Concurrent carboplatin and paclitaxel definitive radiation therapy for locally advanced head and neck cancer.

BACKGROUND: We report the outcomes of cisplatin-ineligible HNSCC patients treated with definitive chemoradiation and concurrent carboplatin and paclitaxel. MATERIALS AND METHODS: We included consecutive HNSCC patients treated from 2013 to 2021 that received definitive chemoradiation with carboplatin and paclitaxel. Locoregional recurrences (LRR) and distant metastases (DM) were estimated using cumulative incidence functions. Progression free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier methods. RESULTS: Sixty-five patients were identified with median age of 71 years (range 44-85). Median radiation dose was 70 Gy and the median doses of carboplatin and paclitaxel were AUC 1 and 40 mg/m2 , respectively. At a median follow-up of 29 (range 5-91) months, the 2-year rates of LRR, DM, PFS, and OS were 8.8%, 9.4%, 72.2%, and 88.7%, respectively. In total, there were 5 LRR, 7 DM, and 12 deaths. CONCLUSIONS: Chemoradiation with carboplatin and paclitaxel is an excellent option for cisplatin-ineligible HNSCC patients.

Early Detection of Leptomeningeal Metastases Among Patients Undergoing Spinal Stereotactic Radiosurgery.

Purpose: The management of patients with advanced solid malignancies increasingly uses stereotactic body radiation therapy (SBRT). Advanced cancer patients are at risk for developing leptomeningeal metastasis (LM), a fatal complication of metastatic cancer. Cerebrospinal fluid (CSF) is routinely collected during computed tomography (CT) myelography for spinal SBRT planning, offering an opportunity for early LM detection by CSF cytology in the absence of radiographic LM or LM symptoms (subclinical LM). This study tested the hypothesis that early detection of tumor cells in CSF in patients undergoing spine SBRT portends a similarly poor prognosis compared with clinically overt LM. Methods and Materials: We retrospectively analyzed clinical records for 495 patients with metastatic solid tumors who underwent CT myelography for spinal SBRT planning at a single institution from 2014 to 2019. Results: Among patients planned for SBRT, 51 (10.3%) developed LM. Eight patients (1.6%) had subclinical LM. Median survival with LM was similar between patients with subclinical versus clinically evident LM (3.6 vs 3.0 months, P = .30). Patients harboring both parenchymal brain metastases and LM (29/51) demonstrated shorter survival than those with LM alone (2.4 vs 7.1 months, P = .02). Conclusions: LM remains a fatal complication of metastatic cancer. Subclinical LM detected by CSF cytology in spine SBRT patients has a similarly poor prognosis compared with standardly detected LM and warrants consideration of central nervous system-directed therapies. As aggressive local therapies are increasingly used for metastatic patients, more sensitive CSF evaluation may further identify patients with subclinical LM and should be evaluated prospectively.

Innate immune signaling drives late cardiac toxicity following DNA-damaging cancer therapies.

Late cardiac toxicity is a potentially lethal complication of cancer therapy, yet the pathogenic mechanism remains largely unknown, and few treatment options exist. Here we report DNA-damaging agents such as radiation and anthracycline chemotherapies inducing delayed cardiac inflammation following therapy due to activation of cGAS- and STING-dependent type I interferon signaling. Genetic ablation of cGAS-STING signaling in mice inhibits DNA damage-induced cardiac inflammation, rescues late cardiac functional decline, and prevents death from cardiac events. Treatment with a STING antagonist suppresses cardiac interferon signaling following DNA-damaging therapies and effectively mitigates cardiac toxicity. These results identify a therapeutically targetable, pathogenic mechanism for one of the most vexing treatment-related toxicities in cancer survivors.

Automatic segmentation of brain metastases using T1 magnetic resonance and computed tomography images.

An increasing number of patients with multiple brain metastases are being treated with stereotactic radiosurgery (SRS). Manually identifying and contouring all metastatic lesions is difficult and time-consuming, and a potential source of variability. Hence, we developed a 3D deep learning approach for segmenting brain metastases on MR and CT images. Five-hundred eleven patients treated with SRS were retrospectively identified for this study. Prior to radiotherapy, the patients were imaged with 3D T1 spoiled-gradient MR post-Gd (T1 + C) and contrast-enhanced CT (CECT), which were co-registered by a treatment planner. The gross tumor volume contours, authored by the attending radiation oncologist, were taken as the ground truth. There were 3 ± 4 metastases per patient, with volume up to 57 ml. We produced a multi-stage model that automatically performs brain extraction, followed by detection and segmentation of brain metastases using co-registered T1 + C and CECT. Augmented data from 80% of these patients were used to train modified 3D V-Net convolutional neural networks for this task. We combined a normalized boundary loss function with soft Dice loss to improve the model optimization, and employed gradient accumulation to stabilize the training. The average Dice similarity coefficient (DSC) for brain extraction was 0.975 ± 0.002 (95% CI). The detection sensitivity per metastasis was 90% (329/367), with moderate dependence on metastasis size. Averaged across 102 test patients, our approach had metastasis detection sensitivity 95 ± 3%, 2.4 ± 0.5 false positives, DSC of 0.76 ± 0.03, and 95th-percentile Hausdorff distance of 2.5 ± 0.3 mm (95% CIs). The volumes of automatic and manual segmentations were strongly correlated for metastases of volume up to 20 ml (r=0.97,p<0.001). This work expounds a fully 3D deep learning approach capable of automatically detecting and segmenting brain metastases using co-registered T1 + C and CECT.

Sublethal doxorubicin promotes migration and invasion of breast cancer cells: role of Src Family non-receptor tyrosine kinases.

BACKGROUND: Doxorubicin (Dox) is a widely used chemotherapy, but its effectiveness is limited by dose-dependent side effects. Although lower Dox doses reduce this risk, studies have reported higher recurrence of local disease with no improvement in survival rate in patients receiving low doses of Dox. To effectively mitigate this, a better understanding of the adverse effects of suboptimal Dox doses is needed. METHODS: Effects of sublethal dose of Dox on phenotypic changes were assessed with light and confocal microscopy. Migratory and invasive behavior were assessed by wound healing and transwell migration assays. MTT and LDH release assays were used to analyze cell growth and cytotoxicity. Flow cytometry was employed to detect cell surface markers of cancer stem cell population. Expression and activity of matrix metalloproteinases were probed with qRT-PCR and zymogen assay. To identify pathways affected by sublethal dose of Dox, exploratory RNAseq was performed and results were verified by qRT-PCR in multiple cell lines (MCF7, ZR75-1 and U-2OS). Regulation of Src Family kinases (SFK) by key players in DNA damage response was assessed by siRNA knockdown along with western blot and qRT-PCR. Dasatinib and siRNA for Fyn and Yes was employed to inhibit SFKs and verify their role in increased migration and invasion in MCF7 cells treated with sublethal doses of Dox. RESULTS: The results show that sublethal Dox treatment leads to increased migration and invasion in otherwise non-invasive MCF7 breast cancer cells. Mechanistically, these effects were independent of the epithelial mesenchymal transition, were not due to increased cancer stem cell population, and were not observed with other chemotherapies. Instead, sublethal Dox induces expression of multiple SFK-including Fyn, Yes, and Src-partly in a p53 and ATR-dependent manner. These effects were validated in multiple cell lines. Functionally, inhibiting SFKs with Dasatinib and specific downregulation of Fyn suppressed Dox-induced migration and invasion of MCF7 cells. CONCLUSIONS: Overall, this study demonstrates that sublethal doses of Dox activate a pro-invasive, pro-migration program in cancer cells. Furthermore, by identifying SFKs as key mediators of these effects, our results define a potential therapeutic strategy to mitigate local invasion through co-treatment with Dasatinib.

Tumor Immunity and Immunotherapy for HPV-Related Cancers.

Human papillomavirus (HPV) infection drives tumorigenesis in the majority of cervical, oropharyngeal, anal, and vulvar cancers. Genetic and epidemiologic evidence has highlighted the role of immunosuppression in the oncogenesis of HPV-related malignancies. Here we review how HPV modulates the immune microenvironment and subsequent therapeutic implications. We describe the landscape of immunotherapies for these cancers with a focus on findings from early-phase studies exploring antigen-specific treatments, and discuss future directions. Although responses across these studies have been modest to date, a deeper understanding of HPV-related tumor biology and immunology may prove instrumental for the development of more efficacious immunotherapeutic approaches. SIGNIFICANCE: HPV modulates the microenvironment to create a protumorigenic state of immune suppression and evasion. Our understanding of these mechanisms has led to the development of immunomodulatory treatments that have shown early clinical promise in patients with HPV-related malignancies. This review summarizes our current understanding of the interactions of HPV and its microenvironment and provides insight into the progress and challenges of developing immunotherapies for HPV-related malignancies.

A role for caspase-2 in sphingosine kinase 1 proteolysis in response to doxorubicin in breast cancer cells - implications for the CHK1-suppressed pathway.

Sphingosine kinase 1 (SK1) is a lipid kinase whose activity produces sphingosine 1-phosphate, a prosurvival lipid associated with proliferation, angiogenesis, and invasion. SK1 overexpression has been observed in numerous cancers. Recent studies have demonstrated that SK1 proteolysis occurs downstream of the tumor suppressor p53 in response to several DNA-damaging agents. Moreover, loss of SK1 in p53-knockout mice resulted in complete protection from thymic lymphoma, providing evidence that regulation of SK1 constitutes a major tumor suppressor function of p53. Given this profound phenotype, this study aimed to investigate the mechanism by which wild-type p53 regulates proteolysis of SK1 in response to the DNA-damaging agent doxorubicin in breast cancer cells. We find that p53-mediated activation of caspase-2 was required for SK1 proteolysis and that caspase-2 activity significantly alters the levels of endogenous sphingolipids. As p53 is mutated in 50% of all cancers, we extended our studies to investigate whether SK1 is deregulated in the context of triple-negative breast cancer cells (TNBC) harboring a mutation in p53. Indeed, caspase-2 was not activated in these cells and SK1 was not degraded. Moreover, caspase-2 activation was recently shown to be downstream of the CHK1-suppressed pathway in p53-mutant cells, whereby inhibition of the cell cycle kinase CHK1 leads to caspase-2 activation and apoptosis. Indeed, knockdown and inhibition of CHK1 led to the loss of SK1 in p53-mutant TNBC cells, providing evidence that SK1 may be the first identified effector of the CHK1-suppressed pathway.

Structure of human nSMase2 reveals an interdomain allosteric activation mechanism for ceramide generation.

Neutral sphingomyelinase 2 (nSMase2, product of the SMPD3 gene) is a key enzyme for ceramide generation that is involved in regulating cellular stress responses and exosome-mediated intercellular communication. nSMase2 is activated by diverse stimuli, including the anionic phospholipid phosphatidylserine. Phosphatidylserine binds to an integral-membrane N-terminal domain (NTD); however, how the NTD activates the C-terminal catalytic domain is unclear. Here, we identify the complete catalytic domain of nSMase2, which was misannotated because of a large insertion. We find the soluble catalytic domain interacts directly with the membrane-associated NTD, which serves as both a membrane anchor and an allosteric activator. The juxtamembrane region, which links the NTD and the catalytic domain, is necessary and sufficient for activation. Furthermore, we provide a mechanistic basis for this phenomenon using the crystal structure of the human nSMase2 catalytic domain determined at 1.85-Å resolution. The structure reveals a DNase-I-type fold with a hydrophobic track leading to the active site that is blocked by an evolutionarily conserved motif which we term the "DK switch." Structural analysis of nSMase2 and the extended N-SMase family shows that the DK switch can adopt different conformations to reposition a universally conserved Asp (D) residue involved in catalysis. Mutation of this Asp residue in nSMase2 disrupts catalysis, allosteric activation, stimulation by phosphatidylserine, and pharmacological inhibition by the lipid-competitive inhibitor GW4869. Taken together, these results demonstrate that the DK switch regulates ceramide generation by nSMase2 and is governed by an allosteric interdomain interaction at the membrane interface.

ATRA transcriptionally induces nSMase2 through CBP/p300-mediated histone acetylation.

Neutral sphingomyelinase-2 (nSMase2) is a key ceramide-producing enzyme in cellular stress responses. While many posttranslational regulators of nSMase2 are known, emerging evidence suggests a more protracted regulation of nSMase2 at the transcriptional level. Previously, we reported that nSMase2 is induced by all-trans retinoic acid (ATRA) in MCF7 cells and implicated nSMase2 in ATRA-induced growth arrest. Here, we further investigated how ATRA regulates nSMase2. We find that ATRA regulates nSMase2 transcriptionally through the retinoic acid receptor-α, but this is independent of previously identified transcriptional regulators of nSMase2 (Sp1, Sp3, Runx2) and is not through increased promoter activity. Epigenetically, the nSMase2 gene is not repressively methylated in MCF7 cells. However, inhibition of histone deacetylases (HDACs) with trichostatin A (TSA) induced nSMase2 comparably to ATRA; furthermore, combined ATRA and TSA treatment was not additive, suggesting ATRA regulates nSMase2 through direct modulation of histone acetylation. Confirming this, the histone acetyltransferases CREB-binding protein and p300 were required for ATRA induction of nSMase2. Finally, use of class-specific HDAC inhibitors suggested that HDAC4 and/or HDAC5 are negative regulators of nSMase2 expression. Collectively, these results identify a novel pathway of nSMase2 regulation and suggest that physiological or pharmacological modulation of histone acetylation can directly affect nSMase2 levels.

Role of Sterylglucosidase 1 (Sgl1) on the pathogenicity of Cryptococcus neoformans: potential applications for vaccine development.

Cryptococcosis caused by Cryptococcus neoformans and Cryptococcus gattii affects a large population and is a cause of significant morbidity and mortality. Despite its public health burden, there are currently no vaccines against cryptococcosis and new strategies against such infections are needed. In this study, we demonstrate that C. neoformans has the biochemical ability to metabolize sterylglucosides (SGs), a class of immunomodulatory glycolipids. Genetic manipulations that eliminate cryptococccal sterylglucosidase lead to the accumulation of SGs and generate a mutant strain (Δsgl1) that is non-pathogenic in the mouse models of cryptococcosis. Interestingly, this mutant strain acts as a vaccine strain and protects mice against cryptococcosis following infection with C. neoformans or C. gattii. The immunity induced by the Δsgl1 strain is not CD4(+) T-cells dependent. Immunocompromised mice, which lack CD4(+) T-cells, are able to control the infection by Δsgl1 and acquire immunity against the challenge by wild-type C. neoformans following vaccination with the Δsgl1 strain. These findings are particularly important in the context of HIV/AIDS immune deficiency and suggest that the Δsgl1 strain might provide a potential vaccination strategy against cryptococcosis.

Roles and regulation of neutral sphingomyelinase-2 in cellular and pathological processes.

Our understanding of the functions of ceramide signaling has advanced tremendously over the past decade. In this review, we focus on the roles and regulation of neutral sphingomyelinase 2 (nSMase2), an enzyme that generates the bioactive lipid ceramide through the hydrolysis of the membrane lipid sphingomyelin. A large body of work has now implicated nSMase2 in a diverse set of cellular functions, physiological processes, and disease pathologies. We discuss different aspects of this enzyme's regulation from transcriptional, post-translational, and biochemical. Furthermore, we highlight nSMase2 involvement in cellular processes including inflammatory signaling, exosome generation, cell growth, and apoptosis, which in turn play important roles in pathologies such as cancer metastasis, Alzheimer's disease, and other organ systems disorders. Lastly, we examine avenues where targeted nSMase2-inhibition may be clinically beneficial in disease scenarios.

Primary undifferentiated embryonal sarcoma of the liver mistaken for hydatid disease.

Primary undifferentiated embryonal sarcoma of the liver is a rare tumor with a peak incidence between the ages of 6 and 10 years. We report a case of a primary hepatic undifferentiated embryonal sarcoma arising in a 21-year-old male mistaken for hydatid disease of the liver. The rapid recurrence of this tumor along the site of attempted percutaneous drainage illustrates some important management points regarding this malignancy.

Unusually young age distribution of primary hepatic leiomyosarcoma: case series and review of the adult literature.

BACKGROUND: Primary hepatic leiomyosarcoma is a rare disease diagnosed in older aged adults with a median age of 58 and occasionally in children with a history of immunosuppression. METHODS: From 1998 to 2009, 215 patients were diagnosed with primary hepatic malignancies at our institution, 4 of which were diagnosed with primary hepatic sarcoma (1.8%). Three cases were primary hepatic leiomyosarcomas (LMS) and one case was primary undifferentiated embryonal sarcoma of the liver; median age 30 (range 20-39) years. RESULTS: One patient is currently 12 months post-resection with no evidence of recurrence. Two patients passed away at 19 days and 22 months from small for size liver and tumor recurrence respectively. CONCLUSION: We have presented 3 cases of primary hepatic leiomyosarcoma diagnosed at our institution with an unusually young age distribution and no evidence of immunosuppression. These cases highlight the diagnostic and therapeutic challenges of this rare tumour.

Ratio between positive lymph nodes and total excised axillary lymph nodes as an independent prognostic factor for overall survival in patients with nonmetastatic lymph node-positive breast cancer.

BACKGROUND: The status of the axillary lymph nodes in nonmetastatic lymph node-positive breast cancer (BC) patients remains the single most important determinant of overall survival (OS). Although the absolute number of nodes involved with cancer is important for prognosis, the role of the total number of excised nodes has received less emphasis. Thus, several studies have focused on the utility of the axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. However, most studies suffered from shortcomings, such as including patients who received neoadjuvant therapy or failing to consider the use of adjuvant therapy and tumor receptor status in their analysis. METHODS: We conducted a single-center retrospective review of 669 patients with nonmetastatic lymph nodepositive BC. Data collected included patient demographics; breast cancer risk factors; tumor size, histopathological, receptor, and lymph node status; and treatment modalities used. Patients were subdivided into four groups according to ALNR value (<0.25, 0.25-0.49, 0.50-0.74, 0.75-1.00). Study parameters were compared at the univariate and multivariate levels for their effect on OS. RESULTS: On univariate analysis, both the absolute number of positive lymph nodes and the ALNR were significant predictors of OS. On multivariate analysis, only the ALNR remained an independent predictor of OS, with a 2.5-fold increased risk of dying at an ALNR of ⩾0.25. CONCLUSIONS: Our study demonstrates that ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes.

Ratio between positive lymph nodes and total excised axillary lymph nodes as an independent prognostic factor for overall survival in patients with nonmetastatic lymph node-positive breast cancer.

BACKGROUND.: The status of the axillary lymph nodes in nonmetastatic lymph node-positive breast cancer (BC) patients remains the single most important determinant of overall survival (OS). Although the absolute number of nodes involved with cancer is important for prognosis, the role of the total number of excised nodes has received less emphasis. Thus, several studies have focused on the utility of the axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. However, most studies suffered from shortcomings, such as including patients who received neoadjuvant therapy or failing to consider the use of adjuvant therapy and tumor receptor status in their analysis. METHODS.: We conducted a single-center retrospective review of 669 patients with nonmetastatic lymph nodepositive BC. Data collected included patient demographics; breast cancer risk factors; tumor size, histopathological, receptor, and lymph node status; and treatment modalities used. Patients were subdivided into four groups according to ALNR value (<.25, .25-.49, .50-.74, .75-1.00). Study parameters were compared at the univariate and multivariate levels for their effect on OS. RESULTS.: On univariate analysis, both the absolute number of positive lymph nodes and the ALNR were significant predictors of OS. On multivariate analysis, only the ALNR remained an independent predictor of OS, with a 2.5-fold increased risk of dying at an ALNR of ≥.25. CONCLUSIONS.: Our study demonstrates that ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes.

Ratio between positive lymph nodes and total excised axillary lymph nodes as an independent prognostic factor for overall survival in patients with nonmetastatic lymph node-positive breast cancer.

BACKGROUND: The status of the axillary lymph nodes in nonmetastatic lymph node-positive breast cancer (BC) patients remains the single most important determinant of overall survival (OS). Although the absolute number of nodes involved with cancer is important for prognosis, the role of the total number of excised nodes has received less emphasis. Thus, several studies have focused on the utility of the axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. However, most studies suffered from shortcomings, such as including patients who received neoadjuvant therapy or failing to consider the use of adjuvant therapy and tumor receptor status in their analysis. METHODS: We conducted a single-center retrospective review of 669 patients with nonmetastatic lymph node-positive BC. Data collected included patient demographics; breast cancer risk factors; tumor size, histopathological, receptor, and lymph node status; and treatment modalities used. Patients were subdivided into four groups according to ALNR value (< .25, .25-.49, .50-.74, .75-1.00). Study parameters were compared at the univariate and multivariate levels for their effect on OS. RESULTS: On univariate analysis, both the absolute number of positive lymph nodes and the ALNR were significant predictors of OS. On multivariate analysis, only the ALNR remained an independent predictor of OS, with a 2.5-fold increased risk of dying at an ALNR of >or= .25. CONCLUSIONS: Our study demonstrates that ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes.