Workshop summary: Potential usefulness and feasibility of a US National Mesothelioma Registry

The burden and prognosis of malignant mesothelioma in the United States have remained largely unchanged for decades, with approximately 3200 new cases and 2400 deaths reported annually. To address care and research gaps contributing to poor outcomes, in March of 2019 the Mesothelioma Applied Research Foundation convened a workshop on the potential usefulness and feasibility of a national mesothelioma registry. The workshop included formal presentations by subject matter experts and a moderated group discussion. Workshop participants identified top priorities for a registry to be (a) connecting patients with high-quality care and clinical trials soon after diagnosis, and (b) making useful data and biospecimens available to researchers in a timely manner. Existing databases that capture mesothelioma cases are limited by factors such as delays in reporting, deidentification, and lack of exposure information critical to understanding as yet unrecognized causes of disease. National disease registries for amyotrophic lateral sclerosis (ALS) in the United States and for mesothelioma in other countries, provide examples of how a registry could be structured to meet the needs of patients and the scientific community. Small-scale pilot initiatives should be undertaken to validate methods for rapid case identification, develop procedures to facilitate patient access to guidelines-based standard care and investigational therapies, and explore approaches to data sharing with researchers. Ultimately, federal coordination and funding will be critical to the success of a National Mesothelioma Registry in improving mesothelioma outcomes and preventing future cases of this devastating disease.

Radiologic Considerations and Standardization of Malignant Pleural Mesothelioma Imaging Within Clinical Trials: Consensus Statement from the NCI Thoracic Malignancy Steering Committee - International Association for the Study of Lung Cancer - Mesothelioma Applied Research Foundation Clinical Trials Planning Meeting

Detailed guidelines pertaining to radiological assessment of malignant pleural mesothelioma are currently lacking due to the rarity of the disease, complex morphology, propensity to invade multiple planes simultaneously, and lack of specific recommendations within the radiology community about assessment, reporting, and follow-up. In March 2017, a multidisciplinary meeting of mesothelioma experts was co-sponsored by the National Cancer Institute Thoracic Malignancy Steering Committee, International Association for the Study of Lung Cancer, and the Mesothelioma Applied Research Foundation. One of the outcomes of this conference was the foundation of detailed, multidisciplinary consensus imaging and management guidelines. Here, we present the recommendations for radiologic assessment of malignant pleural mesothelioma in the setting of clinical trial enrollment. We discuss optimization of imaging parameters across modalities, standardized reporting, and response assessment within clinical trials.

Pathologic Considerations and Standardization in Mesothelioma Clinical Trials

The accurate diagnosis of mesothelioma is critical for the appropriate clinical management of this cancer. Many issues complicate making the diagnosis of mesothelioma including the presence of reactive mesothelial cells in benign pleural effusions, the heterogeneity of mesothelioma histopathology, the relatively high incidence of other epithelial malignancies that metastasize to the pleura, and primary sarcomas that arise within the pleura. Given the rapidly evolving field of molecular profiling and the need for translational correlates in mesothelioma clinical trials, the National Cancer Institute (NCI)-International Association for the Study of Lung Cancer-Mesothelioma Applied Research Foundation Clinical Trials Planning Meeting was convened in March 2017 to develop a consensus on standard pathology guidelines for future NCI-sponsored clinical trials in mesothelioma. This consensus statement covers recommendations for specimen handling, pathologic classification and diagnosis, biobanking, and tissue correlative studies.

The Use of Radiation Therapy for the Treatment of Malignant Pleural Mesothelioma: Expert Opinion from the National Cancer Institute Thoracic Malignancy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation

INTRODUCTION

Detailed guidelines regarding the use of radiation therapy for malignant pleural mesothelioma (MPM) are currently lacking because of the rarity of the disease, the wide spectrum of clinical presentations, and the paucity of high-level data on individual treatment approaches.

METHODS

In March 2017, a multidisciplinary meeting of mesothelioma experts was cosponsored by the U.S. National Cancer Institute, International Association for the Study of Lung Cancer Research, and Mesothelioma Applied Research Foundation. Among the outcomes of this conference was the foundation of detailed, multidisciplinary consensus guidelines.

RESULTS

Here we present consensus recommendations on the use of radiation therapy for MPM in three discrete scenarios: (1) hemithoracic radiation therapy to be used before or after extrapleural pneumonectomy; (2) hemithoracic radiation to be used as an adjuvant to lung-sparing procedures (i.e., without pneumonectomy); and (3) palliative radiation therapy for focal symptoms caused by the disease. We discuss appropriate simulation techniques, treatment volumes, dose fractionation regimens, and normal tissue constraints. We also assess the role of particle beam therapy, specifically, proton beam therapy, for MPM.

CONCLUSION

The recommendations provided in this consensus statement should serve as important guidelines for developing future clinical trials of treatment approaches for MPM.

A Subset of Mesotheliomas With Improved Survival Occurring in Carriers of BAP1 and Other Germline Mutations

PURPOSE

We hypothesized that four criteria could help identify malignant mesotheliomas (MMs) most likely linked to germline mutations of BAP1 or of other genes: family history of MM, BAP1-associated cancers, or multiple malignancies; or age younger than 50 years.

PATIENTS AND METHODS

Over the course of 7 years, 79 patients with MM met the four criteria; 22 of the 79 (28%) reported possible asbestos exposure. They were screened for germline BAP1 mutations by Sanger sequencing and by targeted next-generation sequencing (tNGS) for germline mutations in 55 additional cancer-linked genes. Deleterious mutations detected by tNGS were validated by Sanger sequencing.

RESULTS

Of the 79 patients, 43 (16 probands and 27 relatives) had deleterious germline BAP1 mutations. The median age at diagnosis was 54 years and median survival was 5 years. Among the remaining 36 patients with no BAP1 mutation, median age at diagnosis was 45 years, median survival was 9 years, and 12 had deleterious mutations of additional genes linked to cancer. When compared with patients with MMs in the SEER cohort, median age at diagnosis (72 years), median survival for all MM stages (8 months), and stage I (11 months) were significantly different from the 79 patients with MM in the current study ( P < .0001).

CONCLUSION

We provide criteria that help identify a subset of patients with MM who had significantly improved survival. Most of these patients were not aware of asbestos exposure and carried either pathogenic germline mutations of BAP1 or of additional genes linked to cancer, some of which may have targeted-therapy options. These patients and their relatives are susceptible to development of additional cancers; therefore, genetic counseling and cancer screening should be considered.

Current and Future Management of Malignant Mesothelioma: A Consensus Report from the National Cancer Institute Thoracic Malignancy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation

On March 28- 29, 2017, the National Cancer Institute (NCI) Thoracic Malignacy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation convened the NCI-International Association for the Study of Lung Cancer- Mesothelioma Applied Research Foundation Mesothelioma Clinical Trials Planning Meeting in Bethesda, Maryland. The goal of the meeting was to bring together lead academicians, clinicians, scientists, and the U.S. Food and Drug Administration to focus on the development of clinical trials for patients in whom malignant pleural mesothelioma has been diagnosed. In light of the discovery of new cancer targets affecting the clinical development of novel agents and immunotherapies in malignant mesothelioma, the objective of this meeting was to assemble a consensus on at least two or three practice-changing multimodality clinical trials to be conducted through NCI's National Clinical Trials Network.

Treatment of Malignant Pleural Mesothelioma: American Society of Clinical Oncology Clinical Practice Guideline

Purpose To provide evidence-based recommendations to practicing physicians and others on the management of malignant pleural mesothelioma. Methods ASCO convened an Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, pathology, imaging, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1990 through 2017. Outcomes of interest included survival, disease-free or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations. Results The literature search identified 222 relevant studies to inform the evidence base for this guideline. Recommendations Evidence-based recommendations were developed for diagnosis, staging, chemotherapy, surgical cytoreduction, radiation therapy, and multimodality therapy in patients with malignant pleural mesothelioma. Additional information is available at www.asco.org/thoracic-cancer-guidelines and www.asco.org/guidelineswiki .

Consensus Report of the 2015 Weinman International Conference on Mesothelioma

On November 9 and 10, 2015, the International Conference on Mesothelioma in Populations Exposed to Naturally Occurring Asbestiform Fibers was held at the University of Hawaii Cancer Center in Honolulu, Hawaii. The meeting was cosponsored by the International Association for the Study of Lung Cancer, and the agenda was designed with significant input from staff at the U.S. National Cancer Institute and National Institute of Environmental Health Sciences. A multidisciplinary group of participants presented updates reflecting a range of disciplinary perspectives, including mineralogy, geology, epidemiology, toxicology, biochemistry, molecular biology, genetics, public health, and clinical oncology. The group identified knowledge gaps that are barriers to preventing and treating malignant mesothelioma (MM) and the required next steps to address barriers. This manuscript reports the group’s efforts and focus on strategies to limit risk to the population and reduce the incidence of MM. Four main topics were explored: genetic risk, environmental exposure, biomarkers, and clinical interventions. Genetics plays a critical role in MM when the disease occurs in carriers of germline BRCA1 associated protein 1 mutations. Moreover, it appears likely that, in addition to BRCA1 associated protein 1, other yet unknown genetic variants may also influence the individual risk for development of MM, especially after exposure to asbestos and related mineral fibers. MM is an almost entirely preventable malignancy as it is most often caused by exposure to commercial asbestos or mineral fibers with asbestos-like health effects, such as erionite. In the past in North America and in Europe, the most prominent source of exposure was related to occupation. Present regulations have reduced occupational exposure in these countries; however, some people continue to be exposed to previously installed asbestos in older construction and other settings. Moreover, an increasing number of people are being exposed in rural areas that contain noncommercial asbestos, erionite, and other mineral fibers in soil or rock (termed naturally occurring asbestos [NOA]) and are being developed. Public health authorities, scientists, residents, and other affected groups must work together in the areas where exposure to asbestos, including NOA, has been documented in the environment to mitigate or reduce this exposure. Although a blood biomarker validated to be effective for use in screening and identifying MM at an early stage in asbestos/ NOA-exposed populations is not currently available, novel biomarkers presented at the meeting, such as high mobility group box 1 and fibulin-3, are promising. There was general agreement that current treatment for MM, which is based on surgery and standard chemotherapy, has a modest effect on the overall survival (OS), which remains dismal. Additionally, although much needed novel therapeutic approaches for MM are being developed and explored in clinical trials, there is a critical need to invest in prevention research, in which there is a great opportunity to reduce the incidence and mortality from MM.

Management of Malignant Peritoneal Mesothelioma Using Cytoreductive Surgery and Perioperative Chemotherapy

Malignant peritoneal mesothelioma is a rare disease, with approximately 800 new patients per year in the United States. Its natural history is defined by progression restricted to the peritoneal space. In the past, patients with this disease had a limited lifespan of approximately 1 year. Numerous single-institution studies as well as a systematic review have reported median survival of 3 to 5 years with a combination of cytoreductive surgery and hyperthermic perioperative chemotherapy. These markedly improved survival statistics were achieved in experienced centers with 1% mortality and 20% morbidity rates. Data have shown that knowledgeable patient selection is required to prevent patients unlikely to benefit from undergoing these interventions. The conclusion is that patients with peritoneal mesothelioma can experience long-term progression-free survival or significant palliation with cytoreductive surgery plus hyperthermic perioperative chemotherapy. This management plan should be considered the standard of care for properly selected patients with malignant peritoneal mesothelioma at experienced centers around the world.

Abstract 1179: Combined genetic and genealogic studies uncover a large BAP1 cancer syndrome kindred, tracing back nine generations to a common ancestor from the 1700s

Germline BAP1 mutations cause a cancer syndrome characterized by high incidence of mesothelioma (MM), uveal melanoma and other cancers, and by very high penetrance, as all individuals carrying BAP1 mutations developed at least one, and usually several, malignancies throughout their lives. Through screening MM patients with histories of multiple cancers, we found four supposedly unrelated patients that shared an identical germline BAP1 mutation. We investigated whether this BAP1 mutation occurred in a ‘hot-spot’ for “de novo” mutations or whether these four MM patients shared a common ancestor. Using molecular genomics analyses we found that they are related. By genealogic studies we traced their ancestor to a couple that emigrated from Germany to North America in the early 1700’s; we traced the subsequent migration of their descendants, who are now living in at least three different US States. Our findings demonstrate that BAP1 mutations are transmitted among subsequent generations over the course of centuries. This knowledge and methodology is being used to identify additional branches of the family carrying BAP1 mutations. Our study shows that the application of modern genomic analyses, coupled with “classical” family histories collected by the treating physician, and with genealogical searches, offer a powerful strategy to identify high-risk germline BAP1 mutation carriers that will benefit from genetic counseling and early detection cancer screening.

Citation Format: Michele Carbone, Erin G. Flores, Mitsuru Emi, Giovanni Gaudino, Sandra Pastorino, Haining Yang, Todd Johnson, Tatsuhiko Tsunoda, Mary Hesdorffer, Harvey I. Pass. Combined genetic and genealogic studies uncover a large BAP1 cancer syndrome kindred, tracing back nine generations to a common ancestor from the 1700s. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1179.

Approach to offering remote support to mesothelioma patients: the mesothelioma survivor project

BACKGROUND

From the moment of diagnosis, malignant mesothelioma (MM) decreases health-related quality of life (QOL) in patients and their caregivers. In addition to symptoms of disease, aggressive treatments such as surgery, radiation, and chemotherapy can cause extreme side effects-chemotherapy specifically is associated with chronic fatigue, unremitting nausea, vomiting, and systemic pain. These side effects of treatments can be burdensome enough to lead to noncompliance or outright refusal of continuation of care.

METHODS

The platform for the support group was remote, consisting of online and telephone domains. Participants would utilize both online and phone systems during sessions held once a week for a total of six weeks. Sessions were guided and kept closed, available only to those affected by mesothelioma. Follow-up information and session summaries were provided online after support meetings.

RESULTS

Using a 0-5 Likert Scale, consistent attendees reported support groups as very helpful. Irregular attendees had mixed feelings ranging from extremely helpful to neutral. Eighty per cent of attendees participated in support groups prior to this project.

CONCLUSIONS

Active participation in a guided and closed support group allowed participants to share their experiences and concerns about their diagnoses comfortably, supporting transition beyond active-treatment. Online space gave participants a place to provide more reflective responses outside the main dialogue of support sessions.

Approach to offering remote support to mesothelioma patients: The Mesothelioma Survivor Project

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Background: From the moment of diagnosis, malignant mesothelioma (MM), decreases health-related quality-of-life (QOL) in patients and their caregivers. In addition to symptoms of disease, aggressive treatments such as surgery, radiation, and chemotherapy can cause extreme side effects – specifically, chemotherapy is associated with chronic fatigue, unremitting nausea, vomiting, and systemic pain. These side effects of treatments can be burdensome enough to lead to noncompliance or outright refusal of continuation of care.[1] Data from 13 frequently cited QOL studies focus on chest pain and shortness of breath as the two chief symptoms of pleural mesothelioma. The largest QOL study to date enrolled 495 patients, evaluated MM using the LCSS (lung cancer symptom scale). Investigators reported MM’s most common symptoms as: fatigue (94%), dyspnea (89%), loss of appetite (86%), chest pain (85%), cough (75%), and hemoptysis (24%). In addition, mesothelioma has a number of emotional consequences. A study by the British Lung Foundation (BLF) reported significant impairment of emotional function and/or emotional state in patients with mesothelioma and their family members.[2] Methods: The platform for the support group was remote, consisting of both online and telephone domains. Participants would utilize both online and phone systems during sessions, held once a week for a total of 6 weeks. Sessions were guided and kept closed, available only to those affected by mesothelioma. Participants completed surveys after each support group. Session summaries and follow-up information were provided online after support meetings. Results: Using a 0-5 Likert Scale, consistent attendees reported support groups as very helpful (4). Irregular attendees had mixed feelings ranging from extremely helpful (5) to neutral (3). 80% of attendees participated in support groups prior to ours. Conclusions: Active participation in a guided and closed support group allowed participants to share their experiences and concerns about their diagnoses, comfortably – supporting transition beyond active-treatment. The online portion of the platform was helpful in assuaging common negative concerns.

Survival and fertility in women with malignant peritoneal mesothelioma

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Background: The prognosis of malignant peritoneal mesothelioma (MPM) has improved over the past decade in patients undergoing operative extirpation and intraperitoneal chemotherapy (IC). This study investigates the time from diagnosis to treatment intervention in premenopausal women and its impact on fertility and childbearing options. Methods: A retrospective analysis of 195 patients diagnosed with peritoneal mesothelioma between 1995 and 2015. Patients with unresectable or bicavity disease were not excluded. Kaplan-Meier curves and univariate cox proportional hazards model were used to estimate survival and significant treatment and prognosis factors. Results: The median survival time of all peritoneal mesothelioma patients (n = 195) was 3.21 years with (95% CI: 2.38- 5.53), with median follow-up of 3.44 years (SD = 3.4, minimum = 0.014 and maximum = 16.752) years from first operation. Patient set included 111 men (57%) and 84 women (43.1%) with female sex having favorable survival [HR: 0.442 95% CI: 0.296-0.659), p < 0.001] of 110.1 months with (95% CI: lower bond: 48.3). Of these women, their mean age at diagnosis was 52 years, (SD = 14.5, minimum = 14.7 – maximum = 79.9), with a mean time of 8.20 months from diagnosis to the start of treatment (SD = 18.6, minimum = 0 and maximum = 128.6 months). Overall survival of premenopausal women (N = 23) during follow-up was 72.2% (SE = 27.8%). Mean age at time of diagnosis was 34.7 years, (SD = 9.26, minimum = 14.7, maximum = 48.1), with a mean time of 10.6 months from diagnosis to treatment (SD = 17.9, minimum = 0.63, maximum = 86.7). Of the 195 patients who received a full treatment course, 66 (33.8% CI: 95%) were still alive at the median follow-up, of those alive 37 are female: 7 are premenopausal and have presented with gynecological symptoms, and 17 are premenopausal and have presented with abdominal discomfort. Conclusions: This data suggests that women preparing for treatment of MPM should not be precluded from exploring fertility options. With a mean time of 10.6 months from diagnosis to treatment, it is possible for premenopausal women to take advantage of fertility preservation before starting treatment.

Germline BAP1 Mutational Landscape of Asbestos-Exposed Malignant Mesothelioma Patients with Family History of Cancer

Heritable mutations in the BAP1 tumor suppressor gene predispose individuals to mesothelioma and other cancers. However, a large-scale assessment of germline BAP1 mutation incidence and associated clinical features in mesothelioma patients with a family history of cancer has not been reported. Therefore, we examined the germline BAP1 mutation status of 150 mesothelioma patients with a family history of cancer, 50 asbestos-exposed control individuals with a family history of cancers other than mesothelioma, and 153 asbestos-exposed individuals without familial cancer. No BAP1 alterations were found in control cohorts, but were identified in nine of 150 mesothelioma cases (6%) with a family history of cancer. Alterations among these cases were characterized by both missense and frameshift mutations, and enzymatic activity of BAP1 missense mutants was decreased compared with wild-type BAP1. Furthermore, BAP1 mutation carriers developed mesothelioma at an earlier age that was more often peritoneal than pleural (five of nine) and exhibited improved long-term survival compared to mesothelioma patients without BAP1 mutations. Moreover, many tumors harboring BAP1 germline mutations were associated with BAP1 syndrome, including mesothelioma and ocular/cutaneous melanomas, as well as renal, breast, lung, gastric, and basal cell carcinomas. Collectively, these findings suggest that mesothelioma patients presenting with a family history of cancer should be considered for BAP1 genetic testing to identify those individuals who might benefit from further screening and routine monitoring for the purpose of early detection and intervention.

Combined Genetic and Genealogic Studies Uncover a Large BAP1 Cancer Syndrome Kindred Tracing Back Nine Generations to a Common Ancestor from the 1700s

We recently discovered an inherited cancer syndrome caused by BRCA1-Associated Protein 1 (BAP1) germline mutations, with high incidence of mesothelioma, uveal melanoma and other cancers and very high penetrance by age 55. To identify families with the BAP1 cancer syndrome, we screened patients with family histories of multiple mesotheliomas and melanomas and/or multiple cancers. We identified four families that shared an identical BAP1 mutation: they lived across the US and did not appear to be related. By combining family histories, molecular genetics, and genealogical approaches, we uncovered a BAP1 cancer syndrome kindred of ~80,000 descendants with a core of 106 individuals, whose members descend from a couple born in Germany in the early 1700s who immigrated to North America. Their descendants spread throughout the country with mutation carriers affected by multiple malignancies. Our data show that, once a proband is identified, extended analyses of these kindreds, using genomic and genealogical studies to identify the most recent common ancestor, allow investigators to uncover additional branches of the family that may carry BAP1 mutations. Using this knowledge, we have identified new branches of this family carrying BAP1 mutations. We have also implemented early-detection strategies that help identify cancers at early-stage, when they can be cured (melanomas) or are more susceptible to therapy (MM and other malignancies).

Germline BAP1 mutations cause a cancer syndrome characterized by high incidence of mesothelioma (MM), uveal melanoma and other cancers, and by very high penetrance, as all individuals carrying BAP1 mutations developed at least one, and usually several, malignancies throughout their lives. Through screening MM patients with histories of multiple cancers, we found four supposedly unrelated patients that shared an identical germline BAP1 mutation. We investigated whether this BAP1 mutation occurred in a ‘hot-spot’ for “de novo” mutations or whether these four MM patients shared a common ancestor. Using molecular genomics analyses we found that they are related. By genealogic studies we traced their ancestor to a couple that emigrated from Germany to North America in the early 1700’s; we traced the subsequent migration of their descendants, who are now living in at least three different US States. Our findings demonstrate that BAP1 mutations are transmitted among subsequent generations over the course of centuries. This knowledge and methodology is being used to identify additional branches of the family carrying BAP1 mutations. Our study shows that the application of modern genomic analyses, coupled with “classical” family histories collected by the treating physician, and with genealogical searches, offer a powerful strategy to identify high-risk germline BAP1 mutation carriers that will benefit from genetic counseling and early detection cancer screening.

Abstract 2752: Prevalence of BAP1 germline mutations in asbestos-exposed malignant mesothelioma cases and controls

Malignant mesothelioma (MM) is an uncommon but aggressive cancer that has been linked with asbestos exposure. Contributing genetic factors appear to play a role because familial clustering of MM has been observed and that only a small percentage of asbestos-exposed individuals have been documented to develop MM. Germline mutation of BAP1 has been identified as one such predisposing factor. However, the frequency of germline BAP1 mutations in MM cases is debatable due to small sampling sizes of studies from previous publications. Therefore, we decided to determine the prevalence of germline BAP1 mutations in a large set of asbestos-exposed MM cases and controls, the biggest such population study to date. BAP1 mutation status was compared between 150 MM cases with a family history of cancer and 153 asbestos-exposed controls without indications of familial cancers. Although no alterations of BAP1 were discovered in the controls, BAP1 mutations were identified in 9 of the MM cases (6%). These alterations included 2 splice site changes, 4 insertion/deletions, and 3 missense mutations. In vitro enzymatic assays showed decreased deubiquitinase activity for each of the three BAP1 missense mutant proteins. We observed a statistically significant lower age of MM onset as well as a higher incidence of peritoneal MMs among the 9 BAP1 mutation cases compared to the non-mutated MM cases. The other tumors identified in family members of the 9 individuals included additional MMs, ocular and cutaneous melanomas, renal, breast, lung, and gastric carcinomas, and lymphomas. Interestingly, six of the nine MM cases with a germline BAP1 mutation had two or more primary cancers, suggesting a widespread targeting of tissues of multiple organs caused by the mutation. In summary, these findings suggest that patients presenting with MM and a family history of cancer should be considered for BAP1 mutation testing to identify those who might benefit from screening and regular monitoring of family members to enable early detection and intervention.

Citation Format: Mitchell Cheung, Jacqueline Talarchek, Suzanne E. Howard, Timothy Howard, Hongzhuang Peng, Mary Hesdorffer, Frank J. Rauscher, Jill A. Ohar, Joseph Testa. Prevalence of BAP1 germline mutations in asbestos-exposed malignant mesothelioma cases and controls. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2752. doi:10.1158/1538-7445.AM2015-2752

Abstract 4796: A founder mutation in the BAP1 gene among four caucasian families with high incidences of malignant peritoneal mesothelioma and uveal melanoma: a molecular and genealogical study in a 10-generation BAP1 cancer syndrome kindred

The BAP1 cancer syndrome is characterized by a high incidence of malignant mesothelioma (MM), uveal melanoma (UM), cutaneous melanoma (CM), clear cell renal cell carcinoma (ccRCC), and it is expected that the clinical phenotype will continue to broaden in scope. Molecular screening for BAP1 gene mutations among 29 patients selected for clinically apparent familial MM led to the identification of a heterozygous C base deletion mutation (c.1832delC, p.Leu573fs*3) shared by four of those patients. The frame shift deletion is predicted to truncate the BAP1 protein, and immunohistochemistry analysis of tumor specimens revealed predominant cytoplasmic staining. We genotyped 650K SNPs of the four MM samples and four controls and carried out principal component analysis and whole-genome identity-by-descent analysis using publicly available genotype data from the 1000 Genomes Project, UK10K Project, and NHIBL Exome Sequencing Project. These analyses showed that the four MM patients are of Central Europe ancestry and that some are related by a kinship coefficient of 0.0186. Haplotype analysis showed the presence of significantly shared segments around the BAP1 gene (LOD&gt;37.1). The pairwise extent of shared segments between any of the four MM patients ranged in length from 9.1 to 34.2 Mbp and indicates the c.1832delC variant originated in a recent common ancestor within five to ten generations. Through a combined molecular genomic and genealogical approach, we ascertained, to our knowledge, the largest known genealogically connected BAP1 cancer syndrome kindred (K4), whose members can trace descent from a common ancestor in the 17th century. This pedigree provided a unique opportunity to examine effects of BAP1 alteration on tumor expression on various body sites and would facilitate study of gene-gene and gene-environment interaction involving the BAP1 gene. It also suggests that molecular screening of the BAP1 gene, coupled with genealogical research, would be an effective strategy for the early detection and early intervention for BAP1-associated malignancies.

Citation Format: Erin Flores, Mitsuru Emi, Todd Johnson, Tatsuhiko Tsunoda, Dusty Behner, Harriet Hoffman, Mary Hesdorffer, Masaki Nasu, Andrea Napolitano, Francine Baumann, Haining Yang, Michele Carbone. A founder mutation in the BAP1 gene among four caucasian families with high incidences of malignant peritoneal mesothelioma and uveal melanoma: a molecular and genealogical study in a 10-generation BAP1 cancer syndrome kindred. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4796. doi:10.1158/1538-7445.AM2015-4796

Changing pattern in malignant mesothelioma survival

Survival for mesothelioma has been shown to be poor, with marginal improvement over time. Recent advances in the understanding of pathophysiology and treatment of mesothelioma may impact therapy to improve survival that may not be evident from available clinical trials that are often small and not randomized. Therapies may affect survival differently based on mesothelioma location (pleural vs peritoneal). Data are conflicting regarding the effect of asbestos exposure on mesothelioma location.

OBJECTIVES

We examined survival in a large cohort of mesothelioma subjects analyzed by tumor location and presence and mode of asbestos exposure.

METHODS

Data were analyzed from cases (n = 380) diagnosed with mesothelioma from 1992 to 2012. Cases were either drawn from treatment referrals, independent medical evaluation for medical legal purposes, or volunteers who were diagnosed with mesothelioma. Subjects completed an occupational medical questionnaire, personal interview with the examining physician, and physician review of the medical record.

RESULTS

This study reports better survival for mesothelioma than historical reports. Survival for peritoneal mesothelioma was longer than that for pleural mesothelioma (hazard ratio = 0.36, 95% confidence interval = 0.24-0.54, P < .001) after adjusting for gender and age at diagnosis. Non-occupational cases were more likely to be 1) diagnosed with peritoneal mesothelioma, 2) female, 3) exposed, and 4) diagnosed at a younger age and to have a 5) shorter latency compared to occupational cases (P < .001).

CONCLUSION

Peritoneal mesothelioma was more likely associated with non-occupational exposure, thus emphasizing the importance of exposure history in enhancing early diagnosis and treatment impact.

Two-stage operative cytoreduction and intraperitoneal chemotherapy for diffuse malignant peritoneal mesothelioma: Operative morbidity and mortality in phase I and II trials

AIMS

The standard of care for diffuse malignant peritoneal mesothelioma involves operative cytoreduction and intraperitoneal chemotherapy. Most centers favor aggressive operative cytoreduction, accepting high morbidity and mortality. In our trials, patients underwent less extensive cytoreduction followed by prolonged intraperitoneal chemotherapy. Patients underwent a second cytoreduction with heated intraperitoneal chemotherapy. We hypothesized this would result in lower operative morbidity and mortality with similar survival.

METHODS

Hospital records, discharge summaries, microbiology, radiography, and office records were retrospectively reviewed to supplement a prospective database. 30-day morbidity and mortality were categorized, and classified according to the Clavien methodology.

RESULTS

47 first and 39 second operations were performed with 13% and 26% morbidity, respectively. Mortality was 2%. Infections comprised 59% of the morbidity. Inclusive of both operations, formal peritonectomy was performed in 16% of patients, resection of isolated lesions in less than half, and only 19% had a visceral organs other than the spleen resected. At the completion of the protocol, only 3% of patients had visible intraperitoneal disease. The mean total length of stay for both operations combined was 16 ± 23 days. Overall median survival was 54.9 months, and median survival for the epithelioid subtype was 70.2 months.

CONCLUSIONS

A two-stage cytoreduction with intraperitoneal chemotherapy offers median survival comparable to one-stage protocols, with relatively low morbidity, mortality, visceral resections and length of stay despite two operations. This series supports that our protocol is a feasible and safe approach.

Influence of microscopic malignant peritoneal mesothelioma on posttreatment survival

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Background: Progression of malignant peritoneal mesothelioma to clinically evident disease is poorly understood. Operative cytoreduction and post-operative intraperitoneal chemotherapy, followed by a second operative cytoreduction with heated intraoperative intraperitoneal chemotherapy is protocol at Columbia University. Our ability to assess presence of microscopic disease at a unique second operation provides in vivo insight into disease progression. Methods: Operative, pathology and oncologist records were reviewed for 98 consecutive patients with peritoneal mesothelioma treated between 5/95 and 1/08. Microscopic disease was defined as positive pathology on random biopsies in the absence of gross disease at second operation, and disease-free as absence of gross and microscopic disease. Survival was defined as time from first operation to death or last follow-up. Survival and recurrence were compared using the Kaplan Meier and log-rank methods, and correlations by Fisher's exact method. Results: 98 first and 69 second operations were performed. Patients were 59% male, 88% Caucasian and mean age was 52. At the second operation, 38 had gross disease, 23 were disease-free and 8 had microscopic disease. Median follow-up was 21 months, median overall survival was 48 months, and median survival for the epithelial subtype was 64 months. There was no significant difference in survival between disease- free and microscopic pathologies (log-rank p<0.69). 72% of disease-free (SE 11%) and 80% (SE 18%) of those with microscopic disease were alive at 96 months. 16% of disease-free and 7% of patients with microscopic disease had a recurrence (p<0.4). The time to clinical recurrence for both disease-free and microscopic disease was not significantly different (log-rank p<0.88). Conclusions: Survival and clinical recurrence in those with microscopic disease, none of whom were treated for this entity, were not significantly different from those who were disease-free at the second operation. These in vivo after treatment findings suggest that malignant peritoneal mesothelioma may progress slowly from microscopic to clinical disease and can be closely monitored rather than aggressively treated after initial cytoreduction and intraperitoneal chemotherapy.

No significant financial relationships to disclose.

The use of in-vitro drug resistance levels as a predictor of outcome in soft tissue sarcoma

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Background: We have assayed in-vitro drug resistance and immunohistochemical staining for drug resistance markers (MDR-1, MRP) in patients with metastatic soft tissue sarcoma patients. We looked at resistance to Cisplatin, Doxorubicin, and Ifosphamide, prior to beginning chemotherapy. The aim of this study was to investigate the validity of in-vitro drug resistance testing as a predictor of outcome. Methods: Viable tumor samples obtained at time of recurrence or metastasis from 13 patients with metastatic soft tissue sarcoma were tested by a semiquantitative 12 hour tritiated-thymidine uptake cell-proliferation assay (EDR test, Oncotech Inc., Tusin, California) for resistance to the chemotherapy drugs cisplatin, doxorubicin, and ifosphamide. The mean drug resistance level for these three drugs was plotted against survival in months, both from time of metastasis and time of initiation of chemotherapy. Mean resistance was also correlated with positive staining for either MDR-1 or MRP. Results: There was no relationship found between the mean drug resistance and survival, either from time of metastasis (correlation coefficient -0.0596) or time of initiation of chemotherapy (correlation coefficient - 0.1864). There was no correlation between mean drug resistance and; 1) presence of MDR-1 staining (correlation coefficient -0.1269), 2) presence of MRP staining (correlation coefficient -0.2175), 3) presence of either staining for MDR-1 or MRP (correlation coefficient -0.2636). Conclusions: 1) In-vitro drug resistance is not predictive of outcome in patients with soft tissue sarcoma. 2) There is no correlation between the mean drug resistance and positive staining for either MDR-1 or MRP.

No significant financial relationships to disclose.

18FDG-PET in the management of malignant peritoneal mesothelioma: A retrospective review of 145 scans in 37 patients

20519

Background: Malignant peritoneal mesothelioma is a rare tumor best managed by an interdisciplinary approach. The role of 18FDG-PET scans in monitoring patients with peritoneal mesothelioma has not been defined. Methods: Patients with peritoneal mesothelioma treated at Columbia University (October, 1997 - October, 2006) who had a PET scan were reviewed. Data were gathered on modes of therapy, imaging, and clinical outcome. The frequency with which PET scans led to a change in management, defined as scans that led to a biopsy or initiation of chemotherapy, was evaluated. Results: 37 patients, 21 women (57%) and 16 men (43%), were reviewed. The median age was 50 (range 14 - 79) years. All patients underwent surgery, 35 (95%) intraperitoneal chemotherapy, 15 (41%) external beam radiation, and 17 (46%) intravenous chemotherapy. At 43 (range 8.5 - 127) months median follow-up, 27 (73 %) are alive. Among 145 PET scans, 66 (46%) were PET/CT scans, 52 (26%) were PET scans with a CT scan performed within one month, and 27 (19%) were PET scans only. 8 (6%) of PET scans were for initial staging, and 137 (95%) for monitoring. A change in management based on findings in PET imaging occurred in 11 (30%) patients and 14 (10%) scans. Two patients were started on salvage chemotherapy without further evaluation. Two were diagnosed with peritoneal recurrence, 1 with lung metastasis, 1 with lymph node metastasis, 1 with a second malignancy, and 3 with colon polyps. One had a false positive scan, proven by negative surgical biopsy. PET provided early detection of disease progression in 6 (16%) of patients evaluated. One patient (3%) had biopsy proven progressive disease despite no 18FDG uptake on PET scan. Conclusions: 18FDG-PET findings changed management in 30% of patients with peritoneal mesothelioma undergoing multimodality therapy, and provided early detection of recurrence in 16% of patients. Further evaluation of test characteristics and prognostic value of 18FDG-PET in the setting of peritoneal mesothelioma is warranted.

No significant financial relationships to disclose.

Molecular profiling of malignant peritoneal mesothelioma identifies the ubiquitin–proteasome pathway as a therapeutic target in poor prognosis tumors

Malignant mesothelioma is an aggressive neoplastic proliferation derived from cells lining serosal membranes. The biological and clinical characteristics of epithelial type malignant mesothelioma are distinct from those of biphasic and sarcomatous type tumors. The goal of our study was to examine the molecular basis for this distinction. Microarray analysis confirmed that the molecular signatures of epithelial and biphasic histologic subtypes were distinct. Among the differentially expressed functional gene categories was the ubiquitin-proteasome pathway, which was upregulated in biphasic tumors. Cytotoxicity experiments indicated that 211H cells derived from biphasic tumors were synergistically sensitive to sequential combination regimens containing the proteasome inhibitor bortezomib and oxaliplatin. The mechanism of this synergistic response, which was not detected in cells of epithelial tumor origin, was apoptosis. Together, our results identify the ubiquitin-proteasome pathway as a biomarker of poor prognosis biphasic peritoneal mesothelioma tumors and suggest that proteasome inhibitors could increase the effectiveness of cytotoxic chemotherapy in this subset of patients.

Phase II trial of oxaliplatin and gemcitabine in patients with malignant pleural or peritoneal mesothelioma

17133

Background: A prior phase II trial of oxaliplatin and gemcitabine in malignant pleural mesothelioma reported activity with a 40% partial response rate and stable disease in 24% of 25 previously untreated patients (Schutte W. et al., Clin Lung Cancer 2003;4:294). This trial was designed to further evaluate the efficacy of oxaliplatin and gemcitabine in patients with malignant pleural or peritoneal mesothelioma. Methods: Patients with histologically-confirmed malignant pleural or peritoneal mesothelioma not amenable to curative surgical treatment are eligible for enrollment on this single-institution phase II trial. One prior chemotherapy regimen is allowed, including pemetrexed with a platinum compound or gemcitabine. Presence of at least one radiologically-measurable lesion that has not been previously irradiated is required. Gemcitabine 1000 mg/m2 IV over 90 minutes is administered followed by oxaliplatin 100 mg/m2 IV over 2 hours on day 1 of a 14-day cycle. Treatment is continued for at least 6 cycles unless unacceptable toxicity or disease progression occurs. The primary outcome is to evaluate efficacy as measured by tumor response rate. The sequential two-stage design allows for enrollment of a total of 29 patients if 3 of 18 patients enrolled in the first stage have at least a partial response. Results: Ten eligible patients have been enrolled thus far and 6 are evaluable for response. Sites of disease include pleural (3) and peritoneal (3), and histologic subtypes are epithelioid (5) and sarcomatoid (1). Four patients had received prior chemotherapy. A total of 42 cycles have been given with a median of 8 cycles per patient. There are no partial or complete responses. Four patients have had stable disease for at least 4 months. Two patients with stable disease had received prior pemetrexed/gemcitabine or pemetrexed/cisplatin. Frequently observed toxicities include grade II fatigue, neuropathy and upper gastrointestinal dysmotility. Conclusion: This regimen of gemcitabine and oxaliplatin may provide disease stabilization in a subset of patients with malignant pleural and peritoneal mesothelioma, including those who have received prior chemotherapy. The regimen is well-tolerated. This study remains open to accrual.

No significant financial relationships to disclose.

Molecular profiling of malignant peritoneal mesothelioma identifies the ubiquitin-proteasome pathway as a therapeutic target in poor prognosis tumors

9549

Background: Malignant peritoneal mesothelioma (MPM) is an aggressive neoplasm derived from cells lining serosal membranes. The characteristics of the epithelial (E) type MPM are distinct from those of the biphasic and sarcomatous (BS) type tumors. The goal of our study was to examine the molecular basis for this distinction. Methods: We used global molecular profiling with DNA microarrays to identify pathways associated with histologic subtype of 16 MPM tumor specimens acquired from patients entered into pilot multimodality protocols at our Institution. We performed immunohistochemistry on a tissue microarray and quantitative-real time PCR to validate the microarray results. Results: We performed average linkage agglomerative hierarchical clustering using microdissected MPM specimens and normal peritoneal tissue. The tumors segregated into two clades associated with histological subtype, which were distinct from the controls. 476 genes were differentially expressed between E and BS histologic classes (P < .001, with permutation test P value of .001). To identify biologically important differentially expressed genes and pathways, we examined the functional annotation of mesothelioma histologic subtype classifiers using the Pathway Comparison tool of BRB-Array. Among the differentially expressed categories was the ubiquitin-proteasome (UP) pathway, which was upregulated in BS tumors. Cytoxicity experiments by MTS assay indicated that, by the computation of combination indexes of activity, cells derived from BS tumors were exquisitely sensitive to sequential combination regimens containing the proteasome inhibitor (PI) bortezomib and oxaliplatin. The mechanism of this synergistic response, which was not detected in cells of E tumor origin, was apoptosis. Conclusions: Together, our results identify the ubiquitin-proteasome pathway as a biomarker of poor prognosis biphasic and sarcomatous malignant peritoneal mesothelioma tumors and suggest that proteasome inhibitors could increase the effectiveness of cytotoxic chemotherapy in this subset of patients.

No significant financial relationships to disclose.

P16 loss and mitotic activity predict poor survival in patients with peritoneal malignant mesothelioma

PURPOSE

Peritoneal malignant mesothelioma is an aggressive neoplasm for which intensive therapy improves survival in a subset of patients. We hypothesized that pathologic variables would stratify patients into favorable and unfavorable survival subgroups.

EXPERIMENTAL DESIGN

Fifty-four patients with peritoneal malignant mesothelioma were evaluated for trimodal therapy from 1995 to 2003. Two pathologists evaluated pathologic variables independently, and p16 status was analyzed by immunohistochemistry.

RESULTS

Patients not receiving trimodal therapy had a significantly increased risk of death [hazard ratio (HR), 9.6; 4.3-21.6; P < 0.0001]. Biphasic histology was also associated with increased risk of death (HR, 8.5; 3.4-21.8; P < 0.0001). In multivariate analysis adjusting for treatment modality and histologic type, high mitotic rate and p16 loss were associated with increased risk of death (HR, 3.074; 1.05-9.0; P < 0.04 and HR, 3.65; 1.3-10.2; P < 0.014, respectively).

CONCLUSIONS

Biphasic histology, increased mitotic rate, and p16 loss were independently associated with poorer survival in peritoneal malignant mesothelioma. Among the trimodal treated patients, increased mitotic rate was associated with increased risk of death.

The frequent expression of cancer/testis antigens provides opportunities for immunotherapeutic targeting of sarcoma

Sarcomas are rare but aggressive malignant tumors associated with high mortality, for which the efficacy of standard therapies remains limited. In order to develop immunotherapeutic approaches for the treatment of sarcoma, we studied the relevance of cancer/testis antigens (CTAs), a group of antigens whose expression is developmentally regulated and that is specifically found in some tumor types, as sarcoma vaccine targets. CTA expression was assessed by PCR and/or immunohistochemistry (IHC) in sarcoma tumor samples that included different histological subtypes and sarcoma cell lines. Expression of HLA class I was assessed by IHC in tumor samples and by FACS analysis in cell lines. More than 70% of the tumor samples expressed at least one CTA. The majority of tumors and cell lines expressed normal levels of HLA class I. HLA class I expression in cell lines was enhanced upon treatment with IFN-gamma. CTA expression was enhanced or induced by treatment with the demethylating agent 5-aza-2'-deoxycytidine, resulting in recognition by specific CTLs. Interestingly, a spontaneous humoral and CD8+ T cellular response to the CTA NY-ESO-1 was detected in a synovial sarcoma patient. Together, these findings strongly support the implementation of CTA-based immunotherapy of sarcoma as a means to improve the efficacy of the standard therapy.

A phase II trial of temozolomide in patients with unresectable or metastatic soft tissue sarcoma

BACKGROUND

The objective of this study was to assess the efficacy and toxicity of the imidazotetrazine derivative temozolomide for patients with unresectable or metastatic soft tissue sarcoma.

METHODS

Twenty-five of 26 patients were eligible and assessable for toxicity and response. Temozolomide was administered twice daily on a 12-hour schedule for 5 days as an oral bolus dose of 200 mg/m(2) followed by 9 doses of 90 mg/m(2) every 4 weeks.

RESULTS

There were 2 partial responses, 2 mixed responses, and 3 patients with stable disease that lasted > 6 months, for an overall objective response rate of 8%. At a median follow-up of 13.2 months, the median progression-free survival and the median overall survival were 2.0 months (95% confidence interval [95% CI], 1.7-2.3) and 13.2 months (95% CI, 4.7-31.1), respectively. All responding patients had leiomyosarcoma of uterine or nonuterine origin; and, in a subset analysis of these patients, the objective response rate was 18% (2 of 11 patients), with disease stabilization occurring in 3 of 11 patients (27%). For this subgroup, at a median follow-up of 24.4 months, the median progression-free survival and the median overall survival were 3.9 months (95% CI, 1.9-21.9) and 30.8 months (lower-bound 95% CI, 7.8), respectively. There were no treatment-related deaths or National Cancer Institute Grade 4 toxicities. Grade 3 toxicities included nausea, anemia, fatigue, elevated alkaline phosphatase levels and nonneutropenic fever (1 patient each).

CONCLUSIONS

Temozolomide at the dose schedule employed in the current study was tolerated well and had modest activity against previously treated unresectable or metastatic leiomyosarcoma of both uterine and nonuterine origin.