Scaffolding Protein Connector Enhancer of Kinase Suppressor of Ras 1 (CNKSR1) Regulates MAPK Inhibition Responsiveness in Pancreas Cancer via Crosstalk with AKT Signaling.

Combinatorial molecular therapy in pancreatic ductal adenocarcinoma (PDAC) has yielded largely disappointing results in clinical testing to-date as a multitude of adaptive resistance mechanisms is making selection of patients via molecular markers that capture essential, intersecting signaling routes challenging. Here, we report the scaffolding protein connector enhancer of kinase suppressor of Ras 1 (CNKSR1) as mediator of resistance to MAPK (MEK) inhibition. MEK inhibition in CNKSR1high cancer cells induces translocation of CNKSR1 to the plasma membrane where the scaffolding protein interacts with and stabilizes the phosphorylated form of AKT. CNKSR1-mediated AKT activation following MEK inhibition was associated with increased cellular p-PRAS40 levels and reduced nuclear translocation and cellular levels of FoxO1, a negative regulator of AKT signaling. In clinical PDAC specimens, high cytoplasmatic CNKSR1 levels correlated with increased cellular phospho-AKT and mTOR levels. Pharmacological co-blockade of AKT and MEK ranked top in induced synergies with MEK inhibition in CNKSR1high pancreas cancer cells among other inhibitor combinations targeting known CNKSR1 signaling. In vivo, CNKSR1high pancreatic tumors treated with AKT and MEK inhibitors showed improved outcome in the combination arm compared with single-agent treatment, an effect not observed in CNKSR1low models.Our results identify CNKSR1 as regulator of adaptive resistance to MEK inhibition by promoting crosstalk to AKT signaling via a scaffolding function for the phosphorylated form of AKT. CNSKR1 expression might be a possible molecular marker to enrich patients for future AKT-MEK inhibitor precision medicine studies. IMPLICATIONS: The CNKSR1 scaffold, identified within an RNAi screen as a novel mediator of resistance to MEK inhibition in pancreas cancer, connects the MAPK pathway and AKT signaling and may be adopted as a biomarker to select patients for combined MEK AKT blockade.

Secondary Malignancies: The Cost of Progress.

BACKGROUND: With advances in treatment of cancer, patients who survive their first malignancy are at risk of developing additional malignancies. Data on the risks of secondary malignancies after treatment of some of the more common cancers are lacking. METHODS: Our prospectively maintained database was queried from 1996 to 2016 to identify patients with breast cancer, colorectal cancer, melanoma, sarcoma, gastric, and pancreatic adenocarcinoma who developed additional malignancies. Predisposing clinical factors were included in our analysis. RESULTS: We identified 756 patients diagnosed with a solid malignancy who developed a second malignancy, of which 606 (80.1%) had one of the most common treated cancers. 59.5% of patients were women. 810 additional malignancies were identified in the 606 patients with breast and colon cancer being the most common secondary malignancies. Of these 606 patients, 460 (76%) patients had two malignancies; 145 (23.9%) had 3 or more malignancies. 15.2% of patients were diagnosed under the age of 40.63 years. 8.3% patients had a known genetic mutation, with BReast CAncer gene, and Lynch mutations being the most common. CONCLUSION: Advances in cancer treatment have led to higher cure rates. These patients should continue surveillance and undergo screening as they may be at risk of developing additional malignancies.

Associations of CDH1 germline variant location and cancer phenotype in families with hereditary diffuse gastric cancer (HDGC).

INTRODUCTION: Hereditary diffuse gastric cancer (HDGC) is a cancer syndrome associated with variants in E-cadherin (CDH1), diffuse gastric cancer and lobular breast cancer. There is considerable heterogeneity in its clinical manifestations. This study aimed to determine associations between CDH1 germline variant status and clinical phenotypes of HDGC. METHODS: One hundred and fifty-two HDGC families, including six previously unreported families, were identified. CDH1 gene-specific guidelines released by the Clinical Genome Resource (ClinGen) CDH1 Variant Curation Expert Panel were applied for pathogenicity classification of truncating, missense and splice site CDH1 germline variants. We evaluated ORs between location of truncating variants of CDH1 and incidence of colorectal cancer, breast cancer and cancer at young age (gastric cancer at <40 or breast cancer <50 years of age). RESULTS: Frequency of truncating germline CDH1 variants varied across functional domains of the E-cadherin receptor gene and was highest in linker (0.05785 counts/base pair; p=0.0111) and PRE regions (0.10000; p=0.0059). Families with truncating CDH1 germline variants located in the PRE-PRO region were six times more likely to have family members affected by colorectal cancer (OR 6.20, 95% CI 1.79 to 21.48; p=0.004) compared with germline variants in other regions. Variants in the intracellular E-cadherin region were protective for cancer at young age (OR 0.2, 95% CI 0.06 to 0.64; p=0.0071) and in the linker regions for breast cancer (OR 0.35, 95% CI 0.12 to 0.99; p=0.0493). Different CDH1 genotypes were associated with different intracellular signalling activation levels including different p-ERK, p-mTOR and ß-catenin levels in early submucosal T1a lesions of HDGC families with different CDH1 variants. CONCLUSION: Type and location of CDH1 germline variants may help to identify families at increased risk for concomitant cancers that might benefit from individualised surveillance and intervention strategies.

Underuse of exon mutational analysis for gastrointestinal stromal tumors.

BACKGROUND: Tyrosine kinase inhibitors (TKI) have become the guideline-recommended therapy for high-risk resected and advanced gastrointestinal stromal tumors (GISTs). Exon mutational analysis (EMA) is used to inform pretherapy response to TKI and may predict overall prognosis. Despite these benefits, EMA remains underused, and its impact on TKI therapy decision-making remains unexplored. MATERIALS AND METHODS: A retrospective cohort was established from 104 patients receiving treatment for GISTs from 2006 to 2017. Current National Comprehensive Cancer Network guidelines indicate that EMA should be considered for all patients undergoing TKI therapy to identify genotypes that are likely, or unlikely, to respond to treatment. We first tracked guideline-considered EMA use and subsequent impact on treatment decision-making. A questionnaire was then administered to gastrointestinal medical oncologists to assess EMA perception. RESULTS: Among 104 GIST patients, 54 (52%) received TKI therapy. Of these, only 22 (41%) received EMA. Informed by EMA, treatment decisions included 59% who continued with original TKI therapy, 32% who switched to an alternative TKI, and 9% who discontinued or received no TKI. Although 92% of physicians indicated EMA was a valuable tool, only 62% indicated they used it "frequently" or "always" to inform treatment decisions. CONCLUSIONS: Less than half of patients receiving TKI therapy for GISTs received EMA at a comprehensive cancer center. Despite this low uptake, when it was performed, EMA guided alternative treatment decision in 41% of patients. Physician survey responses indicated that interventions targeting physician education and an electronic medical record reminder may improve EMA uptake.

Metarrestin, a perinucleolar compartment inhibitor, effectively suppresses metastasis.

Metastasis remains a leading cause of cancer mortality due to the lack of specific inhibitors against this complex process. To identify compounds selectively targeting the metastatic state, we used the perinucleolar compartment (PNC), a complex nuclear structure associated with metastatic behaviors of cancer cells, as a phenotypic marker for a high-content screen of over 140,000 structurally diverse compounds. Metarrestin, obtained through optimization of a screening hit, disassembles PNCs in multiple cancer cell lines, inhibits invasion in vitro, suppresses metastatic development in three mouse models of human cancer, and extends survival of mice in a metastatic pancreatic cancer xenograft model with no organ toxicity or discernable adverse effects. Metarrestin disrupts the nucleolar structure and inhibits RNA polymerase (Pol) I transcription, at least in part by interacting with the translation elongation factor eEF1A2. Thus, metarrestin represents a potential therapeutic approach for the treatment of metastatic cancer.

The Changing Paradigm of Management of Liver Abscesses in Chronic Granulomatous Disease.

Background: Chronic granulomatous disease (CGD) is a rare genetic disorder causing recurrent infections. More than one-quarter of patients develop hepatic abscesses and liver dysfunction. Recent reports suggest that disease-modifying treatment with corticosteroids is effective for these abscesses. Comparison of corticosteroid therapy to traditional invasive treatments has not been performed. Methods: Records of 268 patients with CGD treated at the National Institutes of Health from 1980 to 2014 were reviewed. Patients with liver involvement and complete records were included. We recorded residual reactive oxygen intermediate (ROI) production by neutrophils, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase germline mutation status, laboratory values, imaging characteristics, time to repeat hepatic interventions, and overall survival among 3 treatment cohorts: open liver surgery (OS), percutaneous liver-directed interventional radiology therapy (IR), and high-dose corticosteroid management (CM). Results: Eighty-eight of 268 patients with CGD suffered liver involvement. Twenty-six patients with a median follow-up of 15.5 years (8.5-32.9 years of follow-up) had complete records and underwent 100 standard interventions (42 IR and 58 OS). Eight patients received a treatment with high-dose corticosteroids only. There were no differences in NADPH genotype, size, or number of abscesses between patients treated with OS, IR, or CM. Time to repeat intervention was extended in OS compared with IR (18.8 vs 9.5 months, P = .04) and further increased in CM alone (median time to recurrence not met). Impaired macrophage and neutrophil function measured by ROI production correlated with shorter time to repeat intervention (r = 0.6, P = .0019). Conclusions: Treatment of CGD-associated liver abscesses with corticosteroids was associated with fewer subsequent hepatic interventions and improved outcome compared to invasive treatments.

Gastric Adenocarcinoma: A Multimodal Approach.

Despite its declining incidence, gastric cancer (GC) remains a leading cause of cancer-related deaths worldwide. A multimodal approach to GC is critical to ensure optimal patient outcomes. Pretherapy fine resolution contrast-enhanced cross-sectional imaging, endoscopic ultrasound and staging laparoscopy play an important role in patients with newly diagnosed ostensibly operable GC to avoid unnecessary non-therapeutic laparotomies. Currently, margin negative gastrectomy and adequate lymphadenectomy performed at high volume hospitals remain the backbone of GC treatment. Importantly, adequate GC surgery should be integrated in the setting of a multimodal treatment approach. Treatment for advanced GC continues to expand with the emergence of additional lines of systemic and targeted therapies.

Expression of the scaffold connector enhancer of kinase suppressor of Ras 1 (CNKSR1) is correlated with clinical outcome in pancreatic cancer.

BACKGROUND: Despite the near universal occurrence of activating codon 12 KRAS somatic variants in pancreatic cancer, there is considerable heterogeneity in the molecular make-up, MAPK/ERK pathway activation states, and clinical outcome in this disease. We analyzed the expression levels of CNKSR1, a scaffold that influences MAPK/ERK pathway activity, in clinical pancreas cancer specimens and their impact on survival of patients with pancreatic cancer. METHODS: Immunohistochemical staining for CNKSR1 expression was performed on 120 specimens from three independent pancreatic cancer tissue registries, phospho-ERK levels were measured in 86 samples. Expression was divided into CNKSR1 low and CNKSR1 high and correlated with clinicopathological variables including overall survival using multivariate Cox proportional hazard ratio models. RESULTS: CNKSR1 expression was increased in tumors compared to matched normal uninvolved resection specimens (p = 0.004). 28.3% (34/120) of patient specimens stained as CNKSR1 low compared to 71.7% (86/120) of specimens which stained as CNKSR1 high. High CNKSR1 expression was more prevalent in low grade tumors (p = 0.04). In multivariate analysis, low CNKSR1 expression status was independently correlated with decreased overall survival (HR = 2.146; 95% CI 1.34 to 3.43). When stratifying primary, non-metastatic tumor biopsies by CNKSR1 expression, resection was associated with improved survival in patients with high CNKSR1 expression (p < 0.0001) but not low CNKSR1 expression (p = 0.3666). Pancreatic tumors with nuclear in addition to cytoplasmic CNKSR1 staining (32/107) showed increased nuclear phospho-ERK expression compared to tumor with cytoplasmic CNKSR1 staining only (p = 0.017). CONCLUSION: CNKSR1 expression is increased in pancreatic tissue specimens and was found to be an independent prognostic marker of overall survival. CNKSR1 may help to identify patient subgroups with unfavorable tumor biology in order to improve risk stratification and treatment selection. Cellular distribution of CNKSR1 was correlated with nuclear pERK expression.

Why Do Long-Distance Travelers Have Improved Pancreatectomy Outcomes?

BACKGROUND: Centralization of complex surgical care has led patients to travel longer distances. Emerging evidence suggested a negative association between increased travel distance and mortality after pancreatectomy. However, the reason for this association remains largely unknown. We sought to unravel the relationships among travel distance, receiving pancreatectomy at high-volume hospitals, delayed surgery, and operative outcomes. STUDY DESIGN: We identified 44,476 patients who underwent pancreatectomy for neoplasms between 2004 and 2013 at the reporting facility from the National Cancer Database. Multivariable analyses were performed to examine the independent relationships between increments in travel distance mortality (30-day and long-term survival) after adjusting for patient demographics, comorbidity, cancer stage, and time trend. We then examined how additional adjustment of procedure volume affected this relationship overall and among rural patients. RESULTS: Median travel distance to undergo pancreatectomy increased from 16.5 to 18.7 miles (p for trend < 0.001). Although longer travel distance was associated with delayed pancreatectomy, it was also related to higher odds of receiving pancreatectomy at a high-volume hospital and lower postoperative mortality. In multivariable analysis, difference in mortality among patients with varying travel distance was attenuated by adjustment for procedure volume. However, longest travel distance was still associated with a 77% lower 30-day mortality rate than shortest travel among rural patients, even when accounting for procedure volume. CONCLUSIONS: Our large national study found that the beneficial effect of longer travel distance on mortality after pancreatectomy is mainly attributable to increase in procedure volume. However, it can have additional benefits on rural patients that are not explained by volume. Distance can represent a surrogate for rural populations.

Thoracic Surgery in Chronic Granulomatous Disease: a 25-Year Single-Institution Experience.

INTRODUCTION: Chronic granulomatous disease (CGD) is a genetic disorder in which phagocyte dysfunction leads to recurrent infection. Persistent pulmonary infections sometimes require thoracic surgical intervention. We reviewed our 25-year experience to identify outcomes and prognostic factors associated with thoracic surgery in these patients. METHODS: A retrospective single-institution review of all patients with CGD from 1990 through 2015 was performed. Univariate analysis identified prognostic variables to include in a Cox model. Overall survival was estimated by the Kaplan-Meier method. RESULTS: We identified 258 patients who had 2221 admissions (both scheduled and emergent). During the period examined, 51 thoracic operations were performed in 13.6 % (35/258) of patients and 2.3 % (35/2221) of overall admissions. Patients undergoing surgery did not have statistically significant differences in disease genotype compared to those that did not require surgery. Pathogens were identified from 67 % (34/51) of specimens. Complications occurred in 27 % (14/51), including 10 % (5/51) with wound and 12 % (6/51) with pulmonary infections. Mortality at 30 and 90 days was 0 and 6 % (3/51), respectively. Overall survival probabilities were 75 and 62 % at 5- and 10-year follow-up (median potential follow-up: 16.5 years), respectively. Undergoing thoracic surgery was associated with an increased hazard ratio for death of 3.71 (p < 0.0001). Both chest wall resection and EBL > 500 mL were negative prognostic factors (p < 0.05). CONCLUSIONS: A minority of CGD patients required thoracic surgery for infections refractory to antibiotic or antifungal therapy. Patients who had these operations had significant morbidity and relatively poor long-term survival, particularly in the cases of chest wall resection or significant blood loss.

Approach to the surgical management of resectable gastric cancer.

The rates of gastric cancer, which is the third leading cause of cancer-related deaths worldwide, vary depending on geographic location. Margin-negative gastrectomy and adequate lymphadenectomy (removal of ≥15 lymph nodes) are the cornerstones of multimodal treatment for operable gastric cancer. Diagnostic laparoscopy should be included in the armamentarium for newly diagnosed gastric cancer in order to overcome the limitations of cross-sectional imaging in identifying sub-radiographic hepatic or peritoneal metastases. The benefit of surgical therapy is enhanced by at least 13% when it is integrated with multimodal therapy: either surgery followed by adjuvant chemoradiotherapy or surgery with perioperative systemic therapy. This multidisciplinary approach to treatment will continue to be an evolving paradigm, especially with the emergence of systemic and targeted therapies.

Approach to the surgical management of resectable gastric cancer.

The rates of gastric cancer, which is the third leading cause of cancer-related deaths worldwide, vary depending on geographic location. Margin-negative gastrectomy and adequate lymphadenectomy (removal of ≥15 lymph nodes) are the cornerstones of multimodal treatment for operable gastric cancer. Diagnostic laparoscopy should be included in the armamentarium for newly diagnosed gastric cancer in order to overcome the limitations of cross-sectional imaging in identifying sub-radiographic hepatic or peritoneal metastases. The benefit of surgical therapy is enhanced by at least 13% when it is integrated with multimodal therapy: either surgery followed by adjuvant chemoradiotherapy or surgery with perioperative systemic therapy. This multidisciplinary approach to treatment will continue to be an evolving paradigm, especially with the emergence of systemic and targeted therapies.

Common nerve decompressions of the upper extremity: reliable exposure using shorter incisions.

UNLABELLED: Considering that several different specialties perform nerve decompressions in the upper extremity, universal technical standards do not exist. Many of these procedures are performed via incisions that are made unnecessarily long to achieve adequate exposure of the nerves and their known anatomical compression points. The purpose of this article is to introduce reproducible techniques that reliably allow the necessary anatomical exposure while minimizing the length of required skin incisions. METHODS: The senior author's surgical approach to the most common nerve compression syndromes of the upper extremity is presented in detail. Typical incision lengths and surgical exposure are demonstrated photographically. The safety of using this technique is examined by review of the medical records of all patients undergoing this procedure from 2003 to 2011, looking for technical complications such as unintentional damage to nerves or adjacent structures. RESULTS: Three hundred twenty consecutive cases were identified in which the described techniques were used to release known anatomical compression points of the upper extremity nerves, including 161 decompressions of the ulnar nerve at the elbow, 37 decompressions of the anterior interosseous nerve and 45 of the posterior interosseous nerve in the proximal forearm, and 77 decompressions of the radial sensory nerve in the distal forearm. Typical incision lengths we used for these procedures were 5 cm for the ulnar nerve, 4.5 cm for the anterior interosseous nerve, 4 cm for the posterior interosseous nerve, and 3 cm for the radial sensory nerve. Review of medical records revealed no incidences of unintentional injury to nerves or adjacent important structures. Functional and neurological recovery outcomes were not assessed, as those would be the subject of subsequent studies. CONCLUSIONS: Known anatomical compression points can be reliably accessed and decompressed for the treatment of all common upper extremity nerve compression syndromes using minimized skin incisions and the techniques presented in this article. With appropriate knowledge of anatomy, this can be performed without expensive equipment or any additional risk of injury to the patient, making classically described longer incisions unnecessarily morbid.

PCPH/ENTPD5 expression confers to prostate cancer cells resistance against cisplatin-induced apoptosis through protein kinase Calpha-mediated Bcl-2 stabilization.

Prostate cancer (PCa) frequently develops antiapoptotic mechanisms and acquires resistance to anticancer drugs. Therefore, identifying PCa drug resistance determinants should facilitate designing more effective chemotherapeutic regimens. Recently, we described that the PCPH protein becomes highly expressed in human prostatic intraepithelial neoplasia and in PCa, and that the functional interaction between PCPH and protein kinase Cdelta (PKCdelta) increases the invasiveness of human PCa. Here, we report that the functional interaction between PCPH and a different PKC isoform, PKCalpha, confers resistance against cisplatin-induced apoptosis to PCa cells. This interaction elicits a mechanism ultimately resulting in the posttranslational stabilization and subsequent elevated expression of Bcl-2. Stable knockdown of either PCPH, mt-PCPH, or PKCalpha in PCa cells decreased Ser70-phosphorylated Bcl-2 and total Bcl-2 protein, thereby increasing their cisplatin sensitivity. Conversely, forced expression of the PCPH protein or, in particular, of the mt-PCPH oncoprotein increased the levels of phosphorylated PKCalpha concurrently with those of Ser70-phosphorylated and total Bcl-2 protein, thus promoting cisplatin resistance. Consistently, Bcl-2 knockdown sensitized PCa cells to cisplatin treatment and, more importantly, reversed the cisplatin resistance of PCa cells expressing the mt-PCPH oncoprotein. Moreover, reexpression of Bcl-2 in PCPH/mt-PCPH knockdown PCa cells reversed the cisplatin sensitization caused by PCPH or mt-PCPH down-regulation. These findings identify PCPH and mt-PCPH as important participants in the chemotherapy response of PCa cells, establish a role for PCPH-PKCalpha-Bcl-2 functional interactions in the drug response process, and imply that targeting PCPH expression before, or simultaneously with, chemotherapy may improve the treatment outcome for PCa patients.