[Oncologic outcomes of surgical treatments of advanced sinonasal malignancies]

Objective: To investigate the prognoses of advanced (T3-T4) sinonasal malignancies (SNM). Methods: The clinical data of 229 patients with advanced (T3-4) SNM who underwent surgical treatments in the First Affiliated Hospital of Sun Yat-sen University from 2000 to 2018 were retrospectively analyzed, including 162 males and 67 females, aged (46.8±18.5) years old. Among them, 167 cases received endoscopic surgery alone, 30 cases received assisted incision endoscopic surgery, and 32 cases received open surgery. The Kaplan-Meier method was used to estimate the 3-year and 5-year overall survival (OS) and event-free survival (EFS). Univariate and multivariate Cox regression analyses were performed to explore significant prognostic factors. Results: The 3-year and 5-year OS were respectively 69.7% and 64.0%. The median OS time was 43 months. The 3-year and 5-year EFS were respectively 57.8% and 47.4%. The median EFS time was 34 months. The 5-year OS of the patients with epithelial-derived tumors was better than that of the patients with mesenchymal-derived tumors and malignant melanoma (5-year OS was respectively 72.3%, 47.8% and 30.0%, χ²=36.01, P<0.001). Patients with microscopically margin-negative resection (R0 resection) had the best prognosis, followed by macroscopically margin-negative resection (R1 resection), and debulking surgery was the worst (5-year OS was respectively 78.4%, 55.1% and 37.4%, χ²=24.63, P<0.001). There was no significant difference in 5-year OS between the endoscopic surgery group and the open surgery group (65.8% vs. 53.4%, χ²=2.66, P=0.102). Older patients had worse OS (HR=1.02, P=0.011) and EFS (HR=1.01, P=0.027). Patients receiving adjuvant therapy had a lower risk of death (HR=0.62, P=0.038). Patients with a history of nasal radiotherapy had a higher risk of recurrence (HR=2.48, P=0.002) and a higher risk of death (HR=2.03, P=0.020). Conclusion: For patients with advanced SNM, the efficacy of endoscopic surgery can be comparable to that of open surgery when presence of safe surgical margins, and a treatment plan based on transnasal endoscopic surgery as the main comprehensive treatment is recommended.

[Cost-effectiveness of endoscopic nasopharyngectomy in locally recurrent rT1-rT3 nasopharyngeal carcinoma: a study based on Markov model]

Objective: To perform a cost-effectiveness analysis of endoscopic surgery versus intensity-modulated radiotherapy in the treatment of locally recurrent nasopharyngeal carcinoma (rNPC) from a health-economic perspective. Methods: From September 30, 2011 to January 16, 2017, a total of 200 patients were enrolled in the First Affiliated Hospital of Sun Yat-sen University, the First People's Hospital of Foshan, and Sun Yat-sen University Cancer Center. These patients were diagnosed as locally rT1-rT3 stage rNPC and were randomly assigned 1︰1 to the endoscopic surgery group (ENPG) and the intensity-modulated radiotherapy group (IMRT). There were 69 males and 31 females in ENPG, aging from 38 to 55 years. There were 72 males and 28 females in IMRT aging from 41 to 54 years. A retrospective cost-effectiveness analysis of the cohort was conducted using a Markov model. For each modality, data on survival and quality-adjusted life year (QALY) were sourced from relevant articles, and cost prices were included regarding treatment. Weibull distribution was used to estimate time-dependent transition probability. Beta-regression was used to convert the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) to utility. Results: The total cost of ENPG was 29 611.88 yuan, and the total cost of IMRT was 110 082.51 yuan. The incremental cost-effectiveness ratio (ICER) of ENPG versus radiotherapy for locally rNPC was -85 555.88 yuan/QALY, which was less than 3 times of Chinese gross domestic product (GDP) per capita. Sensitivity analysis showed that the cost of IMRT had the greatest impact on ICER. ICER was stable within 10% fluctuation of all the parameters. Conclusion: It is economical cost-effective to treat locally rNPC with ENGP versus IMRT.

Comparison of uric acid reduction and renal outcomes of febuxostat vs allopurinol in patients with chronic kidney disease

Whether the clinical trial treatment effect of urate-lowering therapy (ULT) in patient with chronic kidney disease (CKD) is generalizable to real-word settings is unclear. This study aimed to compare febuxostat with allopurinol for uric acid reduction and renal protection in patients with CKD. Adult CKD patients newly treated with ULT were identified using electronic health records from 2010 to 2015 from a large healthcare delivery system in Taiwan. Patients with renal replacement therapy or undergoing ULT for <3 months were excluded. Propensity score-matched cohort study design was conducted to compare outcomes between patients initiated with febuxostat or allopurinol therapy. Cox regression analyses were employed to compare the adjusted hazards ratio (aHR) of incident event of estimated glomerular filtration rate (eGFR) ≥ 30% decrease, and the difference in longitudinal changes in serum uric acid (SUA) and eGFR between groups was analyzed using linear mixed model. Overall, 1050 CKD patients who initiated febuxostat (n = 525) or allopurinol (n = 525) treatment were observed for 2.5 years. Compared with allopurinol, febuxostat use was associated with higher rate of patients maintaining SUA target <6 mg/dL in >80% of follow-up time with a reduction in mean SUA change. There were no significant differences in the mean eGFR changes over time between the febuxostat and allopurinol groups or in the risk of eGFR decline ≥30% of baseline. Febuxostat was associated with greater reduction in SUA level than allopurinol in patients with CKD. However, febuxostat and allopurinol showed no difference in renal function changes during study follow-up. These findings require further investigation with long-term follow up in CKD patients with hyperuricemia.

[Study on the relationship between urinary polycyclic aromatic hydrocarbons metabolites and pulmonary function in community population]

Objective: To investigate the relationship between urinary polycyclic aromatic hydrocarbons(PAHs) metabolites and pulmonary function in community population. Methods: A total of 4 812 participants were recruited from two communities in Wuhan city from April to May 2011 and two communities in Zhuhai city in May 2012. Information of demographic characteristics and life style was collected by semi-structural questionnaire. Physical examination was performed and pulmonary function was measured. Morning urine was also collected. The concentration of 12 urinary PAHs metabolites was tested and classified into four types by chemical structure, including hydroxynaphthalene, hydroxyfluorene, hydroxyphenanthrene and hydroxypyrene. The level of pulmonary function in different group of urinary PAHs metabolites was compared by using covariance analysis. The association of the urinary PAHs metabolites and pulmonary function was analyzed by using generalized linear model, and the interaction of different population characteristics and life style on the association was analyzed. Results: The age of participants was(51.99±13.64) years old, and 67.66% (n=2 565) of the population were women. The M (P(25), P(75)) of concentration of total urinary PAHs metabolites was 5.72 (3.91,8.72) μg/mmol Cr. After controlling for variables including age, gender, city, Waist-to-Hip Ratio, smoking status, drinking situation, physical activity, cooking meals at home or not, kitchen ventilation and exposure to dust as confounding factors, generalized linear model showed that each 1-unit increase in log-transformed levels of hydroxynaphthalene, hydroxyfluorene, hydroxyphenanthrene, hydroxypyrene and total PAHs was associated with 26.83 (95%CI: -48.18, -5.48) , 21.86 (95%CI: -40.49, -3.23), 26.18(95%CI: -48.27, -4.09), 34.95 (95%CI: -55.95, -13.94), and 35.23 (95%CI: -58.93, -11.54) ml reduction of FVC and 29.36 (95%CI: -47.23, -11.48), 20.79 (95%CI: -36.39, -5.19), 22.65 (95%CI: -41.15, -4.15), 31.44(95%CI: -49.03, -13.85), and 33.20 (95%CI: -53.04, -13.36) ml reduction of FEV(1) respectively (all P values<0.05). Compared to non-alcohol users and participants with home cooking, the association was more evident in alcohol users and participants without home cooking(P for interaction<0.05). Conclusion: The exposure to PAHs was associated with decreased pulmonary function, and the association was more evident in alcohol users and participants without home cooking.

Is asthma a protective factor for dengue fever? In vitro experiment and nationwide population-based cohort analysis

BACKGROUND

Dengue fever (DF) is the most rapidly spreading mosquito-borne viral disease. Practical vaccines or specific therapeutics are still expected. Environmental factors and genetic factors affect the susceptibility of Dengue virus (DV) infection. Asthma is a common allergic disease, with house dust mites (HDMs) being the most important allergens. Asthmatic patients are susceptible to several microorganism infections.

METHODS

A nationwide population-based cohort analysis was designed to assess whether to determine whether asthma can be a risk factor for DF.

RESULTS

Unexpectedly, our data from a nationwide population-based cohort revealed asthmatic patients are at a decreased risk of DF. Compared to patients without asthma, the hazard ratio (HR) for DF in patients with asthma was 0.166 (95% CI: 0.118-0.233) after adjustment for possible confounding factors. In the age stratification, the adjusted HR for DF in young adult patients with asthma was 0.063. Dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) of dendritic cells (DCs) is an important entry for DV. Through another in vitro experiment, we found that HDM can diminish surface expression of DC-SIGN in monocyte-derived DCs and further decrease the cellular entry of DV.

CONCLUSIONS

Decreased DC-SIGN expression in DCs of allergic asthmatic patient may be one of many factors for them to be protected against DF. This could implicate the potential for DC-SIGN modulation as a candidate target for designing therapeutic strategies for DF.

Increased ischemic stroke risk in patients with Behçet's disease: A nationwide population-based cohort study

Background

Behçet’s disease (BD) is a recurrent, multisystemic, inflammatory disorder that mainly affects blood vessels. Because recurrent inflammation of blood vessels in the brain plays a crucial role in the development of ischemic stroke, we hypothesized that patients with BD might have an elevated risk of ischemic stroke. This potential association has been suggested in a few case reports, but not epidemiological studies. Hence, the present study aimed to examine the relation between BD and subsequent ischemic stroke in Taiwan using a nationwide, population-based database.

Methods

To establish a study cohort, the longitudinal data of 306 patients newly diagnosed with BD during 2000–2010 were extracted from the National Health Insurance Research Database, Taiwan. For comparison of ischemic stroke incidence, a control cohort of 1224 subjects without BD was established using a frequency-matched ratio of 1:4 for age, sex, and pre-existing comorbidities.

Results

During the 10-year follow-up, 13 (4.2%) patients with BD and 20 (1.6%) control subjects experienced ischemic stroke. Kaplan–Meier analysis revealed the higher prevalence of ischemic stroke in the BD group (log-rank test, p = 0.001). After adjusting for comorbidities and demographic characteristics, Cox regression analysis revealed that patients with BD had a 2.77-fold risk of ischemic stroke (95% confidence interval, 1.38–5.57) compared to control subjects.

Conclusions

Patients with BD have an elevated risk of ischemic stroke. Hence, BD may affect the vascular system in the brain, resulting in a stroke event.

[Correlation between prognosis and IL-33 expression in head and neck squamous cell carcinoma]

Objective:To determine the correlation between the expression of IL-33 and significance in cancer biologial and patient's prognosis in head and neck squamous cell carcinoma (HNSCC). Method:Twenty pairs of tumor tissue and adjacent normal tissue were collected. qRT-PCR and immunohistochemistry (IHC) were used to detect the expression of IL-33 mRNA and protein in tissues. Correlation between IL-33 expression with clinicopathologic features of 107 HNSCC patients were analyzed. Result:IL-33 mRNA and protein expression levels in normal tissue were higher than paired tumor tissue. IL-33 level was significantly lower in patients with advanced T stages, lymph node metastases and advanced clinical stages, IL-33 expression was higher in well differentiated tumor than moderate or poor differentiated tumor. Low IL-33 expression predicts poor prognosis. Multivariate analysis indicated that IL-33 expression was an independent predictive factor. Conclusion:IL-33 is related with the clinicopathological features in HNSCC and could be an independent predictor of HNSCC prognosis.

Quantitative comorbidity risk assessment of dementia in Taiwan: A population-based cohort study

Dementia is one of the most burdensome illnesses in elderly populations worldwide. However, the literature about multiple risk factors for dementia is scant.To develop a simple, rapid, and appropriate predictive tool for the clinical quantitative assessment of multiple risk factors for dementia.A population-based cohort study.Based on the Taiwan National Health Insurance Research Database, participants first diagnosed with dementia from 2000 to 2009 and aged ≥65 years in 2000 were included.A logistic regression model with Bayesian supervised learning inference was implemented to evaluate the quantitative effects of 1- to 6-comorbidity risk factors for dementia in the elderly Taiwanese population: depression, vascular disease, severe head injury, hearing loss, diabetes mellitus (DM), and senile cataract, identified from a nationwide longitudinal population-based database.This study enrolled 4749 (9.5%) patients first diagnosed as having dementia. Aged, female, urban residence, and low income were found as independent sociodemographic risk factors for dementia. Among all odds ratios (ORs) of 2-comorbidity risk factors for dementia, comorbid depression and vascular disease had the highest adjusted OR of 6.726. The 5-comorbidity risk factors, namely depression, vascular disease, severe head injury, hearing loss, and DM, exhibited the highest OR of 8.767. Overall, the quantitative effects of 2 to 6 comorbidities and age difference on dementia gradually increased; hence, their ORs were less than additive. These results indicate that depression is a key comorbidity risk factor for dementia.The present findings suggest that physicians should pay more attention to the role of depression in dementia development. Depression is a key cormorbidity risk factor for dementia. It is the urgency of evaluating the nature of the link between depression and dementia; and further testing what extent controlling depression could effectively lead to the prevention of dementia.

[Clinical application of supraclavicular flap for oncologic reconstruction of hypopharynx and upper esophagus]

Objective: To assess the efficacy of supraclavicular artery island flap (SCAIF) for the reconstruction of hypopharynx and upper esophagus. Methods: The SCAIF procedure on was used in 10 patients, including 8 with hypopharygeal carcinomas, 1 with esophageal carcinoma and neck skin invasion and 1 with hypopharyngeal leiomyosarcoma, at the Otorhinolaryngology Hospital, the First Affiliated Hospital, Sun Yatsen University between December 2015 and June 2017. The sizes of the flaps were measured in (4-8) cm×(5-12) cm. Clinical indexes such as harvesting time and survival were recorded. Results: Harvesting time for SCAIF ranged from 20 to 30 minutes, averaging 26 minutes. Nine flaps survived, one flap had partially necrosis. Functional outcomes were excellent and the donor sites were direct closed without complications. Conclusions: SCAIF is a versatile, reliable, and easily harvested flap, with good cosmetic and functional outcomes for reconstructing the defects of hypopharynx and upper esophagus.

Misdiagnosed paranasal gossypiboma: a 10-year experience with 21 cases at a tertiary center

BACKGROUND

Different from rhinoliths, the paranasal gossypiboma is a foreign body, such as a surgical sponge, left in the nasal cavity. It is a rare, frequently misdiagnosed disease that has rarely been reported. We summarize its clinical characteristics, management, and possible risk factors.

METHODOLOGY

We reviewed medical records of confirmed paranasal gossypibomas at a tertiary medical center between 2005 and 2015. Clinical symptoms, age, sex, anatomic sites, endoscopic photography, computed tomography, intraoperative findings, and past medical history were reviewed.

RESULTS

The study included 21 patients, each of whom had ultimately undergone two operations. Among them, 20 underwent endoscopic nasal surgery in primary hospitals, and 15 had been misdiagnosed during the second surgery. The average interval to discovery of a retained foreign body was 200 days. Predominant occurrence sites were the maxillary and ethmoid sinuses. Computed tomography showed paranasal gossypiboma as a heterogeneous cystic lesion with a thin calcified shell.

CONCLUSIONS

A history of endoscopic nasal surgery, especially performed at a primary hospital, is a warning sign for clinicians. Computed tomography can add to the warning by showing a heterogeneous cystic lesion with a thin calcified shell. Clinicians should be aware of these characteristics to avoid misdiagnosing paranasal gossypiboma.

Cost-effectiveness Analysis for Genotyping before Allopurinol Treatment to Prevent Severe Cutaneous Adverse Drug Reactions

OBJECTIVE

Patients with an HLA-B*58:01 allele have an increased risk of developing severe cutaneous adverse drug reactions (SCAR) when treated with allopurinol. Although one-off pharmacogenetic testing may prevent life-threatening adverse drug reactions, testing prior to allopurinol initiation incurs additional costs. The study objective was to evaluate the cost-effectiveness of HLA-B*58:01 screening compared with using other available urate-lowering agents (ULA).

METHODS

A decision-analytical model was used to compare direct medical costs and effectiveness [including lifetime saved, quality-adjusted life-yrs (QALY) gained] in treating new patients with the following options: (1) genetic screening followed by allopurinol prescribing for noncarriers of HLA-B*58:01, (2) prescribing benzbromarone without screening, (3) prescribing febuxostat without screening, and (4) prescribing allopurinol without screening. A 1-year time frame and third-party payer perspective were modeled for both the entire cohort (base-case) and for the subgroup of patients with chronic kidney disease (CKD).

RESULTS

The incremental cost-effectiveness ratio of genetic screening prior to ULA therapy was estimated as New Taiwan (NT) $234,610 (US$7508) per QALY gained in the base-case cohort. For patients with CKD, it was estimated as NT$230,925 (US$7390) per QALY. The study results were sensitive to the probability of benzbromarone/febuxostat-related hypersensitivity, and a negative predicted value of genotyping.

CONCLUSION

HLA-B*58:01 screening gave good value for money in preventing allopurinol-induced SCAR in patients indicated for ULA therapy. In addition to the costs of genotyping, it is important to monitor ULA safety closely in adopting HLA-B*58:01 screening in practice.

Abstract S2-02: The landscape of somatic genetic alterations in BRCA1 and BRCA2 breast cancers

Introduction: Women carrying BRCA1 or BRCA2 germline mutations have a 45-80% lifetime risk of developing breast cancer (BC). BRCA1 and BRCA2 are perceived as bona fide tumor suppressor genes, whereby bi-allelic inactivation in tumor cells is required for tumorigenesis. Recent studies have indicated that loss of heterozygosity (LOH) of the wild-type allele of BRCA1 may be heterogeneous and constitute a late event. Therefore, additional somatic events prior to full BRCA1/2 inactivation may be required for tumorigenesis. Given that the somatic events that result in the development of BRCA1/2-BCs and their chronology are not understood, here we sought to define the genomic landscape of BRCA1/2-BCs and whether LOH of BRCA1/2 wild-type allele and/or mutations affecting additional tumor suppressor genes would be clonal or subclonal in these cancers.

Methods: We retrieved 29 BRCA1-BCs and 10 BRCA2-BCs from the Pathology Departments of the authors' institutions. DNA extracted from microdissected tumor and normal breast samples was subjected to targeted capture massively parallel sequencing using either the MSK-IMPACT assay or an assay targeting all exons of 254 genes recurrently mutated in BC or related to DNA repair. Somatic single nucleotide variants, small insertions and deletions and copy number alterations affecting genes present in both sequencing assays (111 genes) were defined using state-of-the-art bioinformatics algorithms. ABSOLUTE and FACETS were employed to define clonal (i.e. present virtually in 100% of the cancer cells of a given case) and subclonal mutations and the presence of LOH of the BRCA1 and BRCA2 wild-type alleles.

Results: Our analysis revealed bi-allelic inactivation of BRCA1 in 28 of 29 BRCA1-BCs (93% harbored LOH of the BRCA1 wild-type allele and 3% harbored a second somatic BRCA1 pathogenic mutation). The only BRCA1-BC lacking bi-allelic inactivation of BRCA1 was an estrogen receptor-positive lobular carcinoma, lacking genomic features consistent with homologous recombination DNA repair defects, diagnosed at 62 years of age. Bi-allelic inactivation of BRCA2 was found in all cases (100% of harbored LOH of the BRCA2 wild-type allele). A clonal somatic 'second hit' resulting in bi-allelic inactivation of BRCA1 or BRCA2 was detected in 76% and 100% of BRCA1-BCs and BRCA2-BCs, respectively. In BRCA1-BCs, TP53 mutations were detected in 76% of cases, and these mutations were found to be clonal in 58% of cases. The repertoire of somatic mutations affecting BRCA1-BCs included clonal somatic mutations or homozygous deletions of known tumor suppressor genes, such as PTEN, RB1, CDKN2A and NF1. In contrast, only 10% of the BRCA2-BCs harbored TP53 somatic mutations. Though clonal somatic mutations in several cancer genes were detected, 40% of BRCA2-BCs had no mutations affecting the cancer genes analyzed.

Conclusions: Bi-allelic inactivation of BRCA1 and BRCA2 are frequent events in BRCA1-BCs and BRCA2-BCs, respectively. In a subset of BRCA1-BCs, however, the second 'hit' appeared to be subclonal, whereas mutations affecting TP53 and other tumor suppressor genes were clonal, supporting the notion that at least in a subset of these tumors, loss of the wild-type allele of BRCA1 may be preceded by inactivation of another tumor suppressor gene.

Citation Format: Geyer FC, Burke KA, Macedo GS, Piscuoglio S, Ng CK, Martelotto LG, Papanastatiou AD, De Filippo MR, Schultheis AM, Brogi E, Robson M, Wen YH, Weigelt B, Schnitt SJ, Tung N, Reis-Filho JS. The landscape of somatic genetic alterations in BRCA1 and BRCA2 breast cancers [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S2-02.

Abstract P1-05-04: Intra-tumor genetic heterogeneity and histologic heterogeneity within metaplastic breast cancers: Genotypic-phenotypic correlations

Introduction: Metaplastic breast carcinoma (MBC) is characterized by the presence of neoplastic cells displaying squamous and/or mesenchymal differentiation. Morphologic intra-tumor heterogeneity is frequent in MBCs and reported to be reflected at the transcriptomic level: whilst squamous and chondroid MBCs are preferentially of basal-like subtype, spindle cell MBCs are of claudin-low subtype. Likewise, histologically distinct components within MBCs have been shown to display distinct focal copy number alterations. Here we sought to investigate whether histologically distinct components within MBCs would be underpinned by different mutational profiles and mutational signatures.

Methods: Ten MBCs with two histologically distinct components (spindle, chondroid, osseous, squamous and/ or ductal) were retrieved from the Department of Pathology of the authors' institution. The distinct components of each case and, in two cases, two regions of the same component were separately microdissected. DNA extracted from tumor samples (n=22) and matched normal tissues was subjected to whole-exome sequencing. Somatic genetic alterations were identified using state-of-the-art bioinformatics algorithms. Somatic mutations were classified as clonal (i.e., present virtually in all tumor cells) or subclonal using ABSOLUTE and FACETS. Mutational signatures were defined using non-negative matrix factorization.

Results: Medians of 146 (56-290) somatic mutations and 108 non-synonymous somatic mutations (39-222) per tumor component were identified. The histologically distinct components of each case harbored identical clonal TP53 mutations. Additional recurrent mutations in cancer genes included those affecting PI3K pathway genes (PIK3CA, 2 cases; PIK3R1, 2 cases). Shared mutations between components of each case ranged from 34% to 99% of all mutations, with a median of 84%, of which 24% (12%-53%) were truncal (i.e., shared by and clonal in both components). Private mutations (i.e., found in only one component) ranged from 1% to 66%, with a median of 16%, of which 72% (0-100%) were non-synonymous and 1% (0-52%) were clonal. In two cases, the comparison of two histologically similar regions revealed less heterogeneity, with 94% (87%-100%) of shared mutations, whereas in these samples the median of private mutations was 6% (0-13%), of which 70% (0-100%) were non-synonymous and none were clonal. Private non-synonymous mutations affecting cancer genes included those in PIK3R1, MED12 and NOTCH1. The mutational signatures (e.g. aging or BRCA) were concordant between distinct components of each case; however, differences in the mutational signatures were observed between truncal somatic mutations and mutations restricted to individual components.

Conclusions: MBCs display substantial genetic intra-tumor heterogeneity, which is more overt between histologically distinct components than between regions of similar histology. Our data suggest a genotypic-phenotypic correlation and corroborate the notion that distinct components within MBCs, although clonally related, may be driven by distinct somatic genetic alterations.

Citation Format: Geyer FC, Burke KA, Papanastatiou AD, Macedo GS, Brogi E, Norton L, Wen YH, Weigelt B, Reis-Filho JS. Intra-tumor genetic heterogeneity and histologic heterogeneity within metaplastic breast cancers: Genotypic-phenotypic correlations [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-04.

Abstract P2-03-01: Mutational landscape of breast cancers from PALB2 germline mutation carriers

Background: The PALB2 gene encodes the partner and localizer of the BRCA2 protein, which participates in homologous recombination during DNA repair via an interaction with BRCA1 and BRCA2. Germline mutations in PALB2 are associated with an increased risk of breast cancer, with a cumulative risk of 35% by age 70 in female PALB2 mutant carriers. The aims of this project were to characterize the genomic landscape of PALB2 breast cancers and define the differences in the repertoire of somatic genetic alterations and mutational signatures between PALB2, BRCA1 and BRCA2 breast cancers.

Methods: Representative samples from fourteen breast cancers from patients with known PALB2 germline mutations (seven frame-shift (2 H1170fs, 3 K346fs, 1 T841fs and 1 L531fs), five truncating (3 W1038* and 2 Q775*) and two missense (W1140G and L35P)) were microdissected to ensure a tumor cell content of &gt;70%. DNA samples from microdissected tumors and their matched normal counterparts were subjected to whole exome sequencing on an Illumina HiSeq2000 to a median depth of 118x (range 33-193x). Somatic single nucleotide variations were detected using MuTect, and small insertions and deletions were identified using Strelka and Varscan2. Using ABSOLUTE and FACETS, we investigated the presence of loss of heterozygosity (LOH) of the PALB2 wild-type allele in these tumors. In addition, the mutational signatures and large scale state transitions (LSTs) were defined. The repertoire of somatic mutations identified in PALB2 breast cancers was compared to that of breast cancers from BRCA1 (n=11) and BRCA2 (n=10) germline mutation carriers from The Cancer Genome Atlas study.

Results: PALB2 breast cancers were found to harbor a median of 80 somatic mutations (range 22-286) and one somatic mutation (range 0-13) affecting known cancer genes. Somatic loss of the PALB2 wild-type allele was found in five cases, and in three additional cases, a second PALB2 somatic mutation likely constituted the second 'hit' (two with truncating mutations, Q479* and Q61*, and one with a Q921fs frameshift mutation). Six PALB2 breast cancers displayed the BRCA mutations signature; of these, five had PALB2 bi-allelic inactivation (three LOH of the wild-type allele and two a second PALB2 somatic mutation). 71% of the samples were found to have LSTs, including all cases with a BRCA mutational signature. A significant association between PALB2 bi-allelic inactivation and concurrent BRCA signature and high LST was observed (p=0.015). Breast cancers from PALB2 mutation carriers had fewer somatic TP53 mutations than BRCA1 breast cancers (3/14, 21% vs 9/11, 82%, p=0.004), but no difference in the repertoire of somatic mutations compared to that of BRCA2 breast cancers.

Conclusions: PALB2 breast cancers were found to harbor pathogenic mutations in driver genes, including TP53, PIK3CA, NF1 and NCOR1, however lacked highly recurrent somatic mutations. Unlike BRCA1/2 breast cancers, the majority of breast cancers from PALB2 germline mutation carriers lacked LOH of the PALB2 wild-type allele. Importantly, however, an association between PALB2 bi-allelic inactivation and the BRCA mutational signature and LSTs was observed, providing additional evidence for a homologous recombination-deficient phenotype at least in a subset of PALB2 cancers.

Citation Format: Burke KA, Berman S, Geyer FC, Piscuoglio S, Ng CK, Wen YH, Mannermaa A, Peterlongo P, Tondini C, Janatova M, Soo Hwang T, Ng P-S, Looi LM, Chenevix-Trench G, Southey MC, Weigelt B, Foulkes W, Tischkowitz M, Reis-Filho JS, PALB2 Interest Group. Mutational landscape of breast cancers from PALB2 germline mutation carriers [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-03-01.

Abstract P1-05-03: The genomic landscape of breast metaplastic carcinoma

Introduction: Metaplastic breast carcinoma (MBC) is a rare histologic type of triple-negative breast cancer (TNBC), characterized by the presence of cells displaying squamous and/or mesenchymal differentiation. The transcriptomic profiles of MBCs have been reported to vary according to the type of metaplastic elements. The somatic genetic alterations that underpin this breast cancer subtype remain to be fully characterized. Here we sought to define the genomic landscape of MBCs, whether different subtypes of MBC would be driven by distinct constellations of genetic alterations, and to investigate functionally the impact of mutations affecting WNT pathway genes using non-malignant breast epithelial cells.

Methods: Thirty-five MBCs were retrieved from the pathology department of the authors' institutions and classified into the MBC histologic subtypes. All but one of the MBCs were of triple-negative phenotype. DNA was extracted from microdissected tumor-normal pairs and subjected to whole-exome sequencing. Somatic genetic alterations were identified using state-of-the-art bioinformatics algorithms. The genomic profiles of MBCs were compared to those of 69 common type TNBCs from The Cancer Genome Atlas. Overall mutation rates were compared using the Mann Whitney U test, and the frequency of mutations in each gene was compared using Fisher's exact test. RNA was extracted from a subset of MBCs and subjected to WNT signaling pathway activation analysis with the RT2 Profiler PCR Array. Triple-negative non-malignant breast epithelial cells (MCF10A and MCF12A) and cancer cell lines were utilized for 2D and 3D functional studies.

Results: Whole-exome analysis revealed that MBCs displayed a median of 103 (15-344) somatic mutations, which did not differ from the median number of somatic mutations in common type TNBCs (76, range 14-233). The most frequent recurrently mutated cancer genes included TP53 (69%) and PIK3CA (29%). MBCs more frequently harbored mutations in PI3K pathway genes than common type TNBCs (57% vs 22%, P&lt;0.05), including mutations affecting PIK3CA (29% vs 7%), PIK3R1 (11% vs 0) and PTEN (11% vs 1%). MBCs also more frequently harbored mutations affecting WNT signaling pathway genes (46% vs 26%, P&lt;0.05), including AXIN1 (6% vs 1%), WNT5A (6% vs 0) and APC (3% vs 0). MBC subtype analysis revealed that PIK3CA mutations were only detected in non-chondroid MBCs (53% vs 0), CHERP mutations were only found in chondroid MBCs (25% vs 0), whereas USP5 mutations only found in squamous MBCs (33% vs 0). MBCs with somatic mutations in WNT pathway genes had significantly higher WNT pathway activation than MBCs lacking mutations in these genes (P=0.0244). Consistent with the mesenchymal phenotype frequently exhibited by MBCs, in vitro experiments provided functional evidence that aberrant WNT pathway activation induces an epithelial-to-mesenchymal transition (EMT) phenotype, with downregulation of epithelial markers and upregulation of EMT transcriptional inducers.

Conclusions: MBCs are significantly enriched for mutations affecting PI3K and WNT pathways, highlighting the importance of the dysregulation of the WNT pathway in MBC carcinogenesis. Moreover, our findings suggest that specific mutations are significantly associated with distinct histologic subtypes of MBCs.

Citation Format: Geyer FC, Ng CK, Piscuoglio S, Wen YH, Wen H-C, Pareja F, Eberle CA, Burke KA, Lim RS, Natrajan R, Mariani O, Brogi E, Norton L, Vincent-Salomon A, Weigelt B, Reis-Filho JS. The genomic landscape of breast metaplastic carcinoma [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-03.

Antipsychotic medications and dental caries in newly diagnosed schizophrenia: A nationwide cohort study

We investigated the association between antipsychotic medications and the risk of dental caries in patients with schizophrenia. We enroled a nationwide cohort of patients with newly diagnosed schizophrenia within 1 year of dental caries development. Exposure to antipsychotics and other medications was categorised according to their type and duration, and the association between exposure and dental caries was assessed through logistic regressions. Of the 3610 patients with newly diagnosed schizophrenia, 2149 (59.5%) exhibited an incidence of treated dental caries. Logistic regression analysis identified a younger age, female sex, high income, a 2-year history of dental caries, and exposure to first-generation antipsychotics, and antihypertensives as independent risk factors for treated dental caries in patients with schizophrenia. Hyposalivation, the adverse effect of first-generation antipsychotics and antihypertensives, was associated with an increased risk of treated dental caries. However, hypersalivation from first-generation antipsychotics for dental caries was associated with a protective factor. These findings suggest that clinicians should pay attention to the aforementioned risk factors for dental caries in patients with schizophrenia, particularly while prescribing first-generation antipsychotics and antihypertensives to such patients.

A Bayesian Approach to Identifying New Risk Factors for Dementia: A Nationwide Population-Based Study

Dementia is one of the most disabling and burdensome health conditions worldwide. In this study, we identified new potential risk factors for dementia from nationwide longitudinal population-based data by using Bayesian statistics.We first tested the consistency of the results obtained using Bayesian statistics with those obtained using classical frequentist probability for 4 recognized risk factors for dementia, namely severe head injury, depression, diabetes mellitus, and vascular diseases. Then, we used Bayesian statistics to verify 2 new potential risk factors for dementia, namely hearing loss and senile cataract, determined from the Taiwan's National Health Insurance Research Database.We included a total of 6546 (6.0%) patients diagnosed with dementia. We observed older age, female sex, and lower income as independent risk factors for dementia. Moreover, we verified the 4 recognized risk factors for dementia in the older Taiwanese population; their odds ratios (ORs) ranged from 3.469 to 1.207. Furthermore, we observed that hearing loss (OR = 1.577) and senile cataract (OR = 1.549) were associated with an increased risk of dementia.We found that the results obtained using Bayesian statistics for assessing risk factors for dementia, such as head injury, depression, DM, and vascular diseases, were consistent with those obtained using classical frequentist probability. Moreover, hearing loss and senile cataract were found to be potential risk factors for dementia in the older Taiwanese population. Bayesian statistics could help clinicians explore other potential risk factors for dementia and for developing appropriate treatment strategies for these patients.

Abstract P2-08-01: PIK3CA mutations associate with decreased Ki67 in early stage breast cancer (BC) and better outcomes in patients even among those with low Ki67 tumors

Background: In studies of over 450 BC patients (pts) with &gt; 10 years follow-up, pts with PIK3CA-mutated primary tumors had improved clinical outcome (Kalinsky et al 2009, Cizkova et al 2012). PIK3CA mutations associated with favorable clinicopathologic features: lower grade, smaller size, lymph node negativity (−), ER positivity (+), HER2−. In BC, several studies have suggested that PIK3CA mutations do not associate with PI3K/mTOR pathway activation (Loi et al 2010, Stemke-Hale et al 2008). To gain additional insight into the favorable biology imparted by a PIK3CA mutation in early stage BC and to identify predictive biomarkers, we performed immunohistochemistry (IHC) on tissue microarrays (TMA) constructed from 590 primary BCs.

Methods: TMAs derived from FFPE tumors previously genotyped for PIK3CA mutations (rate of 32.5%, 192/590) were stained for ER, HER2 and AR (Kalinsky et al 2009). Here, we performed additional stains for MIB1 (Ki67 proliferation index, Ki67), p53 and markers of PI3K pathway activation (pS6, PTEN). Slides were scanned with Aperio ScanScope XT and segmented using TMALab (Aperio). Images were analyzed with the Aperio algorithm based on staining pattern (nuclear, cytoplasmic, membrane) and scored for % + and intensity. Manual review was performed for tumors with less than 3 cores or discordant results. PTEN was scored manually: 0 (no tumor staining, PTEN loss), 1 (tumor &lt; stroma), or 2 (tumor ≥ stroma). P values were based on the log-rank test for comparison of Kaplan-Meier curves for disease free survival (DFS), Chi-square test for categorical variables and t-test for continuous variables.

Results: On average, 66 cases (11%) were non-informative for each IHC stain, due to missing cores or insufficient tumor cells. In a binary analysis of Ki67 using a cutoff of ≥10% + cells, PIK3CA mutated tumors demonstrated significantly lower proliferation index with only 9.4% of tumors (16/170) having high Ki67 as compared to 23.6% of wild-type PIK3CA tumors (82/347) (P = .001). Ki67 was also highly associated with PIK3CA genotype when analyzed with a cutoff of ≥13.25% + cells or as a continuous variable. Importantly, DFS was significantly different when analyzed by PIK3CA genotype and Ki67 (P = .01). Among pts with low Ki67 tumors (n = 419), PIK3CA mutation associated with longer DFS (10yr 79%, CI 69–85) as compared to wild-type PIK3CA (10yr 71%, CI 64–77). When PI3K pathway interactions were analyzed, PTEN loss associated with wild-type PIK3CA (P&lt;.001), although PTEN loss occurred with mutated PIK3CA in 11 hormone receptor (HR)+ tumors. In analysis of pS6 with a binary cutoff of ≥20% + cells, high pS6 associated with HER2+ (P&lt;.001), HR- (P&lt;.001) and high tumor grade (P = 0.003), but did not associate with PIK3CA genotype (P = .13). PIK3CA mutation was associated with lower pS6 when pS6 % + cells was analyzed as a continuous variable (P = .01).

Conclusions: PIK3CA mutation associates with lower Ki67 in early stage BC. Even among pts with low Ki67 tumors, PIK3CA mutation associates with improved clinical oucome. pS6 is not increased in PIK3CA-mutated tumors which likely indicates that mTORC1 signaling is not activated as a result of PIK3CA mutation in early stage ER+ BC.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-08-01.

P4-02-04: Androgen Receptor (AR) Expression in a Cohort of Patients (pts) with Triple Negative Breast Cancer (TNBC)

Background

TNBC, defined by the absence of ER, PR, and HER2, is associated with higher risk of recurrence and BC-related mortality, earlier age at diagnosis, menarche, and 1st pregnancy, increased parity, higher BMI, and African-American/Hispanic race. TNBC is a heterogeneous group. Using gene expression analysis, our group described a subset of AR+ ER/PR- BC that exhibits androgen-dependent growth. In vitro studies confirmed the functional role of AR and showed that growth could be abrogated by antiandrogens.(Doane et al 2006) We translated this work into a phase II trial of bicalutamide in pts with AR+ ER/PR- metastatic BC (MBC). (NCT00468715) We now describe the prevalence and clinicopathological characteristics of AR+TNBC in primary disease in a single-institution retrospective cohort.

Methods: We identified 1,032 pts with resectable, TNBC (ER/PR&lt;1%; HER2&lt;2+/FISH&lt;2.2) who had surgery at MSKCC from 1998–2006. Exclusion criteria: neoadjuvant chemotherapy, prior radiation, inflammatory/MBC. IRB approval was obtained. We constructed tissue microarrays (TMA) from 210 primary tumors (&gt; 1 cm) with each tumor represented by three 0.6mm cores. AR was tested with DAKO antibody (Clone AR441; dilution 1:500). TMAs were digitized with a Mirax scanner. MetaMorph image analysis software was used to quantify the ratio of DAB staining to hematoxylin signal. A ratio &gt;1 SD above mean was defined as AR+. AR+ cores were manually reviewed; false positives due to core artifact were excluded. To evaluate clinicopathological variables and differences in recurrence-free survival (RFS) and overall survival (OS) by AR status we used chi-square/t-tests and Kaplan-Meier methods/log-rank test, respectively.

Results: 169 pts had adequate cores for image analysis/quantification of AR. 10% of pts tested AR+ (17/169). Median (med) followup: AR+=6 years (yr), AR-=5.6yr. Demographic/clinicopathological variables: Table 1 (ages in med yr). Overall med age=54yr (29-84). Adjuvant chemotherapy received: AR+ 82%, AR- 87%, p =0.40; 77% received anthracycline/taxane-based therapy. Med time to distant metastasis (DM)=2.1yr (0.2−6.2yr). We were unable to demonstrate a difference in 5yr RFS (69% vs. 77%; p=0.37) or OS (68% vs. 84%; p=0.25) between AR+ and AR- TNBC.

A pharmacokinetic model for predicting absorption, elimination, and tissue burden of toxaphene in rats

A two-compartment pharmacokinetic model was formulated to predict absorption, elimination, and tissue burden of toxaphene in rats. The model was constructed based on the database of Crowder and Dindal (Bull. Environ. Contam. Toxicol. 12, 320-327, 1974) and included six tissue compartments: blood, brain, liver, muscle, fat, and carcass. The pharmacokinetically based dosimetry indicated that absorption of toxaphene was fast in fat, whole body, carcass, and blood, relatively slow in liver and muscle, and slow in brain. In contrast, the elimination rate was rapid in whole body, muscle, and blood, moderate in carcass and brain, and slow in liver and fat. Tissue burden was highest in fat, whole body, and blood, intermediate in liver, and lowest in brain. The model performance was evaluated by the data set of Pollock and Hillstrand (J. Environ. Sci. Health B 17, 635-648, 1982) on toxaphene absorption and elimination in pregnant rats. Validity of the model was confirmed by the close agreement between the predicted and observed tissue burdens of toxaphene in target tissues. Disposition of toxaphene via feces was a dominant excretory pathway while urinary excretion was a minor elimination route in male rats. However, for pregnant rats, excretion of toxaphene both in urine and feces were of similar magnitude. These characteristics of elimination are valuable for understanding the metabolism of toxaphene in pregnant rats. The model serves as a starting point for a quantitative, mechanism-based understanding of the processes that influence the pharmacokinetics of toxaphene in mammalian systems.

The role of conjugation in hepatotoxicity of troglitazone in human and porcine hepatocyte cultures

In primary human and porcine hepatocyte cultures, we investigated the relationship between metabolism and cytotoxicity of troglitazone. Treatment of human hepatocytes for 2 h with 10, 20, 25, 35, and 50 microM troglitazone in protein-free medium resulted in concentration-dependent decreases in total protein synthesis. Decreases at 10 and 20 microM were reversible by 24 h, however protein synthesis did not recover at concentrations >/=25 microM. Troglitazone at 50 microM caused cellular death. In porcine hepatocytes, 100 microM troglitazone was lethal, whereas at 50 microM, protein synthesis completely recovered by 24 h. Recovery in protein synthesis was associated with metabolism of parent drug, whereas toxicity correlated (r(2) = 0.82) with accumulation of unmetabolized troglitazone. By 1 h, in human hepatocytes, troglitazone was metabolized to similar amounts of sulfate and quinone metabolites with little glucuronide detected. In contrast, porcine hepatocytes metabolized troglitazone to the similar amounts of glucuronide and the quinone metabolites with little sulfate detected. Exposure of human hepatocytes to a combination of 10 microM troglitazone and 10 microM 2,4-dichloro-4-nitrophenol resulted in a 70% decrease in protein synthesis, associated with 90% inhibition in the formation of troglitazone sulfate, a 4-fold increase in unmetabolized troglitazone, and no effect on formation of the quinone metabolite. Treatment with a combination of acetaminophen or phenobarbital with 20 microM troglitazone resulted in sustained decrease in protein synthesis associated with inhibition of sulfation and accumulation of troglitazone. These results suggest that inhibition of troglitazone sulfation may result in increased hepatotoxicity due to exposure to parent drug, or increased metabolism by alternate pathways.

Trace analysis of acetaldehyde as fluorogenic derivative by high performance liquid chromatography

A sensitive method is described for the determination of acetaldehyde as a fluorogenic derivative of decahydroacridin-1,8-dione by high performance liquid chromatography. The analytical derivatization is based on the reaction of acetaldehyde in an acidic aqueous system with 1,3-cyclohexanedione and ammonium acetate. The resulting derivative was separated by a reversed-phase C-18 column and monitored with a fluorescent detector (lambda ex, 375nm; lambda em, 512nm). Several parameters affecting the derivatization of acetaldehyde were studied. The linear range of the method for the quantitation of acetaldehyde was between 20 and 800 pmol in aqueous sample (0.5 mL). Application of the method to the analysis of acetaldehyde in plasma was performed.