Th2 Cells Are Associated with Tumor Recurrence Following Radiation

The curative treatment of multiple solid tumors, including head and neck squamous cell carcinoma (HNSCC), utilizes radiation. The outcomes for HPV/p16-negative HNSCC are significantly worse than HPV/p16-positive tumors, with increased radiation resistance leading to worse locoregional recurrence (LRR) and ultimately death. This study analyzed the relationship between immune function and outcomes following radiation in HPV/p16-negative tumors to identify mechanisms of radiation resistance and prognostic immune biomarkers. A discovery cohort of 94 patients with HNSCC treated uniformly with surgery and adjuvant radiation and a validation cohort of 97 similarly treated patients were utilized. Tumor immune infiltrates were derived from RNAseq gene expression. The immune cell types significantly associated with outcomes in the discovery cohort were examined in the independent validation cohort. A positive association between high Th2 infiltration and LRR was identified in the discovery cohort and validated in the validation cohort. Tumor mutations in CREBBP/EP300 and CASP8 were significantly associated with Th2 infiltration. A pathway analysis of genes correlated with Th2 cells revealed the potential repression of the antitumor immune response and the activation of BRCA1-associated DNA damage repair in multiple cohorts. The Th2 infiltrates were enriched in the HPV/p16-negative HNSCC tumors and associated with LRR and mutations in CASP8, CREBBP/EP300, and pathways previously shown to impact the response to radiation.

Cs-131 prostate brachytherapy boost and effect of hydrogel rectal spacer on long-term patient-reported rectal bleeding and bowel quality of life

PURPOSE

This study evaluates long-term patient-reported bowel quality of life (QOL), rectal bleeding, and bleeding bother in patients with prostate cancer treated with external beam radiation therapy (EBRT) and Cesium-131 LDR brachytherapy (LDR-BT) boost with and without hydrogel rectal spacer.

METHODS AND MATERIALS

This is a retrospective analysis of prostate cancer patients treated between 2007 and 2022 with 45 Gy EBRT followed by 85 Gy Cs-131 LDR-BT boost with or without hydrogel rectal spacer. Expanded Prostate Cancer Index Composite (EPIC) QOL questionnaires pre-treatment and at each follow-up were collected. Patient-reported rectal bleeding occurring more than "rarely" and bother from rectal bleeding occurring more than a "very small problem" were deemed clinically significant. Fisher's exact test was used to test the association of rectal spacer use and the incidence of clinically significant rectal bleeding and bleeding bother. Paired samples t-test was used to analyze mean bowel scores at each time point.

RESULTS

Three hundred and forty-one patients were included in the analysis. The rectal spacer was used in 108 patients. Overall median follow-up was 48 months (IQR, 24-72), with a median follow-up of 24 months (IQR, 12-37.5) for the hydrogel group and 60 months (IQR, 36-84) for the non-hydrogel group. EPIC questionnaire response rates at median follow-up were 33% and 37% for the hydrogel and non-hydrogel groups, respectively. A clinically significant decrease in mean bowel domain scores was seen in the bowel bother domain at 6 and 12 months for patients who did not receive a rectal spacer. At the last follow-up of 60 months, the prevalence of clinically significant rectal bleeding and bleeding bother were 2.2% and 2.2%, respectively. The cumulative incidence of clinically significant long-term rectal bleeding was 2.8% and 18.9% in the hydrogel group and non-hydrogel group, respectively (Fisher's exact test, p < 0.0001). The cumulative incidence of clinically significant long-term bowel bother was 4.6% and 19.7% in the hydrogel group and non-hydrogel group, respectively (Fisher's exact test, p < 0.001).

CONCLUSIONS

Use of hydrogel rectal spacer with EBRT and Cs-131 LDR-BT boost was significantly associated with a lower incidence of patient-reported rectal bleeding and bother from rectal bleeding, and better long-term bowel QOL. Cumulative incidence was 2.8% (hydrogel group) versus 18.9% (non-hydrogel group) and 4.6% (hydrogel group) versus 19.7% (non-hydrogel group) for clinically significant long-term rectal bleeding and long-term bleeding bother, respectively.

Is Programmed Death Ligand 1(PD-L1) Expression in Vulvar Cancer Prognostic for Locoregional Control?

PURPOSE/OBJECTIVE(S)

Vulvar cancer is a rare female genital neoplasm in which surgery and radiotherapy play an integral role in the treatment paradigm; however, locoregional recurrence remains the predominant pattern of failure. Little is known about the impact of PD-L1 status in vulvar cancer and its value for clinical outcomes and response prediction to immunotherapy. We sought to explore clinical outcomes of patients with positive PD-L1 expression in vulvar cancer.

MATERIALS/METHODS

Single-institution retrospective analysis of patients with surgically resectable invasive vulvar carcinoma from 2001-2021 was performed. Patients with locally advanced disease not amendable to upfront surgery or de novo metastatic disease were excluded. Immunohistochemical PD-L1 expression was assessed using the Combined Positive Score (CPS) with positive expression defined as ≥1, and Tumor Proportion Score (TPS) with positive expression defined as ≥1%. Survival and disease control outcomes were calculated using the Kaplan-Meier Method with log-rank t-test. Multivariable analysis was conducted using a parsimonious cox regression analysis using forward conditional selection.

RESULTS

A total of 85 patients were identified with a median age of 69 years old (IQR: 59-78), 54% (n = 46) FIGO stage I-II, 97% (n = 82) squamous cell carcinoma histology, 41% (n = 35) p16 positive status, 74% (n = 63) without a history of lichen sclerosis, 40% (n = 34) without co-existing vulvar intraepithelial neoplasm (VIN), and 49% (n = 42) treated with surgery alone. There were 72% (n = 61) with positive PD-L1 TPS (≥1%), and 81% (n = 69) with positive PD-L1 CPS (≥1) expression. The median follow up was 49 months (IQR: 21-75 months). The 5-year OS was 79% (95% CI, 70%-89%), DFS 55% (95% CI, 43%-67%), local control (LC) 59% (95% CI, 47%-72%), regional control (RC) 86% (95% CI, 78%-94%), and distant metastasis (DM) 96% (95% CI, 92%-100%). PD-L1 expression was associated with lower LC and DFS by TPS ≥1%. The 5-year LC of 82% (95% CI, 65%-98%) for PD-L1 negative versus 50% (95% CI, 34%-65%) positive disease (p = 0.03). The 5-year DFS was 77% (95% CI, 59%-95%) for PD-L1 negative versus 46% (95% CI, 31%-61%) positive disease (p = 0.03). No significant DFS or LC difference was noted by CPS levels ≥1. No significant difference was observed for RC, DM, or OS. On multivariable analysis, PD-L1 TPS remained a significant predictor for LC (HR = 3.01, 95% CI, 1.07-8.95, p = 0.04). No significant difference in DFS was observed for PD-L1 TPS on multivariable analysis.

CONCLUSION

PD-L1 expression is associated with higher rates of local recurrence and may represents a potentially important actionable target independent of p16 status to improve the predominant pattern of relapse in this uncommon malignancy.

Long-Term Urinary Toxicity Follow-Up of Combined External Beam Radiation and Cs-131 LDR Brachytherapy Boost for Prostate Cancer

PURPOSE/OBJECTIVE(S)

To evaluate and update our institutional data on chronic patient-reported urinary symptoms in patients with prostate cancer treated with combined external beam radiation therapy (EBRT) and Cesium-131 (Cs-131) LDR brachytherapy boost.

MATERIALS/METHODS

Patients treated from September 2006-July 2022 and with at least 6 months of follow-up were analyzed. Patients filled out the Expanded Prostate Cancer Index Composite (EPIC) questionnaire pre-treatment and at each scheduled follow-up. Mean EPIC urinary scores were calculated for urinary summary, urinary function, urinary bother, urinary incontinence, and urinary irritative/obstructive domains. Changes of 7-points or more in mean domain scores were deemed clinically significant. The prevalence of urinary bleeding was calculated and bleeding occurring more than "about once a week" ("more than once a week", "about once a day", and "more than once a day") was deemed clinically significant. Outcomes were analyzed at each follow-up timepoint using paired t-test.

RESULTS

A total of 341 patients with prostate cancer were included in the analysis of which 183 were intermediate-risk and 158 high-risk. 174 patients were treated with tri-modality therapy, and SpaceOAR was used in 108 patients. Long-term statistically significant decreases in mean EPIC QOL scores were seen in urinary summary, urinary function, urinary bother, urinary incontinence, and urinary irritative/obstructive domains at 6 months, with clinically and statistically significant decreases in urinary function and urinary incontinence at 6 months (86±17.4, 83.4±22.2 respectively) and up to 18 months post-treatment (84.8±17.4, 83.6±20.7 respectively) compared with pre-treatment scores (93.1±10.7, 90.8±14.8 respectively), with both domains returning to clinical baseline at 24 months. Urinary irritative/obstructive mean scores clinically and significantly decreased at 9 months (77±17.4) compared to pre-treatment (84.7±13.5), returning to clinical baseline at 12 months. The prevalence of clinically significant urinary bleeding at 6, 12, 24, 36, 48, and 60 months was 1.3%, 2.6%, 3.7%, 0.7%, 0.9%, and 2.3% respectively. At the median follow-up of 42 months (IQR 54, 18-72), mean EPIC scores were clinically improved (≥7-point increase) from pre-treatment baseline in 15-30% of patients across the analyzed urinary domains.

CONCLUSION

Long-term patient-reported clinically significant decreases in urinary function and urinary incontinence mean EPIC scores occurred up to 18 months following combined external beam radiation and Cs-131 prostate brachytherapy and returned to baseline at 24 months, while clinically significant decrease in urinary irritability/obstructive mean scores occurred at 9 months and returned to baseline at 12 months. At 42 months follow-up, mean urinary domain scores improved from pre-treatment baseline in 15-30% of patients.

The influence of breast cancer subtype on survival after palliative radiation for osseous metastases

Background

Among patients with osseous metastases, breast cancer (BC) patients typically have the best prognosis. In the palliative setting, BC is often considered a single disease, but based on receptor status there are four distinct subtypes: luminal A (LA), luminal B (LB), triple negative (TN), and HER2‐enriched (HER2). We hypothesize that survival and palliative outcomes following palliative RT for osseous metastases correlate with breast cancer subtype (BCS).

Methods

We identified 3,895 BC patients with known receptor status who received palliative RT for osseous metastases from 2004–2013 in the National Cancer Database. Kaplan–Meier method with log‐rank testing and univariate/multivariate Cox‐regression was used to identify survival factors. Incomplete radiation courses, 30‐day mortality rate, and percentage remaining life spent receiving RT (PRLSRT) were calculated.

Results

Subtypes were 54% LA, 33% LB, 8% TN, and 5% HER2 with median survival of 34.1, 28.2, 5.3, and 15.7 months, respectively (p < 0.001). Overall 82% of patients received ≥10 fractions. Although BCS had limited effect on radiation regimens, TN received nearly twice as many single or hypofractionated (≤5 fractions) treatments, but the overall rate of these fraction schemes was low at 3.7 and 13.7%, respectively. Compared to LA and LB, TN and HER2 patients had worse palliative outcomes; higher rates of incomplete courses at 18.8% and 18.3% versus 12.7%–14.4%; higher 30‐day mortality post‐radiotherapy at 21.5% and 16.0% versus 6.3%–7.9%, and higher median PRLSRT of 7.7% and 3.7% versus 2.2%–2.4% for LA and LB. On multivariate analysis, BCS was associated with overall survival with TN (HR 3.7), HER2 (HR 1.75), and LB (HR 1.28) fairing worse than LA (p < 0.001).

Conclusions

BCS correlated with survival and palliative outcome following radiation to osseous metastases. BCS should be considered by physicians when planning palliative RT to maximize quality‐of‐life, avoid unnecessary treatment, and ensure palliative benefits.

Abstract 6185: In vivo screening in HPV positive and HPV negative head and neck squamous cell carcinoma

Background: The pathogenesis of head and neck squamous cell carcinoma (HNSCC) largely occurs through two pathways, human papillomavirus (HPV) mediated or chemical carcinogenesis secondary to alcohol and tobacco use. HPV status is an important prognostic factor and marker for sensitivity to radiation therapy in HNSCC patients. HPV negative HNSCC has been shown to have increased radioresistance compared to HPV positive HNSCC leading to poorer prognosis. The goal of this work is to utilize in vivo screening technology to identify key differential targets between HPV positive and negative tumors for both therapeutic purposes as well as to identify differential pathways between these two malignancies.

Methods: Pooled, barcoded shRNA libraries focused on DNA damage repair (DDR) and currently targetable genes were transduced into three HPV positive (UM-SCC-147, UD-SCC-2, UPCI:SCC152) and three HPV negative (UM-SCC-22A, Cal-27, HN31) cell lines. Each cell line was injected into the mouse flank and allowed to grow to ~100mm3. Tumors were divided into control and radiation groups; the latter being treated with 6-10 Gy at 2 Gy/treatment. For each tumor type radiation was titrated to generate an approximate 20% reduction in tumor size. Tumors were then allowed to grow for an additional 2 weeks and then harvested. Barcodes from each tumor were sequenced and compared to both the reference input cells as well as untreated control tumors. Barcodes observed at decreased frequency in treated tumors indicated a potential target for therapeutic sensitization. Both p-values as well as percentile median fold change for each gene were calculated. These values were averaged for the three HPV negative and three HPV positive cell lines and used for analysis.

Results: Multiple genes in the DDR and FDA libraries were identified from the HPV negative and HPV positive groups that may be associated with radioresistance in vivo. Example genes that were identified primarily in the HPV negative group include BTK, TXN, TTK, while those in the HPV positive group include RNF168, RAD50, ESR1. Inhibition of these genes may lead to increased cell death following radiation therapy through diminished DNA repair of radiation-induced damage.

Conclusion: Our study identifies targetable genes that may contribute to radioresistance in both HPV negative and HPV positive head and neck squamous cell carcinoma and warrants further analysis.

Citation Format: Mohamed K. Abdelhakiem, Liangpeng Yang, Tongxin Xie, Manish Kumar, David Molkentine, Aakash Sheth, Mitchell Frederick, Jeffrey Myers, Curtis R. Pickering, Heath D. Skinner. In vivo screening in HPV positive and HPV negative head and neck squamous cell carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6185.

Optimizing Otoscopy Competency in Audiology Students through Supplementary Otoscopy Training

Background: Scope of practice in audiology encompasses proficiency in visual inspection of ear canal and tympanic membrane (TM) as well as otoscopy interpretation skills to determine normal versus abnormal conditions of outer and middle ear. Audiology students can develop skills in otoscopy through education and supervised training. Studies have shown that additional otoscopy training increased skills in medical students and general practitioners. However, educational and supervised practices targeting otoscopy competency during audiology graduate coursework are lacking. Also, no studies have attempted to determine otoscopy skills among audiology students.

Purpose: To determine the effectiveness of the otoscopy training model on clinical competency and confidence level of audiology students in performing and interpreting otoscopy.

Research Design: A combination of experimental treatment design with random assignment of treatment and control groups and delayed treatment for control group.

Study Sample: Thirty-two first- and second-year audiology graduate students who were enrolled in a pediatric audiology class participated in this study. Students were randomly assigned to the control (n = 16, 14 females) or experimental (n = 16, 14 females) group.

Intervention: Participants in the experimental group received supplementary otoscopy training including didactic otoscopy lectures as well as clinical training using manikin ears. The control group received the same pretest and posttest and then completed a third assessment (posttest 2) after receiving the same training.

Data Collection and Analysis: An evaluation of knowledge and skills regarding otoscopy between groups and time was conducted at three times: (a) pretraining, (b) upon completion of training for the experimental group, (c) upon completion of training by the control group. The evaluation consisted of a written exam, a clinical exam, and a self-perception rating of confidence. Both written exam scores and clinical exam scores (otoscopy manikin) were analyzed via two-way analyses of variance (ANOVAs), whereas chi-square (χ2) statistic was conducted to evaluate the effects of training on the confidence level of students of both groups.

Results: Experimental and control groups demonstrated significant increased overall competency in otoscopy following the otoscopy training model with didactic and laboratory components. Posttest confidence ratings showed increases in all groups, and there were no significant differences between groups.

Conclusions: The need for supplementary otoscopy training was warranted by low knowledge and clinical competency in otoscopy skills of audiology students as measured by pretest mean scores. After completing the training, both experimental and control groups showed significant improvement in knowledge and competency. Results also suggest that perceived confidence ratings may be misleading in determining students' clinical otoscopy skills.