Effects of EGFR driver mutations on pathologic regression in resectable locally advanced non-small cell lung cancer treated with neoadjuvant chemoradiation and completion surgery

OBJECTIVE

We hypothesized that driver mutations in epidermal growth factor receptor (EGFR) are associated with decreased pathologic response to neoadjuvant chemoradiation (NA-ChRT) in locally advanced non-small cell lung cancer (LA-NSCLC).

METHODS

Patients with Stage IIB-IIIA NSCLC treated with NA-ChRT, completion surgery, and underwent molecular profile testing were identified in a lung cancer database. Pathologic response was quantified using: (i) major pathologic response (MPR), (ii) complete pathologic response (pCR), and (iii) mean residual viable tumor cells (MRTC). Two groups were formed based on the presence or absence of driver mutations. Clinical and pathological correlations between the groups were studied.

RESULTS

Forty-seven patients underwent tumor molecular profile testing, NA-ChRT, and completion surgery. Compared to the no-driver mutation group, the driver mutation group had lower MPR (23% vs 71%, p = 0.003), pCR (0% vs 26%, p = 0.02), and higher MRTC (43.4% vs 15.8%, p = 0.009). Univariate analysis showed an increased MPR rate for smokers, squamous cell histology, ChRT-surgery interval >65 days, and no-driver mutations. Multivariate analysis showed that only no-driver mutations (OR 0.39, p = 0.02) remained significant for MPR. PD-L1 status did not affect MPR. At 2 years, the driver mutation group had lower rates of local control (Hazard ration [HR] 0.67, p = 0.17) and disease-free survival (HR 0.5, p = 0.001). Overall survival was similar for both groups (HR = 1.04, p = 0.86).

CONCLUSION

Following 60 Gray NA-ChRT, tumors with a driver mutation had lower MPR and pCR rates than tumors without a driver mutation. PD-L1 was not associated with tumor regression.

ADVANCES IN KNOWLEDGE

Patients with resectable LA-NSCLC and an EGFR driver mutation treated with neoadjuvant-ChRT and completion surgery have reduced pathologic regression, lower local control rates, and shorter disease-free survival than patients without a driver mutation. Evaluation of molecular testing should be introduced in LA-NSCLC intended for prognostication and treatment decisions.

Upfront rational therapy in BRAF V600E mutated pediatric ameloblastoma promotes ad integrum mandibular regeneration

Ameloblastoma is a neoplasm arising in the craniofacial skeleton. Proliferating odontogenic epithelial cells comprise this benign, yet locally invasive tumor, often causing severe disfiguration. High recurrence rate entails ablative surgical resection, which is the current standard of care, resulting in subsequent critical size osteocutaneous defects. The high incidence of BRAF mutations in ameloblastoma, most notably the BRAF V600E mutation, enabled the use of BRAF inhibiting agent in a neoadjuvant setting. In this investigator-initiated, open-label study, three consecutive pediatric patients, with confirmed BRAF V600E ameloblastoma deemed marginally resectable, were treated with BRAF inhibiting agents, prior to undergoing surgery. The use of upfront BRAF inhibitor treatment resulted in substantial tumor regression, allowing for non-mutilating complete surgical removal, ad integrum bone regeneration and organ preservation. All patients showed a marked radiologic and clinical response to medical treatment, enabling successful conservative surgery. Microscopically, all patients showed evidence of minimal residual tumor with extensive tumor necrosis, fibrosis and generation of new bone. At a median follow-up of 31 months, all patients remained free of disease. Face preservation therapy was achieved in pediatric patients presenting with BRAF V600E mutated ameloblastoma. Our study demonstrates the translational potential of targeted therapy as a neoadjuvant agent. Patient-specific organ preservation therapy should be considered as the new standard of care in ameloblastoma, mainly for children and adolescents.

Multicenter Evaluation of the Idylla NRAS-BRAF Mutation Test in Metastatic Colorectal Cancer

Treatment of colorectal cancer (CRC) with monoclonal antibodies against epidermal growth factor receptor requires the assessment of the mutational status of exons 2, 3, and 4 of the NRAS and KRAS oncogenes. Moreover, the mutational status of exon 15 of the BRAF oncogene is a marker of poor prognosis in CRC. The Idylla NRAS-BRAF Mutation Test is a reliable, simple (<2 minutes hands-on time), and quick (<2 hours turnaround time) sample-to-result solution, enabling the detection of clinically relevant mutations in NRAS (18 mutations) and BRAF (5 mutations). A multicenter study was conducted in 14 centers using the Idylla NRAS-BRAF Mutation Test to assess the NRAS and BRAF mutational status of 418 formalin-fixed, paraffin-embedded tissue samples from CRC patients. Results were compared with those obtained earlier by routine reference methods, including next-generation sequencing, pyrosequencing, mass spectrometry-based assays, PCR-based assays, and Sanger sequencing. In case of discordance, additional tests were performed by digital droplet PCR. Overall, after testing confirmation and excluding invalids/errors by design, concordances between the Idylla NRAS-BRAF Mutation Test and the reference test results were found in almost perfect agreement. In conclusion, the Idylla NRAS-BRAF Mutation Test enables the routine detection of all NRAS and BRAF mutations deemed clinically relevant according to the latest clinical guidelines, without necessitating molecular expertise or infrastructure.

[Correlation between the presence of Kras mutation and the presence of the proteins epiregulin and amphiregulin in colon cancer tissue]

INTRODUCTION

Progress has been made in the treatment of metastatic colorectal cancer with the development of biologic agents such as Cetuximab and Panitumumab. These monoclonal antibodies are directed against EGFR and influence cell division, attachment, angiogenesis, migration and apoptosis. Correlation has been found between the presence of mutations in the K-ras gene and resistance to treatment with Cetuximab.New guidelines require K-ras mutation analysis before anti-EGFR treatment is provided. The proteins Amphiregulin and Epiregulin belong to the Epidermal growth factors family (EGF, that act through the EGFR. Over-expression of these proteins has been seen in a variety of malignancies and non-malignant pathologies. These proteins can be detected in samples from colorectal malignancies and inflammatory bowel disease by immunohistochemical staining. Jacobs et at showed that mRNA expression of these proteins n colorectal malignancy predicts outcomes in wild type K-ras metastatic patients treated with Cetuximab.

AIM

The purpose of our study is to examine whether there is a correlation between the presence of colorectal cancer K-ras mutations and the level of expression of EpireguLin and Amphiregulin in the malignant tissue.

MATERIAL AND METHODS

In a retrospective study we examined 30 tissue samples of colon cancer patients for the presence of K-ras mutation and immunohistochemicaL staining for Epiregulin and AmphireguLin.

RESULTS

A total of 14 (46.66%] samples showed mutation in the K-ras gene; 15 of 30 samples [50%] were positive for AmphireguLin. As for Epiregulin, 10 (33.3%) samples had strong staining, 10 (33.3%) samples had Light staining and the rest, 10 (33.3%) didn't have any staining. In conclusion, we did not find a correlation between the presence of a K-ras mutation and the presence of Epiregulin and Amphiregulin in colon cancer tissue.

Targeting autophagy potentiates tyrosine kinase inhibitor-induced cell death in Philadelphia chromosome-positive cells, including primary CML stem cells

Imatinib mesylate (IM), a potent inhibitor of the BCR/ABL tyrosine kinase, has become standard first-line therapy for patients with chronic myeloid leukemia (CML), but the frequency of resistance increases in advancing stages of disease. Elimination of BCR/ABL-dependent intracellular signals triggers apoptosis, but it is unclear whether this activates additional cell survival and/or death pathways. We have shown here that IM induces autophagy in CML blast crisis cell lines, CML primary cells, and p210BCR/ABL-expressing myeloid precursor cells. IM-induced autophagy did not involve c-Abl or Bcl-2 activity but was associated with ER stress and was suppressed by depletion of intracellular Ca2+, suggesting it is mechanistically nonoverlapping with IM-induced apoptosis. We further demonstrated that suppression of autophagy using either pharmacological inhibitors or RNA interference of essential autophagy genes enhanced cell death induced by IM in cell lines and primary CML cells. Critically, the combination of a tyrosine kinase inhibitor (TKI), i.e., IM, nilotinib, or dasatinib, with inhibitors of autophagy resulted in near complete elimination of phenotypically and functionally defined CML stem cells. Together, these findings suggest that autophagy inhibitors may enhance the therapeutic effects of TKIs in the treatment of CML.

Cardiotoxicity of the cancer therapeutic agent imatinib mesylate

Imatinib mesylate (Gleevec) is a small-molecule inhibitor of the fusion protein Bcr-Abl, the causal agent in chronic myelogenous leukemia. Here we report ten individuals who developed severe congestive heart failure while on imatinib and we show that imatinib-treated mice develop left ventricular contractile dysfunction. Transmission electron micrographs from humans and mice treated with imatinib show mitochondrial abnormalities and accumulation of membrane whorls in both vacuoles and the sarco- (endo-) plasmic reticulum, findings suggestive of a toxic myopathy. With imatinib treatment, cardiomyocytes in culture show activation of the endoplasmic reticulum (ER) stress response, collapse of the mitochondrial membrane potential, release of cytochrome c into the cytosol, reduction in cellular ATP content and cell death. Retroviral gene transfer of an imatinib-resistant mutant of c-Abl, alleviation of ER stress or inhibition of Jun amino-terminal kinases, which are activated as a consequence of ER stress, largely rescues cardiomyocytes from imatinib-induced death. Thus, cardiotoxicity is an unanticipated side effect of inhibition of c-Abl by imatinib.

Autoinhibition of Bcr-Abl through its SH3 domain

Bcr-Abl is a dysregulated tyrosine kinase whose mechanism of activation is unclear. Here, we demonstrate that, like c-Abl, Bcr-Abl is negatively regulated through its SH3 domain. Kinase activity, transformation, and leukemogenesis by Bcr-Abl are greatly impaired by mutations of the Bcr coiled-coil domain that disrupt oligomerization, but restored by an SH3 point mutation that blocks ligand binding or a complementary mutation at the intramolecular SH3 binding site defined in c-Abl. Phosphorylation of tyrosines in the activation loop of the catalytic domain and the linker between the SH2 and catalytic domains (SH2-CD linker) is dependent on oligomerization and required for leukemogenesis. These results suggest that Bcr-Abl has a monomeric, unphosphorylated state with the SH3 domain engaged intramolecularly to Pro1124 in the SH2-CD linker, the form that is sensitive to the inhibitor imatinib (STI-571). The sole function of the coiled-coil domain is to disrupt the autoinhibited conformation through oligomerization and intermolecular autophosphorylation.

A collagenous cementum-derived attachment protein is a marker for progenitors of the mineralized tissue-forming cell lineage of the periodontal ligament

The periodontal ligament (PDL) is a fibrous and cellular connective tissue that mediates tooth attachment to bone, and it comprises fibroblastic and mineralized tissue-forming (MTF) progenitors. The MTF progenitors are believed to give rise to the cementoblastic and osteoblastic lineages. Cementum attachment protein (CAP) is a collagenous cementum-derived protein which binds strongly to osteoblasts, moderately to PDL cells, and weakly to gingival fibroblasts. The aim of the present study was to determine the relationship between the capacity of PDL progenitors to bind CAP and their potential to express alkaline phosphatase (ALP) and form mineralized-like tissue in culture. Cloned human PDL progenitor populations obtained from nine human donors were assayed for their constitutive capacity to bind CAP and express ALP, and for the dexamethasone-induced potential to form mineralized-like tissue in culture in the presence of ascorbic acid and beta-glycerophosphate. Forty percent of the progenitor clones produced mineralized-like tissue. Two patterns of mineralization were observed: a spread and flat pattern similar to that produced by human bone cells in culture and a nodular ridge-like type resembling that formed by human cementoma-derived cells. A direct correlation was found between the percentage of ALP positive cells in each progenitor clone and the amount of mineralized-like tissue formed (r = 0.565). Similar correlations were found between the number of ALP positive cells and the binding capacity of each clone (r = 0.392) and between the CAP binding capacity and mineralized-like tissue formation (r = 0.584). Multiple regression analysis indicated that the constitutive capacity of a clone to bind CAP and express ALP is directly correlated to its dexamethasone-induced potential to form mineralized tissue (r = 0.675). These results indicate that CAP binding and ALP expression can serve as markers for the identification of MTF progenitors in the heterogeneous cultured population of the human periodontal ligament. These data show for the first time that binding capacity to extracellular components of mineralized tissues can be a marker for mineralized tissue-forming progenitors.

1,25-dihydroxyvitamin D3 increases the sensitivity of human renal carcinoma cells to tumor necrosis factor alpha but not to interferon alpha or lymphokine-activated killer cells

Renal cell carcinoma is a chemotherapy-resistant tumor which is relatively responsive to immunotherapy. Immunotherapeutic regimes employ interferons or interleukin 2 with or without lymphokine-activated killer cells. Secondary cytokines, induced by interleukin 2 or interferon, may have an important impact on their anti-neoplastic activity. Notable among them is tumor necrosis factor (TNF alpha). We assessed the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on the susceptibility of the human renal cell carcinoma cell line SK-RC-29 to the cytotoxic and cytostatic actions of TNF alpha, interferon alpha and lymphokine-activated killer cells. Using uptake of the vital dye neutral red as an indicator of viable cell number, we found that addition of 1,25(OH)2D3 (100 nM) to TNF alpha (30 ng/ml)-treated cultures resulted in a 2.6 +/- 0.2-fold (mean +/- S.E.) increase in the cytotoxic effect of the cytokine. The potentiating effect of 1,25(OH)2D3 was dose-dependent, and significant at concentrations equal to or higher than 10 nM. Another dihydroxylated vitamin D metabolite, 24,25(OH)2D3, had no effect on TNF alpha action. The cytotoxic effect of TNF alpha increased whereas the potentiation by 1,25(OH)2D3 decreased with cell density in culture. 1,25(OH)2D3, in contrast to its potentiating effect on TNF alpha action, did not modulate the cytostatic effect of interferon alpha or the susceptibility of SK-RC-29 to killing by lymphokine-activated killer cells. The findings reported here may explain some of the in vivo anti-tumor activity of 1,25(OH)2D3 and provide a rationale for the employment of active vitamin D analogs during immune anti-cancer therapy.

A pilot study of the efficacy of oral midazolam for sedation in pediatric dental patients

Oral midazolam is being used for conscious sedation in dentistry with little documentation assessing its efficacy. In order to accumulate preliminary data, a randomized, double-blind, controlled, crossover, multi-site pilot study was conducted. The objective was to determine if 0.6 mg/kg of oral midazolam was an equally effective or superior means of achieving conscious sedation in the uncooperative pediatric dental patient, compared with a commonly used agent, 50 mg/kg of oral chloral hydrate. Twenty-three children in three clinics who required dentistry with local anesthetic and were determined to exhibit behavior rated as "negative" or "definitely negative" based on the Frankl scale were assessed. They were evaluated with respect to acceptance of medication; initial level of anxiety at each appointment; level of sedation prior to and acceptance of local anesthetic; movement and crying during the procedure; and overall behavior. The results showed that the group randomly assigned to receive midazolam had a significantly greater initial level of anxiety for that appointment (P < 0.02), a finding that could clearly confound further determination of the efficacy of these drugs. Patients given oral midazolam had an increased level of sedation prior to the administration of local anesthetic compared with those given chloral hydrate (P < 0.015). No statistically significant differences were noted in any of the other parameters. The age of the patient was found to have no correlation with the difference in overall behavior (r = -0.09). These preliminary data warrant further clinical trials.

Generalized odontodysplasia concomitant with mild hypophosphatasia--a case report

An abnormal exfoliation pattern of the primary teeth is a sign of a systemic abnormality affecting more than just the oral structures. A prompt investigation of the cause of this condition is mandatory to identify any disease process and to initiate the required treatment. This article presents a case of mild hypophosphatasia concomitant with odontodysplasia in a 4 1/2-year-old female. The child's condition was first detected due to the early exfoliation of her primary teeth. This article also discusses the two different disease entities and the reasoning that led to the final diagnosis.

Ewing's sarcoma: metastatic tumor to the jaw

Metastatic tumors to the jaw are a rare occurrence. The incidence of metastatic Ewing's sarcoma to the jaw has been reported to be less than 2% of all cases of Ewing's sarcoma. Early detection of such lesions is difficult because the signs and symptoms do not appear until the lesion has progressed considerably. The treatment options are therefore limited to palliative care of the patient rather than cure. This article reports a case of Ewing's sarcoma that had metastasized to the mandible and reviews the literature.

The effect of tricyclic antidepressants on cortex- and amygdala-kindled seizures in the rat

The anticonvulsant effects of amitriptyline, imipramine, nortriptyline and desipramine were tested against focal and generalized seizures, triggered from either the amygdala or the cortex in fully kindled rats. Tests were administered on a 72- or a 24-hour schedule. Significant seizure suppression was achieved with only one drug, amitriptyline, and it occurred only at toxic or near-toxic doses. The differential, low-dose suppression of amygdala-kindled seizures, reported in earlier studies, was not seen in the present experiments. It may occur only in the short-interval test paradigms used by previous experimenters.

Melanotic neuroectodermal tumour of infancy. A case report

Melanotic neuroectodermal tumour of infancy is a rare neoplasm of neural crest origin, predominantly affecting the anterior maxilla of infants. Treatment generally consists of surgical excision. Long-term follow-up is important since recurrence and malignant transformation have been reported. The literature about melanotic neuroectodermal tumour of infancy is reviewed and a case occurring in a 4-month old infant is presented.

Composite resin short-post technique for primary anterior teeth

A technique using a "mushroom shaped" composite resin short post constructed inside the pulp-treated root canal provides sufficient retention to build a composite resin crown on the reinforced superstructure of the remaining crown dentin. This technique was tested for 1 year in 92 teeth; they showed no failures of retention of the short post. Recurrent caries and severe bruxism--factors beyond operator control--posed some problems that were readily resolved.

Cheilitis glandularis: a pediatric case report

Cheilitis glandularis is a rare disorder, usually affecting the lower lip of adults. This case involved both lips of an adolescent male. A familial history of the condition may have contributed to the involvement of both lips, and may reinforce the importance of hereditary tendency in the development of cheilitis glandularis. Emotional disturbance and poor oral hygiene also had a role in the disorder in this case, which was successfully treated with surgery.