Outcomes of Wilms tumor treatment in western Kenya

Effectiveness of a Wilms tumour treatment guideline adapted to local circumstances in sub-Saharan Africa: A report from Wilms Africa Phase II-CANCaRe Africa

BACKGROUND

Wilms tumour (WT) is one of the cancer types targeted by the Global Initiative for Childhood Cancer (GICC). The objective of this study was to describe the outcomes of Wilms Africa Phase II in sub-Saharan Africa.

METHODS

Wilms Africa Phase II used a comprehensive WT treatment protocol in a multi-centre, prospective study conducted in eight hospitals in Ethiopia (2), Ghana (2), Malawi, Cameroon, Zimbabwe and Uganda. Eligibility criteria were: age younger than 16 years, unilateral WT, diagnosed between 1 January 2021 and 31 December 2022.

RESULTS

We included 230 WT patients, median age 3 years, 53% male. Median maximum tumour diameter at diagnosis was 13.6 cm and 33% of patients had metastatic disease. Nephrectomy was performed in 71% of patients, of whom 21% had a tumour rupture. Two-year event-free survival (EFS) was 41.3% ± 3.9% after a median follow-up of 17 months (range: 1-33 months), with treatment abandonment considered an event. Treatment abandonment occurred in 26% and death during treatment in 14%. Disease relapse occurred in 10%. Two-year EFS of the 26 patients who received radiotherapy was 64.5% ± 9.7% with no reported disease relapse.

CONCLUSION

Patients continue to present late with advanced WT in sub-Saharan Africa, and their survival is below the 60% GICC target. Prevention of treatment abandonment and treatment-related mortality remain important. Earlier diagnosis and access to radiotherapy are expected to decrease disease-related mortality.

Effect of radiation after surgery on the prognosis of children with Wilms tumor

BACKGROUND

To explore the association between radiation after surgery and the 5-year overall survival (OS) and 5-year cancer-specific survival (CSS) in patients with Wilms tumor.

METHODS

In this cohort study, 1564 participants were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The univariate and multivariable COX proportional risk model as well as competitive risk model were used to explore the covariates associated with 5-year OS and 5-year CSS of patients with Wilms tumor and the correlation between radiation after surgery and 5-year OS or 5-year CSS of patients with Wilms tumor, respectively. The Kaplan-Meier curves of participants were plotted.

RESULTS

The median follow-up was 126.00 (84.00, 178.00) months. Patients receiving surgery had higher 5-year survival probability than those not receiving surgery, while participants receiving radiation after surgery showed poor 5-year survival than those not. After adjusting for covariates including age and SEER stage, increased risk of 5-year overall mortality in patients with Wilms tumor [hazard ratio (HR) = 1.62, 95% confidence interval (CI): 1.10-2.41). After the adjustment for confounding factors including age, SEER stage and ethnicity, increased risk of 5-year cancer-specific mortality of patients with Wilms tumor was observed in those receiving radiation after surgery (HR = 1.77, 95%CI: 1.13-2.79).

CONCLUSION

Radiation after surgery was associated with poor prognosis of patients with Wilms tumor, which indicated that the clinicians should assess whether the patient was suitable for using radiation after surgery.

Vincristine exposure in Kenyan children with cancer: CHAPATI feasibility study

The low incidence of vincristine-induced peripheral neuropathy (VIPN) in Kenyan children may result from low vincristine exposure. We studied vincristine exposure in Kenyan children and dose-escalated in case of low vincristine exposure (NCT05844670). Average vincristine exposure was high. Individual vincristine exposure was assessed with a previously developed nomogram. A 20% dose increase was recommended for participants with low exposure and no VIPN, hyperbilirubinemia, or malnutrition. None of the 15 participants developed VIPN. Low vincristine exposure was seen in one participant: a dose increase was implemented without side effects. In conclusion, the participants did not develop VIPN despite having high vincristine exposure.

Prevention of treatment abandonment remains an important challenge to increase survival of Wilms tumor in sub-Saharan Africa: A report from Wilms Africa-CANCaRe Africa

BACKGROUND

The Wilms Africa studies implemented an adapted Wilm's tumor (WT) treatment protocol in sub-Saharan Africa in two phases. Phase I began with four sites and provided out-of-pocket costs. Phase II expanded the number of sites, but lost funding provision. Objective is to describe the outcomes of Phase II and compare with Phase I.

METHODS

Wilms Africa Phase I (n = 4 sites; 2014-2018) and Phase II (n = 8 sites; 2021-2022) used adapted treatment protocols. Funding for families' out-of-pocket costs was provided during Phase I but not Phase II. Eligibility criteria were age less than 16 years and newly diagnosed unilateral WT. We documented patients' outcome at the end of planned first-line treatment categorized as treatment abandonment, death during treatment, and disease-related events (death before treatment, persistent disease, relapse, or progressive disease). Sensitivity analysis compared outcomes in the same four sites.

RESULTS

We included 431 patients in Phase I (n = 201) and Phase II (n = 230). The proportion alive without evidence of disease decreased from 69% in Phase I to 54% in Phase II at all sites (p = .002) and 58% at the original four sites (p = .04). Treatment abandonment increased overall from 12% to 26% (p < .001), and was 20% (p = .04) at the original four sites. Disease-related events (5% vs. 6% vs. 6%) and deaths during treatment (14% vs. 14% vs. 17%) were similar.

CONCLUSION

Provision of out-of-pocket costs was important to improve patient outcomes at the end of planned first-line treatment in WT. Prevention of treatment abandonment remains an important challenge.

A caregivers' perspective on social reintegration and stigma of childhood cancer survivors in Kenya

OBJECTIVES

Childhood cancer survivors' social reintegration may be hampered in low and middle-income countries. The nature and extent of social challenges and prejudices that survivors encounter in such settings are largely unknown. This study explores caregivers' perspectives on social reintegration and stigmatization of Kenyan childhood cancer survivors.

METHODS

Caretakers of childhood cancer survivors (<18 years) were interviewed using mixed-methods questionnaires during home or clinic visits between 2021 and 2022. Stigma was assessed with an adjusted Social Impact Scale and risk factors were investigated.

RESULTS

Caretakers of 54 survivors (median age 11 years) were interviewed. Families' income (93%) decreased since start of treatment. Caretakers (44%) often lost their jobs. Financial struggles (88%) were a burden that provoked conflicts within communities (31%). School fees for siblings became unaffordable (52%). Families received negative responses (26%) and were left or avoided (13%) by community members after cancer disclosure. Survivors and families were discriminated against because the child was perceived fragile, and cancer was considered fatal, contagious, or witchcraft. Survivors repeated school levels (58%) and were excluded from school activities (19%) or bullied (13%). Performance limitations of daily activities (p = 0.019), male sex (p = 0.032), solid tumors (p = 0.056) and a short time since treatment completion (p = 0.047) were associated with increased stigma. Caretakers recommended educational programs in schools and communities to raise awareness about cancer treatment and curability.

CONCLUSIONS

Childhood cancer survivors and their families experienced difficulties with re-entry and stigmatization in society. Increasing cancer and survivorship awareness in schools and communities should facilitate social reintegration and prevent stigmatization.

Outcomes of Wilms tumor therapy in Lilongwe, Malawi, 2016-2021: Successes and ongoing research priorities

INTRODUCTION

Wilms tumor therapy in low- and middle-income countries (LMICs) relies on treatment protocols adapted to resource limitations, but these protocols have rarely been evaluated in real-world settings. Such evaluations are necessary to identify high-impact research priorities for clinical and implementation trials in LMICs. The purpose of this study was to identify highest priority targets for future clinical and implementation trials in sub-Saharan Africa by assessing outcomes of a resource-adapted treatment protocol in Malawi.

METHODS

We conducted a retrospective cohort study of children treated for Wilms tumor with an adapted SIOP-backbone protocol in Lilongwe, Malawi between 2016 and 2021. Survival analysis assessed variables associated with poor outcome with high potential for future research and intervention.

RESULTS

We identified 136 patients, most commonly with stage III (n = 35; 25.7%) or IV disease (n = 35; 25.7%). Two-year event-free survival (EFS) was 54% for stage I/II, 51% for stage III, and 13% for stage IV. A single patient with stage V disease survived to 1 year. Treatment abandonment occurred in 36 (26.5%) patients. Radiotherapy was indicated for 55 (40.4%), among whom three received it. Of these 55 patients, 2-year EFS was 31%. Of 14 patients with persistent metastatic pulmonary disease at the time of nephrectomy, none survived to 2 years. Notable variables independently associated with survival were severe acute malnutrition (hazard ratio [HR]: 1.9), increasing tumor stage (HR: 1.5), and vena cava involvement (HR: 3.1).

CONCLUSION

High-impact targets for clinical and implementation trials in low-resource settings include treatment abandonment, late presentation, and approaches optimized for healthcare systems with persistently unavailable radiotherapy.

Development of a Therapeutic Drug Monitoring Strategy for the Optimization of Vincristine Treatment in Pediatric Oncology Populations in Africa

BACKGROUND

Recent studies have reported ethnic differences in vincristine exposure and outcomes such as toxicity. This resulted in the hypothesis of subtherapeutic dosing in African children. To optimize individual treatment, a strategy to identify subtherapeutic exposure using therapeutic drug monitoring is essential. The aim of the current study was to develop a strategy for therapeutic drug monitoring of vincristine in African children to meet the following criteria: (1) identify patients with low vincristine exposure with sufficient sensitivity (>70%), (2) determine vincristine exposure with a limited sampling strategy design of 3 samples, and (3) allow all samples to be collected within 4 hours after administration.

METHODS

An in silico simulation study was performed using a previously described population pharmacokinetic model and real-life demographic dataset of Kenyan and Malawian pediatric oncology patients. Two different therapeutic drug monitoring strategies were evaluated: (1) Bayesian approach and (2) pharmacometric nomogram. The sampling design was optimized using the constraints described above. Sensitivity analysis was performed to investigate the influence of missing samples, erroneous sampling times, and different boundaries on the nomogram weight bands.

RESULTS

With the Bayesian approach, 43.3% of the estimated individual exposure values had a prediction error of ≥20% owing to extremely high shrinkage. The Bayesian approach did not improve with alternative sampling designs within sampling constraints. However, the pharmacometric nomogram could identify patients with low vincristine exposure with a sensitivity, specificity, and accuracy of 75.1%, 76.4%, and 75.9%, respectively. The pharmacometric nomogram performed similarly for different weight bands.

CONCLUSIONS

The pharmacometric nomogram was able to identify patients with low vincristine exposure with high sensitivity, with 3 blood samples collected at 1, 1.5, and 4 hours after administration. Missing samples should be avoided, and the 3 scheduled samples should be collected within 15, 5, and 15 minutes of 1, 1.5, and 4 hours after administration, respectively.

One year overall survival of wilms tumor cases and its predictors, among children diagnosed at a teaching hospital in South Western Uganda: a retrospective cohort study

BACKGROUND

Wilms tumor (WT) is the second most common solid tumor in Africa with both low overall survival (OS) and event-free survival (EFS) rates. However, no known factors are predicting this poor overall survival.

OBJECTIVE

The study was to determine the one-year overall survival of WT cases and its predictors among children diagnosed in the pediatric oncology and surgical units of Mbarara regional referral hospital (MRRH), western Uganda.

METHODOLOGY

Children's treatment charts and files diagnosed and managed for WT were retrospectively followed up for the period between January 2017 to January 2021. Charts of children with histologically confirmed diagnoses were reviewed for demographics, clinical and histological characteristics, as well as treatment modalities.

RESULTS

One-year overall survival was found to be 59.3% (95% CI: 40.7-73.3), with tumor size greater than 15 cm (p 0.021) and unfavorable WT type (p 0.012) being the predominant predictors.

CONCLUSION

Overall survival (OS) of WT at MRRH was found to be 59.3%, and predictive factors noted were unfavorable histology and tumor size greater than 115 cm.