Neo-adjuvant capecitabine chemotherapy in women with newly diagnosed locally advanced breast cancer in a resource-poor setting (Nigeria): efficacy and safety in a phase II feasibility study

Pharmacogenetics of Breast Cancer Treatments: A Sub-Saharan Africa Perspective

Breast cancer is the most frequent cause of cancer death in low- and middle-income countries, in particular among sub-Saharan African women, where response to available anticancer treatment therapy is often limited by the recurrent breast tumours and metastasis, ultimately resulting in decreased overall survival rate. This can also be attributed to African genomes that contain more variation than those from other parts of the world. The purpose of this review is to summarize published evidence on pharmacogenetic and pharmacokinetic aspects related to specific available treatments and the known genetic variabilities associated with metabolism and/or transport of breast cancer drugs, and treatment outcomes when possible. The emphasis is on the African genetic variation and focuses on the genes with the highest strength of evidence, with a close look on CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4/5, CYP19A1, UGT1A4, UGT2B7, UGT2B15, SLC22A16, SLC38A7, FcγR, DPYD, ABCB1, and SULT1A1, which are the genes known to play major roles in the metabolism and/or elimination of the respective anti-breast cancer drugs given to the patients. The genetic variability of their metabolism could be associated with different metabolic phenotypes that may cause reduced patients’ adherence because of toxicity or sub-therapeutic doses. Finally, this knowledge enhances possible personalized treatment approaches, with the possibility of improving survival outcomes in patients with breast cancer.

Innovative Strategies for Developing Biomarker-Informed Cancer Clinical Trials to Accelerate Progress in Precision Oncology in Sub-Saharan Africa

Well-designed, pragmatic, patient-centered clinical trials in low- and middle-income countries are essential to drive approval of more effective and less toxic cancer medicines to address the rising burden of cancer among populations in low- and middle-income countries. Moreover, through reverse innovation, clinical trials informed by genomic research enable development of precision medicine strategies for underserved populations within all populations. The African continent is home to many low- and middle-income countries; yet, it has seen very few cancer clinical trials. Considering that Africa is the cradle of humanity, with its diverse populations and geography, this represents a missed opportunity to understand the heterogeneity of cancer genomes and their implications for developmental therapeutics. Since 1998, the Nigerian Breast Cancer Study Group has striven to gain a better understanding of the root causes of breast cancer and accelerate progress in clinical research that will benefit the African ancestry diaspora globally through deployment of innovative "leapfrog" technologies. The University of Chicago supports interdisciplinary and interprofessional teams of researchers through the African Cancer Leaders Institute and in partnership with the African Organization for Research and Training in Cancer. By fostering public-private partnerships, the African Organization for Research and Training in Cancer can identify and integrate significant resources needed to build regional networks and establish clinical trial coordinating centers across African countries, enabling resources to be developed and shared equitably. Such resources include a standardized curriculum for specialist training in oncology, including medical oncology and oncology nursing, to increase the numbers of qualified team leaders and principal investigators. Adequate support for study participants-financial and psychosocial-and patient navigation services will be important in growing a clinical trials network. Finally, full participation of African clinical researchers in global oncology trials will ensure workforce retention in Africa and improve financial security and job satisfaction of health professionals on the African continent.

Implementing oncology clinical trials in Nigeria: a model for capacity building

Background

There is both higher mortality and morbidity from cancer in low and medium income countries (LMICs) compared with high income countries (HICs). Clinical trial activities and development of more effective and less toxic therapies have led to significant improvements in morbidity and mortality from cancer in HICs. Unfortunately, clinical trials remain low in LMICs due to poor infrastructure and paucity of experienced personnel to execute clinical trials. There is an urgent need to build local capacity for evidence-based treatment for cancer patients in LMICs.

Methods

We conducted a survey at facilities in four Teaching Hospitals in South West Nigeria using a checklist of information on various aspects of clinical trial activities. The gaps identified were addressed using resources sourced in partnership with investigators at HIC institutions.

Results

Deficits in infrastructure were in areas of patient care such as availability of oncology pharmacists, standard laboratories and diagnostic facilities, clinical equipment maintenance and regular calibrations, trained personnel for clinical trial activities, investigational products handling and disposals and lack of standard operating procedures for clinical activities. There were two GCP trained personnel, two study coordinators and one research pharmacist across the four sites. Interventions were instituted to address the observed deficits in all four sites which are now well positioned to undertake clinical trials in oncology. Training on all aspects of clinical trial was also provided.

Conclusions

Partnerships with institutions in HICs can successfully identify, address, and improve deficits in infrastructure for clinical trial in LMICs. The HICs should lead in providing funds, mentorship, and training for LMIC institutions to improve and expand clinical trials in LMIC countries.

Panoptic Overview of Triple-Negative Breast Cancer in Nigeria: Current Challenges and Promising Global Initiatives

Purpose

Triple-negative breast cancer (TNBC) is the most deadly form of breast cancer (BC) today. TNBC treatment is fraught with challenges because of the extensive interpatient heterogeneity in clinical behavior and scarcity of stratifying biomarkers and actionable targets. Women of African ancestry face a disproportionate burden resulting from this disease, which affects them earlier and more aggressively and has a higher propensity to spread and resist conventional treatments. A much higher proportion of Nigerian patients with BC have TNBC compared with patients with BC in the United States and Europe.

Methods

This article spotlights Nigeria as an example of a nation wherein genetic and nongenetic spheres of influence intersect to affect the prevalence of this disease, the scale of its challenge, and its toll.

Results

Studies have illuminated the inherently different tumor biology of Nigerian TNBCs, which show distinct genetic variants and gene expression patterns compared with European or European-American TNBCs. Parallels are apparent between TNBC phenotypes among African Americans and Nigerians, implicating the common thread of shared genetic ancestry between these populations. Reproductive, lifestyle, socioeconomic, and cultural factors also shape TNBC outcomes in Nigeria, as do resource constraints in Nigerian health care and research sectors.

Conclusion

Increasing our understanding of how these factors contribute to poorer outcomes among Nigerian women may uncover valuable insights and strategies in alleviating the TNBC burden in many countries of the world and help reduce the racial disparity in BC-related outcomes here in the United States. Importantly, this review also highlights collaborative global and local initiatives that converge expertise and resources to advance research on effective management of TNBC in diverse populations.

Neoadjuvant chemotherapy in combination with surgery in the treatment of local advanced breast cancer

Objective:

To investigate the effect of neoadjuvant chemotherapy combined with surgery on locally advanced breast cancer and its prognosis.

Methods:

One hundred and fifty-four patients with locally advanced breast cancer who were admitted to our hospital from February 2014 to April 2015 were selected as the study subjects. They were divided into an observation group and a control group according to the principle of random equalization, 77 each group. The observation group was treated with TAC scheme, neoadjuvant chemotherapy combined with modified radical resection, and continuously treated with the same scheme after operation until the end of the course of treatment. The control group was treated with modified radical resection and TAC scheme. The clinical efficacy of the two groups was observed, and the perioperative indications, prognosis and occurrence of adverse reactions were compared between the two groups.

Results:

The total effective rate of the observation group was 76.62%, significantly higher than that of the control group (55.84%, P<0.05). The observation group had shorter operation time and hospitalization time and less bleeding amount compared to the control group (P<0.05). The metastasis rate and recurrence rate of the observation group were significantly lower than those of the control group (P<0.05); there was a significant difference between the two groups (P<0.05). The one-year and three-year survival rates of the observation group were significantly higher than those of the control group (P<0.05). There was no significant difference in the incidence of adverse reactions between the two groups after operation (P>0.05).

Conclusion:

Preoperative neoadjuvant chemotherapy in combination with TAC scheme can reduce the difficulty of operation, improve the curative effect of patients, significantly improve the prognosis of patients and prolong the survival time, which is worth clinical application.

Pharmacogenomics in the Nigerian population: the past, the present and the future

The Nigerian population exhibits huge ethnic and genetic diversity, typical of African populations, which can be harnessed for improved drug-response and disease management. Existing data on genes relevant to drug response, so far generated for the population, indeed confirm the prevalence of some clinically significant pharmacogenes. These reports detail prevailing genetic alleles and metabolic phenotypes of vital drug metabolizing monooxygenases, transferases and drug transporters. While the utilization of existing pharmacogenomic data for healthcare delivery remains unpopular, several past and on-going studies suggest that a future shift toward genotype-stratified dosing of drugs and disease management in the population is imminent. This review discusses the present state of pharmacogenomics in Nigeria and the potential benefits of sustained research in this field for the population.

Global Inequities in Precision Medicine and Molecular Cancer Research

Precision medicine based upon molecular testing is heralded as a revolution in how cancer is prevented, diagnosed, and treated. Large efforts across the world aim to conduct comprehensive molecular profiling of disease to inform preclinical models, translational research studies and clinical trials. However, most studies have only been performed in patients from high-income countries. As the burden on non-communicable diseases increases, cancer will become a pressing burden across the world, disproportionately affecting low-middle income settings. There is emerging evidence that the molecular landscape of disease differs geographically and by genetic ancestry, which cannot be explained by environmental factors alone. There is a lack of good quality evidence that characterises the molecular landscape of cancers found in low-middle income countries. As cancer medicine becomes increasingly driven by molecular alterations in high-income settings, low-income settings may become left behind. Further efforts on an international scale must be made by researchers, funders, and policymakers to ensure cancer research addresses disease across the world, so models are not limited to subtypes of disease found in high-income countries. In this review, we discuss differences found in the molecular profiles of tumours worldwide and the implication this has for the future of global cancer care. Finally, we identify several barriers currently limiting progress in this field and innovative solutions, which may address these shortcomings.

Relationship between tumour size and response to neoadjuvant chemotherapy among breast cancer patients in a tertiary center in Nigeria

Background

Tumour biology, physiologic features such as growth fraction and physical features such as size may influence response of breast cancer to neoadjuvant chemotherapy. Molecular biology is an established basis for predicting response and selecting neoadjuvant chemotherapy. Whether physical characteristics such as size should influence chemotherapy regimen is inconclusive and has not been adequately studied in developing countries.

Aim

To determine the relationship between breast tumour size and response to neoadjuvant chemotherapy and hence define the role of tumour size during selection of neoadjuvant chemotherapy regimen for locally advanced breast cancer.

Method

Records of women managed at the University of Ilorin Teaching Hospital, Ilorin Nigeria, with neoadjuvant chemotherapy (NAC) for locally advanced breast cancer were reviewed between January 2013 and June 2015. Data was analyzed as 2 subgroups; primary tumour ≥100mm as group 1 and primary tumour ≥100mm as group 2. Primary outcome was 50% reduction in tumour size. Comparison was by chi-square test of independence at p value 0.05.

Results

57 records were reviewed (group1=24, group2=33). Majority (37( 65%)) were premenopausal. Mean age was 47.9 ± 13.1 (range 28–85). NAC was either taxane or anthracycline based regimen. Median chemotherapy dose was 4 (range 2–6). Widest diameter of tumours was 30mm to 180mm (mean 96 ±3.8mm, median 100mm). Mean tumour diameter for groups 1 and 2 was 7.2 ±1.6mm and 12.2± 2.9mm respectively. 50% reduction in tumour size was 45.8% and 6.0% for groups 1 and 2 respectively (p=0.0001)

Conclusion

There was relationship between breast tumour size and response to neoadjuvant chemotherapy at a cut-off of 10mm. Well-designed prospective studies are required to confirm this relationship.

Neoadjuvant chemotherapy among patients treated for nonmetastatic breast cancer in a population with a high HIV prevalence in Johannesburg, South Africa

Background

Neoadjuvant (primary) chemotherapy (NACT) is the standard of care for locally advanced breast cancer. It also allows for the short-term assessment of chemotherapy response; a pathological complete responses correspond to improved long-term breast cancer outcomes. In sub-Saharan Africa, many patients are diagnosed with large nonresectable tumors. We examined NACT use in breast cancer patients who visited public hospitals in Johannesburg, South Africa.

Methods

We assessed demographic characteristics, tumor stage and grade, hormone receptor status, and human immunodeficiency virus (HIV) status of female patients diagnosed with nonmetastatic invasive carcinoma of the breast at Chris Hani Baragwanath Academic Hospital between January 1, 2009, and December 31, 2011. The patients received neoadjuvant, adjuvant, or no chemotherapy. Trastuzumab was unavailable. We developed logistic regression models to analyze the factors associated with NACT receipt in these patients.

Results

Of 554 women with nonmetastatic breast cancer, the median age at diagnosis was 52 years (range: 28–88 years). Only 5.8% of patients were diagnosed with stage I disease; 49.3% and 44.9% were diagnosed with stages II and III, respectively. Most patients had hormone-responsive tumors: luminal A, 38.1%; luminal B₁ (human epidermal growth factor receptor 2 [HER2]-negative and high grade), 12.5%, and luminal B₂ (HER2-positive any grade), 11.6%; 11.6% had a HER2-enriched tumor and 20.6% a triple-negative tumor. Eighty (14.4%) patients were HIV-positive. In total, 195 patients (35.2%) received NACT, 264 (47.7%) patients received adjuvant chemotherapy, and 95 patients (17.1%) received no chemotherapy, including 62 (11.2%) patients who received only hormonal therapy. Of patients receiving NACT, 125 (64.1%) were evaluable for clinical response. Eighty (64.0%) patients had a clinically significant response; 19 (15.2%) patients had a stable disease, and 26 (20.8%) patients had a progressive disease. Multivariate analysis showed age <40 years and disease stage to be independently associated with the receipt of NACT.

Conclusion

Most women receiving NACT with available response data showed a clinical benefit. Stage III disease at diagnosis and age <40 years were predictors of neoadjuvant versus adjuvant chemotherapy treatment.

Evaluation of the clinical benefits of adjuvant capecitabine monotherapy in elderly women with breast cancer: A retrospective study

Capecitabine is orally administered and may be safely and conveniently used in patients with cancer. The antitumor activity of capecitabine in breast cancer was mostly demonstrated in the salvage therapy setting, whereas the effect of adjuvant capecitabine monotherapy in breast cancer remains unclear. The aim of the present study was to evaluate adjuvant capecitabine monotherapy in elderly women with breast cancer. A total of 251 patients were enrolled and survival was compared between elderly breast cancer patients who received adjuvant capecitabine monotherapy and those who received no chemotherapy. Cancer-specific and disease-free survival curves were compared using log-rank tests and survival curves were calculated using the Kaplan-Meier method. Multivariate analyses were conducted using Cox's proportional hazard regression model. There was no significant difference between the clinicopathological characteristics, including age, tumor size, lymph node status, histological grade and hormone status, between patients in the two groups. The breast cancer-specific survival rate was 89.3% in the capecitabine monotherapy group vs. 81.3% in the no chemotherapy group; the difference was not statistically significant (P=0.128). The disease-free survival rate was 81.7% in the capecitabine monotherapy group vs. 65.3% in the no chemotherapy group. Kaplan-Meier analysis indicated a longer disease-free survival in the capecitabine monotherapy group (P=0.015). On Cox regression analysis, capecitabine monotherapy was found to be associated with the disease-free survival rate (P=0.014, hazard ratio=0.500) but not with the cancer-specific survival rate (P=0.181). The adverse events of capecitabine monotherapy were recorded and there was no chemotherapy interruption due to severe adverse reactions. Therefore, adjuvant capecitabine monotherapy in elderly women with breast cancer is a safe and effective option, as well as a viable alternative for elderly breast cancer patients who refuse standard adjuvant therapy.

An update on the management of breast cancer in Africa

Background

There is limited information about the challenges of cancer management and attempts at improving outcomes in Africa. Even though South and North Africa are better resourceds to tackle the burden of breast cancer, similar poor prognostic factors are common to all countries. The five-year overall Survival rate for breast cancer patients does not exceed 60% for any low and middle-income country (LMIC) in Africa. In spite of the gains achieved over the past decade, certain characteristics remain the same such as limited availability of breast conservation therapies, inadequate access to drugs, few oncology specialists and adherence to harmful socio-cultural practices. This review on managing breast cancer in Africa is authored by African oncologists who practice or collaborate in Africa and with hands-on experience with the realities.

Methods

A search was performed via electronic databases from 1999 to 2016. (PubMed/Medline, African Journals Online) for all literature in English or translated into English, covering the terms “breast cancer in Africa and developing countries”. One hundred ninety were deemed appropriate.

Results

Breast tumors are diagnosed at earlier ages and later stages than in highincome countries. There is a higher prevalence of triple-negative cancers. The limitations of poor nursing care and surgery, inadequate access to radiotherapy, poor availability of basic and modern systemic therapies translate into lower survival rate. Positive strides in breast cancer management in Africa include increased adaptation of treatment guidelines, improved pathology services including immuno-histochemistry, expansion and upgrading of radiotherapy equipment across the continent in addition to more research opportunities.

Conclusion

This review is an update of the management of breast cancer in Africa, taking a look at the epidemiology, pathology, management resources, outcomes, research and limitations in Africa from the perspective of oncologists with local experience.

A comparison of toxicity profiles between the lower and standard dose capecitabine in breast cancer: a systematic review and meta-analysis

Capecitabine 1000 mg/m(2) bid × 14 days every 21 days (14/21) has been reported to have similar efficacy but more favorable toxicity profile than the approved dosage of 1250 mg/m(2). However, a dose-toxicity relationship of capecitabine in breast cancer patients has not been fully elucidated. We performed a systematic review and meta-analysis to compare a safety profile between capecitabine starting dose of 1000 and 1250 mg/m(2) bid. Studies were identified using PubMed, ASCO, and San Antonio Breast Cancer Symposium abstract databases through December 2015. Eligible trials included phase II/III trials of capecitabine monotherapy at 1000 or 1250 mg/m(2) bid (14/21) for breast cancer patients that reported adequate safety data for all (grade 1-4) or high (grade 3-4) grade hand foot syndrome (HFS), diarrhea, fatigue, nausea, vomiting, stomatitis, neutropenia, thrombocytopenia, or anemia, as well as dose reductions, treatment discontinuation or treatment-related deaths. The summary incidence was calculated using random-effects models. A total of 4833 patients from 34 trials were included. 1218 and 3615 patients were treated with capecitabine 1000 and 1250 mg/m(2) bid, respectively. A significantly lower incidence of dose reduction (15.9 vs. 39.0 %; P = 0.007), high-grade HFS (12.0 vs. 19.0 %; P = 0.01), diarrhea (5.3 vs. 9.1 %; P = 0.01), and neutropenia (1.8 vs. 7.3 %; P < 0.01), and all-grade neutropenia (5.8 vs. 25.4 %; P = 0.01) was seen in capecitabine 1000 mg/m(2) compared to 1250 mg/m(2). Capecitabine monotherapy at 1000 mg/m(2) bid (14/21) has a clinically meaningful and significantly better toxicity profile compared to 1250 mg/m(2) bid (14/21).

A Review on Breast Cancer Care in Africa

BACKGROUND

The global incidence of breast cancer (BC) is rising, especially in low- and middle-income countries. The purpose of this review is to summarize existing publications on BC care in Africa.

PATIENTS AND METHODS

A systematic search in MEDLINE and smaller databases was carried out to identify African studies on BC treatment, and an additional PubMed search was performed for relevant topics on BC care.

RESULTS

A total of 219 publications, mainly from North and West Africa, were found by systematic search. We also selected articles on BC epidemiology, risk factors, clinical presentation, and cancer control in Africa.

CONCLUSIONS

Publications on BC treatment are mostly from hospital case series. Evidence on treatment from prospective randomized trials that address the specific characteristics of African patients is lacking. The epidemiologic data shows rising incidences in Africa. The prevalence of risk factors is changing by age group, geographic region, and over time. The clinical picture of BC differs from that of Western countries due to the high proportion of young patients (on account of the African population with a high proportion of young people) and late presentation. Global collaborative efforts are needed to address the rising need for improved BC care in Africa.

How Effective is the Treatment of Locally Advanced and Metastatic Breast Cancer in Developing Centres?: A Retrospective Review

BACKGROUND

The use of chemotherapy in advanced metastatic breast cancer remains a subject of controversy. The thought of MicKinnon et al (early 1950s) that the course of breast cancer was unaffected by chemotherapy has been refuted by results of treatment in the developed countries. The poor result of treatment in developing centres still compares with prechemotherapy era. Consequently, The McKinnon's thought may still lurk. We compared the survival of chemotherapy treated with chemotherapy untreated cancer of breast patients.

METHOD

Records of breast cancer patients who presented and died between January 2010 and May 2014 were reviewed. The primary outcome was overall survival. Records of patients that received chemotherapy with or without other tumor directed specific therapy were compared with records of patients who did not receive any tumor directed therapy.

RESULT

Thirty-one patients received chemotherapy while 25 patients did not. All were females, more than 90% were of the patients had advanced or metastatic disease. Treatments were not biologically directed and treatment plans were largely compromised and suboptimal. The overall mean survival was 19.2 ±9.2 months, and the median duration was 17.5 months(range 6-44months). The overall survival was not statistically different between the two groups (p= 0.230, unequal variance assumed). The objective of using neoadjuvant chemotherapy for fungating lesions was not achieved.

CONCLUSION

In advanced and metastatic breast cancer, outcomes of patients who receive suboptimal regimen of cytotoxic chemotherapy do not differ from chemotherapy untreated patients.

Bik subcellular localization in response to oxidative stress induced by chemotherapy, in Two different breast cancer cell lines and a Non-tumorigenic epithelial cell line

Cancer chemotherapy remains one of the preferred therapeutic modalities against malignancies despite its damaging side effects. An expected outcome while utilizing chemotherapy is apoptosis induction. This is mainly regulated by a group of proteins known as the Bcl-2 family, usually found within the endoplasmic reticulum or the mitochondria. Recently, these proteins have been located in other sites and non-canonic functions have been unraveled. Bik is a pro-apoptotic protein, which becomes deregulated in cancer, and as apoptosis is associated with oxidative stress generation, our objective was to determine the subcellular localization of Bik either after a direct oxidative insult due to H2 O2 , or indirectly by cisplatin, an antineoplastic agent. Experiments were performed in two human transformed mammary gland cell lines MDA-MB-231 and MCF-7, and one non-tumorigenic epithelial cell line MCF-10A. Our results showed that in MCF-7, Bik is localized within the cytosol and that after oxidative stress treatment it translocates into the nucleus. However, in MDA-MB-231, Bik localizes in the nucleus and translocates to the cytosol. In MCF10A Bik did not change its cellular site after either treatment. Interestingly, MCF10A were more resistant to cisplatin than transformed cell lines. This is the first report showing that Bik is located in different cellular compartments depending on the cancer stage, and it has the ability to change its subcellular localization in response to oxidative stress. This is associated with increased sensitivity when exposed to toxic agents, thus rendering novel opportunities to study new therapeutic targets allowing the development of more active and less harmful agents.

Building capacity for sustainable research programmes for cancer in Africa

Cancer research in Africa will have a pivotal role in cancer control planning in this continent. However, environments (such as those in academic or clinical settings) with limited research infrastructure (laboratories, biorespositories, databases) coupled with inadequate funding and other resources have hampered African scientists from carrying out rigorous research. In September 2012, over 100 scientists with expertise in cancer research in Africa met in London to discuss the challenges in performing high-quality research, and to formulate the next steps for building sustainable, comprehensive and multi-disciplinary programmes relevant to Africa. This was the first meeting among five major organizations: the African Organisation for Research and Training in Africa (AORTIC), the Africa Oxford Cancer Foundation (AfrOx), and the National Cancer Institutes (NCI) of Brazil, France and the USA. This article summarizes the discussions and recommendations of this meeting, including the next steps required to create sustainable and impactful research programmes that will enable evidenced-based cancer control approaches and planning at the local, regional and national levels.