Policy Priorities in Cancer Care for Transgender People

This Viewpoint calls for health care systems, oncologists, and staff to prioritize and adopt policies that are inclusive and respectful of transgender patients with cancer.

Multicenter Evaluation of Radiation and Immune Checkpoint Inhibitor Therapy in Mucosal Melanoma and Review of Recent Literature

Purpose

Optimal integration of local therapy and systemic immune therapy for patients with mucosal melanoma (MM) is uncertain. We evaluated treatment patterns and outcomes following radiation therapy (RT) in combination with immune checkpoint inhibition (ICI) in MM.

Methods and Materials

Thirty-seven patients with localized (n = 32, 87%) or node-positive (n = 5, 14%) MM were treated across 4 institutions with RT to the primary tumor with or without oncologic resection (n = 28, 76%) and ICI from 2012 to 2020. Recurrence rates were estimated using cumulative incidence in the presence of the competing risk of death.

Results

Mucosal sites were head/neck (n = 29, 78%), vaginal (n = 7, 19%), and anorectal (n = 1, 3%). Patients received ICI prior to or concurrent with RT (n = 14, 38%), following RT (n = 5, 14%), or at recurrence (n = 18, 49%). The objective response rate for evaluable patients was 31% for ICI as initial treatment (95% CI, 11%-59%) and 19% for ICI at recurrence (95% CI, 4%-46%). Median follow-up was 26 months for living patients; median overall survival (OS) was 54 months (95% CI, 31 months-not reached). Two-year OS was 85%; distant metastasis-free survival 44%. The 2-year cumulative incidence of local recurrence (LR) was 26% (95% CI, 13%-41%). For 9 patients with unresectable disease, 2-year OS was 88% (95% CI, 35%-98%); LR was 25% (95% CI, 3%-58%). For 5 patients with positive nodes at diagnosis, 2-year OS was 100%; LR was 0%.

Conclusions

High rates of local control were achieved with RT with or without oncologic resection and ICI for localized and locally advanced MM. In particular, favorable local control was possible even for patients with unresectable or node-positive disease. Although risk of distant failure remains high, patients with MM may benefit from aggressive local therapy including RT in the setting of immunotherapy treatment.

Portal Vein or Superior Mesenteric Vein Thrombosis with Dose-Escalated Radiation for Borderline or Locally Advanced Pancreatic Cancer

PURPOSE

Portal vein and superior mesenteric vein thrombosis (PVT/SMVT) are potentially morbid complications of radiation dose-escalated local therapy for pancreatic cancer. We retrospectively reviewed records for patients treated with and without intraoperative radiation (IORT) to identify risk factors for PVT/SMVT.

METHODS

Ninety-six patients with locally advanced or borderline resectable pancreatic adenocarcinoma received neoadjuvant therapy followed by surgical exploration from 2009 to 2014. Patients at risk for close or positive surgical margins received IORT boost to a biologically effective dose (BED10) > 100. Prognostic factors for PVT/SMVT were evaluated using competing risks regression.

RESULTS

Median follow-up was 79 months for surviving patients. Fifty-six patients (58%) received IORT. Twenty-nine patients (30%) developed PVT/SMVT at a median time of 18 months. On univariate competing risks regression, operative blood loss and venous repair with a vascular interposition graft, but not IORT dose escalation or diabetes history, were significantly associated with PVT/SMVT. The development of thrombosis in the absence of recurrence was significantly associated with a longstanding diabetes history, post-neoadjuvant treatment CA19-9, and operative blood loss. All 4 patients who underwent both IORT and vascular repair with a graft developed PVT/SMVT. PVT/SMVT in the absence of recurrence is not associated with significantly worsened overall survival but led to frequent medical interventions.

CONCLUSIONS

Approximately 30% of patients who underwent neoadjuvant chemoradiation for PDAC developed PVT/SMVT a median of 18 months following surgery. This was significantly associated with venous reconstruction with vascular grafts, but not with escalating radiation dose. PVT/SMVT in the absence of recurrence was associated with significant morbidity.

Gender-Affirming Surgery and Cancer: Considerations for Radiation Oncologists for Pelvic Radiation in Transfeminine Patients

Access to gender-affirming surgery is increasing for many transgender and nonbinary people in the United States, and radiation oncologists must be equipped to care for patients who have undergone such surgery in the region of their planned radiation treatment field. There are no guidelines for radiation treatment planning after gender-affirming surgery, and most oncologists do not receive training in the unique needs of transgender people with cancer. We review common gender-affirming genitopelvic surgeries for transfeminine people, including vaginoplasty, labiaplasty, and orchiectomy, and summarize the existing literature on the treatment of cancers of the neovagina, anus, rectum, prostate, and bladder in these patients. We also describe our systematic treatment approach and rationale for pelvic radiation treatment planning.

Clinical outcomes of radiation therapy for transgender and gender-expansive people with cancer

Introduction

Approximately 1.6 million people in the US identify as transgender, many of whom undergo gender-affirming medical or surgical therapies. While transgender individuals are diagnosed with cancer at similar rates as those who are cisgender, the impacts of radiation therapy on outcomes of gender-affirming care in transgender, nonbinary, and gender-expansive people with cancer are understudied. We report on the experiences and outcomes of transgender and gender-expansive patients receiving radiation therapy for cancer treatment.

Methods

This study is a multi-institutional retrospective review of patients evaluated from 2005-2019 identified as transgender or gender-expansive in the medical record and treated with radiation therapy.

Results

We identified 23 patients who received radiation to 32 sites, including 12 (38%) to the brain, head, or neck, 8 (25%) to the thorax, and 7 (22%) to the pelvis. Seventeen patients (74%) received gender-affirming hormone therapy and 13 patients (57%) underwent gender-affirming surgery. Four patients had pelvic radiation before or after gender-affirming pelvic surgery, including two trans women who had pelvic radiation after vaginoplasty. Four patients had radiation to the chest or thorax and gender-affirming chest or breast surgery, including two trans men with breast cancer. Two pediatric patients developed hypopituitarism and hypogonadism secondary to radiation therapy and, as adults, changed their hormone replacement therapy to affirm their transgender identities.

Discussion

Transgender people with cancer undergo radiation therapy for a wide range of cancers. Understanding their prior gender-affirming medical or surgical treatments and future gender affirmation goals may identify important considerations for their oncologic care.

Organizational Strategies and Inclusive Language to Build Culturally Responsive Health Care Environments for Lesbian, Gay, Bisexual, Transgender, and Queer People

This report shares examples of organizational strategies and inclusive language that can be integrated into standard patient-facing processes, forms, and materials to create culturally responsive health care environments for lesbian, gay, bisexual, transgender, and queer people.

Hypofractionated Radiation Therapy for Unresectable/Locally Recurrent Intrahepatic Cholangiocarcinoma

OBJECTIVE

The aim of this study was to evaluate outcomes for patients with unresectable intrahepatic cholangiocarcinoma (ICC) treated with hypofractionated proton or photon radiation therapy (HF-RT).

METHODS

We retrospectively identified 66 patients with ICC who were treated with HF-RT from 2008 to 2018. Median age at RT was 76 years (range 30-92), including 27 patients (41%) aged ≥ 80 years. Median RT dose was 58.05 Gy (range 37.5-67.5), all delivered in 15 daily fractions. Thirty-two patients received proton RT and 34 patients received photon RT.

RESULTS

Median follow-up times from diagnosis and RT start were 21 months and 14 months, respectively. In total, five patients (7.6%) developed local failure. The 2-year outcomes were 84% local control (LC) and 58% OS. Among the 51 patients treated with definitive intent, the 2-year LC rate was 93% and the OS rate was 62%. On multivariate analysis for LC, older age was associated with a lower risk of local failure [hazard ratio (HR) 0.91; p = 0.02], while prior surgery (HR 16.5; p = 0.04) and macrovascular invasion (HR 123.93; p = 0.02) were independently associated with an increased risk of local failure. On multivariate analysis for OS, female sex (HR 0.33; p = 0.001) and prior chemotherapy (HR 0.38; p = 0.003) remained significantly associated with OS. On multivariate analysis for OS, compared with photon RT, there was a trend towards improved survival with proton RT (HR 0.50; p = 0.05). The rate of overall grade 3 + toxicity was 11%. One patient developed radiation-induced liver disease and was treated with corticosteroids.

CONCLUSIONS

HF-RT yields high rates of local control and is an effective modality to optimize biliary control for unresectable/locally recurrent ICC.

Microplastic accumulation and biomagnification in a coastal marine reserve situated in a sparsely populated area

Toxic chemicals within and adsorbed to microplastics (0.05-5 mm) have the potential to biomagnify in food webs. However, microplastic concentrations in highly productive, coastal habitats are not well understood. Therefore, we quantified the presence of microplastics in a benthic community and surrounding environment of a remote marine reserve on the open coast of California, USA. Concentrations of microplastic particles in seawater were 36.59 plastics/L and in sediments were 0.227 ± 0.135 plastics/g. Densities of microplastics on the surfaces of two morphologically distinct species of macroalgae were 2.34 ± 2.19 plastics/g (Pelvetiopsis limitata) and 8.65 ± 6.44 plastics/g (Endocladia muricata). Densities were highest in the herbivorous snail, Tegula funebralis, at 9.91 ± 6.31 plastics/g, potentially due to bioaccumulation. This study highlights the need for further investigations of the prevalence and potential harm of microplastics in benthic communities at remote locations as well as human population centers.

Intron retention is a source of neoepitopes in cancer

We present an in silico approach to identifying neoepitopes derived from intron retention events in tumor transcriptomes. Using mass spectrometry immunopeptidome analysis, we show that retained intron neoepitopes are processed and presented on MHC I on the surface of cancer cell lines. RNA-derived neoepitopes should be considered for prospective personalized cancer vaccine development.

Abstract 5719: RNA-based tumor neoantigens from intron retention

Background: Tumor neoantigens contribute to cancer immunity and may influence selective immune checkpoint inhibitor response. Translation of nonsynonymous somatic mutations in tumor cells generates mutant peptides that can be recognized as foreign by the host immune system. Alterations in tumor RNA, rather than DNA, may also contribute to the tumor neoantigen landscape. Intron retention, a widespread feature of cancer transcriptomes, represents a novel source of tumor neoantigens.

Methods: We developed an in silico pipeline leveraging existing tools and novel methods to computationally identify retained-intron neoantigens (RI-neoantigens) from transcriptome sequencing data. We applied our computational pipeline to three cohorts of melanoma patients (n = 89) treated with immune checkpoint blockade.

Results: This approach identified a mean RI-neoantigen burden of 3,643 across cohorts, which augments the mean DNA-derived somatic neoantigen burden by roughly 4.5-fold. 3,253 RI-neoantigens were exclusively present in two or more patients who responded to immunotherapy. A subset of responder-exclusive RI-neoantigens were validated by peptide restimulation assay. A candidate RI-neoantigen from a cancer cell line was identified in complex with MHC I by mass spectrometry, supporting the hypothesis that aberrant splicing results in intron retention, which generates abnormal transcripts that are translated into immunogenic peptides and presented to the immune system.

Conclusions: Our results demonstrate the contribution of transcriptional dysregulation to the overall burden of tumor neoantigens. Further study of RI-neoantigens may expand our understanding of tumor immunity and identify immunogenic peptide sequences for personalized cancer vaccines.

Citation Format: Claire A. Margolis, Alicia C. Smart, Dennis Adeegbe, Diana Miao, Meng Xiao He, Harold Pimentel, Tim Fugmann, Kwok-Kin Wong, Eliezer M. Van Allen. RNA-based tumor neoantigens from intron retention [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5719.

Abstract 5647: Intron retention as a novel source of tumor neoantigens associated with response to checkpoint inhibitor therapy

Background: Development of immune checkpoint inhibitors has substantially improved outcomes in patients diagnosed with metastatic melanoma. However, only a minority of patients treated experience long-term clinical benefit, and clinicians have limited ability to predict which patients will respond. Recent studies have demonstrated that the burden of tumor neoantigens generated by expressed somatic mutations is predictive of response to immunotherapy. Intron retention, which is widespread in cancer transcriptomes, represents a putative source of tumor neoantigens by generating peptides that are available for presentation through the MHC I pathway.

Methods: We developed a neoantigen prediction pipeline to identify patient-specific neoantigens from transcriptome sequencing data, which enables identification of retained intron neoantigens from clinical cohorts receiving checkpoint inhibitor therapy. This pipeline incorporates published methods for detecting intron retention events from transcriptome data, detects open reading frames that extend from normal transcripts into intronic sequences, and identifies neoepitopes predicted as strong binders based on the patient’s HLA molecules. We applied this pipeline to a cohort of 41 melanoma patients receiving checkpoint inhibitor therapy and classified patient outcomes as receiving clinical benefit (CB) (n=14), no clinical benefit (NCB) (n=22), or long-term survival without clinical benefit (LS) (n=5).

Results: Our initial analysis identified a mean retained intron neoantigen burden of 7709 per sample, without significant difference between response groups. In one patient who derived clinical benefit from checkpoint inhibition, neoantigen load from nonsynonymous mutations was low (407, 0.34 standard deviations (SD) below a mean of 1,015 among CB patients), while retained intron neoantigen load was high (14579, 1.7 SDs above a mean of 7517 among CB patients), suggesting that retained intron neoantigen load may explain response in some patients with low mutational burden. Preliminary analysis of specific neoantigens suggests that a retained intron in ZNF880 identified in patients expressing HLA-A01:01 is present in 6 of 6 patients experiencing clinical benefit, but only 2 of 7 patients not experiencing clinical benefit. The same analysis was performed on two additional cohorts of melanoma tumor samples to assess whether a larger sample size could aid in the identification of recurrent neoepitopes generated by retained introns.

Conclusions: Application of this approach to data from patients receiving checkpoint blockade with selective response identifies response-associated neoantigens that may warrant further investigation. Identification of a novel source of neoantigens associated with immunotherapy response will provide valuable prognostic information to patients and inform the development of next generation immunotherapeutics.

Citation Format: Alicia C. Smart, Claire Margolis, Diana Miao, David Liu, Jihye Park, Meng Xiao He, Brendan Reardon, Stephanie Mullane, Bastian Schilling, Levi A. Garraway, Dirk Schadendorf, Eliezer M. Van Allen. Intron retention as a novel source of tumor neoantigens associated with response to checkpoint inhibitor therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5647. doi:10.1158/1538-7445.AM2017-5647