Patterns of Undertreatment and Overtreatment in Adjuvant Radiotherapy for Early-Stage Endometrial Cancer Based on Molecular Classification

The quality improvement study examines the use of risk-adaptive adjuvant radiotherapy in women with non–mismatch repair deficiency endometrial cancer.

Safety and efficacy of durvalumab after concurrent chemoradiation in Black patients with locally advanced non-small cell lung cancer

BACKGROUND

The PACIFIC trial established consolidative durvalumab after concurrent chemoradiation as standard-of-care in patients with stage III or unresectable non-small cell lung cancer (NSCLC). Black patients, however, comprised just 2% (n = 14) of randomized patients in this trial, warranting real-world evaluation of the PACIFIC regimen in these patients.

METHODS

This single-institution, multi-site study included 105 patients with unresectable stage II/III NSCLC treated with concurrent chemoradiation followed by durvalumab between 2017 and 2021. Overall survival (OS), progression-free survival (PFS), and grade ≥3 pneumonitis-free survival (PNFS) were compared between Black and non-Black patients using Kaplan-Meier and Cox regression analyses.

RESULTS

A total of 105 patients with a median follow-up of 22.8 months (interquartile range, 11.3-37.3 months) were identified for analysis, including 57 Black (54.3%) and 48 (45.7%) non-Black patients. The mean radiation prescription dose was higher among Black patients (61.5 ± 2.9 Gy vs. 60.5 ± 1.9 Gy; p = .031), but other treatment characteristics were balanced between groups. The median OS (not-reached vs. 39.7 months; p = .379) and PFS (31.6 months vs. 19.3 months; p = .332) were not statistically different between groups. Eight (14.0%) Black patients discontinued durvalumab due to toxicity compared to 13 (27.1%) non-Black patients (p = .096). The grade ≥3 pneumonitis rate was similar between Black and non-Black patients (12.3% vs. 12.5%; p = .973), and there was no significant difference in time to grade ≥3 PNFS (p = .904). Three (5.3%) Black patients and one (2.1%) non-Black patient developed grade 5 pneumonitis.

CONCLUSIONS

The efficacy and tolerability of consolidative durvalumab after chemoradiation appears to be comparable between Black and non-Black patients.

Biochemical Relapse-Free Survival in Post-Prostatectomy Patients Receiving 18F-Fluciclovine-Guided Prostate Bed Only Radiation: Post-Hoc Analysis of a Prospective Randomized Trial

PURPOSE/OBJECTIVE(S)

Whole pelvis (WP) radiation therapy (XRT) significantly improved biochemical relapse free survival (bRFS) compared to prostate-bed (PB)-only XRT in RTOG 0534, yet increased toxicity and was performed in an era prior to PET staging (Pollack et al, Lancet, 2022). Separately, 18F-fluciclovine PET/CT (PET)-guided post-prostatectomy XRT demonstrated improved bRFS compared to XRT guided by conventional imaging alone. We hypothesized that patients whose decisions were changed from whole pelvic XRT to PB-only XRT after PET imaging would have bRFS that was (a) not significantly different than patients initially planned for PB-only XRT, and (b) significantly improved over patients planned for WP XRT without PET guidance.

MATERIALS/METHODS

We conducted a post-hoc analysis of a prospective, randomized, single-institution trial comparing conventional (Arm A) v. PET-guided (Arm B) post-prostatectomy XRT. For patients randomized to Arm B, pre-PET treatment field decisions were recorded, and post-fluciclovine fields were rigidly defined per protocol: pN0 patients with no pelvic or extrapelvic PET uptake received PB-only XRT. Three- and four-year bRFS were compared in patients initially planned for WP with change to PB-only XRT [Arm B (WP→PB)] v Arm B patients initially planned for PB-only with final XRT to PB-only [Arm B(PB→PB)] & Arm A patients treated with whole pelvic XRT [Arm A(WP)] using Z test and log-rank test. Demographics were compared using Chi-square test, Fisher's exact test, or ANOVA as appropriate.

RESULTS

We identified 10 Arm B (WP→PB), 31 Arm B (PB→PB), and 25 Arm A (WP) patients. Androgen deprivation was used in 50.0% of Arm B (WP→PB) and 3.2% of Arm B (PB→PB) patients, p<0.01. Mean pre-XRT PSA was significantly higher (1.56 v 0.32 ng/mL, respectively, p<0.01) in Arm B (WP→PB) v Arm B (PB→PB) patients, however, there was no significant difference in extracapsular extension (p = 1.00), seminal vesical invasion (p = 1.00), Gleason score ≥8 (p = 0.58) or margin positivity (p = 0.73) between cohorts. Three- and four-year bRFS was 80% in Arm B (WP→PB) & 87.4% in Arm B (PB→PB), p = 0.47, respectively. Arm A (WP) patients had significantly worse three- (35.2%) and four-year (13.2%) bRFS compared to Arm B (WP→PB), p<0.01.

CONCLUSION

Patients initially planned for WP XRT whose treatment field decisions were changed to PB-only XRT after PET guidance had, in this post-hoc analysis, (a) relapse rates not significantly different than patients initially planned for PB-only XRT and (b) improved relapse rates over patients treated with WP XRT without PET guidance. PET-guided volume de-escalation in selected patients may be one approach to mitigating excess toxicity seen with WP XRT without compromising outcomes and warrants further exploration.

Association of Radiation Facility Volume with Overall Survival in Patients with Very High-Risk Prostate Cancer Treated with Radiation and Androgen Deprivation Therapy

PURPOSE/OBJECTIVE(S)

Studies suggest an association of treatment at high volume facilities with improved survival in cancer patients receiving surgery or radiation therapy. This association has not been studied in patients with very high-risk prostate cancer, who are treated using a multimodality approach that often requires specialized care with advanced diagnostic imaging, complex radiotherapeutic planning, and multidrug antiandrogen regimens. We used the National Cancer Database (NCDB) to study the association of radiation treatment facility volume (FV) with overall survival (OS).

MATERIALS/METHODS

We selected for patients with very high risk, localized prostate cancer by NCCN criteria (cT3b-T4, primary Gleason pattern 5, >4 cores with grade group 4-5, and/or 2-3 high risk features). We included patients who received hormone therapy with either external beam radiation to a dose of ≥60 Gy or external beam radiation to a dose of ≥45 Gy combined with brachytherapy. Association of FV with OS was evaluated through a bias-adjusted log-rank test to identify the optimal cut point of FV for dichotomization. Kaplan-Meier curves were used to study the association of binary FV with overall survival (OS) with and without IPTW (inverse probability treatment weighting) balancing the following confounders: age, race, median income, education, insurance, academic treatment facility, Charlson comorbidity score, T stage, PSA, Gleason score, total radiation dose, year of diagnosis, and patient distance from treatment facility. Cox proportional hazards model was built using backward variable selection strategy (α of 0.05 for removal).

RESULTS

We identified 25,219 very high-risk prostate cancer patients by NCCN criteria (median follow up 57.36 months; 95% CI 56.67 - 58.09) diagnosed between 2004 and 2015. High FV (n = 6,438) was associated with better OS on univariable analysis (hazard ratio [HR] = 0.81; 95% confidence interval [CI] 0.77 - 0.86; p < 0.001) and multivariable analysis (HR = 0.89; 95% CI 0.84 - 0.95; p < 0.001). Other factors associated with improved OS on multivariable analysis included younger age, non-white/black race, higher income, private insurance, academic/research treatment facility, lower comorbidity, lower T-stage, lower PSA, and lower Gleason score. After IPTW adjustment, high FV remained associated with better OS (HR = 0.90; 95% CI 0.85 - 0.95; p < 0.001).

CONCLUSION

Patients with NCCN very high-risk prostate cancer treated at a radiation facility with high case volume had better OS than patients treated at a facility with low volume, after adjustment for confounders. This may suggest that for very high-risk patients, outcomes may be improved by the expertise and optimal multidisciplinary care that typically accompany high facility treatment volume.

Risk Factors and Clinical Features of Fistula after Concurrent Chemoradiation and Brachytherapy for Locally Advanced Cervical Cancer

PURPOSE/OBJECTIVE(S)

The standard treatment for locally advanced cervical cancer (LACC) is concurrent chemoradiation and brachytherapy (CRT-B). Fistula formation is a serious complication of treatment; however, risk factors and clinical outcomes are not well described. We sought to identify the incidence, risk factors and prognosis of radiation-induced fistula in women who underwent CRT-B for LACC.

MATERIALS/METHODS

A single institution retrospective review of patients treated with CRT-B for LACC from July 2013 to August 2022 across 3 centers was performed. Inclusion criteria were Stage IB-IVB cervical cancer treated with definitive intent. Patients with upfront or adjuvant surgery were excluded. Cox-proportional hazards model was performed to assess factors associated with fistula. Local control and fistula-free survival were estimated using the Kaplan-Meyer method. Clinical significance was defined as p < 0.05.

RESULTS

A total of 105 patients met the inclusion criteria and were included in this analysis. Patients consisted of FIGO Stage I (n = 20, 19%), Stage II (n = 22, 21%), Stage III (n = 46, 43.8%) or Stage IV disease (n = 17, 16.2%). 12 (11.4%) patients developed fistula following CRT-B; 1/12 patients (8.3%) had fistula present at time of diagnosis. Median time to fistula development was 12 months. Fistula was characterized as vesicovaginal/urethrovaginal in 58.3% (n = 7) and rectovaginal/intestinovaginal in 83.3% (n = 10), including 8 patients (66.7%) who had more than one type of fistula. 4/12 (33.3%) of patients with fistula had concurrent local recurrence. Patients were treated with conservative management (41.7%), hyperbaric oxygen (16.7%) and/or surgery (83.3%). Complications included infection (50.0%), urinary/bowel diversion (83.3%), hospitalization (50.0%) and death (8.3%). Fistula was resolved in 7/12 patients (58.3%) at time of last follow up. Higher BMI (p = 0.04) and use of hybrid applicators (p = 0.02) were associated with decreased likelihood of fistula development. Disease extension into bladder was associated with increased likelihood of fistula development (p = 0.03). Compared to former and never smoking, current smoking was associated with a higher risk of developing fistula (p = 0.04, OR 4.42, CI:1.07-18.34). Compared to intracavitary and hybrid applicators, the use of a Syed applicator was associated with increased likelihood of fistula development (p = 0.02, OR 8.00, CI: 1.37-46.55). Two-year local control was 82.5% (CI: 64.5-91.9) for Stage I-II, 80.7% (CI: 62.8-90.6) for Stage III, and 62.2% (CI: 30.1-82.9) for Stage IV. Two-year fistula free survival was 89.9% (CI: 80.6 - 94.9).

CONCLUSION

Women who undergo definitive chemoradiation for treatment of LACC have a 11.4% risk of fistula formation overall. The risk is higher amongst patients with current smoking, disease extension into bladder and Syed applicators. Overall two-year local control was 78.7% and fistula free survival was 89.9%.

Single Institution Experience of the Effect of Adjuvant Radiation on Outcomes for Patients with Uterine Carcinosarcoma

PURPOSE/OBJECTIVE(S)

Uterine carcinosarcoma (UCS) is a rare but aggressive malignancy with poor outcomes. Due to its low incidence, there is no well-established optimal treatment. Standard treatment involves surgery and chemotherapy (CT) +/- adjuvant radiation therapy (RT). Our primary aim was to determine if patients who underwent adjuvant RT had improved distant metastasis free survival (DMFS) and locoregional recurrence free survival (LRRFS). Our secondary aim was to determine the effect of adjuvant RT on overall survival (OS).

MATERIALS/METHODS

We performed a single institutional retrospective review of all patients with UCS who underwent primary surgical resection +/- CT and +/- RT between 2007 to 2021. Patients without at least 3 months of documented follow-up were excluded. We assessed DMFS, LRRFS, and OS between patients who did and did not receive adjuvant RT, consisting of vaginal brachytherapy (VBT), external beam radiation therapy (EBRT), or EBRT + VBT. Statistical analysis was performed with spreadsheet and statistical software.

RESULTS

Sixty-four patients underwent primary surgical resection for FIGO stage I-IV UCS. Sixty six percent (n = 42) had early stage, FIGO I-II disease and 34% (n = 22) had late stage, FIGO III-IV disease. Eleven percent (n = 7) underwent surgery alone, 28% (n = 18) underwent surgery + CT, 6% (n = 4) underwent surgery + adjuvant RT, and 55% (n = 35) underwent surgery + CT + RT. Most patients who underwent surgery + CT + EBRT + VBT (n = 9) had worse clinicopathologic features including late stage (56%), lymphovascular invasion positive (78%) disease with 50% or greater myometrial invasion (56%). EBRT doses ranged from 45-50.4 Gray (Gy) in 1.8 Gy per fraction. VBT doses ranged from 21-25 Gy in 3-5 fractions when delivered alone and 10-15 Gy in 2-3 fractions when delivered as a boost. Median DMFS was 20.3 months, median LRRFS was 22.6 months, median DFS was 19.4 months, and median OS was 24.7 months. Rate of distant metastasis appeared to drive rate of disease-free survival (Table 1). Patients who underwent adjuvant RT had improved median DMFS (71.5 vs. 11.3 months, p = .002), median LRRFS (71.5 vs 22.5 months, p = .002), and median OS (60.7 vs. 22.5 months, p = .002) compared to those who did not receive RT.

CONCLUSION

Prognosis of patients with UCS remains poor; however, adjuvant RT delivered after CT may offer potential benefit in survival outcomes despite worse clinicopathologic features in these patients.

Differences in Failure-Free Survival After Salvage Radiotherapy Guided by Conventional Imaging Versus 18F-Fluciclovine PET/CT in Postprostatectomy Patients: A Post Hoc Substratification Analysis of the EMPIRE-1 Trial

The EMPIRE-1 (Emory Molecular Prostate Imaging for Radiotherapy Enhancement 1) trial reported a survival advantage in recurrent prostate cancer salvage radiotherapy (SRT) guided by 18F-fluciclovine PET/CT versus conventional imaging. We performed a post hoc analysis of the EMPIRE-1 cohort stratified by protocol-specified criteria, comparing failure-free survival (FFS) between study arms. Methods: EMPIRE-1 randomized patients to SRT planning via either conventional imaging only (bone scanning plus abdominopelvic CT or MRI) (arm A) or conventional imaging plus 18F-fluciclovine PET/CT (arm B). Randomization was stratified by prostate-specific antigen (PSA) level (<2.0 vs. ≥ 2.0 ng/mL), adverse pathology, and androgen-deprivation therapy (ADT) intent. We subdivided patients in each arm using the randomization stratification criteria and compared FFS between patient subgroups across study arms. Results: Eighty-one and 76 patients received per-protocol SRT in study arms A and B, respectively. The median follow-up was 3.5 y (95% CI, 3.0-4.0). FFS was 63.0% and 51.2% at 36 and 48 mo, respectively, in arm A and 75.5% at both 36 and 48 mo in arm B. Among patients with a PSA of less than 2 ng/mL (mean, 0.42 ± 0.42 ng/mL), significantly higher FFS was seen in arm B than arm A at 36 mo (83.2% [95% CI, 70.0-91.0] vs. 66.5% [95% CI, 51.6-77.8], P < 0.001) and 48 mo (83.2% [95% CI, 70.0-91.0] vs. 56.2% [95% CI, 40.5-69.2], P < 0.001). No significant difference in FFS between study arms in patients with a PSA of at least 2 ng/mL was observed. Among patients with adverse pathology, significantly higher FFS was seen in arm B than arm A at 48 mo (68.9% [95% CI, 52.1-80.8] vs. 42.8% [95% CI, 26.2-58.3], P < 0.001) though not at the 36-mo follow-up. FFS was higher in patients without adverse pathology in arm B versus arm A (90.2% [95% CI, 65.9-97.5] vs. 73.1% [95% CI, 42.9-89.0], P = 0.006) at both 36 and 48 mo. Patients in whom ADT was intended in arm B had higher FFS than those in arm A, with the difference reaching statistical significance at 48 mo (65.2% [95% CI, 40.3-81.7] vs. 29.1 [95% CI, 6.5-57.2], P < 0.001). Patients without ADT intent in arm B had significantly higher FFS than patients in arm A at 36 mo (80.7% [95% CI, 64.9-90.0] vs. 68.0% [95% CI, 51.1-80.2]) and 48 mo (80.7% [95% CI, 64.9-90.0] vs. 58.6% [95% CI, 41.0-72.6]). Conclusion: The survival advantage due to the addition of 18F-fluciclovine PET/CT to SRT planning is maintained regardless of the presence of adverse pathology or ADT intent. Including 18F-fluciclovine PET/CT to SRT leads to survival benefits in patients with a PSA of less than 2 ng/mL but not in patients with a PSA of 2 ng/mL or higher.

Impact of 18 F-Fluciclovine PET/CT Findings on Failure-Free Survival in Biochemical Recurrence of Prostate Cancer Following Salvage Radiation Therapy

PURPOSE

We aimed to evaluate the impact of 18 F-fluciclovine PET/CT imaging on failure-free survival (FFS) post-salvage radiotherapy (SRT) for prostate cancer (PCa) recurrence.

METHODS

Seventy-nine patients were recruited in a phase 2/3 clinical trial to undergo 18 F-fluciclovine PET/CT before SRT for PCa. Four patients with extrapelvic disease were excluded. All patients were followed up at regular intervals up to 48 months. Treatment failure was defined as a serum prostate-specific antigen level of ≥0.2 ng/mL above the nadir after SRT, confirmed with an additional measurement, requiring systemic treatment or clinical progression. Failure-free survival was computed and compared between patients grouped according to 18 F-fluciclovine PET/CT imaging findings.

RESULTS

Eighty percent (60/75) of patients had a positive finding on 18 F-fluciclovine PET/CT, of which 56.7% (34/60) had prostate bed-only uptake, whereas 43.3% (26/60) had pelvic nodal ± bed uptake. Following SRT, disease failure was detected in 36% (27/75) of patients. There was a significant difference in FFS between patients who had a positive versus negative scan (62.3% vs 92.9% [ P < 0.001] at 36 months and 59.4% vs 92.9% [ P < 0.001] at 48 months). Similarly, there was a significant difference in FFS between patients with uptake in pelvic nodes ± bed versus prostate bed only at 36 months (49.8% vs 70.7%; P = 0.003) and at 48 months (49.8% vs 65.6%; P = 0.040). Failure-free survival was also significantly higher in patients with either negative PET/CT or prostate bed-only disease versus those with pelvic nodal ± prostate bed disease at 36 (78% vs 49.8%, P < 0.001) and 48 months (74.4% vs 49.8%, P < 0.001).

CONCLUSIONS

Findings on pre-SRT 18 F-fluciclovine PET/CT imaging, even when acted upon to optimize the treatment decisions and treatment planning, are predictive of post-SRT FFS in men who experience PCa recurrence after radical prostatectomy. A negative 18 F-fluciclovine PET/CT is most predictive of a lower risk of failure, whereas the presence of pelvic nodal recurrence portends a higher risk of SRT failure.

Definitive intensity modulated proton re-irradiation for lung cancer in the immunotherapy era

Introduction

As immunotherapy has improved distant metastasis-free survival (DMFS) in Non-Small Cell Lung Cancer (NSCLC), isolated locoregional recurrences have increased. However, management of locoregional recurrences can be challenging. We report our institutional experience with definitive intent re-irradiation using Intensity Modulated Proton Therapy (IMPT).

Method

Retrospective cohort study of recurrent or second primary NSCLC or LS-SCLC treated with IMPT. Kaplan-Meier method and log-rank test were used for time-to-event analyses.

Results

22 patients were treated from 2019 to 2021. After first course of radiation (median 60 Gy, range 45-70 Gy), 45% received adjuvant immunotherapy. IMPT re-irradiation began a median of 28.2 months (8.8-172.9 months) after initial radiotherapy. The median IMPT dose was 60 GyE (44-60 GyE). 36% received concurrent chemotherapy with IMPT and 18% received immunotherapy after IMPT. The median patient's IMPT lung mean dose was 5.3 GyE (0.9-13.9 GyE) and 5 patients had cumulative esophagus max dose >100 GyE with 1-year overall survival (OS) 68%, 1-year local control 80%, 1-year progression free survival 45%, and 1-year DMFS 60%. Higher IMPT (HR 1.4; 95% CI 1.1-1.7, p=0.01) and initial radiotherapy mean lung doses (HR 1.3; 95% CI 1.0-1.6, p=0.04) were associated with worse OS. Two patients developed Grade 3 pneumonitis or dermatitis, one patient developed Grade 2 pneumonitis, and seven patients developed Grade 1 toxicity. There were no Grade 4 or 5 toxicities.

Discussion

Definitive IMPT re-irradiation for lung cancer can prolong disease control with limited toxicity, particularly in the immunotherapy era.

Incidence and predictors of toxicity in the management of vulvar squamous cell carcinoma treated with radiation therapy

Purpose/Objective

Given the rarity of vulvar cancer, data on the incidence of acute and late severe toxicity and patients' symptom burden from radiotherapy (RT) are lacking.

Materials/Methods

This multi-center, single-institution study included patients with vulvar squamous cell carcinoma treated with curative intent RT between 2009 and 2020. Treatment-related acute and late grade ≥ 3 toxicities and late patient subjective symptoms (PSS) were recorded.

Results

Forty-two patients with predominantly stage III/IV disease (n = 25, 59.5 %) were treated with either definitive (n = 25, 59.5 %) or adjuvant (n = 17, 40.5 %) external beam RT to a median dose of 64 Gy and 59.4 Gy, respectively. Five patients received a brachytherapy boost with a median total dose of 84.3 Gy in 2 Gy-equivalent dose (EQD2). Intensity-modulated RT was used in 37 (88.1 %) of patients, and 25 patients (59.5 %) received concurrent chemotherapy. Median follow-up was 27 months. Acute grade ≥ 3 toxicity occurred in 17 patients (40.5 %), including 13 (31.0 %) acute grade 3 skin events. No factors, including total RT dose (p = 0.951), were associated with acute skin toxicity. Eleven (27.5 %) patients developed late grade ≥ 3 toxicity events, including 10 (23.8 %) late grade ≥ 3 skin toxicity events. Patients with late grade ≥ 3 skin toxicity had a higher mean body-mass index (33.0 vs 28.2 kg/m²; p = 0.009). Common late PSS included vaginal pain (n = 15, 35.7 %), skin fibrosis (n = 10, 23.8 %), and requirement of long-term opiates (n = 12, 28.6 %).

Conclusion

RT for vulvar cancer is associated with considerable rates of severe acute and late toxicity and PSS burden. Larger studies are needed to identify risk factors, explore toxicity mitigation strategies, and assess patient-reported outcomes.

Randomized Trial of Conventional Versus Conventional Plus Fluciclovine (18F) Positron Emission Tomography/Computed Tomography-Guided Postprostatectomy Radiation Therapy for Prostate Cancer: Volumetric and Patient-Reported Analyses of Toxic Effects

PURPOSE

Postprostatectomy radiation therapy planning with fluciclovine (¹⁸F) positron emission tomography (PET)/computed tomography has demonstrated improved disease-free survival over conventional only (computed tomography- or magnetic resonance imaging-based) treatment planning. We hypothesized that incorporating PET would result in larger clinical target volumes (CTVs) without increasing patient-reported toxic effects.

METHODS AND MATERIALS

From 2012 to 2019, 165 postprostatectomy patients with detectable prostate-specific antigen were randomized (arm 1 [no PET]: 82; arm 2 [PET]: 83). Prostate bed target volumes with (CTV1: 45.0-50.4 Gy/1.8 Gy) or without (CTV2/CTV: 64.8-70.2 Gy/1.8 Gy) pelvic nodes, as well as organ-at-risk doses, were compared pre- versus post-PET (arm 2) using the paired t test and between arms using the t test. Patient-reported outcomes used International Prostate Symptom Score and Expanded Prostate Cancer Index Composite for Clinical Practice (EPIC-CP). Univariate and multivariable analyses were performed and linear mixed models were fitted.

RESULTS

Median follow-up of the whole cohort was 3.52 years. All patients had baseline patient-reported outcomes, 1 patient in arm 1 and 3 patients in arm 2 withdrew, and 4 arm 2 patients had extrapelvic uptake on PET with radiotherapy aborted, leaving 81 (arm 1) and 76 patients (arm 2) for analysis of toxic effects. Mean CTV1 (427.6 vs 452.2 mL; P = .462, arm 1 vs arm 2) and CTV2/CTV (137.18 vs 134.2 mL; P = .669) were similar before PET incorporation. CTV1 (454.57 vs 461.33 mL; P = .003) and CTV2/CTV (134.14 vs 135.61 mL; P < .001) were modestly larger after PET incorporation. Although V40 Gy (P = .402 and P = .522 for rectum and bladder, respectively) and V65 Gy (P = .157 and P = .182 for rectum and bladder, respectively) were not significantly different pre- versus post-PET, penile bulb dose significantly increased post-PET (P < .001 for both V40 Gy and V65 Gy). On univariate and multivariable analyses, arm was not significant for any EPIC-CP subdomain. International Prostate Symptom Score and EPIC-CP linear mixed models were not significantly different between arms.

CONCLUSIONS

Despite larger CTVs after incorporation of fluciclovine (¹⁸F) PET, we found no significant difference in patient-reported toxic effects with long-term follow-up.

Impact of Radiation Dose to the Immune Cells in Unresectable or Stage III Non-Small Cell Lung Cancer in the Durvalumab Era

BACKGROUND /PURPOSE

Higher estimated radiation doses to immune cells (EDIC) have correlated with worse overall survival (OS) in patients with locally-advanced non-small cell lung cancer (NSCLC) prior to the PACIFIC trial, which established consolidative durvalumab as standard-of-care. Here, we examine the prognostic impact of EDIC in the durvalumab era.

MATERIALS/METHODS

This single-institution, multi-center study included patients with unresectable stage II/III NSCLC treated with chemoradiation followed by durvalumab. Associations between EDIC [analyzed continuously and categorically (≤6 Gy vs. >6 Gy)] and OS, progression-free survival (PFS), and locoregional control (LRC) were evaluated by Kaplan-Meier and Cox proportional methods.

RESULTS

100 patients were included with median follow-up of 23.7 months. The EDIC >6 Gy group had a significantly greater percentage of stage IIIB/IIIC disease (76.0% vs. 32.6%; p<0.001) and larger tumor volumes (170cc vs. 42cc; p<0.001). There were no differences in early durvalumab discontinuation from toxicity (24.1% vs. 15.2%; p=0.27). Median OS was shorter among the EDIC >6 Gy group (29.6 months vs. not reached; p<0.001). On multivariate analysis, EDIC >6 Gy correlated with worse OS (HR: 4.15, 95%CI: 1.52-11.33; p=0.006), PFS (HR: 3.79; 95%CI: 1.80-8.0; p<0.001), and LRC (HR: 2.66, 95%CI: 1.15-6.18; p=0.023). Analyzed as a continuous variable, higher EDIC was associated with worse OS (HR: 1.34; 95%CI: 1.16-1.57; p<0.001), PFS (HR: 1.52; 95%CI: 1.29-1.79; p<0.001), and LRC (HR: 1.34, 95%CI: 1.13-1.60; p=0.007).

CONCLUSIONS

In the immunotherapy era, EDIC is an independent predictor of OS and disease control in locally advanced NSCLC, warranting investigation into techniques to reduce dose to the immune compartment.

Abstract 5940: Impact of obesity on sexual functioning in women with gynecologic cancer pre-and post-radiotherapy

Background: As the prevalence of obesity in women increases in the US, a better understanding of the effect of obesity on women with gynecologic cancer (GynCa) is imperative. However, whether obesity impacts sexual functioning (SF) in GynCa patients has been understudied. Limited studies have used body mass index (BMI) as the only obesity indicator, which may result in a misunderstanding of the effect of obesity on SF in GynCa patients with different body compositions. This study aimed to explore the role of obesity via two different measures in determining SF in GynCa patients pre-and post-radiotherapy (RT).

Methods: In this secondary analysis, obesity was measured pre-RT by both BMI and body fat percentage (BFP). BFP was calculated by using the Clinica Universidad de Navarra-Body Adiposity Estimator. SF, physical and emotional well-being were assessed pre-RT by the Female Sexual Function Index and the Functional Assessment of Cancer Therapy-General. At 6 months post-RT, SF was reassessed. Generalized linear models (GLM) and generalized linear mixed models (GLMM) with a log-link were implemented to identify the effect of obesity (using BMI and BFP) on SF pre-and post-RT. Regression-based mediation analysis was used to identify mediating effects of physical and emotional well-being between obesity and SF.

Results: Among 54 (24 cervical and 30 endometrial) patients, 48% were Black, 52% were married or in a domestic partnership, and 59% were treated with surgery and/or chemotherapy pre-RT (i.e. prior treatment). Less patients were classified as being obese when obesity was measured by BMI (48%) compared to BFP (61%). Patients with endometrial cancer and prior treatment history were more likely to be obese and reported better SF. Unadjusted GLM showed that patients with obesity had better SF than those without obesity pre-RT regardless of obesity measures (BMI p = .018; BFP p = .016). However, we found no association between obesity (both BMI-and BFP-based obesity) and SF pre-RT after adjusting for cancer type and prior treatment history. GLMM showed that BFP-based obesity had a negative effect on the improvement in SF from pre-RT to post-RT (p = .013) after adjusting for cancer type and prior treatment history. Patients without BFP-based obesity showed a significant improvement post-RT (p = .019), but those with obesity (per BFP) showed no changes in SF post-RT (p = .949) compared to pre-RT. BMI-based obesity did not affect the changes in SF post-RT. We found no mediation effects of physical and emotional well-being between obesity and SF.

Conclusions: Obesity may play a negative role in SF improvement in GynCa patients post-RT. More rigorous research and clinical attention to obesity measurement are necessary to determine the association between obesity and SF in GynCa patients and thus lead to the discovery of new interventions for this long-neglected topic of SF in GynCa patients, particularly for those who are obese.

Citation Format: Haerim Lee, Deborah W. Bruner, Yi-Juan Hu, Jinbing Bai, Tony Y. Eng, Joseph W. Shelton, Pretesh R. Patel, Namita Khanna, Isabelle Scott, Katherine A. Yeager. Impact of obesity on sexual functioning in women with gynecologic cancer pre-and post-radiotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5940.

Impact of rectal spacer on toxicity reduction in men treated with proton versus photon therapy

247

Background: Dose escalation in prostate cancer (PCa) radiotherapy (RT) is limited by toxicity to surrounding tissue, including the rectum. Rectal spacers improve bowel toxicity in men treated with photons (i.e. IMRT). However, the relative benefit of rectal spacers in men treated with protons remains unknown. Further, proton therapy may result in high-dose exposure to the anterior rectal wall due to lateral penumbra with conventional opposed lateral beam arrangement. We hypothesize that rectal spacers will confer greater toxicity benefit in the setting of proton therapy compared with photon therapy. Methods: We conducted an IRB approved, single institution, retrospective review of patients receiving definitive conventional or moderate hypofractionated photon IMRT or pencil-beam scanning proton RT for localized PCa from 2018-2021. Four cohorts were compared: Photon with (Ph+RS) or without (Ph-RS) rectal spacer, and proton with (Pr+RS) or without (Pr-RS) rectal spacer. Rates of pelvic nodal treatment were equivalent between protons and photons within the +/- rectal spacer cohorts. Acute (<3 months) and late (≥ 3 month) toxicity was compared amongst the four cohorts. Cumulative incidence of physician-reported grade 1-2 gastrointestinal (GI) toxicity (CTCAE V5.0) was compared using Chi-square or Fisher’s exact test. Patient-reported bowel toxicity was evaluated using International Prostate Expanded Prostate Composite Index- Clinical Practice (EPIC-CP) and compared using linear mixed modeling. Results: 164 patients were eligible for analysis: 38 Ph-RS, 50 Ph+RS, 26 Pr-RS, & 50 Pr+RS. Median follow-up was 17.6 months. In men treated with protons, physician-reported acute G1-2 GI toxicity was significantly lower in men with versus without rectal spacer (6.12 vs 30.77%, Pr+RS vs Pr-RS, respectively; p=0.009) and there was a trend towards lower late G1-2 GI toxicity (8.51 vs 26.09%, Pr+RS vs Pr-RS, respectively; p=0.08). In men treated with photons, there were no significant differences in physician-reported acute or later GI toxicity with versus without rectal spacer. No significant differences in patient-reported outcomes were observed with versus without spacer in the proton or photon cohorts. Conclusions: Rectal spacer use was associated with a lower CTCAE grade 1-2 acute GI toxicity in men treated with protons, and this difference was not observed in men treated with photons. While this study is limited by low sample size, a relatively greater benefit of rectal spacer with proton vs. photon therapy was observed. Further prospective analyses in larger cohorts are ongoing to validate these hypothesis-generating findings.

Bone Marrow Suppression during Postoperative Radiation for Bladder Cancer and Comparative Benefit of Proton Therapy—Phase 2 Trial Secondary Analysis

Purpose

For patients with high-risk bladder cancer (pT3⁺ or N⁺), local regional failure remains a challenge after chemotherapy and cystectomy. An ongoing prospective phase 2 trial (NCT01954173) is examining the role of postoperative photon radiation therapy for high-risk patients using volumetric modulated arc therapy. Proton beam therapy (PBT) may be beneficial in this setting to reduce hematologic toxicity. We evaluated for dosimetric relationships with pelvic bone marrow (PBM) and changes in hematologic counts before and after pelvic radiation therapy and explored the potential of PBT treatment plans to achieve reductions in PBM dose.

Materials and Methods

All enrolled patients were retrospectively analyzed after pelvic radiation per protocol with 50.4 to 55.8 Gy in 28 to 31 fractions. Comparative PBT plans were generated using pencil-beam scanning and a 3-beam multifield optimization technique. Changes in hematologic nadirs were assessed using paired t test. Correlation of mean nadirs and relative PBM dose levels were assessed using the Pearson correlation coefficient (CC).

Results

Eighteen patients with a median age of 70 were analyzed. Mean cell count values after radiation therapy decreased compared with preradiation therapy values for white blood cells (WBCs), absolute neutrophil count (ANC), absolute lymphocyte count (all P < .001), and platelets (P = .03). Increased mean PBM dose was associated with lower nadirs in WBC (Pearson CC −0.593, P = .02), ANC (Pearson CC −0.597, P = .02), and hemoglobin (Pearson CC −0.506, P = .046), whereas the PBM V30 to V40 correlated with lower WBC (Pearson CC −0.512 to −0.618, P < .05), and V20 to V30 correlated with lower ANC (Pearson CC −0.569 to −0.598, P < .04). Comparative proton therapy plans decreased the mean PBM dose from 26.5 Gy to 16.1 Gy (P < .001) and had significant reductions in the volume of PBM receiving doses from 5 to 40 Gy (P < .001).

Conclusion

Increased PBM mean dose and V20 to V40 were associated with lower hematologic nadirs. PBT plans reduced PBM dose and may be a valuable strategy to reduce the risk of hematologic toxicity in these patients.

18F-fluciclovine-PET/CT imaging versus conventional imaging alone to guide postprostatectomy salvage radiotherapy for prostate cancer (EMPIRE-1): a single centre, open-label, phase 2/3 randomised controlled trial

BACKGROUND

Molecular imaging is increasingly used to guide treatment decisions and planning in prostate cancer. We aimed to evaluate the role of ¹⁸F-fluciclovine-PET/CT in improving cancer control compared with conventional imaging (bone scan and either CT or MRI) alone for salvage postprostatectomy radiotherapy.

METHODS

In EMPIRE-1, a single-centre, open-label, phase 2/3 randomised controlled trial, patients with prostate cancer with detectable PSA after prostatectomy and negative conventional imaging (no extrapelvic or bone findings) were randomly assigned in a 1:1 ratio to radiotherapy directed by conventional imaging alone or to conventional imaging plus ¹⁸F-fluciclovine-PET/CT. Computer-generated randomisation was stratified by PSA concentration, adverse pathology indicators, and androgen deprivation therapy intent. In the ¹⁸F-fluciclovine-PET/CT group, radiotherapy decisions were rigidly determined by PET findings, which were also used for target delineation. The primary endpoint was 3 year event-free survival, with events defined as biochemical or clinical recurrence or progression, or initiation of systemic therapy, using univariate and multivariable analyses in patients who received radiotherapy. This trial is registered with ClinicalTrials.gov, NCT01666808 and is closed to new participants.

FINDINGS

From Sept 18, 2012, to March 4, 2019, 165 patients were randomly assigned, with median follow-up of 3·52 years (95% CI 2·98-3·95). PET findings resulted in four patients in the ¹⁸F-fluciclovine-PET/CT group having radiotherapy aborted; these patients were excluded from survival analyses. Median survival was not reached (95% CI 35·2-not reached; 33% of 81 patients had events) in the conventional imaging group compared with not reached (95% CI not reached-not reached; 20% of 76 patients) in the ¹⁸F-fluciclovine-PET/CT group, and 3 year event-free survival was 63·0% (95% CI 49·2-74·0) in the conventional imaging group versus 75·5% (95% CI 62·5-84·6) for ¹⁸F-fluciclovine-PET/CT (difference 12·5; 95% CI 4·3-20·8; p=0·0028). In adjusted analyses, study group (hazard ratio 2·04 [95% CI 1·06-3·93], p=0·0327) was significantly associated with event-free survival. Toxicity was similar in both study groups, with the most common adverse events being late urinary frequency or urgency (37 [46%] of 81 patients in the conventional imaging group and 31 [41%] of 76 in the PET group), and acute diarrhoea (11 [14%] in the conventional imaging group and 16 [21%] in the PET group).

INTERPRETATION

Inclusion of ¹⁸F-fluciclovine-PET into postprostatectomy radiotherapy decision making and planning significantly improved survival free from biochemical recurrence or persistence. Integration of novel PET radiotracers into radiotherapy decisions and planning for prostate cancer patients warrants further study.

FUNDING

National Institutes of Health/National Cancer Institute, Blue Earth Diagnostics, and Winship Cancer Institute of Emory University.

Small-Cell Carcinoma of the Prostate: Report of Outcomes of Localized Disease Using the National Cancer Database

BACKGROUND

Small-cell carcinoma of the prostate (SCCP) is a rare but aggressive prostate cancer histology. We studied the reported comparative outcomes of the efficacy of radiotherapy (RT) versus surgery for nonmetastatic SCCP.

METHODS

The National Cancer Database (NCDB) was queried for nonmetastatic disease diagnosed from 2004 to 2015 as SCCP (defined as having a component of SCCP) receiving a single definitive local control modality (RT or surgery).

RESULTS

A total of 243 patients were included (177 RT and 66 surgery). A total of 142 patients received chemotherapy (CHT). Mean age was 68 years. One hundred forty patients had adenocarcinoma concurrently with the SCCP while 103 patients had pure histology. For pure histology, multivariable analysis (MVA) showed nonacademic facility, stage 4 disease, and poorly differentiated grade were associated with worse survival. On MVA, receipt of CHT (hazard ratio [HR] = 0.84, P = .644) or receipt of androgen deprivation therapy (HR = 0.88, P = .715) did not affect overall survival. Receipt of RT was nonsignificant compared to surgery (HR = 0.75, P = .475). For mixed histology, MVA showed receipt of CHT and prostate-specific antigen > 20 ng/mL were associated with worse survival. Receipt of androgen deprivation therapy (HR = 1.35, P = .414) did not affect overall survival. Receipt of RT was also nonsignificant compared to surgery (HR = 1.42, P = .344).

CONCLUSION

RT and surgery for nonmetastatic SCCP yield comparable options as local therapies.

Trajectories of sexual dysfunction and its risk factors in women with gynecologic cancer across radiation therapy and healthy controls

e24097

Background: Women with gynecological cancer (GynCa) reported an increased risk for acute and long-term sexual dysfunction across cancer treatments, especially radiation therapy (RT). However, limited data exist on the course of sexual dysfunction across RT and its risk factors are unknown. This study sought to characterize women’s sexual dysfunction trajectories and identified risk factors of persistent sexual dysfunction. Methods: Using a longitudinal study design, patient-reported sexual dysfunction, demographic and clinical data were collected. Women receiving RT for GynCa older than 18 years or age, race, and BMI matched healthy controls were enrolled. Female Sexual Function Index (FSFI) was used to assess women’s sexual dysfunction. Patients completed all the questionnaires pre-RT, at the end of RT, 6- and 12-month post-RT. Group-based trajectory modeling was used to identify trajectories of sexual dysfunction and risk factors of persistent sexual dysfunction. Results: Eighty-two patients were analyzed, including 36 GynCa patients receiving RT and 46 healthy post-menopausal women, comprising of 33 Blacks, 44 Whites, and 5 others. Three trajectory groups of sexual dysfunction (total FSFI score) were identified: low risk (17.4%), moderate risk (12.3%), and high risk (70.4%). All three trajectory groups were significantly different from each other (p<0.01). Similarly, three trajectories were identified for each of six FSFI domains: desire (low [6.3%], moderate [62.5%], high [31.2%], p<0.01); arousal (low [38.1%], moderate [46.4%], high [15.4%], p<0.01); lubrication (low [49.7%], moderate [44.6%], high [5.7%], p<0.01); orgasm (low [43.8%], moderate [31.3%], high [24.9%], p<0.01); pain (low [25.5%], moderate [64.2%], high [10.3%], p<0.01); and satisfaction (low [8.3%], moderate [61.4%], high [30.3%], p<0.01). Risk factors of sexual dysfunction were high pH (p=0.007) and without chemotherapy (p=0.019). Young women had more arousal (p=0.011); high education level was associated with high arousal (p=0.039); low pH was associated with high arousal (p=0.018) and orgasm (p=0.036). No risk factors were found for desire and satisfaction domains. BMI, surgery, and study cohort (cancer vs healthy) were not predictors of sexual dysfunction trajectories. Conclusions: This study identified three trajectories of sexual dysfunction. Low education, high pH, no chemotherapy, and elder women were risk factors of severe sexual dysfunction. Sexual dysfunction interventions should address these risk factors.

Lung Stereotactic Body Radiation Therapy and Concurrent Immunotherapy: A Multicenter Safety and Toxicity Analysis

PURPOSE

Radical treatment of metastases with stereotactic body radiation therapy (SBRT) is commonly implemented in patients receiving concurrent immune checkpoint inhibition (ICI), despite limited safety and toxicity data. The purpose of this study was to evaluate the safety and tolerability of lung SBRT with concurrent ICI.

METHODS AND MATERIALS

Records from a single academic institution were reviewed to identify patients treated with lung SBRT and concurrent (within 30 days) ICI; a contemporaneous cohort receiving lung SBRT alone was included for reference. Treatment-related adverse effects occurring within 30 days (acute) and 180 days (subacute) of SBRT were evaluated.

RESULTS

Our study included 117 patients; 54 received SBRT with concurrent ICI (56 courses, 69 target lesions), and 63 received SBRT alone (68 courses, 79 lesions). Median follow-up was 9.2 months in the SBRT + ICI cohort. Among the patients, 67.9% received ICI monotherapy, 17.9% ICI/chemotherapy, and 14.3% ICI/ICI combinations; 25% received ICI between SBRT fractions, and 42.9% received ICI both before and after SBRT. The risk of grade 3 pneumonitis was higher in the SBRT + ICI versus SBRT alone cohort (10.7% vs 0%, P < .01) and any-grade pneumonitis was similar (33.9% vs 27.9%, SBRT + ICI vs SBRT, P = .47). The risk of any-grade pneumonitis appeared elevated with ICI/ICI combinations (62.5% vs 29.2%). Receipt of ICI, planning treatment volume, and lobes involved in SBRT were linked to high-grade pneumonitis. Subacute grade 3+ adverse effects occurred in 26.8% of SBRT + ICI and 2.9% of SBRT-alone patients.

CONCLUSIONS

Overall, concurrent lung SBRT + ICI is safe. Given the clinically meaningful risk of pneumonitis, closer monitoring should be considered for SBRT + ICI patients, especially those receiving radiation therapy with ICI/ICI combinations.

Health care disparities among octogenarians and nonagenarians with stage III lung cancer

BACKGROUND

To the authors' knowledge, the practice patterns for patients aged more than 80 years with stage III non-small cell lung cancer (NSCLC) is not well known. The purpose of the current study was to investigate factors predictive of and the impact on overall survival (OS) after concurrent chemoradiation (CRT) among patients aged ≥80 years with American Joint Committee on Cancer stage III NSCLC in the National Cancer Data Base (NCDB).

METHODS

In the NCDB, patients aged ≥80 years who were diagnosed with stage III NSCLC from 2004 to 2013 with complete treatment records were identified. Multivariable logistic regression and Cox proportional hazard models were generated and propensity score-matched analysis was used.

RESULTS

A total of 12,641 patients met the entry criteria: 6018 (47.6%) had stage IIIA disease and 6623 (52.4%) had stage IIIB disease. The median age at the time of diagnosis was 83.0 years (range, 80-91 years). A total of 7921 patients (62.7%) received no therapy. Black race (odds ratio [OR], 1.23; 95% confidence interval [95% CI], 1.06-1.43) and living in a lower educated census tract of residence (OR, 1.20; 95% CI, 1.03-1.40) were found to be associated with not receiving care, whereas treatment at an academic center (OR, 0.80; 95% CI, 0.70-0.92) was associated with receiving cancer-directed therapy. Receipt of no treatment (hazard ratio [HR], 2.69; 95% CI, 2.57-2.82) or definitive radiation alone (HR, 1.15; 95% CI, 1.07-1.24) compared with CRT was associated with worse OS. On propensity score matching, not receiving CRT was found to be associated with worse OS (HR, 1.58; 95% CI, 1.44-1.72).

CONCLUSIONS

In this NCDB analysis, approximately 62.7% of patients aged ≥80 years with stage III NSCLC received no cancer-directed care. Black race and living in a lower educated census tract were associated with not receiving cancer-directed care. OS was found to be improved in patients receiving CRT. Cancer 2018;124:775-84. © 2018 American Cancer Society.

Next-generation sequencing and clinical outcomes of patients with lung adenocarcinoma treated with stereotactic body radiotherapy

BACKGROUND

Genetic aberrations are well characterized in lung adenocarcinomas (LACs) and clinical outcomes have been influenced by targeted therapies in the advanced setting. Stereotactic body radiotherapy (SBRT) is the standard-of-care therapy for patients with nonoperable, early-stage LAC, but to the authors' knowledge, no information is available regarding the impact of genomic changes in these patients. The current study sought to determine the frequency and clinical impact of genetic aberrations in this population.

METHODS

Under an Institutional Review Board-approved protocol, the records of 242 consecutive patients with early-stage lung cancers were reviewed; inclusion criteria included LAC histology with an adequate tumor sample for the successful use of next-generation sequencing and fluorescence in situ hybridization testing. Univariate analysis was performed to identify factors associated with clinical outcomes.

RESULTS

LAC samples from 98 of the 242 patients were reviewed (40.5%), of whom 45 patients (46.0%) had genetic testing. The following mutations were noted: KRAS in 20.0% of samples, BRAF in 2.2% of samples, SMAD family member 4 (SMAD4) in 4.4% of samples, epidermal growth factor receptor (EGFR) in 15.6% of samples, STK1 in 2.2% of samples, tumor protein 53 (TP53) in 15.6% of samples, and phosphatase and tensin homolog (PTEN) in 2.2% of samples. The following gene rearrangements were observed: anaplastic lymphoma kinase (ALK) in 8.9% of samples, RET in 2.2% of samples, and MET amplification in 17.8% of samples. The median total delivered SBRT dose was 50 grays (range, 48-60 grays) over a median of 5 fractions (range, 3-8 fractions). The KRAS mutation was associated with worse local control (odds ratio [OR], 3.64; P<.05). MET amplification was associated with worse regional (OR, 4.64; P<.05) and distant (OR, 3.73; P<.05) disease control.

CONCLUSIONS

To the authors' knowledge, the current series is the first to quantify genetic mutations and their association with clinical outcomes in patients with early-stage LAC treated with SBRT. KRAS mutations were associated with worse local control and MET amplification was associated with worse regional and distant disease control, findings that need to be validated in a prospective setting. Cancer 2017;123:3681-3690. © 2017 American Cancer Society.

Health care disparities among octogenarians and nonagenarians with stage III lung cancer

e18075

Background: Octogenarians and nonagenarians with stage III lung cancer are underrepresented in randomized trials that established the standard of care therapy of concurrent chemoradiation (CRT). The purpose of this study was to investigate factors predictive of and the impact on overall survival (OS) following CRT among patients ≥80 years old with stage III non-small cell lung cancer (NSCLC) in the National Cancer Data Base (NCDB). Methods: In the NCDB, patients ≥80 years old from 2004 to 2013 with stage III NSCLC were queried. Logistic regression, Kaplan-Meier method, and Cox-proportional hazard regression analyses were performed as well as propensity-score matched (PSM) analysis to reduce treatment selection bias. Results: A total of 12,641 stage III NSCLC patients ≥80 years old were identified with complete treatment and OS records; 7,921 (62.7%) received no treatment, 1,153 received definitive radiation alone (9.1%), and 3,567 (28.2%) received CRT. On multivariable analysis (MVA), black race, female gender, advancing age, residence in a lower-educated county, adenocarcinoma histology, and patients with stage IIIB tumors were associated with receiving no anti-cancer therapy while treatment at an academic facility and lower comorbidity status were associated with receiving anti-cancer treatment (all p < 0.05). On MVA, male gender, advancing age, non-adenocarcinoma histology, higher tumor grade, larger tumors, advancing T and N stage, stage IIIB tumors (vs. IIIA), delayed start to CRT, and not receiving CRT were associated with worse OS (all p < 0.05). OS rates at 1 and 5 years was 53.7% and 10.1% respectively for patients receiving CRT compared to 16.4% and 3.3% respectively for all other therapies (p < 0.01). PSM analysis confirmed that not receiving CRT was associated with worse OS (HR = 1.23, 95% CI 1.11-1.34; p < 0.01). Conclusions: A significant portion of patients ≥80 years old with stage III NSCLC do not receive treatment. Black race, female gender, advancing age, and residence in a lower-educated county were associated with not receiving therapy. In this NCDB series, OS is higher in patients ≥80 years old receiving CRT, even when adjusting for patient- and tumor-related factors.

Clinical outcomes and the role of adjuvant therapy sequencing in Type II uterine cancer following definitive surgical treatment

PURPOSE OF INVESTIGATION

Because of rarity, consensus on adjuvant therapies for Type II endometrial cancers (BC) remains undefined. Reporting their institutional outcomes, the present authors assessed the impact of adjuvant therapies on recurrence and overall survival in women with 2009 FIGO Stage I-III Type II BC.

MATERIAL AND METHODS

The authors identified 108 women, treated with definitive surgery between 2000-2013, with pathologically-confirmed Type II EC (non-endometrioid [NEM, n=801 and high grade endometrioid [G3EEC, n=28]) Cox proportional hazard models were used to assess the effect of prognostic variables on disease-free (DFS) and overall survival (OS). Kaplan-Meier method was used to assess survival.

RESULTS

Of the 108 women, 83 (77%) were African American (AA). Fifty-nine (55%), 12 (11%), and 37 (34%) were Stage I, II, and III, respectively. Ninety-seven patients received adjuvant therapy: 52 (radiation only), four (chemotherapy only), and 40 (combined). During follow-up (median 41 months), 44 patients (41%) recurred. Five-year DFS was 53% overall (48% [NEM], 80% [G3EEC]). Five-year OS was 75% overall (68% [NEM], 95% [G3EEC]). On multivariate analysis, lower stage and adjuvant radiation improved DFS. Higher stage, NEM, and increasing age were poor prognostic indicators of OS.

CONCLUSION

Representing a large single institutional cohort for Type II BC, the present study's observed sur- vival rates are consistent with previous studies, despite the relatively high frequency of carcinosarcoma and Stage III/nodal disease. The protective effect on recurrence was not lost when radiation was delayed for chemotherapy. The present results support a multimodal adjuvant approach for treating all stages of invasive NEM EC.

Radiotherapy patterns of care in gastric adenocarcinoma: a single institution experience

BACKGROUND

Gastric adenocarcinoma (GAC) is one of the most commonly diagnosed cancers worldwide. Two standard approaches for treatment of resectable GAC include adjuvant 5-fluorouracil-based chemoradiotherapy [per Intergroup 0116 (INT-0116) trial and perioperative epirubicin, cisplatin, fluorouracil (ECF) chemotherapy per Medical Research Council Adjuvant Gastric Infusional Chemotherapy (MAGIC) trial]. Controversy remains regarding the most appropriate treatment strategy to decrease recurrence rates and improve survival following surgery. The purpose of this study was to analyze how patterns of care for patients with GAC treated at Emory University Hospital changed following publication of the MAGIC trial in 2006.

METHODS

We analyzed a prospectively maintained database of 150 patients who underwent resection for GAC between December 2000 and June 2013. Patients were divided into two cohorts, Early [2000-2006] and late [2007-2013]. The primary objective was to compare the number of patients assigned to adjuvant chemoradiotherapy (aCRT) vs. perioperative chemotherapy (PC) throughout the study period and secondarily assess for recurrence patterns and survival outcomes for patients assigned to those two strategies.

RESULTS

Between 2000 and 2013, 124 patients received adjuvant therapy for GAC. Fifty-four patients were treated with PC and 70 patients with aCRT. The early cohort included 56 patients, and the late cohort included 94 patients. There was no statistical difference in the number of patients receiving aCRT between the Early and Late cohorts [n=23 (50%) vs. 35 (38%) respectively, P=0.21]. PC increased from 2 patients (3.6%) in the Early cohort to 32 patients (34%) in the Late cohort (P<0.001). Four-year overall survival (OS) was 32.6% for the Early cohort and 68.8% for the Late cohort (P=0.010). Overall recurrence rate was 25.3% with no significant difference in rates of recurrence seen between the Early and Late cohorts.

CONCLUSIONS

PC has become more prevalent in patients treated at Emory following publication of the MAGIC trial in 2006. OS, but not recurrence rates, has also improved since publication. Although improved survival is suggestive of improved care, the question of optimal treatment regimen remains open. Further prospective comparisons of PC and aCRT are needed to identify patient and disease parameters that may guide therapy selection.

CHD7 expression predicts survival outcomes in patients with resected pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with poor outcomes with current therapies. Gemcitabine is the primary adjuvant drug used clinically, but its effectiveness is limited. In this study, our objective was to use a rationale-driven approach to identify novel biomarkers for outcome in patients with early-stage resected PDAC treated with adjuvant gemcitabine. Using a synthetic lethal screen in human PDAC cells, we identified 93 genes, including 55 genes linked to DNA damage responses (DDR), that demonstrated gemcitabine sensitization when silenced, including CHD7, which functions in chromatin remodeling. CHD7 depletion sensitized PDAC cells to gemcitabine and delayed their growth in tumor xenografts. Moreover, CHD7 silencing impaired ATR-dependent phosphorylation of CHK1 and increased DNA damage induced by gemcitabine. CHD7 was dysregulated, ranking above the 90th percentile in differential expression in a panel of PDAC clinical specimens, highlighting its potential as a biomarker. Immunohistochemical analysis of specimens from 59 patients with resected PDAC receiving adjuvant gemcitabine revealed that low CHD7 expression was associated with increased recurrence-free survival (RFS) and overall survival (OS), in univariate and multivariate analyses. Notably, CHD7 expression was not associated with RFS or OS for patients not receiving gemcitabine. Thus, low CHD7 expression was correlated selectively with gemcitabine sensitivity in this patient population. These results supported our rationale-driven strategy to exploit dysregulated DDR pathways in PDAC to identify genetic determinants of gemcitabine sensitivity, identifying CHD7 as a novel biomarker candidate to evaluate further for individualizing PDAC treatment.

Low CHD5 expression activates the DNA damage response and predicts poor outcome in patients undergoing adjuvant therapy for resected pancreatic cancer

The DNA damage response (DDR) promotes genome integrity and serves as a cancer barrier in precancerous lesions but paradoxically may promote cancer survival. Genes that activate the DDR when dysregulated could function as useful biomarkers for outcome in cancer patients. Using a siRNA screen in human pancreatic cancer cells, we identified the CHD5 tumor suppressor as a gene, which, when silenced, activates the DDR. We evaluated the relationship of CHD5 expression with DDR activation in human pancreatic cancer cells and the association of CHD5 expression in 80 patients with resected pancreatic adenocarcinoma (PAC) by immunohistochemical analysis with clinical outcome. CHD5 depletion and low CHD5 expression in human pancreatic cancer cells lead to increased H2AX-Ser139 and CHK2-Thr68 phosphorylation and accumulation into nuclear foci. On Kaplan-Meier log-rank survival analysis, patients with low CHD5 expression had a median recurrence-free survival (RFS) of 5.3 vs 15.4 months for patients with high CHD5 expression (P=0.03). In 59 patients receiving adjuvant chemotherapy, low CHD5 expression was associated with decreased RFS (4.5 vs 16.3 months; P=0.001) and overall survival (OS) (7.2 vs 21.6 months; P=0.003). On multivariate Cox regression analysis, low CHD5 expression remained associated with worse OS (HR: 3.187 (95% CI: 1.49-6.81); P=0.003) in patients undergoing adjuvant chemotherapy. Thus, low CHD5 expression activates the DDR and predicts for worse OS in patients with resected PAC receiving adjuvant chemotherapy. Our findings support a model in which dysregulated expression of tumor suppressor genes that induce DDR activation can be utilized as biomarkers for poor outcome.

Pronecrotic mixed lineage kinase domain-like protein expression is a prognostic biomarker in patients with early-stage resected pancreatic adenocarcinoma

BACKGROUND

Mixed lineage kinase domain-like protein (MLKL) is a necrosome component mediating programmed necrosis that may be an important determinant of cancer cell death. The goal of the current study was to evaluate the prognostic value of MLKL expression in patients with pancreatic adenocarcinoma (PAC).

METHODS

Tissue from 80 patients was collected from a prospectively maintained database of patients with PAC who underwent pancreaticoduodenectomy between January 2000 and October 2008. Immunohistochemistry analysis was performed and scored using an established scoring system. Kaplan-Meier survival curves were generated for recurrence-free survival (RFS) and overall survival (OS) for all patients and for patients receiving adjuvant chemotherapy. MLKL scores were correlated with RFS and OS using univariate and multivariate Cox regression analyses incorporating clinically relevant covariates.

RESULTS

The median age of the patients was 63 years and 53% were men. Low MLKL expression was associated with decreased OS (6 months vs 17 months; P = .006). In the subset of 59 patients who received adjuvant chemotherapy, low MLKL expression was associated with decreased RFS (5 months vs 15 months; P = .006) and decreased OS (6 months vs 19 months; P < .0001). On multivariate analysis, low MLKL expression was associated with poor OS in all patients (hazards ratio, 4.6 [95% confidence interval, 1.6-13.8]; P = .006) and in patients receiving adjuvant chemotherapy (hazards ratio, 8.1 [95% confidence interval, 2.2-29.2]; P = .002).

CONCLUSIONS

Low expression of MLKL is associated with decreased OS in patients with resected PAC and decreased RFS and OS in the subset of patients with resected PAC who receive adjuvant chemotherapy. The use of this biomarker in patients with PAC may provide important prognostic information.

Abstract 1767: A synthetic lethal screen identifies determinants of gemcitabine sensitivity in pancreatic cancer

Purpose/Objectives:

Pancreatic cancer is notorious for its devastating disease course and prognosis. Gemcitabine is a widely used regimen for pancreatic cancer treatment but lack of response and resistance often limits its effectiveness. Thus, a better understanding of which patients are likely to respond to gemcitabine treatment would allow the personalization of therapies that are most effective for a patient while potentially reducing toxicity. The objective of this study was to identify the genes and mechanisms involved in determining gemcitabine sensitivity in pancreatic cancer.

Materials/Methods:

We completed a loss of function genetic screen to identify genes, which when silenced cause sensitization of resistance to a low dose of gemcitabine in human pancreatic cancer cells. We optimized a high-throughput assay using ATR or CHK1 siRNA as positive controls and ATM or non-targeting (NT) siRNA as negative controls. Our siRNA library included 4,474 siRNAs corresponding to 1,006 unique human genes arrayed in a one-gene:one-well format in 96-well plates. Genes chosen for our library consisted predominantly of nuclear enzymes, which we reasoned were more likely to function directly in DNA repair processes and be targetable. Mia PaCa-2 cells were transfected with 25 nM siRNA and treated 48 hours later with or without 13 nM gemcitabine for 72 hours prior to assaying for cell proliferation using WST-1 reagent. Candidate genes were deconvoluted with individual siRNAs to eliminate off-target effects and validated by secondary screens for cell cycle recovery after a challenge of hydroxyurea (HU) and γH2AX phosphorylation in the absence of exogenous damage following gene silencing. A rigorous statistical algorithm was used to determine positive hits. Genes with variable expression in pancreatic cancer tissue samples were identified by mining through published data sets.

Results:

We identified 49 genes in which at least 2 unique siRNAs yielded gemcitabine sensitization and 17 genes in which at least 2 unique siRNAs yielded gemcitabine resistance. Positive hits included 25 known genome maintenance genes, including well characterized ATR signaling pathway genes CHK1, RAD9, HUS1, and CDC25A, 27 putative ATM/ATR substrates, and 26 genes identified in previously published DNA damage sensitivity screens. Eight of our genes are above the 90th percentile in variability of expression amongst a panel of pancreatic cancer tissue samples.

Conclusion:

We identified gemcitabine sensitization and resistance genes that are variably expressed in pancreatic cancer, which may function as novel targets or biomarkers for individualizing treatment for patients with pancreatic cancer.

Citation Format: Matthew D. Warren, Claire W. Hardy, Brooke G. Pantazides, Khanjan Gandhi, Jerome C. Landry, Joseph W. Shelton, Shishir K. Maithel, Bassel El-Rayes, Jeanne Kowalski, David S. Yu. A synthetic lethal screen identifies determinants of gemcitabine sensitivity in pancreatic cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1767. doi:10.1158/1538-7445.AM2013-1767

In vitro and in vivo enhancement of chemoradiation using the oral PARP inhibitor ABT-888 in colorectal cancer cells

PURPOSE

Poly(ADP-ribose) polymerase plays a critical role in the recognition and repair of DNA single-strand breaks and double-strand breaks (DSBs). ABT-888 is an orally available inhibitor of this enzyme. This study seeks to evaluate the use of ABT-888 combined with chemotherapy and radiation therapy (RT) in colorectal carcinoma models.

METHODS AND MATERIALS

RT clonogenic assays were performed on HCT116 and HT29 cells treated with 5-fluorouracil, irinotecan, or oxaliplatin with or without ABT. The surviving fraction at 2 Gy and dose-modifying factor at 10% survival were analyzed. Synergism was assessed by isobologram analysis for combination therapies. γH2AX and neutral comet assays were performed to assess the effect of therapy on DSB formation/repair. In vivo assessments were made by use of HCT116 cells in a xenograft mouse model. Tumor growth delay was measured at a volume of 500 mm(3).

RESULTS

Both lines were radiosensitized by ABT alone, and ABT further increased chemotherapy dose-modifying factors to the 1.6 to 1.8 range. All combinations were synergistic (combination indices <0.9). ABT treatment significantly increased DSB after RT (γH2AX, 69% vs 43%; P=.017) and delayed repair. We found tumor growth delays of 7.22 days for RT; 11.90 days for RT and ABT; 13.5 days for oxaliplatin, RT, and ABT; 14.17 days for 5-fluorouracil, RT, and ABT; and 23.81 days for irinotecan, RT, and ABT.

CONCLUSION

ABT-888 radiosensitizes at similar or higher levels compared with classic chemotherapies and acts synergistically with these chemotherapies to enhance RT effects. In vivo confirmation of these results indicates a potential role for combining its use with existing chemoradiation regimens.

Abstract 3119: A synthetic lethal screen identifies genetic determinants for gemcitabine sensitivity in pancreatic cancer

Pancreatic cancer is notorious for its devastating disease course and prognosis. Gemcitabine is a widely used regimen for pancreatic cancer treatment but lack of response and resistance often limits its use. To identify the genes and mechanisms involved in determining gemcitabine sensitivity in pancreatic cancer, we completed a loss of function genetic screen using RNA interference to identify genes which when silenced are synthetically lethal with a low dose of gemcitabine in human pancreatic cancer cells. We optimized an assay using ATR or CHK1 siRNA as positive controls and ATM or non-targeting (NT) siRNA as negative controls. Our siRNA library included 4,474 siRNAs corresponding to 1,006 unique human genes arrayed in a one-gene:one-well format in 96-well plates. Genes chosen for our library consisted predominantly of nuclear enzymes, including but not limited to kinases, phosphatases, ubiquitinylation proteins, sumoylation proteins, acetylases, deactylases, nucleases, helicases, and chromatin modifiers, which we reasoned were more likely to function directly in DNA repair processes and be targetable. MIA PaCa-2 cells were transfected with 25 nM siRNA and treated 48 hours later with or without 13 nM gemcitabine for 72 hours prior to the cell proliferation assay using WST-1 reagent. Using this assay, we identified 87 genes which when silenced caused gemcitabine sensitization and 42 genes which when silenced caused gemcitabine resistance. Positive hits included 16 known genome maintenance genes including well-characterized ATR signaling pathway genes - CHK1, RAD9, HUS1, and CDC25A, 5 putative ATM/ATR substrates, and 20 genes identified in previously published DNA damage sensitivity screens. 21 of the genes are somatically mutated or differentially expressed in pancreatic cancer, suggesting that our gemcitabine sensitivity genes may function as useful predictive biomarkers or novel targets for the treatment of pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3119. doi:1538-7445.AM2012-3119

Computer literacy in today's medical center environment

The need for computer literacy is becoming increasingly important across the broad scope of the American work scene. At the Wilford Hall USAF Medical Center (WHMC) numerous computer systems have been introduced into the operational environment. Training for these systems has been restricted primarily to transaction processing and routine report generation for those actually involved as users of these systems. WHMC has developed and implemented a broad computer literacy program designed generally to raise the computer literacy of the overall staff, and specifically to inform executive and middle management of the general capabilities of the computer systems. The program consists of a brown-bag lunchtime videotape theater on a series of computer-related subjects as well as formal classes developed in a modular format. Each formal class is tailored to the specific needs of the target executive or middle-management group.