The spectrum of TP53 mutations in Rwandan patients with gastric cancer.

BACKGROUND: Gastric cancer is the sixth most frequently diagnosed cancer and third in causing cancer-related death globally. The most frequently mutated gene in human cancers is TP53, which plays a pivotal role in cancer initiation and progression. In Africa, particularly in Rwanda, data on TP53 mutations are lacking. Therefore, this study intended to obtain TP53 mutation status in Rwandan patients with gastric cancer. RESULTS: Formalin-fixed paraffin-embedded tissue blocks of 95 Rwandan patients with histopathologically proven gastric carcinoma were obtained from the University Teaching Hospital of Kigali. After DNA extraction, all coding regions of the TP53 gene and the exon-intron boundary region of TP53 were sequenced using the Sanger sequencing. Mutated TP53 were observed in 24 (25.3%) of the 95 cases, and a total of 29 mutations were identified. These TP53 mutations were distributed between exon 4 and 8 and most of them were missense mutations (19/29; 65.5%). Immunohistochemical analysis for TP53 revealed that most of the TP53 missense mutations were associated with TP53 protein accumulation. Among the 29 mutations, one was novel (c.459_477delCGGCACCCGCGTCCGCGCC). This 19-bp deletion mutation in exon 5 caused the production of truncated TP53 protein (p.G154Wfs*10). Regarding the spectrum of TP53 mutations, G:C > A:T at CpG sites was the most prevalent (10/29; 34.5%) and G:C > T:A was the second most prevalent (7/29; 24.1%). Interestingly, when the mutation spectrum of TP53 was compared to three previous TP53 mutational studies on non-Rwandan patients with gastric cancer, G:C > T:A mutations were significantly more frequent in this study than in our previous study (p = 0.013), the TCGA database (p = 0.017), and a previous study on patients from Hong Kong (p = 0.006). Even after correcting for false discovery, statistical significance was observed. CONCLUSIONS: Our results suggested that TP53 G:C > T:A transversion mutation in Rwandan patients with gastric cancer is more frequent than in non-Rwandan patients with gastric cancer, indicating at an alternative etiological and carcinogenic progression of gastric cancer in Rwanda.

Clinicopathological Characteristics and Mutational Landscape of APC, HOXB13, and KRAS among Rwandan Patients with Colorectal Cancer.

Cancer research in Rwanda is estimated to be less than 1% of the total African cancer research output with limited research on colorectal cancer (CRC). Rwandan patients with CRC are young, with more females being affected than males, and most patients present with advanced disease. Considering the paucity of oncological genetic studies in this population, we investigated the mutational status of CRC tissues, focusing on the Adenomatous polyposis coli (APC), Kirsten rat sarcoma (KRAS), and Homeobox B13 (HOXB13) genes. Our aim was to determine whether there were any differences between Rwandan patients and other populations. To do so, we performed Sanger sequencing of the DNA extracted from formalin-fixed paraffin-embedded adenocarcinoma samples from 54 patients (mean age: 60 years). Most tumors were located in the rectum (83.3%), and 92.6% of the tumors were low-grade. Most patients (70.4%) reported never smoking, and 61.1% of patients had consumed alcohol. We identified 27 variants of APC, including 3 novel mutations (c.4310_4319delAAACACCTCC, c.4463_4470delinsA, and c.4506_4507delT). All three novel mutations are classified as deleterious by MutationTaster2021. We found four synonymous variants (c.330C>A, c.366C>T, c.513T>C, and c.735G>A) of HOXB13. For KRAS, we found six variants (Asp173, Gly13Asp, Gly12Ala, Gly12Asp, Gly12Val, and Gln61His), the last four of which are pathogenic. In conclusion, here we contribute new genetic variation data and provide clinicopathological information pertinent to CRC in Rwanda.

Pathological Characteristics, Prognostic Determinants and the Outcome of Patients Diagnosed with Colorectal Adenocarcinoma at the University Teaching Hospital of Kigali.

Worldwide, colorectal cancer (CRC) is the second most diagnosed cancer in female and the third in men, arising from the epithelium of the colorectum. It is known that colorectal cancer is common in developed countries than in developing countries which may be due to inaccurate data on the existence of the disease in that region combined with embracing western lifestyle expressed by the current trend of changes in cultural, social, and lifestyle practices playing a major part in the etiology of CRC. The aim of this study was to document epidemiological, pathological characteristics, and prognostics determinants of patients diagnosed with CRC in Rwanda. The data from patients' files and reviewed glass slides for 101 cases all from Kigali University Teaching Hospital (CHUK) were statistically analyzed and patient characteristics were described as mean and frequency accordingly. Comparisons were performed using chi square tests, Fisher's exact test and odds ratio with 95% confidence interval (CI). Survival curves were plotted using the Kaplan-Meier method, and log-rank test was used to assess the statistical differences in the observed survival curves by each categorical variable. A P value < 0.05 was considered statistically significant. Statistical analyses were performed using Statistical Product and Service Solutions (SPSS), GraphPad Prism, and MedCalc, accordingly. Mean age of the participants was 54.26 years, the main symptom was rectal bleeding (46.5%), rectal adenocarcinoma NOS represented 40.6%, conventional adenocarcinoma was 60.4%, most tumors were of Grade II (54.5%), most common stage was pT3N0 (20.8%), resection margins were free at 71.3%, lympho-vascular invasion was 49.5% of cases, a high immune response was in 71.3% of cases and of 101cases, and 55.4% were still alive at the end of the data collection, with 29.3% of patients have overall survival of 5 years. Prognostic determinants also affect the outcome in this study and overall survival period was 3 years for CRC diagnosed in Rwanda.

Knowledge, Barriers and Motivators to Cervical Cancer Screening in Rwanda: A Qualitative Study.

Background: Cervical cancer is a global public health problem with marked geographical disparity. High morbidity and mortality rates in developing countries are associated with low screening rates. In 2020, in Rwanda, 3.7 million women aged 15-59 years were at risk of developing cervical cancer, the most commonly diagnosed female cancer in Rwanda. Despite Rwanda being the first African country to vaccinate against human papilloma virus with a three-dose regimen vaccination coverage of nearly 93% in the target population of girls aged <15 years, and having established cervical cancer screening program, recent studies have found low screening rates. Our study sought to determine knowledge, motivators and barriers of cervical cancer screening. Methods: We conducted a qualitative descriptive study; using focus group interview in an urban health facility (Muhima district hospital) and a rural health center (Nyagasambu health center) offering cervical screening services in Rwanda. Participants were women seeking these services and other women attending the health facility for any reason, and female staff working in these facilities. Interviews were recorded and transcribed, and data were analyzed using content analysis. Results: Thirty women participated in focus group interview, with an average age of 39 years. Many of women showed knowledge about cervical cancer existence and prevention methods. However, fear for pain, lack of knowledge about screening, how and where the screening was done, and concern for privacy were recurring subthemes. Some participants also mentioned lack of health insurance as a barrier for cervical cancer screening. Conclusion: Barriers to uptake cervical cancer screening services in Rwanda are related to poor information about cervical cancer and the importance of screening as well as non-adherence to medical insurance. Population sensitization through campaign and community outreach activities could have a positive impact on increasing the usage of cervical cancer screening in Rwanda.

Experience and Perception of Patients and Healthcare Professionals on Acute Leukemia in Rwanda: A Qualitative Study.

Purpose: To explore challenges associated with the timely diagnosis, therapy, and prognosis of acute leukemia in Rwanda. Methods: This is a qualitative study using a phenomenological approach that involved patients, patients' guardians, and healthcare professionals such as physicians from district hospitals and specialists from referral hospitals, as well as healthcare administrators. The primary data were collected from district and referral hospitals and central healthcare administration in Rwanda. The data were collected between July and October 2019. In-depth interviews were conducted, and thematic analysis was employed to interpret the results. Results: We identified barriers to seeking healthcare such as (i) insufficient knowledge within the population may lead patients and their guardians to consult traditional healers before seeking qualified medical care, and (ii) financial constraints that preclude payment of healthcare fees or other out-of-pocket cost related to diagnosis and treatment. We also observed that the referral system is tedious and primary healthcare facilities lack the competence and resources for the necessary diagnostic practices. Both may further delay diagnosis and therapy. Accordingly, healthcare professionals at the referral hospitals stated that most patients were seen at an advanced stage of the disease. For the treatment of acute lymphoblastic leukemia (ALL), only chemotherapy is utilized in Rwanda, while bone marrow (BM) transplantation is not available. Palliation is the only available treatment for the vast majority of Rwandan acute myeloid leukemia (AML) patients. Conclusion: ALL and AML are likely under-reported in Rwanda and diagnosis may be delayed, which may be explained by patient-related factors (lack of knowledge, financial constraints), a tedious referral system, and suboptimal diagnostic resources.

Premenopausal Breast Cancer Risk Factors and Associations with Molecular Subtypes: A Case-Control Study.

BACKGROUND: Breast cancer (BC) is the most prevalent cancer in women and the leading cause of women's cancer-related deaths and morbidity worldwide. In Rwanda, BC incidence is increasing with an unacceptably high mortality rate in premenopausal women. OBJECTIVES: The purpose was to identify modifiable BC risk factors and assess associations between common breast cancer risks factors and molecular subtypes in premenopausal women in Rwanda. METHODS: This was a case-control study. Premenopausal women with histological confirmation of BC and frequency-matched for age controls were recruited. A preestablished questionnaire was administered to both cases and controls for sociodemographics, BC probable risk factors, and clinical and pathological characteristics. BC was classified into luminal A, luminal B, HER2-type, basal-like (triple negative), and unclassified molecular subtypes by immunohistochemistry (IHC). Odds ratio (OR) and 95% confidence interval (CI) were estimated using multivariate logistic regression analysis. RESULTS: 340 participants were recruited into the study (170 cases vs. 170 controls). The median age was 39 years. The majority of cases presented at advanced stages of the disease (51.2% in stages III and IV) and had invasive ductal carcinoma (98.2%). 60.6% had subtypes of poor prognosis (HER2 enriched 14.7%, triple negative 12.9%, and unclassified 32.9%). Alcohol intake (AOR = 3.73, 95%CI 2.19 - 6.32, p < 0.001), obesity/overweight in adolescence or early adulthood (AOR = 10.86, 95%CI 4.82 - 24.4, p < 0.001), history of primary infertility (AOR = 33.8, 95%CI 3.5 - 321.5, p = 0.002), nulliparity (AOR = 3.75, 95%CI 1.61 - 8.75, p = 0.002), and a history of benign breast disease (AOR = 6.06, 95%CI 1.19 - 30.73, p = 0.03) were associated with the occurrence of premenopausal breast cancer. There was no significant difference between risk factor stratification per molecular subtype. CONCLUSION: Several reproductive, environmental, and lifestyle risk factors have been identified to be associated with premenopausal BC. Among them, alcohol intake and obesity/overweight during adolescence/early adulthood can be modified. Interventions targeting alcohol consumption and obesity/overweight in adolescents and young adults may decrease the incidence of premenopausal breast cancer.

Use of the Xpert Breast Cancer STRAT4 for Biomarker Evaluation in Tissue Processed in a Developing Country.

OBJECTIVES: Breast cancer immunohistochemistry (IHC) biomarker testing is limited in low-resource settings, and an alternative solution is needed. A point-of-care mRNA STRAT4 breast cancer assay for ESR1, PGR, ERBB2, and MKi67, for use on the GeneXpert platform, has been recently validated on tissues from internationally accredited laboratories, showing excellent concordance with IHC. METHODS: We evaluated STRAT4/IHC ESR1/estrogen receptor (ER), ERBB2/human epidermal growth factor receptor 2 (HER2) concordance rates of 150 breast cancer tissues processed in Rwanda, with undocumented cold ischemic and fixation time. RESULTS: Assay fail/indeterminate rate was 2.6% for ESR1 and ERBB2. STRAT4 agreement with ER IHC was 92.5% to 93.3% and 97.8% for HER2, for standard (1x) and concentrated (4x) reagent-conserving protocols, respectively. Eleven of 12 discordant ER/ESR1 cases were ESR1- negative/IHC-positive. These had low expression of ER by IHC in mostly very small tumor areas tested (7/12; <25 mm2). In two of three discordant HER2 cases, the STRAT4-ERBB2 result correlated with the subsequent fluorescence in situ hybridization (FISH) result. STRAT4-ERBB2 results in 9 of 10 HER2-IHC equivocal cases were concordant with FISH. CONCLUSIONS: The STRAT4 assay is an alternative for providing quality-controlled breast cancer biomarker data in laboratories unable to provide quality and/or cost-efficient IHC services.

Occurrence of Helicobacter Pylori in Specimens of Chronic Gastritis and Gastric Adenocarcinoma Patients: A Retrospective Study at University Teaching Hospital, Kigali, Rwanda.

INTRODUCTION: Helicobacter pylori (H. pylori) infection is the major cause of gastroduodenal diseases in populations of different ages. We conducted aretrospective studyusing archived tissue samples to determine the prevalence of H. pylori infection among patients diagnosed with gastritis and gastric adenocarcinoma by histopathology cases in one hospital in Rwanda. MATERIALS AND METHODS: Cases of chronic gastritis and gastric adenocarcinoma histologically diagnosed in a tertiary hospital in Rwanda over the period of 2016-2018 were studied for the presence of H. pylori using immunohistochemistry. Diagnosis of positive cases considered immunoreactivity as well as bacterial morphology, including spiral, rod-shaped, angulated and coccoid forms. RESULTS: Three hundred and seven cases were included in this study; chronic gastritis and gastric adenocarcinoma representing 39% and 61%, respectively. The overall frequency of H. pylori infection was 77.5% (80% among chronic gastritis cases versus 76% among gastric adenocarcinoma cases). Prevalence of H. pylori infection in chronic gastritis and adenocarcinoma did not significantly associate with age and sex. CONCLUSION: The prevalence of H. pylori was high among chronic gastritis and gastric adenocarcinoma cases in Rwanda. Pathologists should investigate the presence of H. pylori in gastric biopsies. Our data shows immunohistochemistry method is feasible and adequate to facilitate detection of H. pylori, which may guide timely treatment.

Pathology Characteristics of Lymphomas in Rwanda: A Retrospective Study.

BACKGROUND: Lymphomas have been a global challenge for many decades and despite measures for prevention and management, the incidence continues to increase. There are two main categories, which are Non-Hodgkin's Lymphomas and Hodgkin's Lymphomas and most common etiologies are environmental, genetic alteration, radiation and some viruses. OBJECTIVE: To describe pathology characteristics of lymphomas in Rwanda based on Hematoxylin and Eosin stained glass slides and immuno histo chemistry, and classify them according to clinical aggressiveness. PATIENTS AND METHODS: We conducted a retrospective observational and descriptive study from January 2013 to December 2019. Lymphoma cases were retrieved together with relevant clinical and pathological information, and reviewed by independent pathologists. Histological diagnosis was classified according to the 2008 World Health Organization system in order to assign clinical aggressiveness of the lymphoma. RESULTS: Three hundred and six lymphoma cases were enrolled. Males contributed to 57% of all reviewed case, and slightly over 50% were young aged ≤35 years. Approximately 191 (62%) of cases were nodal lymphomas. Approximately one fifth (18%) of lymphoma cases were HIV positive. Most 213(70%) cases were Non-Hodgkin's Lymphomas of aggressive forms 164(77%). Among 164 cases of aggressive Non-Hodgkin's Lymphomas, diffuse large B cell lymphoma was the leading subtype 91(55.5%), followed by solid lymphoblastic lymphoma 32(19.5%) and Burkitt lymphoma 17(10.4%). Among all Hodgkin lymphoma cases, 90(97%) were classical Hodgkin lymphomaof nodular sclerosis subtype. Hodgkin lymphoma patients were younger compared to Non-Hodgkin's Lymphomas patients (mean age of 24.78±16.3 years versus 38.6±22. 5years, p=.000). CONCLUSION: Substantial proportion of Lymphomapatients in Rwanda were also HIV positive. Interestingly, Non-Hodgkin's Lymphomas in Rwanda are predominated by the most aggressive forms, and these mostly affect a younger population. Optimal characterisation of such cases, using advanced methods, is recommended.

Metaplastic Carcinoma of the Breast with Squamous Differentiation: A Case Report from the University Teaching Hospital of Kigali (CHUK), Rwanda.

Metaplastic breast carcinoma is a rare and aggressive condition, accounting less than 1% of breast malignancies. It presents with large mass and frequently with distant metastasis at time of diagnosis. Morphologically, it is characterized by the differentiation of neoplastic epithelium into epithelial or mesenchymal-looking elements like squamous cells, spindle cells, cartilage, or bone and has poor prognosis with its triple negative status.

State of Cancer Control in Rwanda: Past, Present, and Future Opportunities.

Rwanda is a densely populated low-income country in East Africa. Previously considered a failed state after the genocide against the Tutsi in 1994, Rwanda has seen remarkable growth over the past 2 decades. Health care in Rwanda is predominantly delivered through public hospitals and is emerging in the private sector. More than 80% of patients are covered by community-based health insurance (Mutuelle de Santé). The cancer unit at the Rwanda Biomedical Center (a branch of the Ministry of Health) is responsible for setting and implementing cancer care policy. Rwanda has made progress with human papillomavirus (HPV) and hepatitis B vaccination. Recently, the cancer unit at the Rwanda Biomedical Center launched the country's 5-year National Cancer Control Plan. Over the past decade, patients with cancer have been able to receive chemotherapy at Butaro Cancer Center, and recently, the Rwanda Cancer Center was launched with 2 linear accelerator radiotherapy machines, which greatly reduced the number of referrals for treatment abroad. Palliative care services are increasing in Rwanda. A cancer registry has now been strengthened, and more clinicians are becoming active in cancer research. Despite these advances, there is still substantial work to be done and there are many outstanding challenges, including the need to build capacity in cancer awareness among the general population (and shift toward earlier diagnosis), cancer care workforce (more in-country training programs are needed), and research.

Human papillomavirus genotypes in cervical and other HPV-related anogenital cancer in Rwanda, according to HIV status.

The study aim was to describe human papillomavirus (HPV)-attributable cancer burden in Rwanda, according to anogenital cancer site, HPV type, age and HIV status. Tissue specimens of cervical, vulvar, vaginal, penile and anal cancer diagnosed in 2012-2018 were retrieved from three cancer referral hospitals and tested for high-risk (HR) HPV DNA. Cervical cancer represented the majority of cases (598 of 738), of which 96.0% were HR-HPV positive. HPV-attributable fractions in other cancer sites varied from 53.1% in 81 penile, through 76.7% in 30 vulvar, 83.3% in 24 vaginal, up to 100% in 5 anal cases. HPV16 was the predominant HR-HPV type in cervical cancer (55.0%), followed by HPV18 (16.6%) and HPV45 (13.4%). HPV16 also predominated in other cancer sites (60-80% of HR-HPV-attributable fraction). For cervical cancer, type-specific prevalence varied significantly by histology (higher alpha-9 type prevalence in 509 squamous cell carcinoma vs. higher alpha-7 type prevalence in 80 adenocarcinoma), but not between 501 HIV-negative and 97 HIV-positive cases. With respect to types targeted, and/or cross-protected, by HPV vaccines, HPV16/18 accounted for 73%, HPV31/33/45/52/58 for an additional 22% and other HR-HPV types for 5%, of HPV-attributable cancer burden, with no significant difference by HIV status nor age. These data highlight the preventive potential of the ongoing national HPV vaccination program in Rwanda, and in sub-Saharan Africa as a whole. Importantly for this region, the impact of HIV on the distribution of causal HPV types was relatively minor, confirming type-specific relevance of HPV vaccines, irrespective of HIV status.

Clinicopathological Findings of Retinoblastoma: A 10-Year Experience from a Tertiary Hospital in Kampala, Uganda.

BACKGROUND: Retinoblastoma (RB) is one of the most common cancers occurring in young children in sub-Saharan Africa. The incidence rate reported in the literature is 9,000 new cases per year, which corresponds to 1 in 15,000 births. This study aimed at analyzing the clinicopathological findings in children with RB in Uganda. PURPOSE: The purpose of this study was to describe and analyze the clinicopathological findings in the patients with RB. DESIGN: This was a cross-sectional analytical study involving 234 eyeball surgical specimens from 214 patients with RB diagnosed between January 2006 and December 2015. RESULTS: The mean age of the patients was 27.8 months (SD = 21.413, range: 1-132 months). More than half of the cases, 50.9%, presented with leucokoria. Invasion of choroid, sclera, anterior chamber, and optic nerve was found in 26.5% (n = 58), 51.2% (n = 88), 26.2% (n = 45), and 29.2% (n = 49), respectively. Twenty-six percent (n = 56) of the cases with intraocular tumour were at stage I and all patients with metastasis 4.7% (n = 11) had stage IV. The correlation between postlaminar optic nerve invasion and massive choroidal invasion was statistically significant (P = 0.002). Also, there was a statistical significance difference between metastasis and postlaminar invasion (P = 0.004). CONCLUSION: The majority of children with RB in Uganda present clinically with leucokoria, and their parents or guardians seek medical intervention at a later stage. Moreover, there was a noticeably significant lag period for the patients to begin treatment after the diagnosis was done.

Evaluation of human-papillomavirus testing and visual inspection for cervical cancer screening in Rwanda.

BACKGROUND: A pilot screening campaign in Rwanda, based on careHPV-testing followed by visual inspection with acetic acid triage (careHPV+VIA triage), was evaluated against other WHO-recommended screening options, namely HPV screen-and-treat and VIA screen-and-treat. METHODS: 764 women aged 30-69 underwent at visit 1: i) VIA, and cervical cell collection for ii) careHPV in Rwanda, and iii) liquid-based cytology and GP5+/6+ HR-HPV PCR in The Netherlands. All 177 women positive by VIA, careHPV and/or PCR were recalled, of whom 84% attended. At visit 2, VIA was again used to triage screen-positive women for treatment and to obtain biopsies from all women either from visible lesions or at 12 o'clock of the squamocolumnar junction. Cross-sectional screening indices were estimated primarily against histological high-grade squamous intraepithelial lesions or worse (hHSIL+), after imputation of missing histology data, based on 1-visit or 2-visit approaches. RESULTS: In a 1-visit screen-and-treat approach, VIA had sensitivity and specificity of 41% and 96%, respectively, versus 71% and 88% for careHPV, and 88% and 86% for PCR. In a 2-visit approach (in which hHSIL+ imputed among women without visit 2 were considered untreated) careHPV sensitivity dropped to 59% due to loss of 13% of hHSIL+. For careHPV+VIA triage, sensitivity dropped further to 35%, as another 24% of hHSIL+ were triaged to no treatment. CONCLUSIONS: CareHPV was not as sensitive as gold-standard PCR, but detected considerably more hHSIL+ than VIA. However, due to careHPV-positive hHSIL+ women being lost to follow-up and/or triaged to no treatment, 2-visit careHPV+VIA triage did not perform better than VIA screen-and-treat.

Coats' disease in Tanzania: first case report and literature review.

BACKGROUND: Coats' disease is an exudative retinal detachment with vascular telangiectasis occurring mostly in male children, the age group most affected by retinoblastoma. OBJECTIVES: Compare the differential diagnoses of Coats' disease Establish recommendation to early disease detection. MATERIALS AND METHODS: A 3-year-old female child was referred to Muhimbili National Hospital (MNH), Tanzania, in September 2011. She had presented at the peripheral hospital with gradual onset of left eye leukocoria for 1 year and pain for 2 months. B-scan showed a mass in the left eye. A clinical diagnosis of retinoblastoma was made. Left eye enucleation was performed; the patient was referred to MNH, with the enucleated specimen. RESULTS: Brain and orbits scan revealed no residual tumour. The globe measured 2 x 1.8 cm, the optic nerve stump measured 3 mm. A whitish mass filled the vitreous, with complete retinal detachment. Microscopy showed retinal gliosis, detachment with sub retinal PAS positive exudates, vacuolation and cholesterol clefts. Foreign body giant cells were present; telangiectatic thin-walled blood vessels were identified. Clinico-pathological findings were of stage 4 Coats' disease. CONCLUSION: Coats' disease is an important differential diagnosis of retinoblastoma. Delay to detect Coats' disease leads to vision loss which necessitates eye enucleation as was in this child.

Pericardial cyst with right ventricular compression.

Pericardial cysts are infrequent and benign mediastinal lesions. While most pericardial cysts are asymptomatic, some patients may present with compression symptoms. We present the case of a 22-year-old man who presented with a right pericardial cyst that caused compression of the right ventricle.