Trends in the Use of Hypofractionation in Treatment of Breast Cancer in Botswana

PURPOSE/OBJECTIVE(S)

Clinical trials have shown that moderate hypofractionation (HF) is clinically effective as adjuvant treatment to breast conserving surgery or following mastectomy with advanced disease. ASTRO issued updated guidelines in 2018, expanding the population eligible to receive HF to all patients, regardless of age and tumor stage. Use of HF can promote efficient resource utilization for over-burdened health care systems; however, global adoption of HF has been previously only reported via ESTRO survey of individual physicians. These data note that HF following lumpectomy is 40% in Africa vs. >90% in North America, with limited data on the uptake of HF within individual African countries. In this study, we characterize temporal trends and clinical, socio-demographic factors associated with the use of HF in breast cancer in Botswana.

MATERIALS/METHODS

We retrospectively analyzed a cohort of breast cancer patients receiving curative intent radiation between 2015 and 2022 at the only radiation clinic in Botswana. We compared patients' characteristics between those who received HF vs. standard fractionation (SF) and report chi-square statistics when appropriate. We fit a multilevel mixed-effects logistic regression model with a random intercept for district while adjusting for fixed effects such as HIV infection status, laterality, hormone receptor status, and marital status.

RESULTS

A total of 234 patients were prescribed curative intent radiation between 2015 and 2022 in Gaborone, Botswana. Median age at diagnosis was 51 years old, and the majority of patients presented with stage III disease (61.9%, 109/234). 26.9% of this population were women living with HIV (WLWH), and 71% lived >100km from the hospital. HF was utilized overall in 59.4% (139/234) of patients. Most common fractionation patterns included: 4005cGy/15fx and 4267cG/16fx. One patient received ultra-HF (2600cGy/5fx). In unadjusted chi-square analysis, a higher proportion of HF was seen in right vs left-sided breast cancer (65.8% vs. 50.9%, p = 0.02), increasing year of diagnosis from 2015 - 2022 (p<0.001), and among patients >/ = 40 years of age vs. those <40 years of age (62.8% vs 42.1%, p = 0.017). Temporal trends show a significant increase in the utilization of HF starting from 23.8% (5/21) in 2015, to 61.5% (32/52) in 2018, and finally 100% (11/11) of cases in 2022. Our regression analysis shows that there is no statistically significant between-district variance or patient-level factors that associate with the uptake of HF. The overall utilization rate for HF between 2015-2022 was 59.4% (95% CI: 53.0%-65.5%).

CONCLUSION

Based on recent survey results the uptake of HF among African countries is lower than that of North America. To our knowledge, this is the first quantitative analysis of the utilization of HF over 5 years in an African country. Further analysis on factors related to physician prescription of hypofractionation is warranted, including influence of breast laterality, age, and primary surgery type.

SCCAg as a Biomarker of Advanced Stage and OS in Limited Resource Setting for Cervical Cancer

PURPOSE/OBJECTIVE(S)

Elevated serum squamous cell antigen (SCCAg) has been previously correlated with poor survival, extensive tumor involvement, and recurrence for cervical cancer. Failure of serum SCCAg to normalize after treatment completion has also been studied as a poor prognostic indicator. This is the first study describing the association of SCCAg with stage and outcomes in patients diagnosed with cervical cancer in Botswana, in a population with a majority of women who are living with HIV (WLWH).

MATERIALS/METHODS

Patients with histologically confirmed cervical cancer were enrolled in a prospective observational study between August 2016 and April 2020 in Botswana. Among all patients undergoing definitive chemoradiation, serum SCCAg was determined at pre-treatment baseline, end of treatment (EOT), and 3-month follow-up (normal reference range 0.3 -1.9 ng/ml). Normalization of SCCAg was defined as return to the reference range after treatment (SCCAg response), and was measured first at EOT; if EOT values were not available, 3-month values were utilized. Patients were staged according to FIGO 2009 criteria, early stage was defined as Stage I-II; while advanced stage was defined as Stage III-IV. Median follow-up was 44 months. A significant cut-off point for baseline and SCCAg response correlated with overall survival (OS) was calculated utilizing a log-rank test RESULTS: Among 234 patients who were diagnosed with histologically confirmed cervical cancer, 73.5% were WLWH (mean CD4 count 466 cells/mL). 92.9% of all cancers were squamous cell carcinoma. 68.8% of patients had elevated SCCAg at time of diagnosis. There was no significant difference in mean baseline SCCAg between WLWH (13.3 ng/mL) and women living without HIV (9.07 ng/mL), p = 0.1052. There was a significant difference seen in mean SCCAg between early (7.9 ng/mL ± SD 13.4) and advanced (18.9 ng/mL, ± SD 29.8) stage disease at diagnosis, p < 0.0001. Baseline SCCAg > 7.9 ng/mL was found to be associated with worse OS (p < 0.001). 5-year OS was significantly different among patients with SCCAg response < = 2.8 (5-year OS 66.2%), vs. SCCAg >2.8 ng/mL (5-year OS 42.4%). There was no significant difference in average SCCAg values between EOT (p = 0.68) and 3-month follow-up (p = 0.24). There was no difference in the proportion of patients who experienced normalized SCCAg by HIV status (p = 0.67).

CONCLUSION

There was no significant difference in SCCAg among WLWH and women living without HIV. Among patients with elevated SCCAg above normal at baseline, SCCAg was associated with early vs. advanced stage disease. Additionally, there was a significant difference seen in overall survival by two measurement points: baseline SCCAg >7.9 ng/mL and response SCCAg >2.8 ng/mL. SCCAg may be utilized as a biomarker in low-resource settings to refine prognosis. Further studies will be needed to determine utility and validation in predicting recurrence risk and/or lymph node metastases.

Impact of Chemotherapy Stock-Out on Standard Therapy Delivery Among Cancer Patients in Botswana

Background: Cancer drug shortages represent a complex global issue with potentially adverse survival outcomes. Up to 98% of oncologists and pharmacists surveyed in North America reported at least 1 drug shortage in the prior year and 66% reported at least one patient who had clinical care impacted by the shortage. In low- and middle-income countries (LMICs), these shortages are even more frequent. No studies to our knowledge have evaluated the impact of chemotherapy stock-out on receipt of standard cancer therapy in LMICs. Aim: Quantify the association between the duration of chemotherapy stock-out and the risk of having a suboptimal therapy delivery event, compared with standard delivery of therapy among cancer patients in Botswana. Methods: Prevalent cohort study of patients with cervical, breast, prostate, esophagus, Kaposi sarcoma, head and neck cancers, lung, uterine, ovarian and colorectal cancers who received any systemic therapy between 01/01/16-12/31/16 at Princess Marina Hospital, Botswana. Primary exposure was stock-out duration per cycle interval calculated by generating a code for the six different patterns for chemotherapy stock-out, using stock data at the Central Medical Stores. Primary outcome was suboptimal therapy delivery defined as a dose reduction, dose delay or switch in intended therapy. We measured statistical associations using two sample t-test and mixed effects univariate and multivariate logistic regression models. Results: 378 patients were identified who met diagnostic criteria and received systemic chemotherapy in 2016. Of these, 293 received commonly prescribed standard regimens who contributed 1452 cycle intervals and were included in our analysis. Majority of the patients (48%) had breast cancer. The mean duration of stock-out for receipt of standard therapy without events was 3.2 days (95% CI: 2.8-3.7) compared with 7.8 days for patients who had a suboptimal therapy delivery event (95% CI: 6.6-9) ( P < 0.0001). Male sex, age < 65 and HIV-positive status were also significantly associated with an increased risk of experiencing dose reduction, change in therapy or switch in therapy. Adjusting for these factors in a mixed effects logistic regression, each week of stock-out was independently associated with an 80% increased risk of having a suboptimal therapy delivery event (OR=1.8 (95% CI: 1.6-2.0, P < 0.0001)). Conclusion: Chemotherapy stock-out is independently associated with an 80% increased risk of a patient experiencing dose reduction, change in therapy or delay in therapy. The risk increases with longer duration of stock out. Given prior data showing that these events lead to worse survival outcomes, our further analysis is focusing on quantifying risk of stock-out on survival outcomes in this population. to determine whether interventions promoting standard therapy delivery are warranted to optimize survival outcomes.

First Things First: Adopting a Holistic, Needs-Driven Approach to Improving the Quality of Routinely Collected Data

Background and context: Routine collection of quality oncology data remains underprioritized in resource limited settings. For breast cancer (BC) care at Princess Marina Hospital (PMH) in Botswana, this hampers its use for oncology program evaluation and clinical research. The Peo Data Acquisition Core (DAC), part of a consortium for planning of a noncommunicable diseases center for research excellence in Southern Africa, engaged relevant stakeholders and departments at PMH to establish health care worker driven processes that support sustained improvements in the quality of routinely collected breast cancer data. Aim: Assess PMH BC care needs to support the improvement of routinely collected data. Strategy/Tactics: Conventional routine data quality assessments guide iterative identification of data quality gaps for improvement, but tend to consume additional human resources to implement and prioritize data quality over existing provider concerns. We undertook a holistic approach to identifying needs challenging the improvement of data routinely collected about PMH BC patients. Program/Policy process: A need assessment began with mapping of patient care process, capturing process steps, including subprocesses, actors, and an inventory of related data capture systems. The assessment also gathered care providers' perceptions of challenges to providing care as well as perceptions of the up-time of an existing electronic health record (EHR). Outcomes: BC patient management involves multiple care providers who attend to patients in different locations within the hospital. Except for EHR captured laboratory data, nearly all other documentation of patient care occurred through paper-based registers, diaries and general clinical forms. Providers indicated the overbooking of patient appointments and use of different formats to manage patient data as key challenges for them. EHR appointment scheduling components appear underutilized by providers, and a brief monitoring of provider perceptions of the EHR's speed and reliability suggests it is poorest in the mornings - at a time when providers are the busiest attending to patients. What was learned: Needs assessment findings suggest several opportunities to respond to provider recognized challenges through greater adoption of EHR usage. Establishment of a Quality Improvement (QI) group that champions improvements in routine BC data quality should integrate standardization of patient data formats and EHR centralized appointment booking. QI group composition should include both care providers and an EHR IT technician.