Structural Variants at the BRCA1/2 Loci are a Common Source of Homologous Repair Deficiency in High-grade Serous Ovarian Carcinoma.

PURPOSE: The abundance and effects of structural variation at BRCA1/2 in tumors are not well understood. In particular, the impact of these events on homologous recombination repair deficiency (HRD) has yet to be demonstrated. EXPERIMENTAL DESIGN: Exploiting a large collection of whole-genome sequencing data from high-grade serous ovarian carcinoma (N = 205) together with matched RNA sequencing for the majority of tumors (N = 150), we have comprehensively characterized mutation and expression at BRCA1/2. RESULTS: In addition to the known spectrum of short somatic mutations (SSM), we discovered that multi-megabase structural variants (SV) were a frequent, unappreciated source of BRCA1/2 disruption in these tumors, and we found a genome-wide enrichment for large deletions at the BRCA1/2 loci across the cohort. These SVs independently affected a substantial proportion of patients (16%) in addition to those affected by SSMs (24%), conferring HRD and impacting patient survival. We also detail compound deficiencies involving SSMs and SVs at both loci, demonstrating that the strongest risk of HRD emerges from combined SVs at both BRCA1 and BRCA2 in the absence of SSMs. Furthermore, these SVs are abundant and disruptive in other cancer types. CONCLUSIONS: These results extend our understanding of the mutational landscape underlying HRD, increase the number of patients predicted to benefit from therapies exploiting HRD, and suggest there is currently untapped potential in SV detection for patient stratification.

Pain in Malignant Pleural Mesothelioma: A Prospective Characterization Study.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is associated with severe pain. The underlying neurobiology of this is complex. The primary aim of this study was to characterize pain in MPM. METHODS: This study was undertaken as part of a trial examining radiotherapy for the treatment of pain in MPM (ISRCTN 10644347). Patients had MPM with associated pain for which radiotherapy was planned and a worst pain score ≥ 4/10. The following assessments were undertaken: clinical neuropathic pain assessment, Brief Pain Inventory (BPI), Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), Short form of the McGill Pain Questionnaire (SF-MPQ), and Quantitative Sensory Testing (QST). The relationship of these characteristics and response to radiotherapy was assessed. Unless stated, medians and interquartile range (IQR) are used. RESULTS: Thirty-seven patients were recruited. Average pain and worst pain was 4 (4-6) and 8 (6-8), respectively. Higher average pain and higher worst pain scores were associated with higher interference scores on the BPI, P < 0.001 and P < 0.0005. Twenty patients (54%) had a clinical diagnosis of neuropathic pain, and of these, only six patients (40%) screened positively for neuropathic pain using the LANSS. Patients with a high LANSS also had higher BPI and SF-MPQs. The presence of neuropathic pain (clinically or by LANSS) did not predict response to radiotherapy, P < 0.05. The SF-MPQ scores were higher in those with abnormal cool sensation on QST (P = 0.016). CONCLUSION: Pain in mesothelioma varies among patients and may have neuropathic components. An adequate pain assessment is necessary to guide the clinician in the appropriate choice of analgesics.

Is Radiotherapy Useful for Treating Pain in Mesothelioma?: A Phase II Trial.

INTRODUCTION: Radiotherapy is often used to treat pain in malignant pleural mesothelioma (MPM), although there is limited evidence to support this. The aim of this trial was to assess the role of radiotherapy for the treatment of pain in MPM. METHODS: A multicentre, single arm phase II trial was conducted. Eligible patients fulfilled the following criteria: pathological or radiological diagnosis of MPM; pain secondary to MPM; radiotherapy indicated for pain control; and more than 18 years of age. Patients had assessments of pain and other symptoms at baseline and then received 20 Gy in five daily fractions. Key follow-up points were 5 and 12 weeks posttreatment. The primary end point measure was assessment of pain at the site of radiotherapy at 5 weeks. Secondary end points included effects on quality of life, breathlessness, fatigue, mood, toxicity, and the radiological response. RESULTS: Forty patients were recruited from three UK oncology centers. Fourteen patients had a clinically meaningful improvement in their pain 5 weeks post radiotherapy (intention to treat), with five patients having a complete improvement. On the basis of a complete case analysis of the 30 patients assessable at week 5, 47% (confidence intervals, 28.3-65.7) of patients alive at week 5 had an improvement in their pain. There was no improvement in other key symptoms or quality of life. CONCLUSIONS: Radiotherapy for pain control in MPM is an effective treatment in a proportion of patients. Future studies examining differing radiotherapy regimens with a view to improving response rates are warranted.