Prostate cancer is among the most common malignancies in males in the United States and adenocarcinoma accounts for 95% of all malignancies of prostate. Rarely prostate cancer can also present as small cell carcinoma. Pure small cell carcinoma is rare at time of initial diagnosis (<2%) however neuroendocrine differentiation into small cell carcinoma may emerge in men who have had previous treatment with ADT for prostate adenocarcinoma. These tumors, sometimes called treatment-related neuroendocrine prostate cancers or aggressive-variant prostate cancers, are increasingly recognized in the castration-resistant phases of disease progression. They account for less than 1% of all prostate cancers. A 73-year-old otherwise male had routine health screening in May 2018. Prostate specific antigen (PSA) level was elevated at 9.53 ng/mL. He had not had a screening PSA for at least two prior years but this was a significant change from prior levels. Patient was asymptomatic however the abnormal laboratory evaluation prompted consultation with Urology. Biopsy of prostate gland confirmed prostatic adenocarcinoma with Gleason's score of 5+ 4 = 9 with bilateral gland involvement. Imaging studies including CT scan of abdomen and pelvis, a bone scan and a PET scan showed no clear evidence of metastatic disease. Patient's clinical stage was determined to be IIIC with T2c N0 M0 disease. Patient began treatment with androgen deprivation therapy and received definitive radiation treatment with external bean radiation therapy from July to September 2018. PSA was 0.08 ng/ml at the end of radiation treatment. Patient did well for about 15 months, after which he had multiple hospital admissions for dyspnea, fluid retention and lower extremity edema. He was also found to have refractory hypokalemia. Patient underwent MRI brain which revealed numerous small enhancing calvarial and skull base lesions consistent with bony metastasis in the skull. Patient also underwent PET/CT scan which showed numerous thoracic spine bony lesions, numerous to count bony metastasis throughout the lumbar spine and pelvis, as well as multiple hepatic lesions. Patient underwent biopsy of right hepatic lobe lesion and pathology was consistent with small cell carcinoma with positive neuroendocrine markers including CD56, synaptophysin and TTF-1. Interestingly patient’s PSA was only 0.09ng/dL. Given refractory hypokalemia, paraneoplastic syndrome was suspected and further work-up was initiated. Serum cortisol levels were elevated at 119.6 mcg/dL (3.7-19.4) and ACTH level was 333 pg/mL (7.2 - 63.3). Aldosterone level was <1 ng/dL (0 - 30.0). Patient was diagnosed with paraneoplastic Cushing syndrome. Given aggressive nature of this small cell transformation, patient was started on treatment with systemic chemotherapy with Carboplatin/Etoposide during the hospital stay, with stabilization of potassium levels. Prostate small cell carcinoma poses a challenge for diagnosis and treatment. In contrast to adenocarcinoma of the prostate, serum prostate-specific antigen (PSA) is not predictive of disease severity, nor is it a useful tumor marker for monitoring progression or surveillance. Patients with prostate small cell cancer presents with more diverse symptoms than any other prostate cancer since it tends to metastasize early. Also paraneoplastic syndromes are more common in prostate small cell cancers as well.

Tumor lysis syndrome is an oncologic emergency that usually occurs after chemotherapy in patients with hematologic malignancies. Tumor lysis syndrome is rare in cases of solid tumors, especially when it occurs spontaneously. Herein, we present a case of spontaneous tumor lysis syndrome in a 55-year-old woman who presented with dyspnea and was found to have extensive metastatic small cell lung cancer. She developed acute oliguric renal failure and multiple electrolyte abnormalities requiring hemodialysis. The findings of this case suggest that clinicians should maintain a high index of suspicion for patients with malignancies who demonstrate the classic symptom of laboratory abnormalities even in the absence of chemotherapy.

Introduction: Small Cell Lung Cancer (SCLC) is an aggressive malignancy with poor prognosis that accounts for 10% of all clinical lung cancer. SCLC commonly metastasizes to the mediastinum, liver, bone, adrenals, and the brain but secondary endotracheal metastasis is an especially rare occurrence. We discuss the case of a 74-year-old male with principal complaint of cough, wheezing and hemoptysis found to have secondary endotracheal lesions on bronchoscopy. Case report: A 74-year-old male, former smoker with a past medical history of pulmonary embolism, bullous emphysema, and limited stage small cell lung cancer with wedge resection and chemotherapy 3 years ago presented with cough, wheezing, weight loss and intermittent hemoptysis ongoing for few weeks. CT scan of the chest showed multiple polypoid masses arising in the anterior wall of the trachea. He underwent bronchoscopy with biopsy. Pathology was consistent with small-cell lung cancer. Conclusion: Secondary tracheal metastasis from early stage small cell cancer is a rare occurrence. The likelihood of tracheal metastasis of lung cancer is amplified when an endotracheal nodule or eccentric thickening of the tracheal wall is seen on CT of patients with high suspicion. It is important for clinicians to suspect endotracheal lesions when a patient presents with recurrent respiratory complaints despite stable surveillance CT scan of chest in patients with history of lung cancer.

Accurate diagnosis of small‐cell carcinoma of the lung (SCLC) is clinically important because of the therapeutic implications. SCLC must be distinguished from non‐small‐cell carcinoma (NSCLC) and lymphoma. Paranuclear blue inclusions (PBIs) were recently described as a feature of metastatic SCLC on air‐dried Wright‐stained bone marrow aspirate smears. To determine the utility of PBIs in distinguishing SCLC from NSCLC and lymphoma, we evaluated air‐dried Diff‐Quik‐stained smears from 103 fine‐needle aspiration (FNA) specimens and 14 touch imprint specimens. PBIs were identified in 24 (89%) of 27 cases of SCLC, in 6 (9%) of 64 non‐small‐cell carcinomas (P < 0.00001), and in two (8%) of the 26 lymphoma cases (P < 0.00001). No PBIs were seen on any of the alcohol‐fixed Papanicolaou or hematoxylin‐eosin (HandE) stained smears examined. In conclusion, PBIs appear to be a feature of SCLC on air‐dried cytologic material stained with Romanowsky type stains. In the presence of cytologic features of SCLC, the identification of PBIs provides a useful diagnostic feature for diferentiating between SCLC and NSCLC carcinomas, and between SCLC and lymphomas in FNA specimens and touch imprints from surgical specimens.

Small cell (neuroendocrine) carcinoma of the uterine cervix (SMCC) is a rare, highly aggressive malignant neoplasm. Both conventional and liquid-based cytology (LBC) cervical smears have low sensitivity in diagnosing SMCC, requiring immunocytochemical (ICH) confirmation. We present the first series of SMCC primarily diagnosed in cytology specimens, and ICH studies performed on the residual LBC specimens with subsequent confirmation of the diagnosis on surgical pathology specimens. Immunocytochemical stains for keratin, p16INK4, and neuroendocrine markers (synaptophysin, chromogranin, CD56) were performed on additional ThinPrep slides. HPV test used chromogenic in situ hybridization high risk HPV DNA probe. The Pap smears in all three specimens were highly cellular with a mixture of squamous cells and numerous well-preserved single or small cohesive clusters of malignant epithelial cells. Tumor cells were small, monomorphic with minimal cytoplasm and high nuclear/cytoplasmic ratio. There was significant nuclear overlap, but no nuclear molding, or smudging of nuclear chromatin. The chromatin pattern was stippled. A background tumor diathesis was prominent. Atypical squamous cells of undetermined significance (ASCUS) were noted in one case, and markedly abnormal squamous cells were seen in another case. The main cytology differential diagnoses included high-grade squamous intraepithelial lesion and an endometrial adenocarcinoma. Immunocytochemical positivity for the neuroendocrine markers supported the diagnoses of SMCC in all three cases. The morphologic features of the concurrent surgical pathology specimens were typical of SMCC. The tissue diagnoses were also confirmed by immunohistochemistry. Our study allows us to conclude that SMCC can be primarily diagnosed in LBC specimens using a panel of immunocytochemical stains.

Small Cell Lung Cancer (SCLC) is a highly aggressive neuroendocrine tumor with a 5% survival rate over 5 years. Though SCLC comprises 13% of all cases of lung cancer the median survival time of 14.5 months has seen little improvement over the last four decades. Standard treatment relies on DNA damaging agents such as Cisplatin/Etoposide (EP) which induce a high response rate of 60-70%. Despite this initial response, nearly all patients will relapse rendering first-line therapies ineffective. Furthermore, SCLC has been shown to develop chemotherapy cross-resistance in which resistance to first-line chemotherapies will confer resistance to additional DNA damaging agents thereby reducing treatment efficacy and duration of response. Cross-Resistance constitutes a major clinical issue whose underlying mechanisms remain a mystery. The modest improvements in SCLC patient outcomes over the decades may be partially explained by the existing systems of study. Current methodologies of SCLC study rely on cell lines, patient samples, and Genetically Engineered Mouse Models which have little functional correlation to clinical outcomes. While few sources have proposed Patient Derived Xenograft (PDX) systems as an improved alternative, significant data remains sparse. Without a robust model system which accurately recapitulates patient outcomes, molecular pathways driving resistance cannot be uncovered. Here we present the generation of 34 SCLC PDX models which maintain both genomic and functional fidelity. Furthermore, treatment of a 30-model subset with first-line chemotherapy EP and a novel chemotherapy Olaparib/Temozolomide (OT) allowed for functional and molecular comparison between groups. Our findings demonstrate incomplete independent resistance mechanisms between EP and OT treatment with a small overlap of 31 genes involved in glycolysis and xenobiotic metabolism.

No description available.

No description available.

Brain metastasis (BM), the most common tumor of the central nervous system, occurs in 20-36% of primary cancers. In particular, 20-40% of patients with non-small cell lung cancer (NSCLC) develop brain metastases, with a dismal survival of approximately 4-11 weeks without treatment, and 16 months with treatment. This highlights a large unmet need to develop novel targeted therapies for the treatment of lung-to-brain metastases (LBM). Genomic interrogation of LBM using CRISPR technology can inform preventative therapies targeting genetic vulnerabilities in both primary and metastatic tumors. Loss-of-function studies present limitations in metastasis research, as knocking out genes essential for survival in the primary tumor cells can thwart the metastatic cascade prematurely. However, transcriptional overexpression of genes using CRISPR activation (CRISPRa) has the potential for overcoming dependencies of gene essentiality. In this thesis, we created and utilized an in vivo genome-wide CRISPRa screening platform to identify novel genes, that when overexpressed, drive LBM. We have developed a patient-derived orthotopic murine xenograft model of LBM using a patient-derived NSCLC cell line (termed CRUK cells) from the Swanton Lab TRACERx study. We introduced a human genome-wide CRISPRa single guide RNA (sgRNA) library into non-metastatic and pro-metastatic lung cancer CRUK cells to achieve 500X representation of each sgRNA in the activation library. We then injected the cells into the lungs of immunocompromised mice and tracked lung tumor development and BM formation. Upon sequencing primary lung tumors and subsequent BM, we will identify enriched sgRNAs which may represent novel drivers of primary lung tumor formation and LBM. To the best of our knowledge, this study is the first in vivo genome-wide CRISPR activation screen using patient-derived NSCLC cells to help elucidate drivers of LBM. This work serves to provide a framework to gain a deeper understanding of the regulators of BM formation which will hopefully lead to targeted drug discovery that will ultimately be used in clinical trials to help eradicate brain metastasis in NSCLC patients. / Thesis / Master of Science (MSc) / Brain metastasis, or the spread of a primary cancer from another organ to the brain, is the most common adult brain tumor. Brain metastases can arise after the treatment of primary tumors and are only detected in the clinic at a highly malignant stage. Current treatments for brain metastasis consist of surgical removal and palliative chemoradiotherapy, which fail to fully eliminate the brain tumor. Over 20% of cancer patients develop brain metastases, with lung, breast, and skin cancers leading as the top three sources of metastasis. In particular, 40% of patients with non-small cell lung cancer develop brain metastasis, with survival of only 4-11 weeks once diagnosed without treatment, and 16 months with treatment. As systemic therapies for the treatment of non-small cell lung cancer are becoming increasingly effective at controlling primary disease, patients are ironically succumbing to their brain tumors. This highlights a large unmet need to develop novel targeted therapies for the treatment of lung-to-brain metastases (LBM). Functional genomic tools provide the opportunity to investigate the genetic underpinnings of LBM. With the advent of gene editing technologies, we are able to overexpress various genes and observe the impact genetic perturbations have on tumor initiation, growth, and metastasis. In this thesis, we devised a pre-clinical animal model of LBM that could be used to study genetic drivers of LBM using a gene overexpression tool such that one gene per tumor cell gets activated. We are then able to model the disease trajectory from a lung tumor to brain metastasis development using patient samples in our animal model and identify genes that, upon overexpression, drive LBM. This platform will lead to potential therapeutic targets to prevent the formation of LBM and prolong the survival of patients with non-small cell lung cancer.

Cancer is known for its unregulated and mutagenic characteristics. The topic of targeting cancer by inhibiting the metabolic pathways it uses to thrive has been a focus of modern cancer research. Specifically, in lung cancer, the transformation from non-small cell lung cancer (NSCLC) to small cell lung cancer (SCLC) is a focus. This transformation often comes with a grimmer prognosis and reduced survival rate. This is primarily due to SCLC being resistant to epidermal growth factor receptor (EGFR) inhibitors. This frontline treatment for EGFR mutant NSCLC has shown to be quite effective until transformation to SCLC occurs. To further study the metabolic factors responsible for this transformation, a metabolic screening was conducted on SCLC transformed lung tissues and tumor adjacent normal lung tissues. This analysis revealed that the amino acid L-arginine and intermediates in its biosynthetic pathway were severely dysregulated. While L-arginine supplementation has shown to inhibit the growth of breast and colorectal cancers, there is little literature about its effects on lung cancer. Using cell viability and gene expression screening tools, we have identified arginine metabolizing genes ARG2, GATM, and OAT as being upregulated in NSCLC treated with high concentrations of an EGFR inhibitor. These high treatments also correlate with increased expression of neuronal differentiation factor 1 (NEUROD1), which has been shown to drive tumorigenesis, metastasis, and SCLC transformation. These findings show a role for altering arginine metabolism to accomplish drug resistance through SCLC transformation. These findings will hopefully pave the way for later clinical use of arginine converting enzymes and NEUROD1 expression levels as predictive markers of early drug resistance and SCLC transformation.