Publications by authors named "Dianna Ng"

Objective: Few studies characterizing clinical outcomes of head and neck cancer (HNC) patients in sub-Saharan Africa report the proportion of patients who initiate and complete treatment, information integral to contextualizing survival outcomes. This retrospective cohort study describes HNC patients who presented to Muhimbili National Hospital and Ocean Road Cancer Institute in 2018, the highest-volume oncology tertiary referral centers in Tanzania. Logistic regression was applied to assess predictors of treatment initiation and completion.

View Article and Find Full Text PDF
Article Synopsis
  • A study was conducted to evaluate the STRAT4 Assay's effectiveness using fine-needle aspiration biopsy (FNAB) samples for breast cancer testing in Tanzania, aiming to improve biomarker accessibility in low-resource settings.
  • The research involved collecting FNAB specimens from patients with palpable breast masses, using various testing protocols and excluding those with previous breast cancer diagnoses or specific conditions like pregnancy.
  • The analysis compared STRAT4's performance against established testing methods based on factors like concordance, sensitivity, specificity, and diagnostic accuracy over a three-year period involving 208 patients.
View Article and Find Full Text PDF

Context.—: Breast pathology reports include many important details to guide clinical management. Reports with missing critical data elements are commonly seen in non-subspecialized pathology practices.

View Article and Find Full Text PDF

Breast cancer is a substantial source of morbidity and mortality worldwide. It is particularly more difficult to treat at later stages, and treatment regimens depend heavily on both staging and the molecular subtype of the tumor. However, both detection and molecular analyses rely on standard imaging and histological method, which are costly, time-consuming, and lack necessary sensitivity/specificity.

View Article and Find Full Text PDF

As the burden of cancers impacting low- and middle-income countries is projected to increase, formation of strategic partnerships between institutions in high-income countries and low- and middle-income country institutions may serve to accelerate cancer research, clinical care, and training. As the US National Cancer Institute and its Center for Global Health continue to encourage cancer centers to join its global mission, academic cancer centers in the United States have increased their global activities. In 2015, the Helen Diller Family Comprehensive Cancer Center at the University of California, San Francisco, responded to the call for international partnership in addressing the global cancer burden through the establishment of the Global Cancer Program as a priority initiative.

View Article and Find Full Text PDF

Background: Esophageal squamous cell carcinoma (ESCC) comprises 90% of all esophageal cancer cases globally and is the most common histology in low-resource settings. Eastern Africa has a disproportionately high incidence of ESCC.

Methods: We describe the genomic profiles of 61 ESCC cases from Tanzania and compare them to profiles from an existing cohort of ESCC cases from Malawi.

View Article and Find Full Text PDF

Context.—: Rapid onsite evaluation (ROSE) is critical in determining sample adequacy and triaging cytology samples. Although fine-needle aspiration biopsy (FNAB) is the primary method of initial tissue sampling in Tanzania, ROSE is not practiced.

View Article and Find Full Text PDF

Introduction: Phantoms and simulators are widely accepted methods to gain valuable experience and confidence for inexperienced trainees prior to seeing their patient and for refining their skills. A phantom model that is durable, simple, and inexpensive to produce and use would be ideal to train practitioners in ultrasound-guided fine-needle aspiration biopsy (USFNA) technique.

Materials And Methods: In this study, we systematically compared several low-cost phantom models including gelatin, extra firm tofu, canned cooked pork, ballistics gel, and chicken breast for their haptic properties, echogenicity, teaching utility, and overall performance based on a Likert scale (1-5; 5 = best).

View Article and Find Full Text PDF

Purpose: The proportion of head and neck cancers (HNCs) with human papillomavirus (HPV) positivity in sub-Saharan Africa (SSA) is poorly characterized. Characterizing this has implications in staging, prognosis, resource allocation, and vaccination policies. This study aims to determine the proportion of HPV-associated HNC in SSA.

View Article and Find Full Text PDF
Article Synopsis
  • Urinary cytology is crucial for checking blood in urine and monitoring patients with bladder tumors.
  • A positive test typically indicates the presence of bladder cancer, but in women, it might also suggest cancer in the lower reproductive system or even the rectum.
  • There are no clear guidelines for evaluating women with a positive cytology who have normal urinary tract results, prompting a review of existing literature and case scenarios to highlight this challenge for doctors.
View Article and Find Full Text PDF
Article Synopsis
  • Esophageal squamous cell carcinoma (ESCC) is more common in certain areas of Africa and Asia, with new research suggesting a link between poor oral health and ESCC.
  • An analysis of tumor samples from ESCC patients has identified specific bacteria, such as Fusobacterium and Prevotella, present in higher amounts in tumors from various high-incidence regions.
  • The study also found that the microbiomes of saliva and tumors in ESCC patients were similar, indicating that oral bacteria may contribute to the development of ESCC.
View Article and Find Full Text PDF

Context.—: The incidence of human epidermal growth factor receptor 2 (HER2) positivity in gastric cancers differs widely across various populations and is unknown in many low-resource settings.

Objective.

View Article and Find Full Text PDF

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection causes coronavirus disease-2019 (COVID-19) in some individuals, while the majority remain asymptomatic. Natural killer (NK) cells play an essential role in antiviral defense. NK cell maturation and function are regulated mainly by highly polymorphic killer cell immunoglobulin-like receptors (KIR) and cognate HLA class I ligands.

View Article and Find Full Text PDF

Background And Study Aim: Immunohistochemistry is one of the superior methods and is regarded as the gold standard for the detection of Helicobacter pylori. We aimed to detect the presence of Helicobacter pylori in gastric biopsies among patients at the Muhimbili National Hospital from January 2012 to December 2016. Also, we determined the predictors of Helicobacter pylori infection.

View Article and Find Full Text PDF

In less than nine months, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) killed over a million people, including >25,000 in New York City (NYC) alone. The COVID-19 pandemic caused by SARS-CoV-2 highlights clinical needs to detect infection, track strain evolution, and identify biomarkers of disease course. To address these challenges, we designed a fast (30-minute) colorimetric test (LAMP) for SARS-CoV-2 infection from naso/oropharyngeal swabs and a large-scale shotgun metatranscriptomics platform (total-RNA-seq) for host, viral, and microbial profiling.

View Article and Find Full Text PDF

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease-19 (COVID-19), has emerged as the cause of a global pandemic. We used RNA sequencing to analyze 286 nasopharyngeal (NP) swab and 53 whole-blood (WB) samples from 333 patients with COVID-19 and controls. Overall, a muted immune response was observed in COVID-19 relative to other infections (influenza, other seasonal coronaviruses, and bacterial sepsis), with paradoxical down-regulation of several key differentially expressed genes.

View Article and Find Full Text PDF

Purpose: Clinical breast examination (CBE) is one of the most common methods used for early detection of breast cancer in low- and middle-income countries. CBE alone is limited by lack of specificity and may result in unnecessary diagnostic procedures. We evaluated the feasibility of integrating CBE, fine-needle aspiration biopsy (FNAB), and rapid on-site evaluation (ROSE) in triaging palpable breast masses for specialized cancer care.

View Article and Find Full Text PDF

Prior studies evaluating thyroid fine needle aspiration biopsies (FNABs) have limited the calculation of risk of malignancy (ROM) to cytologic specimens with corresponding histologic specimens, and clinical follow-up for those patients who do not undergo immediate surgery has been largely disregarded. Moreover, there is marked variability in how researchers have approached thyroid FNAB statistical analyses. This study addresses the urgent need for information from a large cohort of patients with long-term clinical follow-up to more accurately determine the performance of thyroid FNAB and ROM for each diagnostic category.

View Article and Find Full Text PDF

Context.—: Breast cancer biomarker assessment is critical in determining treatment and prognosis. In Tanzania, immunohistochemistry (IHC) is limited to surgical specimens and core biopsies.

View Article and Find Full Text PDF

Comprehensive understanding of the serological response to SARS-CoV-2 infection is important for both pathophysiologic insight and diagnostic development. Here, we generate a pan-human coronavirus programmable phage display assay to perform proteome-wide profiling of coronavirus antigens enriched by 98 COVID-19 patient sera. Next, we use ReScan, a method to efficiently sequester phage expressing the most immunogenic peptides and print them onto paper-based microarrays using acoustic liquid handling, which isolates and identifies nine candidate antigens, eight of which are derived from the two proteins used for SARS-CoV-2 serologic assays: spike and nucleocapsid proteins.

View Article and Find Full Text PDF

Given the limited availability of serological testing to date, the seroprevalence of SARS-CoV-2-specific antibodies in different populations has remained unclear. Here, we report very low SARS-CoV-2 seroprevalence in two San Francisco Bay Area populations. Seroreactivity was 0.

View Article and Find Full Text PDF
Article Synopsis
  • - The study evaluated the performance of ten quick lateral flow assays and two lab-based tests for detecting antibodies against SARS-CoV-2, focusing on the time after symptom onset and previous test samples.
  • - It found that seropositivity increased over time, peaking over 20 days after symptoms began, but test specificity varied between 84.3% and 100%, mainly influenced by IgM results.
  • - Recommendations from the study emphasize optimizing seropositivity thresholds and ensuring proper reader training to improve the reliability of these assays, with four tests showing over 80% positivity and over 95% specificity in later time intervals.
View Article and Find Full Text PDF