate peer-reviewed journals for academic publishing. The growing challenge of predatory publication in the broader scientific realm and its relevancy to resident training is also briefly discussed.

Methods and Materials

A survey was opened to residents of all Accreditation Council for Graduate Medical Education–accredited RO programs in the United States, focusing on 3 categories: (1) demographics; (2) submission, peer review, and publication of academic research; and (3) subjective ranking of factors for choosing an appropriate publisher/journal. Results were stratified by level of training and number of publications.

Results

Overall, 150 of 690 residents (19.8%) responded, with a 98% (147 of 150) completion rate. Twenty of 150 residents (13.3%) reported formal training in manuscript preparation and choosing academic journals. Only 3.4% of residents reported departmental guidelines regarding publication in “predatory” journals; 57.7% were unsure. The 3 most important factors influencing publisher and journal choice were impact factor (ranked first for 59.0%), whether a journal is found in a major index (ranked first for 18.0%), and association with a reputable organization (ranked first for 17.0%). Importance of impact factor increased with number of publications (50% with 0 publications, 48.3% with 1-5, 63.9% with 5-10, 76.2% with 10-15, and 70.6% with >15). Cost considerations influenced journal choice at least once for 79 (52.7%) residents.

Conclusions

Impact factor was the most important consideration for residents when choosing an appropriate publisher, with increased emphasis with increasing number of publications. A minority had formal training in choosing appropriate academic journals and knowing how to identify so-called predatory journals or were aware if their department has proscriptions regarding publication in such journals. Additional emphasis on formal training for RO residents in manuscript preparation and choosing academic journals is warranted.

Short Course Adjuvant Vaginal Cuff Brachytherapy (VCB) in Early Endometrial Cancer: Primary Endpoint Results of the SAVE Randomized Clinical Trial

PURPOSE/OBJECTIVE(S)

Prospective trials in early stage endometrial cancer demonstrate increased locoregional control with adjuvant radiotherapy for patients with high risk features. VCB is widely utilized, yet there is substantial practice variation and limited randomized data examining optimal dose/fractionation. We aimed to study the safety and efficacy of short course VCB compared to commonly used regimens.

MATERIALS/METHODS

We conducted a prospective, randomized, multicenter trial examining short course adjuvant VCB (11 Gy x 2 fractions at the surface) compared with other standard regimens (7 Gy x 3 fractions at 0.5 cm depth, 6 Gy x 5 fractions at the surface, or 5-5.5 Gy x 4 fractions at 0.5 cm depth). Eligible patients underwent hysterectomy and had pathologically confirmed endometrioid adenocarcinoma, serous, clear cell, or carcinosarcoma. Patients with stage I and II cancers were included, with lymphovascular invasion (LVI) required for stage IAG1. The primary outcome was Global Health Status measured by the EORTC QLQ-C30 with a pre-specified non-inferiority margin of 15 points. Secondary outcomes included patient-reported outcomes, toxicities as assessed by CTCAEv5, and patterns of recurrence. Data were collected at each brachytherapy fraction and at 1-, 6-, and 12-month follow-up.

RESULTS

One hundred eight patients were enrolled, 54 in each study arm. Data completion was 94%, 91%, and 77% at 1 month, 6 months, and 12 months, respectively. 70% of patients had endometrioid adenocarcinoma, 18% serous carcinoma, and 12% other histologies. 23% were FIGO grade 1, 33% grade 2, and 43% grade 3 or high risk histologies. The majority of patients were stage I (56% IA, 38% IB). 22% of patients had LVI. The QLQ-C30 Global Health Status for the experimental arm was within the predefined boundary and thus 2 fractions were non-inferior to standard of care at one month (p = 0.000005) and 12 months (p = 0.0005). Using EORTC EN24 for patient reported vaginal/sexual, urologic, and gastrointestinal symptoms, the change in mean patient reported symptom score from baseline to 1 month and baseline to 12 months were not significantly different between arms. Using CTCAEv5, 51 patients experienced short-term AEs related to study treatment, 20 in the experimental arm and 31 in the control arm (p = 0.053). All study treatment-related AEs were grade 1-2, except for two grade 3-4 AEs, both on the control arm. At median follow-up of 19 months, the isolated vaginal control rate in each arm was 100%. There was no significant difference in the total number of recurrences between study arms, with 3 distant and 3 distant/pelvic/vaginal recurrences in the experimental arm, and 2 distant, 2 pelvic, and 1 pelvic/vaginal recurrence in the control arm.

CONCLUSION

Short course VCB is safe with acceptable acute toxicity and non-inferior patient reported outcomes. Short course VCB improves patient convenience and may improve access to care for rural or underserved populations while providing similar local control.

Association between Radiation Dose and Local Failure in Recurrent High-Risk Neuroblastoma

PURPOSE/OBJECTIVE(S)

Historically, standard-of-care (SoC) for high-risk neuroblastoma recurrences is irradiation to 2160 cGy for gross or microscopic disease. Boosting gross disease to 3000-3600 cGy remains controversial. Prior reports have demonstrated worse local control with gross disease irradiated to <3000 cGy. We sought to evaluate whether higher radiation doses delivered to sites of recurrence affected local control.

MATERIALS/METHODS

We identified seventy-five high-risk neuroblastoma patients aged 6 months to 26 years that completed definitive treatment between 2007 and 2021 at two large academic centers. Only patients with distant recurrences treated with radiotherapy were included for analysis. Treatments were stratified into 1800-2160 cGy or 3000-3600 cGy dose levels. Local failure after irradiation was defined as progression within the radiation field after salvage RT. The Fine-Gray competing risk model was used to identify cumulative incidence of local failure (CILF) after irradiation with competing risk of death.

RESULTS

Thirteen patients experienced recurrence after completion of definitive treatment, representing 30 metastatic lesions. Thirteen lesions received 1800-2160 cGy and seventeen received 3000-3600 cGy. With a median follow-up of 42.0 months (IQR 30.8-60.8), local failure after irradiation occurred in 10% (3/30) of metastatic lesions. Median time to failure was 7 months. All three failures had been treated to 2160 cGy; two in the calvarium and one in the femur. There were no local failures among patients treated to 3000-3600 cGy. The 1-year and 2-year CILF for the low- versus high-dose levels were 15% versus 0% (p<0.01) and 25% versus 0% (p<0.01), respectively. Four of the 13 patients (31%) died at a median time of 12.5 months after first recurrence; all four had distant recurrences.

CONCLUSION

Dose-escalated irradiation ≥3000 cGy was associated with improved local control in recurrent high-risk neuroblastoma; prospective study and validation is warranted.

Use of Radiation Therapy in the Management of Vulvar Cancers-Identification and Management of Acute and Late Toxicities

Radiation therapy plays a critical role in the management of locally advanced vulvar cancers but can lead to a unique spectrum of side effects, with >25% of patients experiencing high-grade toxicities. The treatment phase requires meticulous perineal skincare and may require pharmacologic management of dysuria and cystitis, diarrhea, nausea, and dermatitis/mucositis. The addition of chemotherapy warrants close laboratory monitoring for hematologic and metabolic derangements.

Is Robust Optimization Essential When Planning Pencil Beam Scanned Proton Therapy for Intracranial Lesions?

PURPOSE/OBJECTIVE(S)

Creating intensity modulated proton therapy (IMPT) plans usually involves a robust optimization step to account for uncertainties in proton range and positioning instead of using the PTV margins typically seen in photon IMRT planning. Because robust optimization adds significant planning time per iteration, and proton planning typically involves many iterations to obtain an optimal plan, this project evaluates whether a PTV approach can be used to more efficiently create plans for intracranial lesions by comparing plan quality from both approaches to determine if they produce equivalent plans.

MATERIALS/METHODS

Five patients with intracranial lesions treated with IMPT at our center were randomly chosen for this study. 3-4 beams were used to treat CTVs ranging between 46 and 246 cc. Patients were treated on a Mevion S250i single-vault proton machine with Hyperscan. Static blocks (7mm conformed to the CTV) were used for all cases and plans were created in a treatment planning system using robustness criteria of 3mm (position uncertainty) and 3.5% (range uncertainty). For each patient, the CTV was uniformly grown by 3 mm to create a PTV. The optimization criteria used in the clinical plan were used as baseline to create two plans - one using robust optimization for CTV coverage and one without robust optimization for PTV coverage. A script was used to time two otherwise identical optimization runs. All plans were normalized so that the prescription was delivered to 95% of the CTV. The plan was robustly evaluated under conditions of 3.5% range uncertainty and 2mm positional uncertainty. For each nominal plan, the CTV dose heterogeneity and conformity as well as the following dose metrics were collected: CTV D99% and D98%, Normal Brain V100%, V90%, V80%, V50% as well as overall plan Dmax (to 0.03cc). For each plan, the minimum CTV D99 and maximum Brain Dmax were also collected for the robust evaluation scenarios. All collected metrics were compared between the robust CTV-based and non-robust PTV-based plans using paired t-tests with 5% significance.

RESULTS

For the five cases investigated here, all dosimetric metrics investigated were not significantly different between the CTV-based and PTV-based plans except for the plan maximum dose (CTV-based: 104.6% Rx - 110.0% Rx, PTV-based: 105.6% Rx-110.6% Rx, p = 0.029). The optimization times were also significantly different, averaging 1532 s for CTV-based plans versus 252 s for the PTV-based plans (p = 0.004).

CONCLUSION

For the plans investigated here, non-robust PTV planning approach creates plans of very similar quality to a robust CTV-based plan, while having significantly shorter planning times.

Abstract PS15-12: Initial outcomes of adjuvant proton pencil beam scanning radiation for patients with breast cancer requiring comprehensive nodal irradiation within a single institution

Background:Following lumpectomy or mastectomy, locally advanced breast cancer (LABC)requires adjuvant radiation (RT) to the chest wall (CW) and comprehensiveregional nodal basins (CNI). Proton therapy (PBT) has demonstrated dosimetricadvantages in heart, lung, and esophageal exposures compared to photon RT, butlittle is published regarding oncologic outcomes of PBT for LABC. Methods:Consecutive patients treated from 2016-2019 wereretrospectively reviewed. Men and women over the age of 18 requiring adjuvantRT with CNI were included; all patients had at least 6 months of follow up fromRT completion. Initial treatment volumes, excluding boosts to scars or grossdisease, (CTV_init) included CW-CNI per the RADCOMP atlas. CTV_init coveragewas prescribed as 95% CTV_init at 100% Rx dose. All patients were treated with proton pencil-beam scanning RT (PBS-PBT),typically with a two-field anterior SFO technique. Patient, tumor, and dosimetric characteristics wereanalyzed. Tumoral control and survival rates were estimated by the Kaplan Meiermethod. Toxicities were recorded prospectively by treating physicians andreviewed retrospectively. Local recurrence was defined as in-breast, or skin/chestwall; regional recurrence was defined as a nodal failure. Results:One hundred patients were included with a median follow upof 15.4 months (6-42). Ninety-eight percent were female, and 61% were white.Median age was 52 years, and 94% of patients had an ECOG PS ≤1.AJCC 8th edition anatomic staging was predominantly stage II (49%)or III (48%).Sixty-five percent of patients were treated for left-sideddisease; 7% of patient received bilateral RT; 87% received cytotoxicchemotherapy (63% neoadjuvant, 37% adjuvant). Twenty six patients receivedconcurrent systemic therapy with trastuzumab (H)/pertuzumab (P)(38% ),capecitabine (29%), H-emtansine (21%), or H (12%). The median initial RT dosewas 50.4 (45-50.4) while median total RT dose was 50.4Gy (45-70.2). Forty-twopercent of patient underwent an RT boost to nodal areas and/or the scar. Allpatients were treated in 1.8 or 2.0Gy fractions. Eighty-seven percent oflesions were invasive ductal carcinomas; 52% were ER+/Her2-, 17% weretriple-negative (TNBC), and 31% were Her2+.Nine (9%) of patients experienced a ≥G3 acute toxicity, all in theform of radiation dermatitis. There was one acute G4 incidence of skinnecrosis. There were no ≥G3 late toxicities or documented major cardiac events atthe time of last follow up. Median doses to critical organs at risk (OARs) were asfollows: mean heart 0.9Gy (&lt;0.1 - 3.9), V25 heart 0.9% (0 - 6.6) ipsilaterallung V20 15% (4.6 - 29.2) ipsilateral lung V5 41.1% (17.5 - 62.2), volume ofthe esophagus receiving 70% Rx dose 0.1cc (0 - 5.3). For bilateral plans, themedian total lung V20 was 15.6% (6.6 - 23.5) and V5 was 41.5% (18.5 - 45.0). Overall, there were 3 local, 3 regional, and 8 distantfailures. All local failures were TNBC; regional and distant failures wereequally distributed between histologies. All distant failures occurred in patientswith at least AJCC 8th Edition anatomic stage IIIA. Actuarial ratesof 2-year local, regional, locoregional, and distant failures were 4% (±3),2% (±2),6% (±3%),and 11% (±4).Two-year actuarial survival was 94% (±3).Conclusions:We present a large series of patients with high-risk or LABCtreated with adjuvant PBS-PBT and CNI. Our series includes significant percentagesof TNBC, non-white patients, and patients requiring dose-escalated RT boosts overalldemonstrating promising initial oncologic outcomes and very favorable acutetoxicity and dosimetric profiles. Continued follow up is warranted to confirmlong-term oncologic outcomes.

Citation Format: Cristina DeCesaris, Ariel Pollock, Emily Kowalski, Kayla Paulosky, Sung Choi, Mark Mishra, Elizabeth Nichols. Initial outcomes of adjuvant proton pencil beam scanning radiation for patients with breast cancer requiring comprehensive nodal irradiation within a single institution [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS15-12.

Patterns of Care in Adjuvant Radiation Therapy for Stage II Endometrioid Endometrial Adenocarcinoma: A National Cancer Database Analysis

Purpose

Treating stage II endometrial cancer involves total hysterectomy, bilateral salpingo-oophorectomy, and risk-adapted adjuvant therapy. Professional guidelines support various adjuvant treatments, but high-level data supporting specific options are conflicting. We sought to evaluate adjuvant radiation therapy (RT) trends for these patients, hypothesizing increased utilization of pelvic external beam RT (EBRT) over time.

Methods and Materials

Patients diagnosed in 2004-2019 with stage II endometrioid endometrial cancer who underwent total hysterectomy, bilateral salpingo-oophorectomy, and surgical staging were identified in the National Cancer Database. Patient characteristics per adjuvant RT received were compared using Wilcoxon rank sum and analysis of variance testing. Multivariable regression analysis (MVA) identified variables associated with EBRT, vaginal brachytherapy (VBT), or RT omission. A P value < .05 was significant, except in MVA, where Bonferroni correction was employed (p value < .017).

Results

Patients meeting criteria totaled 18,798; 19% received adjuvant EBRT alone, 25% VBT alone, 24% EBRT + VBT, and 32% no RT. Adjuvant RT use increased from 2004 to 2019, particularly EBRT + VBT (p < .05). In MVA, community hospital treatment (odds ratio [OR], 1.8; p < .001), Midwest location (OR, 1.2; p = .02), single-agent chemotherapy receipt (OR, 6.9; p < .001), lymphovascular space invasion (OR, 1.4; p < .001), and positive surgical margins (OR, 1.8; p < .001) were positively associated with EBRT. No variables were positively associated with VBT. Black race (OR, 1.2; p = .03), community hospital treatment (OR, 1.4; p = .04), South (OR, 2.2; p < .001) or West (OR, 2.1; p < .001) location, distance >50 miles from the treatment center (OR, 1.5; p < .001), and grade 2 (OR, 1.2; p < .001) or 3 (OR, 1.3; p = .01) disease were associated with RT omission.

Conclusions

Adjuvant RT for stage II endometrial cancer increased over time, particularly EBRT + VBT. Patient-related factors such as race, region, and distance from the treatment center were associated with RT omission, suggesting sociodemographic barriers to care. Tumor-related factors such as positive surgical margins and lymphovascular space invasion were associated with EBRT receipt, suggesting consideration of high-risk factors for locoregional recurrence in adjuvant RT approaches.

Vulvar Cancer: Histopathologic Considerations and Nuances to Management

Vulvar cancer, although rare, poses significant challenges in diagnosis and treatment because of its histopathologic complexities and nuances. This paper reviewed key aspects of the management of vulvar cancer, focusing on histopathologic diagnosis, margin status interpretation, lymph node involvement assessment, and ongoing clinical trials.

Off study utilization of an unpublished trial regimen: A real-world analysis of GOG258-eligible cohorts

e18763

Background: Practice patterns in the management of advanced endometrial cancer are widely variable and treatment paradigms are rapidly changing given the evolving clinical trial landscape. Prior studies have demonstrated “medical reversals” where clinicians favor or utilize the experimental approach only to find inferiority on publication of results. The objective of this study was to examine the utilization of the GOG 258 arms-- (adjuvant chemotherapy (CT) vs chemoradiotherapy (CRT)-- for patients with advanced or high-risk endometrial cancer. Methods: Patients 18 years or older who underwent staging surgery with stage III/IVA endometrial carcinoma of any histology or stage I/II clear cell or serous histologies with positive washings diagnosed between 2004 and 2018 were identified in the National Cancer Database. Utilization of adjuvant CT and CRT were examined in the pre-GOG 258 era (before 2009), during GOG 258 enrollment (2010-2017), and after publication of results (2018). Two-sided Cochrane-Armitage test assessed trends over time. T-test and chi-square tests assessed differences in groups receiving CT alone vs CRT. Multivariable logistic regression assessed factors associated with receipt of CRT. Propensity score matching accounted for baseline differences in groups receiving CT vs CRT. Results: 40,028 patients were included. 16,342 (41%) received adjuvant CT and 23,686 (59%) received adjuvant CRT. The majority of patients (39,185, 98%) were advanced stage and 19,616 (49%) were endometrioid histology. 90% of patients receiving both CT and CRT received multiagent therapy. Utilization of CRT was 54% before GOG 258 opening, 60% during GOG 258 enrollment, and 67% after publication of results (p < 0.001). Factors associated with receipt of CT alone were age greater than 70 (adjusted odds ratio [aOR] 0.68, 95% confidence interval [CI] 0.46-0.99), non-Hispanic Black race (aOR 0.84, CI 0.77-0.92), serous and clear cell histologies (aOR 0.68, CI 0.59-0.77; aOR 0.74, CI 0.57-0.95), living greater than 50 miles from treatment facility (aOR 0.84, CI 0.77-0.92), and receiving care in the Midwest, South, and West regions (aOR 0.84, CI 0.78-0.90; aOR 0.69, CI 0.64-0.76; aOR 0.72, CI 0.66-0.78). Compared to an academic medical center, receiving care at a comprehensive community cancer center was associated with receipt of CRT (aOR 1.2, CI 1.2-1.3). Compared to pre-GOG 258 opening in 2009, patients were more likely to receive CRT during GOG 258 enrollment (aOR 1.2, CI 1.1-1.3) and immediately after results announcement in 2018 (aOR 1.7, CI 1.5-1.8), despite results showing that CRT was not associated with longer relapse-free or overall survival. Conclusions: For patients with advanced endometrial cancer, there was significant use of both study arms with increases in CRT use during the study enrollment period and immediately after reporting of GOG 258 results, despite lack of benefit in the CRT arm.

Patterns of failure after radiosurgery for WHO grade 1 or imaging defined meningiomas: Long-term outcomes and implications for management

BACKGROUND

We analyzed long-term control and patterns of failure in patients with World Health Organization Grade 1 meningiomas treated with definitive or postoperative stereotactic radiosurgery at the authors' affiliated institution.

METHODS

96 patients were treated between 2004 and 2019 with definitive (n = 57) or postoperative (n = 39) stereotactic radiosurgery. Of the postoperative patients, 17 were treated adjuvantly following subtotal resection and 22 were treated as salvage at time of progression. Patients were treated to the gross tumor alone without margin or coverage of the dural tail to a median dose of 15 Gy. Median follow up was 7.4 years (inter-quartile range 4.8-11.3). Local control, marginal control, regional control, and progression-free survival were analyzed.

RESULTS

Local control at 5 and 10 years was 97 % and 95 %. PFS at 5 and 10 years was 94 % and 90 % with no failures reported after 6 years. Definitive and postoperative local control were similar at 5 (95 % [82-99 %] vs. 100 %) and 10 years (92 % [82-99 %] vs. 100 %). Patients treated with postoperative SRS did not have an increased marginal failure rate (p = 0.83) and only 2/39 (5 %) experienced recurrence elsewhere in the cavity.

CONCLUSIONS

Stereotactic radiosurgery targeting the gross tumor alone provides excellent local control and progression free survival in patients treated definitively and postoperatively. As in the definitive setting, patients treated postoperatively can be treated to gross tumor alone without need for additional margin or dural tail coverage.

Role of Brachytherapy in Adjuvant Radiation Practices for FIGO Stage II Endometrial Cancer

PURPOSE/OBJECTIVE(S)

FIGO stage II endometrial adenocarcinoma (EAC) involves the cervical stroma but is otherwise confined to the uterus. Management involves total hysterectomy and bilateral salpingo-oophorectomy (TH/BSO) followed by risk-adapted adjuvant therapy which may include radiation and chemotherapy (CHT). We sought to investigate whether patients with FIGO II EAC undergoing adjuvant radiation benefit from addition of vaginal cuff brachytherapy (VCB).

MATERIALS/METHODS

The National Cancer Database was queried to identify patients with FIGO II EAC diagnosed in 2010-2019 who received TH/BSO followed by adjuvant EBRT alone, VCB alone, or EBRT+VCB. Patients <18 years old or with <6 months follow-up were excluded. Clinical and demographic data were compared by treatment received using two-sided Z-tests and χ2 tests. Predictors of VCB were identified using multinomial logistic regression. Multivariate regression was used to identify predictors of death. Survival was evaluated with Kaplan-Meier estimators and Cox proportional hazards modeling.

RESULTS

A total of 6152 women with FIGO II EAC met inclusion criteria. After TH/BSO, 1792 (29%) patients received EBRT alone, 2428 (40%) received VCB alone, and 1923 (31%) received EBRT+VCB. Lymphovascular space invasion (LVSI) was present in 2224 (36%) patients, of which 751 (34%) received EBRT alone, 698 (31%) received VCB alone, and 775 (35%) received EBRT+ VCB. CHT was given to 548 (31%) treated with EBRT alone, 248 (16%) with VCB alone, and 414 (21%) with EBRT+VCB. Positive surgical margins (+SM) were present in 211 patients (3%), of which 92 (44%) were treated EBRT alone and 70 (33%) with EBRT+VCB. Compared to EBRT alone, relevant relative risk ratios (RRR) of receiving VCB alone include grade 2 (RRR -0.25, p = 0.020) or 3 (RRR -0.41, p = 0.004) disease, single agent CHT (RRR -0.83, p = 0.001), and LVSI (RRR -0.56, p<0.001). RRR of receiving EBRT+VCB include age>70 (RRR -0.37, p = 0.022), grade 3 disease (RRR 0.30, p = 0.024), and single (RRR -0.42, p = .046) or multi- (RRR -0.24, p = 0.026) agent CHT. Predictors of death in the study cohort include age 50-69 (OR 1.8, p<0.001) and >70 (OR 4.1, p<0.001), Charlson-Deyo Comorbidity Index ≥1 (OR 1.4, p<0.001), grade 2 (OR 1.8, p<0.001) or 3 (OR 3.0, p<0.001) disease, cervical stromal invasion (OR 1.4, p = 0.001), and LVSI (OR 1.5, p<0.001). Compared to EBRT alone, both VCB alone (OR 0.81, p = 0.023) and EBRT+VCB (OR 0.70, p<0.001) were associated with decreased risk of death. Five-year overall survival in patients receiving EBRT alone was 77.9% (95% CI 75.8-79.8%), whereas VCB alone and EBRT+VCB were 84.8% (83.2-86.2%, log rank p<0.001) and 82.9% (81.0-84.6%, log rank p<0.001) respectively. Survival differences remained significant when isolating patients with LVSI, grade 3, and +SM.

CONCLUSION

VCB as monotherapy or in combination with EBRT in patients with FIGO II EAC was associated with improved survival. Inclusion of adjuvant VCB maintains an important role in treating patients with FIGO II EAC.