Predictive value and diagnostic accuracy of F-18-fluoro-deoxy-glucose positron emission tomography treated grade 1 and 2 follicular lymphoma.

F-18-fluoro-deoxy-glucose positron emission tomography (PET) is a powerful tool for the imaging of aggressive B-cell lymphomas. In contrast, there is relatively little data on PET in follicular lymphoma grade 1 (FL-1) and grade 2 (FL-2). In this manuscript, we present our findings utilizing PET in treated FL-1 and FL-2. A retrospective review of patients who underwent PET examinations at our institution produced 95 PET examinations among 31 patients with FL-1 and FL-2. PET was obtained at initial staging, mid-induction and post-treatment. Results were compared with clinical follow-up. PET had high sensitivity (95%) and specificity (88%) for lesion detection in treated FL-1 and FL-2. Abnormal foci in FL-1 and FL-2 had similar intensities. Post-induction PET positive patients had shorter mean progression free survivals compared with PET negative patients (p-value < or =0.001), post-salvage PET positive trended toward shorter mean response duration compared with negative patients (p-value: 0.09). Our results indicate that PET is accurate in the diagnostic assessment of treated FL-1 and FL-2 and, post-treatment PET positive patients are likely to relapse prior to PET negative patients.

MUC1 and HIF-1alpha Signaling Crosstalk Induces Anabolic Glucose Metabolism to Impart Gemcitabine Resistance to Pancreatic Cancer.

Poor response to cancer therapy due to resistance remains a clinical challenge. The present study establishes a widely prevalent mechanism of resistance to gemcitabine in pancreatic cancer, whereby increased glycolytic flux leads to glucose addiction in cancer cells and a corresponding increase in pyrimidine biosynthesis to enhance the intrinsic levels of deoxycytidine triphosphate (dCTP). Increased levels of dCTP diminish the effective levels of gemcitabine through molecular competition. We also demonstrate that MUC1-regulated stabilization of hypoxia inducible factor-1α (HIF-1α) mediates such metabolic reprogramming. Targeting HIF-1α or de novo pyrimidine biosynthesis, in combination with gemcitabine, strongly diminishes tumor burden. Finally, reduced expression of TKT and CTPS, which regulate flux into pyrimidine biosynthesis, correlates with better prognosis in pancreatic cancer patients on fluoropyrimidine analogs.

Pulmonary langerhans cell histiocytosis: PET/CT for initial workup and treatment response evaluation.

A 40-year-old man underwent pan-endoscopy owing to abdominal pain. Biopsies of the gastrointestinal tract demonstrated diffuse Langerhans cell histiocytosis. PET/CT was done, with CT demonstrating classic pulmonary manifestations of Langerhans cell histiocytosis that had association with intense FDG uptake on PET. Bowel appeared normal. Treatment was initiated with smoking cessation and 6 cycles of cytarabine. Follow-up PET/CT after initial treatment demonstrated improvement of parenchymal abnormalities seen on CT, with resolution of hypermetabolic activity. Maintenance chemotherapy was initiated. PET/CT is increasingly being used for initial staging and treatment response assessment in this rare disorder.

Occult breast cancer presenting as metastatic adenocarcinoma of unknown primary: clinical presentation, immunohistochemistry, and molecular analysis.

We report a rare presentation of a 66-year-old female with diffuse metastatic adenocarcinoma of unknown primary involving liver, lymphatic system and bone metastases. The neoplastic cells were positive for CK7 and OC125, while negative for CK20, thyroid transcription factor 1, CDX2, BRST-2, chromogranin, synaptophysin, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2/neu). Fluorescence in situ hybridization showed no amplification of the HER2/neu gene. Molecular profiling reported a breast cancer origin with a very high confidence score of 98%. The absence of immunohistochemistry staining for ER, PR, and HER2/neu further classified her cancer as triple-negative breast cancer. Additional studies revealed high expression levels of topoisomerase (Topo) I, androgen receptor, and ribonucleoside-diphosphate reductase large subunit; the results were negative for thymidylate synthase, Topo II-a and O6-methylguanine-DNA methyltransferase. The patient was initially treated with a combination regimen of cisplatin and etoposide, and she experienced a rapid resolution of cancer-related symptoms. Unfortunately, her therapy was complicated by a cerebrovascular accident (CVA), which was thought to be related to cisplatin and high serum mucin. After recovery from the CVA, the patient was successfully treated with second-line chemotherapy based on her tumor expression profile. We highlight the role of molecular profiling in the diagnosis and management of this patient and the implication of personalized chemotherapy in this challenging disease.