Exceptional chemotherapy response in metastatic colorectal cancer associated with hyper-indel-hypermutated cancer genome and comutation of POLD1 and MLH1

Purpose A 73-year-old woman with metastatic colon cancer experienced a complete response to chemotherapy with dose-intensified irinotecan that has been durable for 5 years.Wesequenced her tumor and germ line DNA and looked for similar patterns in publicly available genomic data from patients with colorectal cancer. Patients and Methods Tumor DNA was obtained from a biopsy before therapy, and germ line DNA was obtained from blood. Tumor and germline DNA were sequenced using a commercial panel with approximately 250 genes. Whole-genome amplification and exome sequencing were performed for POLE and POLD1. A POLD1 mutation was confirmed by Sanger sequencing. The somatic mutation and clinical annotation data files from the colon (n = 461) and rectal (n = 171) adenocarcinoma data sets were downloaded from The Cancer Genome Atlas data portal and analyzed for patterns of mutations and clinical outcomes in patients withPOLE- and/orPOLD1- mutated tumors. Results The pattern of alterations included APC biallelic inactivation and microsatellite instability high (MSI-H) phenotype, with somatic inactivation of MLH1 and hypermutation (estimated mutation rate > 200 per megabase). The extremely high mutation rate led us to investigate additional mechanisms for hypermutation, including loss of function of POLE. POLE was unaltered, but a related gene not typically associated with somatic mutation in colon cancer, POLD1, had a somatic mutation c.2171G > A[p.Gly724Glu]. Additionally, we noted that the high mutation rate was largely composed of dinucleotide deletions. A similar pattern of hypermutation (dinucleotide deletions, POLD1 mutations, MSI-H) was found in tumors from The Cancer Genome Atlas. Conclusion POLD1 mutation with associated MSI-H and hyper-indel-hypermutated cancer genome characterizes a previously unrecognized variant of colon cancer that was found in this patient with an exceptional response to chemotherapy

Comparison of Patient- and Practitioner-Reported Toxic Effects Associated With Chemoradiotherapy for Head and Neck Cancer

Agreement between patient- and practitioner-reported toxic effects during chemoradiotherapy for head and neck cancer is unknown. To compare patient-reported symptom severity and practitioner-reported toxic effects among patients receiving chemoradiotherapy for head and neck cancer. Forty-four patients participating in a phase 2 trial of deintensified chemoradiotherapy for oropharyngeal carcinoma were included in the present study (conducted from February 8, 2012, to March 2, 2015). Most treatment (radiotherapy, 60 Gy, with concurrent weekly administration of cisplatin, 30 mg/m2) was administered at academic medical centers. Included patients had no prior head and neck cancers, were 18 years or older, and had a smoking history of 10 pack-years or less or more than 10 pack-years but 30 pack-years or less and abstinent for the past 5 years. Cancer status was untreated human papillomavirus or p16-positive squamous cell carcinoma of the oropharynx or unknown head and neck primary site; and cancer staging was category T0 to T3, category N0 to N2c, M0, and Eastern Cooperative Oncology Group performance status 0 to 1. Baseline, weekly, and posttreatment toxic effects were assessed by physicians or nurse practitioners using National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), version 4.0. Patient-reported symptom severity was measured using the Patient-Reported Outcomes version of the CTCAE (PRO-CTCAE). Descriptive statistics were used to characterize raw agreement between CTCAE grades and PRO-CTCAE severity ratings. Baseline, weekly, and posttreatment toxic effects assessed using CTCAE, version 4.0, and PRO-CTCAE. Raw agreement indices between patient-reported toxic effects, including symptom frequency, severity, and interference with daily activities (score range, 0 [none] to 4 [very severe]), and practitioner-measured toxic effects, including swallowing, oral pain, and hoarseness (score range, 1 [mild] to 5 [death]). Of the 44 patients included in the analysis (39 men, 5 women; mean [SD] age, 61 [8.4] years), there were 327 analyzable pairs of CTCAE and PRO-CTCAE symptom surveys and no treatment delays due to toxic effects. Patient-reported and practitioner-reported symptom severity agreement was high at baseline when most symptoms were absent but declined throughout treatment as toxic effects increased. Most disagreement was due to lower severity of toxic effects reported by practitioners (eg, from 45% agreement at baseline to 27% at the final week of treatment for pain). This was particularly noted for domains that are not easily evaluated by physical examination, such as anxiety and fatigue (eg, severity of fatigue decreased from 43% at baseline to 12% in the final week of treatment). Practitioner-reported toxic effects are lower than patient self-reports during head and neck chemoradiotherapy. The inclusion of patient-reported symptomatic toxic effects provides information that can potentially enhance clinical management and improve data quality in clinical trials

Use of mobile device technology to continuously collect patient-reported symptoms during radiation therapy for head and neck cancer: A prospective feasibility study

AbstractPurposeAccurate assessment of toxicity allows for timely delivery of supportive measures during radiation therapy for head and neck cancer. The current paradigm requires weekly evaluation of patients by a provider. The purpose of this study is to evaluate the feasibility of monitoring patient reported symptoms via mobile devices.Methods and materialsWe developed a mobile application for patients to report symptoms in 5 domains using validated questions. Patients were asked to report symptoms using a mobile device once daily during treatment or more often as needed. Clinicians reviewed patient-reported symptoms during weekly symptom management visits and patients completed surveys regarding perceptions of the utility of the mobile application. The primary outcome measure was patient compliance with mobile device reporting. Compliance is defined as number of days with a symptom report divided by number of days on study.ResultsThere were 921 symptom reports collected from 22 patients during treatment. Median reporting compliance was 71% (interquartile range, 45%-80%). Median number of reports submitted per patient was 34 (interquartile range, 21-53). Median number of reports submitted by patients per week was similar throughout radiation therapy and there was significant reporting during nonclinic hours. Patients reported high satisfaction with the use of mobile devices to report symptoms.ConclusionsA substantial percentage of patients used mobile devices to continuously report symptoms throughout a course of radiation therapy for head and neck cancer. Future studies should evaluate the impact of mobile device symptom reporting on improving patient outcomes

PIK3CA mutation in HPV-associated OPSCC patients receiving deintensified chemoradiation

PIK3CA is the most frequently mutated gene in human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC). Prognostic implications of such mutations remain unknown. We sought to elucidate the clinical significance of PIK3CA mutations in HPV-associated OPSCC patients treated with definitive chemoradiation (CRT). Seventyseven patients with HPV-associated OPSCC were enrolled on two phase II clinical trials of deintensified CRT (60 Gy intensitymodulated radiotherapy with concurrent weekly cisplatin). Targeted next-generation sequencing was performed. Of the 77 patients, nine had disease recurrence (two regional, four distant, three regional and distant). Thirty-four patients had mutation( s) identified; 16 had PIK3CA mutations. Patients with wild-type-PIK3CA had statistically significantly higher 3-year disease-free survival than PIK3CA-mutant patients (93.4%, 95% confidence interval [CI] = 85.0% to 99.9% vs 68.8%, 95% CI = 26.7% to 89.8%; P=.004). On multivariate analysis, PIK3CA mutation was the only variable statistically significantly associated with disease recurrence (hazard ratio = 5.71, 95% CI = 1.53 to 21.3; P=.01). PIK3CA mutation is associated with worse diseasefree survival in a prospective cohort of newly diagnosed HPV-associated OPSCC patients treated with deintensified CRT

Human DNA mismatch repair: coupling of mismatch recognition to strand-specific excision

Eukaryotic mismatch-repair (MMR) proteins MutSα and MutLα couple recognition of base mismatches to strand-specific excision, initiated in vivo at growing 3′ ends and 5′ Okazaki-fragment ends or, in human nuclear extracts, at nicks in exogenous circular substrates. We addressed five biochemical questions relevant to coupling models. Excision remained fully efficient at DNA:MutSα ratios of nearly 1 to 1 at various mismatch-nick distances, suggesting a requirement for only one MutSα molecule per substrate. As the mismatch-nick DNA contour distance D in exogenous substrates increased from 0.26 to 0.98 kbp, initiation of excision in extracts decreased as D−0.43 rather than the D−1 to D−2 predicted by some translocation or diffusion models. Virtually all excision was along the shorter (3′–5′) nick-mismatch, even when the other (5′–3′) path was less than twice as long. These observations argue against stochastically directed translocating/diffusing recognition complexes. The failure of mismatched DNA in trans to provoke excision of separate nicked homoduplexes argues against one-stage (concerted) triggering of excision initiation by recognition complexes acting through space. However, proteins associated with gapped DNA did appear to compete in trans with those in cis to mismatch-associated proteins. Thus, as in Escherichia coli, eukaryotic MMR may involve distinct initial-activation and excision-path-commitment stages

Isothermal folding of G-quadruplexes

Thermodynamic studies of G-quadruplex stability are an essential complement to structures obtained by NMR or x-ray crystallography. An understanding of the energetics of quadruplex folding provides a necessary foundation for the physical interpretation of quadruplex formation and reactivity. While thermal denaturation methods are most commonly used to evaluate quadruplex stability, it is also possible to study folding using isothermal titration methods. G-quadruplex folding is tightly coupled to specific cation binding. We describe here protocols for monitoring the cation-driven quadruplex folding transition using circular dichroism or absorbance, and for determination of the distribution of free and bound cation using a fluorescence indicator. Together these approaches provide insight into quadruplex folding at constant temperature, and characterize the linkage between cation binding and folding

Clinical and immunological responses after CD30-specific chimeric antigen receptor-redirected lymphocytes

BACKGROUND. Targeting CD30 with monoclonal antibodies in Hodgkin lymphoma (HL) and anaplastic large cell lymphoma (ALCL) has had profound clinical success. However, adverse events, mainly mediated by the toxin component of the conjugated antibodies, cause treatment discontinuation in many patients. Targeting CD30 with T cells expressing a CD30- specific chimeric antigen receptor (CAR) may reduce the side effects and augment antitumor activity. METHODS. We conducted a phase I dose escalation study in which 9 patients with relapsed/refractory HL or ALCL were infused with autologous T cells that were gene-modified with a retroviral vector to express the CD30-specific CAR (CD30. CAR-Ts) encoding the CD28 costimulatory endodomain. Three dose levels, from 0.2 - 108 to 2 - 108 CD30.CAR-Ts/m2, were infused without a conditioning regimen. All other therapy for malignancy was discontinued at least 4 weeks before CD30. CAR-T infusion. Seven patients had previously experienced disease progression while being treated with brentuximab. RESULTS. No toxicities attributable to CD30.CAR-Ts were observed. Of 7 patients with relapsed HL, 1 entered complete response (CR) lasting more than 2.5 years after the second infusion of CD30.CAR-Ts, 1 remained in continued CR for almost 2 years, and 3 had transient stable disease. Of 2 patients with ALCL, 1 had a CR that persisted 9 months after the fourth infusion of CD30.CAR-Ts. CD30.CAR-T expansion in peripheral blood peaked 1 week after infusion, and CD30.CAR-Ts remained detectable for over 6 weeks. Although CD30 may also be expressed by normal activated T cells, no patients developed impaired virus-specific immunity. CONCLUSION. CD30.CAR-Ts are safe and can lead to clinical responses in patients with HL and ALCL, indicating that further assessment of this therapy is warranted

CAR T Cells Administered in Combination with Lymphodepletion and PD-1 Inhibition to Patients with Neuroblastoma

Targeting disialoganglioside (GD2) on neuroblastoma (NB) with T cells expressing a first-generation chimeric antigen receptor (CAR) was safe, but the cells had poor expansion and long-term persistence. We developed a third-generation GD2-CAR (GD2-CAR3) and hypothesized that GD2-CAR3 T cells (CARTs) would be safe and effective. This phase 1 study enrolled relapsed or refractory NB patients in three cohorts. Cohort 1 received CART alone, cohort 2 received CARTs plus cyclophosphamide and fludarabine (Cy/Flu), and cohort 3 was treated with CARTs, Cy/Flu, and a programmed death-1 (PD-1) inhibitor. Eleven patients were treated with CARTs. The infusions were safe, and no dose-limiting toxicities occurred. CARTs were detectable in cohort 1, but the lymphodepletion induced by Cy/Flu increased circulating levels of the homeostatic cytokine interleukin (IL)-15 (p = 0.003) and increased CART expansion by up to 3 logs (p = 0.03). PD-1 inhibition did not further enhance expansion or persistence. Antitumor responses at 6 weeks were modest. We observed a striking expansion of CD45/CD33/CD11b/CD163+ myeloid cells (change from baseline, p = 0.0126) in all patients, which may have contributed to the modest early antitumor responses; the effect of these cells merits further study. Thus, CARTs are safe, and Cy/Flu can further increase their expansion

In Vivo Fate and Activity of Second- versus Third-Generation CD19-Specific CAR-T Cells in B Cell Non-Hodgkin's Lymphomas

Second-generation (2G) chimeric antigen receptors (CARs) targeting CD19 are highly active against B cell malignancies, but it is unknown whether any of the costimulatory domains incorporated in the CAR have superior activity to others. Because CD28 and 4-1BB signaling activate different pathways, combining them in a single third-generation (3G) CAR may overcome the limitations of each individual costimulatory domain. We designed a clinical trial in which two autologous CD19-specific CAR-transduced T cell products (CD19.CARTs), 2G (with CD28 only) and 3G (CD28 and 4-1BB), were infused simultaneously in 16 patients with relapsed or refractory non-Hodgkin's lymphoma. 3G CD19.CARTs had superior expansion and longer persistence than 2G CD19.CARTs. This difference was most striking in the five patients with low disease burden and few circulating normal B cells, in whom 2G CD19.CARTs had limited expansion and persistence and correspondingly reduced area under the curve. Of the 11 patients with measurable disease, three achieved complete responses and three had partial responses. Cytokine release syndrome occurred in six patients but was mild, and no patient required anti-IL-6 therapy. Hence, 3G CD19.CARTs combining 4-1BB with CD28 produce superior CART expansion and may be of particular value when treating low disease burden in patients whose normal B cells are depleted by prior therapy. CD19.CAR-T cells are highly active against B cell malignancies, but the optimal CAR structure is controversial. Ramos et al. show that combining 4-1BB and CD28 endodomains produces superior CD19-CAR-T cell expansion and persistence compared to CD28 alone and that these cells are clinically effective and safe in aggressive lymphomas

Alterations of LKB1 and KRAS and risk of brain metastasis: Comprehensive characterization by mutation analysis, copy number, and gene expression in non-small-cell lung carcinoma

Brain metastases are one of the most malignant complications of lung cancer and constitute a significant cause of cancer related morbidity and mortality worldwide. Recent years of investigation suggested a role of LKB1 in NSCLC development and progression, in synergy with KRAS alteration. In this study, we systematically analyzed how LKB1 and KRAS alteration, measured by mutation, gene expression (GE) and copy number (CN), are associated with brain metastasis in NSCLC