Bilateral ulna hemimelia with humeroradial synostosis and oligodactyly: A case report

Hemimelia denotes the partial or complete absence of the distal half of a limb. Ulna hemimelia, a rare congenital anomaly, involves the complete or partial absence of the ulna in the upper limb, with an incidence of 1 in 150,000. This condition has been classified into 4 types, with the rare Type 4 variant involving humeroradial synostosis. We present a unique case of bilateral complete ulna hemimelia, humeroradial synostosis, and oligodactyly, in an 11-month-old female with bilateral upper limb shortening and restricted elbow movement since birth. Clinical examination revealed bilateral upper limb shortening, medial deviation of both wrist joints, fixed extension of both elbow joints, and bilateral absence of the cubital fossa. Radiographs confirmed bilateral micromelia, absence of ulna, humeroradial synostosis, and oligodactyly. This case, exhibiting bilateral Type 4 ulna hemimelia with Class 1 humeroradial synostosis, is a complex variant, rarely reported, and the first documented in Ghana. It also highlights the importance of radiological assessment in ensuring accurate diagnosis. Long-term follow-up and potential surgical interventions are crucial for optimizing upper limb function in such cases.

Patient-derived tumor organoids with p53 mutations, and not wild-type p53, are sensitive to synergistic combination PARP inhibitor treatment

Poly (ADP-ribose) polymerase inhibitors (PARPi) are used for patients with BRCA1/2 mutations, but patients with other mutations may benefit from PARPi treatment. Another mutation that is present in more cancers than BRCA1/2 is mutation to the TP53 gene. In 2D breast cancer cell lines, mutant p53 (mtp53) proteins tightly associate with replicating DNA and Poly (ADP-ribose) polymerase (PARP) protein. Combination drug treatment with the alkylating agent temozolomide and the PARPi talazoparib kills mtp53 expressing 2D grown breast cancer cell lines. We evaluated the sensitivity to the combination of temozolomide plus PARPi talazoparib treatment to breast and lung cancer patient-derived tumor organoids (PDTOs). The combination of the two drugs was synergistic for a cytotoxic response in PDTOs with mtp53 but not for PDTOs with wtp53. The combination of talazoparib and temozolomide induced more DNA double-strand breaks in mtp53 expressing organoids than in wild-type p53 expressing organoids as shown by increased γ-H2AX protein expression. Moreover, breast cancer tissue microarrays (TMAs) showed a positive correlation between stable p53 and high PARP1 expression in sub-groups of breast cancers, which may indicate sub-classes of breast cancers sensitive to PARPi therapy. These results suggest that mtp53 could be a biomarker to predict response to the combination of PARPi talazoparib-temozolomide treatment.

Spontaneous resolution of tuberculosis related Rasmussen aneurysm in a young West African: A case report

Rasmussen aneurysm (RA) is an uncommon cause of hemoptysis in pulmonary tuberculosis, first described in 1868 by Rasmussen. It is often treated with surgery or endovascular coiling. A few cases of spontaneous resolution with conservative management have been recorded in literature. We present the case of a 44-year old patient who reported with hemoptysis, weight loss, chronic cough and night sweats and was diagnosed of pulmonary tuberculosis on the basis of clinical assessment and chest X-ray. Subsequently, chest CT scan done showed a giant left RA, treated conservatively with antituberculous chemotherapy with complete radiological resolution of aneurysm after 18-month follow-up. We conclude that conservative management of RA is a good alternative in a low resource setting for hemodynamically stable patients.

Patient-derived tumor organoids with p53 mutations, and not wild-type p53, are sensitive to synergistic combination PARP inhibitor treatment

Poly (ADP-ribose) polymerase inhibitors (PARPi) are used for patients with BRCA1/2 mutations, but patients with other mutations may benefit from PARPi treatment. Another mutation that is present in more cancers than BRCA1/2 is mutation to the TP53 gene. In 2D breast cancer cell lines, mutant p53 (mtp53) proteins tightly associate with replicating DNA and Poly (ADP-ribose) polymerase (PARP) protein. Combination drug treatment with the alkylating agent temozolomide and the PARPi talazoparib kills mtp53 expressing 2D grown breast cancer cell lines. We evaluated the sensitivity to the combination of temozolomide plus PARPi talazoparib treatment to breast and lung cancer patient-derived tumor organoids (PDTOs). The combination of the two drugs was synergistic for a cytotoxic response in PDTOs with mtp53 but not for PDTOs with wtp53. The combination of talazoparib and temozolomide induced more DNA double-strand breaks in mtp53 expressing organoids than in wild-type p53 expressing organoids as shown by increased γ-H2AX protein expression. Moreover, breast cancer tissue microarrays (TMAs) showed a positive correlation between stable p53 and high PARP1 expression in sub-groups of breast cancers, which may indicate sub-classes of breast cancers sensitive to PARPi therapy. These results suggest that mtp53 could be a biomarker to predict response to the combination of PARPi talazoparib-temozolomide treatment.

African Ancestry-Associated Gene Expression Profiles in Triple-Negative Breast Cancer Underlie Altered Tumor Biology and Clinical Outcome in Women of African Descent

Women of sub-Saharan African descent have disproportionately higher incidence of triple-negative breast cancer (TNBC) and TNBC-specific mortality across all populations. Population studies show racial differences in TNBC biology, including higher prevalence of basal-like and quadruple-negative subtypes in African Americans (AA). However, previous investigations relied on self-reported race (SRR) of primarily U.S. populations. Due to heterogeneous genetic admixture and biological consequences of social determinants, the true association of African ancestry with TNBC biology is unclear. To address this, we conducted RNA sequencing on an international cohort of AAs, as well as West and East Africans with TNBC. Using comprehensive genetic ancestry estimation in this African-enriched cohort, we found expression of 613 genes associated with African ancestry and 2,000+ associated with regional African ancestry. A subset of African-associated genes also showed differences in normal breast tissue. Pathway enrichment and deconvolution of tumor cellular composition revealed that tumor-associated immunologic profiles are distinct in patients of African descent.

SIGNIFICANCE

Our comprehensive ancestry quantification process revealed that ancestry-associated gene expression profiles in TNBC include population-level distinctions in immunologic landscapes. These differences may explain some differences in race-group clinical outcomes. This study shows the first definitive link between African ancestry and the TNBC immunologic landscape, from an African-enriched international multiethnic cohort. See related commentary by Hamilton et al., p. 2496. This article is highlighted in the In This Issue feature, p. 2483.

Abstract PO-141: The role of African Duffy-null allele related inflammation on the tumor microenvironment

DARC/ACKR1 erythrocyte expression, also known as the “Duffy blood group,” is understood to sequester pro-inflammatory chemokines and thereby regulate circulating gradients that direct immune cell infiltration. We hypothesize that this function also determines immune cell landscapes in the tumor microenvironment. Due to evolutionary selection pressures of malaria, individuals with sub-Saharan African ancestry typically carry the Duffy-null allele (rs4849887) and this lack of DARC/ACKR1 expression gives immunity to malaria while also allowing chronically high inflammation levels. Over 68% of African Americans (AA) have been found to have the Duffy-null genotype, compared to a rare 1-3% in European American individuals and we have shown it increases predisposition for Triple-Negative Breast Cancer (TNBC). In addition, we are currently studying if Duffy-null may contribute to higher breast cancer mortality that disproportionately affects AA women. This may be in part due to the role that low-DARC/ACKR1 expression plays in chronic inflammation, altering levels of several chemokines that modulate the migration and differentiation of specific immune cells. This role will impact tumor immune cell infiltration as well as the immune cell population composition overall, depending upon levels of DARC/ACKR1. Using RNA sequencing, our initial results indicated that for breast cancer tumors with high DARC/ACKR1 expression there was a higher estimated presence of CD8+ T cells, CD4+ T cells, regulatory T cells, follicular helper T cells, and memory B cells. Whereas with low DARC/ACKR1 expression, there was markedly less expression of resting dendritic cells and memory B cells. Therefore, in order to ascertain the influence DARC status has on spatial deposition and functional status of immune cell landscapes across the tumor microenvironment, we performed imaging mass cytometry on primary TNBC tumors. The panel contained tumor, structural, and immune markers, and was used to characterize the spatial differences between samples that had been verified to be DARC-high or DARC-low through immunohistochemistry. Our imaging analyses indicated that high DARC/ACKR1 expression correlates with infiltration of monocytes, macrophages, and cytotoxic T cells into the solid tumor microenvironment. Conversely, tumors with low DARC/ACKR1 expression showed monocytes and cytotoxic T cells contained in the tumor stroma. Using single-cell phenotyping, we were also able to identify distinct cell populations between DARC-high and -low. The tSNE analysis and heatmaps performed using Histology Topography Cytometry Analysis Toolbox (histoCAT), allowed us to visualize the spatial distribution of these cell populations, indicating an immune-suppressive tumor microenvironment in DARC-low tumors. These differences may be implicated in the causality of tumor progression as well as how to approach treatment given the cell heterogeneity of TNBC. This work provides greater context on the role that Duffy-null plays in chronic inflammation on the tumor microenvironment.

Citation Format: Yanira Guerra, Rachel Martini, Jessica Bensenhaver, Yalei Chen, Joseph K. Oppong, Ishmael Kyei, Frances S. Aitpillah, Michael O. Adinku, Joseph K. Oppong, Ernest K. Adjei, Aisha Jibril, Baffour Awuah, Mahteme Bekele, Engida Abebe, Kwasi Ankomah, Ernest B. Osei-Bonsu, Kofi K. Gyan, Clayton Yates, Kim Blenman, Olivier Elemento, Lisa Newman, Melissa B. Davis. The role of African Duffy-null allele related inflammation on the tumor microenvironment [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-141.

A case of spontaneous intramural duodenal hematoma in a young African man: Imaging findings

Intramural duodenal hematoma has been reported as a rare condition first described by McLauchlan in 1838. It is now thought to be an uncommon condition due to the increase in the number of reported cases in the medical literature. It has been reported to usually occur secondary to blunt trauma mainly in young men and children, with 82% of the patients being younger than 30 years. Association between spontaneous intramural duodenal hematoma and coagulopathy, coagulating drugs, endoscopic procedures, acute pancreatitis, and pancreatic malignancy has been made. We present the case of a 35-year-old African male lumberjack with no known previous history of trauma, risk factors, or associated predisposing condition that presented to our facility with acute abdominal pain and vomiting and diagnosed as spontaneous intramural duodenal haematoma on CT scan and MR imaging with a complete resolution on conservative management.

Investigation of triple-negative breast cancer risk alleles in an International African-enriched cohort

Large-scale efforts to identify breast cancer (BC) risk alleles have historically taken place among women of European ancestry. Recently, there are new efforts to verify if these alleles increase risk in African American (AA) women as well. We investigated the effect of previously reported AA breast cancer and triple-negative breast cancer (TNBC) risk alleles in our African-enriched International Center for the Study of Breast Cancer Subtypes (ICSBCS) cohort. Using case-control, case-series and race-nested approaches, we report that the Duffy-null allele (rs2814778) is associated with TNBC risk (OR = 3.814, p = 0.001), specifically among AA individuals, after adjusting for self-indicated race and west African ancestry (OR = 3.368, p = 0.007). We have also validated the protective effect of the minor allele of the ANKLE1 missense variant rs2363956 among AA for TNBC (OR = 0.420, p = 0.005). Our results suggest that an ancestry-specific Duffy-null allele and differential prevalence of a polymorphic gene variant of ANKLE1 may play a role in TNBC breast cancer outcomes. These findings present opportunities for therapeutic potential and future studies to address race-specific differences in TNBC risk and disease outcome.

Use of Magnetic Resonance Imaging (MRI) in the Management of Diagnostic Uncertainty in Low-Resource Settings: A Case Report of Cesarean Ectopic Pregnancy in a Tertiary Hospital in Ghana

Patient: Female, 35-year-old

Final Diagnosis: Cesarean section ectopic pregnancy

Symptoms: Amenorrhea

Medication:—

Clinical Procedure: Exploratory laparotomy • MRI • ultrasonography

Specialty: Obstetrics and Gynecology