Comparative Uptake Patterns of Radioactive Iodine and [18F]-Fluorodeoxyglucose (FDG) in Metastatic Differentiated Thyroid Cancers.

Background: Metastatic differentiated thyroid cancer (DTC) represents a molecularly heterogeneous group of cancers with varying radioactive iodine (RAI) and [18F]-fluorodeoxyglucose (FDG) uptake patterns potentially correlated with the degree of de-differentiation through the so-called "flip-flop" phenomenon. However, it is unknown if RAI and FDG uptake patterns correlate with molecular status or metastatic site. Materials and Methods: A retrospective analysis of metastatic DTC patients (n = 46) with radioactive 131-iodine whole body scan (WBS) and FDG-PET imaging between 2008 and 2022 was performed. The inclusion criteria included accessible FDG-PET and WBS studies within 1 year of each other. Studies were interpreted by two blinded radiologists for iodine or FDG uptake in extrathyroidal sites including lungs, lymph nodes, and bone. Cases were stratified by BRAF V600E mutation status, histology, and a combination of tumor genotype and histology. The data were analyzed by McNemar's Chi-square test. Results: Lung metastasis FDG uptake was significantly more common than iodine uptake (WBS: 52%, FDG: 84%, p = 0.04), but no significant differences were found for lymph or bone metastases. Lung metastasis FDG uptake was significantly more prevalent in the papillary pattern sub-cohort (WBS: 37%, FDG: 89%, p = 0.02) than the follicular pattern sub-cohort (WBS: 75%, FDG: 75%, p = 1.00). Similarly, BRAF V600E+ tumors with lung metastases also demonstrated a preponderance of FDG uptake (WBS: 29%, FDG: 93%, p = 0.02) than BRAF V600E- tumors (WBS: 83%, FDG: 83%, p = 1.00) with lung metastases. Papillary histology featured higher FDG uptake in lung metastasis (WBS: 39%, FDG: 89%, p = 0.03) compared with follicular histology (WBS: 69%, FDG: 77%, p = 1.00). Patients with papillary pattern disease, BRAF V600E+ mutation, or papillary histology had reduced agreement between both modalities in uptake at all metastatic sites compared with those with follicular pattern disease, BRAF V600E- mutation, or follicular histology. Low agreement in lymph node uptake was observed in all patients irrespective of molecular status or histology. Conclusions: The pattern of FDG-PET and radioiodine uptake is dependent on molecular status and metastatic site, with those with papillary histology or BRAF V600E+ mutation featuring increased FDG uptake in distant metastasis. Further study with an expanded cohort may identify which patients may benefit from specific imaging modalities to recognize and surveil metastases.

Genetic diversity in the transmission-blocking vaccine candidate Plasmodium vivax gametocyte protein Pvs230 from the China-Myanmar border area and central Myanmar.

BACKGROUND: Sexual stage surface antigens are potential targets of transmission-blocking vaccines (TBVs). The gametocyte and gamete surface antigen P230, a leading TBV candidate, is critical for red blood cell binding during exflagellation and subsequent oocyst development. Here, the genetic diversity of Pvs230 was studied in Plasmodium vivax parasite isolates from the China-Myanmar border (CMB) and central Myanmar. METHODS: Plasmodium vivax isolates were collected in clinics from malaria-endemic areas of the CMB (143 samples) and Myanmar (23 samples). The interspecies variable part (IVP, nucleotides 1-807) and interspecies conserved part (ICP, 808-2862) of Pvs230 were amplified by PCR and sequenced. Molecular evolution studies were conducted to evaluate the genetic diversity, signature of selection, population differentiation, haplotype network, and population structure of the study parasite populations and publicly available Pvs230 sequences from six global P. vivax populations. RESULTS: Limited genetic diversity was observed for the CMB (π = 0.002) and Myanmar (π = 0.001) isolates. Most amino acid substitutions were located in the IVP and cysteine-rich domain of Pvs230. Evidence of positive selection was observed for IVP and purifying selection for ICP. Codon-based tests identified specific codons under natural selection in both IVP and ICP. The fixation index (FST) showed low genetic differentiation between East and Southeast Asian populations, with FST ranging from 0.018 to 0.119. The highest FST value (FST = 0.503) was detected between the Turkey and Papua New Guinea populations. A total of 92 haplotypes were identified in global isolates, with the major haplotypes 2 and 9 being the most abundant and circulating in East and Southeast Asia populations. Several detected non-synonymous substitutions were mapped in the predicted structure and B-cell epitopes of Pvs230. CONCLUSIONS: We detected low levels of genetic diversity of Pvs230 in global P. vivax populations. Geographically specific haplotypes were identified for Pvs230. Some mutations are located within a potential B-cell epitope region and need to be considered in future TBV designs.

Non-Iodine-Avid Disease Is Highly Prevalent in Distant Metastatic Differentiated Thyroid Cancer With Papillary Histology.

CONTEXT: Patients with radioactive iodine (RAI) refractory metastatic differentiated thyroid cancer (DTC) have poor prognosis. Early identification of RAI refractoriness may improve care. OBJECTIVE: This work aimed to characterize DTC patients with distant metastases (DM) at diagnosis who presented with non-iodine-avid disease. METHODS: Retrospective analyses of DTC patients with DM at diagnosis who presented between 2012 and 2020 were performed. Iodine uptake in DM was correlated with tumor histology and mutational profile. The difference in uptake between BRAFV600E-like (BVL) and RAS-like (RL) cancers based on insights from The Cancer Genome Atlas was evaluated. RESULTS: Among 78 patients, 48.7% had negative uptake in DM on the first posttherapy scan. Negative scans were highly prevalent in papillary thyroid carcinoma (PTC) with papillary architecture, PTC with BRAFV600E mutation, and PTC with both BRAFV600E and TERT promoter mutations (71.1%, 80.9%, and 100%, respectively). BVL and RL tumors exhibited distinct uptake patterns with negative scan prevalence of 76.9% and 14.3% (P = .005). Multivariate logistical regression confirmed high odds of negative uptake in BVL tumors with either BVL mutations or papillary architecture, 19.8 (95% CI, 2.72-144), and low odds of negative uptake in RL tumors with either RL mutations or follicular architecture, 0.048 (95% CI, 0.006-0.344), after adjusting for age, sex, race, RAI preparation method, bone metastases, and RAI dose. Patients with negative scans were significantly older (62.4 vs 47.0 years, P = .03). CONCLUSION: Among DTC patients with DM at diagnosis, non-iodine-avid disease is highly prevalent in patients with BVL cancers, particularly with BRAFV600E and TERT promoter mutations, and is associated with an older age. Better strategies are needed to improve RAI treatment response for these patients.

SDHB knockout and succinate accumulation are insufficient for tumorigenesis but dual SDHB/NF1 loss yields SDHx-like pheochromocytomas.

Inherited pathogenic succinate dehydrogenase (SDHx) gene mutations cause the hereditary pheochromocytoma and paraganglioma tumor syndrome. Syndromic tumors exhibit elevated succinate, an oncometabolite that is proposed to drive tumorigenesis via DNA and histone hypermethylation, mitochondrial expansion, and pseudohypoxia-related gene expression. To interrogate this prevailing model, we disrupt mouse adrenal medulla SDHB expression, which recapitulates several key molecular features of human SDHx tumors, including succinate accumulation but not 5hmC loss, HIF accumulation, or tumorigenesis. By contrast, concomitant SDHB and the neurofibromin 1 tumor suppressor disruption yields SDHx-like pheochromocytomas. Unexpectedly, in vivo depletion of the 2-oxoglutarate (2-OG) dioxygenase cofactor ascorbate reduces SDHB-deficient cell survival, indicating that SDHx loss may be better tolerated by tissues with high antioxidant capacity. Contrary to the prevailing oncometabolite model, succinate accumulation and 2-OG-dependent dioxygenase inhibition are insufficient for mouse pheochromocytoma tumorigenesis, which requires additional growth-regulatory pathway activation.

Cancer Incidence and Mortality in Central Myanmar: Report of Nay Pyi Taw Population-Based Cancer Registry.

BACKGROUND: Cancer is a major public health problem in Myanmar, and cancer registration activities are currently underway through both hospital-based and population-based approaches. So far, there are no population-based cancer incidence and mortality estimates in the country. METHODS: According to the 2014 census, the total population of Nay Pyi Taw Union Territory was 1,160,242 within the area of 70,571 km2. Nay Pyi Taw Cancer Registry team collected data of new cancer cases both actively and passively from all data sources in the region. The data were registered, updated, cross-checked, quality-assured, and analyzed in CanReg5. The results were presented as the number of cases by site, sex, and age, cumulative risk (CR), crude rate, age-specific, and age-standardized incidence rates (ASRs) per 100,000. RESULTS: Total 5,952 new cancer cases and 1874 cancer deaths were recorded among the population of the Nay Pyi Taw Union Territory between 2013 and 2017. The age-standardized incidence rate for all cancer sites excluding non-melanoma skin cancers in males was 125.9 and 107.3 for females. For both sexes combined, the most common cancers were lung (14%), breast (11.4%), liver (10.2%), mouth and pharynx (8.5%), and stomach cancers (7.8%). In males, the most common were lung (18.1%), liver (14.8%), mouth and pharynx (13%), stomach (8.9%) and colon, rectum, and anus (7.4%) cancers. In females, these were breast (21.2%), cervix (13.0%), lung (10.3%), stomach (6.9%) and colon, rectum, and anus (6.3%) cancers. The most common cancer deaths were caused by liver (20.8%), lung (15.7%), mouth and pharynx (9.3%), stomach (7.5%), and Colon, rectum, and anus (6.8%) cancers. CONCLUSION: The findings in this study are salient and have potential to serve as important information for the National Cancer Control Program to formulate prevention and control strategies.

Quilting suture versus conventional closure in prevention of seroma after total mastectomy and axillary dissection in breast cancer patients.

BACKGROUND: Total mastectomy and axillary dissection is a common procedure for breast cancer patients in our institution. Seroma is common. This study aimed to compare the quilting suture and conventional closure in prevention of seroma after total mastectomy and axillary dissection. METHODS: This randomized comparative study was carried out from January 2018 to June 2019 in Yangon General Hospital. One hundred and forty patients (70 conventional and 70 quilting) were included. For quilting group, customized strategically placed interrupted alternate sutures were placed 2-3 cm apart with 3/0 vicryl sutures between skin flap and pectoral muscle. RESULTS: Age, body mass index and tumour diameter were comparable between the groups. The mean duration of operation was 111.44 ± 7.045 min in conventional and 124.5 ± 6.39 min in quilting (P = 0.0001). The mean drain output for conventional group was not significantly different from quilting group. In quilting, some area developed dimpling which resolved within a week. A total of 21 (30%) patients in the conventional group and 10 patients (14.3%) in the quilting group developed seroma (P = 0.041). The mean frequency and amount of seroma aspiration were significantly lower in the quilting group. Shoulder movement limitation and analgesia use showed no significant difference. CONCLUSION: Although total amount of drain output, duration of drain, hospital stay and post-operative complications were not different, the incidence of seroma was significantly lower in quilting group. Seroma is treated with more ease in the quilting group as the frequency and amount of aspiration were lower and less frequent follow-up visits were required. Quilting can reduce the seroma incidence in total mastectomy and axillary dissection for breast cancer patients.

Immunohistochemical Mapping of Bcl9 Using Two Antibodies that Recognize Different Epitopes Is Useful to Characterize Juvenile Development of Hepatocellular Carcinoma in Myanmar.

B-cell lymphoma 9 (Bcl9) is the core component of Wnt/ß-catenin signaling and overexpressed in nuclei of various tumors, including hepatocellular carcinoma (HCC). However, the extent of Bcl9 expression relative to HCC differentiation stage and its functional aspects are poorly understood. In this study, we examined the expression pattern of Bcl9 immunohistochemically, using two anti-Bcl9 antibodies; one was a conventional polyclonal-antibody (anti-Bcl9ABC) against amino acid no.800-900 of human-Bcl9, while the other (anti-Bcl9BIO) was against amino acid no.50-200, covering Pygopus-binding sites of Bcl9. Immunohistochemistry using anti-Bcl9BIO demonstrated distinctive staining in the cytoplasm, while the anti-Bcl9ABC signal was detected in both cytoplasm and nuclei of HCC cells, reflecting different states of Bcl9 function because Pygopus-binding to Bcl9 is essential to exert its function together with ß-catenin in nucleus. Quantitative analysis revealed a significantly higher immunohistochemical-score by anti-Bcl9BIO in normal liver comparing various differentiation grades of HCC (P < 0.004), whereas no significant difference was noted with anti-Bcl9ABC. Interestingly, immunohistochemical-score of anti-Bcl9BIO in patients aged < 40 years was significantly lower than that of ≥ 40 years group (P < 0.01). The results indicated that anti-Bcl9BIO detected cytoplasmic Bcl9, which does not bind to Pygopus suggesting it could be a useful indicator for development of HCC in young Myanmar patients.

Small Cell Lung Cancer with Pituitary Metastasis Presenting as Secondary Adrenal Insufficiency: A Case Report and Literature Review.

BACKGROUND Pituitary gland metastasis is rarely the initial presentation of metastatic cancer. Most cases of pituitary gland metastasis are asymptomatic with diabetes insipidus being the most common symptomatic presentation. It can rarely present with symptoms of hormone underproduction such as secondary adrenal insufficiency. Although pituitary gland metastasis is rare, it is underestimated, as it is commonly misdiagnosed with pituitary gland adenoma due to the lack of clear radiological criteria differentiating between both. CASE REPORT We present a case of a 62-year-old male who presented with weakness, blurry vision, and persistent hypoglycemia despite intravenous dextrose infusion and having discontinued taking his diabetes medications. Chest x-ray showed a left hilar mass, while computed tomography scan demonstrated a left superior hilar mass and hilar lymphadenopathy with bilateral adrenal nodules and a T6 vertebral lesion suspicious for metastasis. Further workup showed secondary adrenal insufficiency with a low adrenocorticotropic hormone (ACTH) level. Vertebral biopsy was performed and confirmed the diagnosis of small cell carcinoma of the lung. This was followed by a brain magnetic resonance imaging (MRI), which showed multiple metastatic lesions with an enhancing mass involving the right clivus, sella, and suprasellar cistern with mass effect on the optic chiasm and involvement of the cavernous sinus supporting the diagnosis of pituitary gland metastasis of small cell lung cancer. The patient received brain radiation, and repeated MRI showed regression of the previous MRI findings. CONCLUSIONS Secondary adrenal insufficiency is an unusual presentation of pituitary gland metastasis. Physicians should take into consideration both radiological findings and presentation to differentiate between pituitary gland metastasis and pituitary adenoma.

Pericardial effusion due to pembrolizumab-induced immunotoxicity: A case report and literature review.

The advent of immune checkpoint inhibitors has revolutionized cancer treatment. These novel agents have provided promising treatment options in patients with different types of cancers. One of these agents is pembrolizumab, which works by blocking the binding of T-lymphocytes to programmed cell death ligand 1 receptors on tumor cells, thus enabling immune activation of T-lymphocytes against tumor cells. Pembrolizumab is commonly used in metastatic nonsmall cell lung cancer and melanoma. However, despite the remarkable efficacy this agent has achieved, multiple immune-related adverse events have been reported including hepatitis, colitis, thyroid dysfunction, and pneumonitis. Only 2 other cases of pericardial effusion as a side effect of pembrolizumab have been cited in the literature; however, its incidence may be on the rise. Despite the rarity of this side effect, its complications are potentially life threatening and no clear platform currently exists to help guide healthcare professionals in the management of these adverse events. Herein we present the case of a 66-year-old female who developed pericardial effusion as a side effect of pembrolizumab and review the data currently available to assist in the management of this life-threatening condition.

Histone deacetylase inhibitors suppress transdifferentiation of gonadotrophs to prolactin cells and proliferation of prolactin cells induced by diethylstilbestrol in male mouse pituitary.

Diethylstilbestrol (DES), an estrogen agonist, increases prolactin (PRL) cells through transdifferentiation of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) cells to PRL cells as well as proliferation of PRL cells in adult male mouse pituitary. Since hyperacetylation of histone H3 is implicated in the regulation of activation of various genes, we examined the effect of DES on the state of histone H3 acetylation. DES significantly reduced the immunohistochemical signal for acetylated histone H3 at lysine 9 (H3K9ac) in PRL, LH and FSH cells, but not for H3K18ac or H3K23ac. DES-treated mice were injected intraperitoneally with HDAC inhibitors (HDACi), sodium phenylbutyrate (NaPB) or valproic acid (VPA), to mimic the acetylation level of histone H3. As expected, HDACi treatment restored the level of H3K9ac expression in these cells, and also inhibited DES-induced increase in PRL cells. Furthermore, NaPB and VPA also abrogated the effects of DES on the population density of both LH and FSH cells. Similarly, the numbers of proliferating and apoptotic cells in the pituitary in NaPB- or VPA-treated mice were comparable to those of the control mice. Considered together, these results indicated that the acetylation level of histone H3 plays an important role in DES-induced transdifferentiation of LH to PRL cells as well as proliferation of PRL cells.

Beyond the Dual Paraneoplastic Syndromes of Small-Cell Lung Cancer with ADH and ACTH Secretion: A Case Report with Literature Review and Future Implications.

We present a case of small-cell lung cancer (SCLC) with syndrome of inappropriate antidiuretic hormone secretion (SIADH) in which serum sodium gradually normalized with the onset of hypertension, refractory hypokalemia, and chloride-resistant metabolic alkalosis due to ectopic adrenocorticotrophic hormone (ACTH) secretion (EAS). In this case report, we discuss the diagnostic challenges of dual paraneoplastic syndromes with SIADH and EAS, management of SCLC with paraneoplastic endocrinopathies, and their prognostic impact on SCLC. In addition, we discuss neuroendocrine differentiation and ectopic hormone production in relation to intratumoral heterogeneity in SCLC and propose tumor microenvironment and hormonal and metabolic dependence as important determinants of tumor growth and survival.

Drug-Induced Thrombotic Microangiopathy due to Cumulative Toxicity of Ixazomib.

Drug-induced thrombotic microangiopathies (DTMAs) are increasingly being recognized as an important category of thrombotic microangiopathies (TMAs). Cancer therapeutic agents including proteasome inhibitors (PIs) are among the most common medications reported to cause DTMA. PIs could cause DTMA either by an immune mechanism or dose-dependent/cumulative toxicity. Eleven cases of DTMA have been reported with bortezomib and carfilzomib. To the best of our knowledge, only one case of DTMA has been reported with ixazomib due to an immune-mediated mechanism. Here, we report the first case of ixazomib-induced DTMA due to cumulative toxicity rather than immune-mediated mechanism. In this article, we discuss the precipitating factors for cumulative toxicity of ixazomib, resulting in DTMA, diagnostic workup, and management of DTMA. We also discuss clinical reasoning based analysis of DTMA versus cancer-associated TMA as well as DTMA versus cyclic thrombocytopenia seen in PI use.