Guideline Concordance of Treatment and Outcomes Among Adult Non-Hodgkin Lymphoma Patients in Sub-Saharan Africa: A Multinational, Population-Based Cohort

BACKGROUND

Although non-Hodgkin lymphoma (NHL) is the 6th most common malignancy in Sub-Saharan Africa (SSA), little is known about its management and outcome. Herein, we examined treatment patterns and survival among NHL patients.

METHODS

We obtained a random sample of adult patients diagnosed between 2011 and 2015 from 11 population-based cancer registries in 10 SSA countries. Descriptive statistics for lymphoma-directed therapy (LDT) and degree of concordance with National Comprehensive Cancer Network (NCCN) guidelines were calculated, and survival rates were estimated.

FINDINGS

Of 516 patients included in the study, sub-classification was available for 42.1% (121 high-grade and 64 low-grade B-cell lymphoma, 15 T-cell lymphoma and 17 otherwise sub-classified NHL), whilst the remaining 57.9% were unclassified. Any LDT was identified for 195 of all patients (37.8%). NCCN guideline-recommended treatment was initiated in 21 patients. This corresponds to 4.1% of all 516 patients, and to 11.7% of 180 patients with sub-classified B-cell lymphoma and NCCN guidelines available. Deviations from guideline-recommended treatment were initiated in another 49 (9.5% of 516, 27.2% of 180). By registry, the proportion of all patients receiving guideline-concordant LDT ranged from 30.8% in Namibia to 0% in Maputo and Bamako. Concordance with treatment recommendations was not assessable in 75.1% of patients (records not traced (43.2%), traced but no sub-classification identified (27.8%), traced but no guidelines available (4.1%)). By registry, diagnostic work-up was in part importantly limited, thus impeding guideline evaluation significantly. Overall 1-year survival was 61.2% (95%CI 55.3%-67.1%). Poor ECOG performance status, advanced stage, less than 5 cycles and absence of chemo (immuno-) therapy were associated with unfavorable survival, while HIV status, age, and gender did not impact survival. In diffuse large B-cell lymphoma, initiation of guideline-concordant treatment was associated with favorable survival.

INTERPRETATION

This study shows that a majority of NHL patients in SSA are untreated or undertreated, resulting in unfavorable survival. Investments in enhanced diagnostic services, provision of chemo(immuno-)therapy and supportive care will likely improve outcomes in the region.

Diagnosis and monitoring of virus-associated cancer using cell-free DNA

Viral-associated cancers are a distinct group of malignancies with a unique pathogenesis and epidemiology. Liquid biopsy is a minimally invasive way to identify tumor-associated abnormalities in blood derivatives, such as plasma, to guide the diagnosis, prognosis, and treatment of patients with cancer. Liquid biopsy encompasses a multitude of circulating analytes with the most extensively studied being cell-free DNA (cfDNA). In recent decades, substantial advances have been made toward the study of circulating tumor DNA in nonviral-associated cancers. Many of these observations have been translated to the clinic to improve the outcomes of patients with cancer. The study of cfDNA in viral-associated cancers is rapidly evolving and reveals tremendous potential for clinical applications. This review provides an overview of the pathogenesis of viral-associated malignancies, the current state of cfDNA analysis in oncology, the current state of cfDNA analysis in viral-associated cancers, and perspectives for the future of liquid biopsies in viral-associated cancers.

Patient characteristics and outcome of CD20-positive HIV-associated lymphoma: a single-center KwaZulu-Natal, South African hospital 12-year retrospective review

BACKGROUND

Due to the high prevalence of HIV, HIV-associated lymphoma (HAL) is a common malignancy in South Africa. However, there is a paucity of literature on HAL from this region. The objective of this study was to profile the clinical characteristics and outcome of CD20-positive HAL treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), with or without rituximab (R), from a single center in KwaZulu -Natal, South Africa.

METHODS

Retrospective chart review of adult patients treated from 2006 to 2018 for HIV-associated CD20-positive lymphoma. The clinical characteristics, complete response (CR), and 2-year overall survival (OS) are described.

RESULTS

The analysis included 102 patients, 54% females, median age of 39 years, and median CD4 cell count of 196 cells/μL. Bone marrow involvement was noted in 5%. Eighty-six percent of the cohort received concomitant antiretroviral therapy and chemotherapy, 76% of the CHOP group, and 92% of the R-CHOP group. Overall, a CR was seen in 55% (95% CI 45%; 65%), with a 2-year OS of 59% (95% CI 50%, 69%). A CR was attained in 46% on CHOP and 64% on R-CHOP, with a 2-year disease-free survival (DFS) for CHOP of 42% and 50% for R-CHOP.

CONCLUSION

Although the clinical characteristics and laboratory findings are similar to other higher-income cohorts, there was a difference in gender and incidence of marrow involvement. The low incidence of marrow involvement has prompted more routine use of immunohistochemistry and flow cytometry in staging marrows of HAL locally. Further randomized studies are required for the establishment of locally validated, cost-effective treatment guidelines.

Significance of lymph node fine needle aspiration for the diagnosis of HIV-associated lymphoma in a low-resource setting

OBJECTIVE

Fine needle aspiration (FNA) is an early step in the work-up of lymphadenopathy in people with HIV (PWH). We set out to characterize the FNA cytology in PWH and report on the time to lymphoma diagnosis through the FNA clinics in the public healthcare system in Johannesburg, South Africa.

DESIGN

Retrospective review of laboratory database.

METHODS

A retrospective chart review of patients undergoing FNA through the department of cytopathology at the National Health Laboratory Service (NHLS) was undertaken. Results of FNAs performed between March and May 2018 were reviewed. Medical record chart abstraction included general demographics, HIV status, site and results of FNA, prior history of malignancy and other laboratory data.

RESULTS

Five hundred and thirty-nine lymph node FNAs were performed on PWH. Pathological findings included tuberculosis 47% (252), inadequate sampling 14% (75), reactive adenopathy 13% (71), benign disease 12% (63), suspicious for lymphoproliferative neoplasm 8% (45), other malignancy 4% (21) and inflammation 2% ( n  = 12). Only 53% (24) of lymphomas were confirmed by biopsy. Those not confirmed had a high mortality (57%) and loss to follow-up rate (29%) over the following year. The median diagnostic interval exceeded 8 weeks from time of FNA to lymphoma diagnosis.

CONCLUSION

FNA is an important screening modality in this high HIV and tuberculosis (TB) burden region. Patients with cytology suggestive for lymphoma, but without biopsy confirmation, have a high mortality rate suggesting undiagnosed lymphoma. A better understanding of the barriers to appropriate diagnostic triage for lymphoma is needed.

Changing Patterns of Lymphoma in the Antiretroviral Therapy Era in Johannesburg, South Africa

BACKGROUND

South Africa has a high HIV prevalence, which associates with an increased risk of lymphoma. Antiretroviral therapy (ART) became accessible in 2004, but the program has substantially expanded. Changes in lymphoma patterns are documented in high-income countries after wide-scale ART including declining high-grade B-cell non-Hodgkin lymphomas (HG B-NHLs), particularly diffuse large B-cell lymphoma, and increased Hodgkin lymphoma (HL). There are limited data from Africa. This study aimed to compare HG B-NHL characteristics in the early (2007) and later (2017) ART era.

METHODS

All incident lymphomas at the National Health Laboratory Service, Johannesburg, were identified using the laboratory information system, and data were collected for each patient.

RESULTS

The total number of lymphoma cases increased from 397 (2007) to 582 (2017). This was associated with improved lymphoma classification and patient referral for oncological care. HG B-NHL remained the most diagnosed lymphoma subtype in 2017 comprising 70% of HIV-associated lymphomas, followed by HL (24%). Diffuse large B-cell lymphoma comprised 65% of all HG B-NHLs and 45% of all lymphomas in people with HIV in 2017. Significantly more patients were on ART in 2017, with improvements in virological control documented. Despite this, 47.6% of patients were not virologically suppressed, and 37.5% of patients were ART-naive at time of diagnosis in 2017. Immunological reconstitution was suboptimal, which may reflect late initiation of ART.

CONCLUSION

Public health initiatives to initiate ART as early as possible and to retain patients in ART programs may assist in decreasing the number of HIV-associated lymphomas in our setting.

Feasibility of Cell-Free DNA Collection and Clonal Immunoglobulin Sequencing in South African Patients With HIV-Associated Lymphoma

PURPOSE

Diagnosis of AIDS lymphoma in low-resource settings, like South Africa, is often delayed, leaving patients with limited treatment options. In tuberculosis (TB) endemic regions, overlapping signs and symptoms often lead to diagnostic delays. Assessment of plasma cell-free DNA (cfDNA) by next-generation sequencing (NGS) may expedite the diagnosis of lymphoma but requires high-quality cfDNA.

METHODS

People living with HIV with newly diagnosed aggressive B-cell lymphoma and those with newly diagnosed TB seeking care at Chris Hani Baragwanath Academic Hospital and its surrounding clinics, in Soweto, South Africa, were enrolled in this study. Each participant provided a whole blood specimen collected in cell-stabilizing tubes. Quantity and quality of plasma cfDNA were assessed. NGS of the immunoglobulin heavy chain was performed.

RESULTS

Nine HIV+ patients with untreated lymphoma and eight HIV+ patients with TB, but without lymphoma, were enrolled. All cfDNA quantity and quality metrics were similar between the two groups, except that cfDNA accounted for a larger fraction of recovered plasma DNA in patients with lymphoma. The concentration of cfDNA in plasma also trended higher in patients with lymphoma. NGS of immunoglobulin heavy chain showed robust amplification of DNA, with large amplicons (> 250 bp) being more readily detected in patients with lymphoma. Clonal sequences were detected in five of nine patients with lymphoma, and none of the patients with TB.

CONCLUSION

This proof-of-principle study demonstrates that whole blood collected for cfDNA in a low-resource setting is suitable for sophisticated sequencing analyses, including clonal immunoglobulin NGS. The detection of clonal sequences in more than half of patients with lymphoma shows promise as a diagnostic marker that may be explored in future studies.

MYC status in HIV-associated plasmablastic lymphoma: dual-colour CISH, FISH and immunohistochemistry

AIMS

We utilised chromogenic and fluorescence in-situ hybridisation (CISH and FISH) to evaluate MYC gene copy numbers and rearrangements within HIV-associated plasmablastic lymphomas (PBLs). Thereafter, clinicopathological features were explored retrospectively.

METHODS AND RESULTS

Sixty-seven (n = 67) patients were included and the HIV seropositive status was confirmed in 98% (63 of 64) with a median viral load of 55 587 (IQR 273 582) copies/ml and median CD4 count of 170 (IQR 249) cells/µl. The mean age was 41 ± 10.1 years and females comprised 54%. PBL was documented predominantly at extra-oronasal topographic regions. Starry-sky (SS) appearance was evident in 33% in association with monomorphic morphology (P-value 0.02). c-MYC protein was expressed in 81% and latent EBV infection was detected in 90%. EBER ISH-positive status and MYC rearrangement occurred in 67% of HIV PBL. MYC aberrations included MYC rearrangement (70%), low-level increase in MYC gene copy numbers (43%), concurrent MYC rearrangement and increased MYC gene copy numbers (49%) as well as low-level chromosome 8 polysomy (6%). MYC aberrations in HIV PBLs were significantly associated with SS appearance (P -0.01), monomorphic morphology (P - 0.03), c-MYC protein expression ≥40% (P - 0.03) and mortality (P - 0.03). There was advanced stage (Ann Arbor III/IV) at presentation (77%) and the median overall survival for HIV PBL was 75 days (95% CI 14-136).

CONCLUSION

Majority of the HIV-associated PBL tumours harbour MYC aberrations. Due to the persistently inferior survival outcome of HIV-associated PBL in the era of antiviral treatment, targeted and/or intensified therapy of oncogenic MYC may need to be explored in future.

Gastrointestinal Tract Plasmablastic Lymphoma in HIV-Infected Adults: A Histopathological Review

BACKGROUND.

Plasmablastic lymphoma (PBL) is an aggressive B-cell lymphoma that is characterized by the expression of plasma cell antigens and loss of pan B-cell antigens. The neoplasm is extensively reported in the oral cavity and anorectal region but rarely in the gastrointestinal tract, where only isolated case reports and small case series have been reported. In the current study, morphologic, immunohistochemical, and molecular features of 17 cases of gastrointestinal tract PBL were reviewed.

METHODS.

Ten-year retrospective study that reappraised the histomorphological and immunophenotypical profiles of HIV-associated PBLs in the gastrointestinal tract.

RESULTS.

The mean age of the study patients was 41 years with a 3:1 ratio of males to females. The most common site of tumor origin was the small intestine (42%), followed by the stomach (29%) and the colon (29%). Majority of the cases showed a predominant diffuse (82%) growth pattern. Immunoblasts and plasmablasts were observed in all cases. Plasmacytic differentiation was seen in 5 (29%) cases. Additional observations not previously described or emphasized in literature includes pseudo-alveolar growth pattern, centroblast-predominance, multinucleated giant cells, and clear cell change. Immunohistochemistry revealed absence of pan B-cell antigens and expression of plasma cell antigens in all cases. Epstein-Barr virus-encoded RNA was expressed in 53% of the cases.

CONCLUSIONS.

This study highlights the spectrum of histopathological features seen in gastrointestinal tract PBLs. Awareness of this entity and its histopathological features in the gastrointestinal tract is essential for making a timely and accurate diagnosis and improving patient outcomes.

Clinical presentation and diagnosis of adult patients with non-Hodgkin lymphoma in Sub-Saharan Africa

Non-Hodgkin lymphoma (NHL) is the sixth most common cancer in Sub-Saharan Africa (SSA). Comprehensive diagnostics of NHL are essential for effective treatment. Our objective was to assess the frequency of NHL subtypes, disease stage and further diagnostic aspects. Eleven population-based cancer registries in 10 countries participated in our observational study. A random sample of 516 patients was included. Histological confirmation of NHL was available for 76.2% and cytological confirmation for another 17.3%. NHL subclassification was determined in 42.1%. Of these, diffuse large B cell lymphoma, chronic lymphocytic leukaemia and Burkitt lymphoma were the most common subtypes identified (48.8%, 18.4% and 6.0%, respectively). We traced 293 patients, for whom recorded data were amended using clinical records. For these, information on stage, human immunodeficiency virus (HIV) status and Eastern Cooperative Oncology Group Performance Status (ECOG PS) was available for 60.8%, 52.6% and 45.1%, respectively. Stage at diagnosis was advanced for 130 of 178 (73.0%) patients, HIV status was positive for 97 of 154 (63.0%) and ECOG PS was ≥2 for 81 of 132 (61.4%). Knowledge about NHL subclassification and baseline clinical characteristics is crucial for guideline-recommended treatment. Hence, regionally adapted investments in pathological capacity, as well as standardised clinical diagnostics, will significantly improve the therapeutic precision for NHL in SSA.

In the South African setting, HIV-associated Burkitt lymphoma is associated with frequent leukaemic presentation, complex cytogenetic karyotypes, and adverse clinical outcomes

South Africa (SA) has a high prevalence of human immunodeficiency virus (HIV) infection. People living with HIV are at markedly increased risk of developing Burkitt lymphoma (BL), which is characterized by the MYC translocation. There is a paucity of survival data of HIV-associated Burkitt lymphoma/leukaemia (HIV-BL) cases from SA, and the relationship between karyotype and outcomes has not been widely reported. Here we report the clinico-pathological characteristics of a cohort of cytogenetically confirmed HIV-BL cases. A retrospective, descriptive review was conducted of clinico-pathological features of HIV-BL patients newly diagnosed and treated between 2005 and 2014 at our tertiary academic institution in Cape Town. Only HIV-BL patients with cytogenetic evidence of a MYC translocation were included for analysis. A multivariable Cox proportional hazards model assessed the impact of variables on overall survival (OS). Forty-nine patients met inclusion criteria. Their median age was 37 years (IQR 30-43 years) and 57% (n = 28) were females. Their median CD4 count was 240 cells/μl (IQR 103-423 cells/μl). The majority, 61% (n = 30), had leukaemic presentation, and 20% (n = 10) had a complex karyotype on conventional karyotyping. Seventy-seven percent (n = 36) received various protocols of combination intensive chemotherapy, excluding rituximab. Their OS was 64% (95% CI 45-77%) at 6 months, and 34% (95% CI 17-51%) at 5 years. Leukaemic presentation and a complex karyotype gave a 2.7-fold (95% CI 1.0-6.7) and 2.6-fold (95% CI 1.1-6.6) increased risk of mortality respectively, which were statistical significant (p < 0.05). We report 49 newly diagnosed, cytogenetically confirmed HIV-BL patients at our institution over a 10-year period. There was a high proportion of complex karyotypes and leukaemic presentation, which both independently adversely affected survival. This may be due to differences in the pathobiology of HIV-BL that requires further study and could lead to therapeutic advances in this patient group.

Extraoral plasmablastic lymphomas in a high human immunodeficiency virus endemic area

AIMS

Plasmablastic lymphoma (PBL) occurs mainly in immunocompromised individuals, usually secondary to human immunodeficiency virus (HIV) infection. It classically occurs intraorally, but has been described in extraoral locations. The aim of this study was to define the immunophenotype and Epstein-Barr virus (EBV) status in a large single-centre cohort of extraoral PBL (EPBL) in South Africa, a high-prevalence HIV setting.

METHODS AND RESULTS

This retrospective study of 45 EPBLs included patients' age, gender, race, HIV status, and site. Cases were reviewed histologically, and classified morphologically as pure plasmablastic or plasmablastic with plasmacytic differentiation, and assessed immunohistochemically with antibodies against CD45, CD20, CD79a, PAX5, CD138, MUM1/IRF4, BLIMP1, VS38c, Ki67, bcl-6, CD10, cyclin D1, and human herpesvirus-8, by the use of standard automated procedures. EBV was assessed by the use of chromogenic in-situ hybridisation. Tumours were assessed with a fluorescence in-situ hybridisation (FISH) MYC break-apart probe. Twenty-seven PBLs showed pure plasmablastic morphology, and 18 showed plasmacytic differentiation. The male/female ratio was 1.5:1. The anus was the favoured extraoral site (31.1%), followed by lymph nodes (15.6%). All 29 patients with known HIV status were HIV-positive. The immunohistochemical profile recapitulated that reported for oral PBLs and EPBLs in HIV-positive and HIV-negative patients. EBV was positive in 92.5% of PBLs. FISH analysis showed MYC rearrangement in 48% of cases.

CONCLUSION

This study showed a strong association of EPBLs with HIV and EBV infection, similarly to the previously described oral PBL. The strong EBV association together with other clinicopathological parameters and an immunohistochemical profile that includes CD45, CD20, MUM1/IRF4, CD138 and Ki67 may be used in distinguishing PBL from diffuse large B-cell lymphoma and plasma cell myeloma.

Impact of HIV Infection on the Clinical Presentation and Survival of Non-Hodgkin Lymphoma: A Prospective Observational Study From Botswana

PURPOSE

Botswana has a high prevalence of HIV infection. Currently, there are few data regarding the sociodemographic factors, clinical characteristics, and outcomes of non-Hodgkin lymphoma (NHL)-an AIDS-defining cancer-in the country.

PATIENTS AND METHODS

This study used a prospective cancer registry to identify patients with a new diagnosis of NHL reporting for specialty cancer care at three hospitals in Botswana between October 2010 and August 2016. Treatment patterns and clinical outcomes were analyzed.

RESULTS

One hundred four patients with a new diagnosis of NHL were enrolled in this study, 72% of whom had HIV infection. Compared with patients not infected with HIV, patients infected with HIV were younger (median age, 53.9 v 39.1 years; P = .001) and more likely to present with an aggressive subtype of NHL (65.5% v 84.0%; P = .008). All patients infected with HIV received combined antiretroviral therapy throughout the course of the study, and similar chemotherapeutic regimens were recommended for all patients, regardless of subtype or HIV status (six to eight cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone; or cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab). There was no difference in 1-year mortality among patients not infected with HIV and patients infected with HIV (unadjusted analysis, 52.9% v 37.1%; hazard ratio [HR], 0.73; P = .33; adjusted analysis, HR, 0.57; P = .14). However, when compared with a cohort of patients in the United States matched by subtype, stage, age, sex, and race, patients in Botswana fared worse (1-year mortality, 22.8% v 46.3%; HR, 1.89; P = .001).

CONCLUSION

Among patients with NHL reporting for specialty cancer care in Botswana, there is no association between HIV status and 1-year survival.

Inter-observer variability influences the Lugano classification when restaging lymphoma

Background

Lymphoma is an important and potentially curable oncological disease in South Africa. The staging and restaging of lymphoma have evolved over the years, with the latest international consensus guideline being the Lugano classification (LC). Prior to routine implementation of the LC, its robustness in the local setting should be determined.

Objectives

To determine the Inter-observer variability in response assignment when applying the LC in patients with lymphoma who were staged and restaged with computed tomography. In case of excessive discordance, specific mitigating measures will have to be taken before and during any proposed implementation of the LC.

Method

A total of 61 computed tomography scans in 21 patients were evaluated independently by four reviewers according to the LC, of which 21 scans were done at baseline, 21 at initial restaging and 19 at follow-up restaging. A retrospective comparative analysis was performed. Kappa values were calculated to determine agreement between observers.

Results

Only a moderate inter-observer agreement of 52% in the overall response classification was demonstrated. The most important sources of discrepancy were inconsistency in the assessment of target lesion regression to normal, determining the percentage change in the summed cross-sectional area of the target lesions and ascribing new lesions as either due to lymphoma or other causes.

Conclusion

Implementing the Lugano classification when restaging lymphoma is desirable to improve consistency and to conform to international guidelines. However, our study shows substantial inter-observer variability in response classification, potentially altering the treatment plan. Dedicated training and continuous quality control should, therefore, accompany the process.

The utility of bone marrow sampling in the diagnosis and staging of lymphoma in South Africa

INTRODUCTION

The bone marrow biopsy (BMB) is a diagnostic and staging tool in lymphoma that remains practically useful and relevant in resource-constrained settings, despite restricted applications in international staging guidelines, which favour less invasive nuclear medicine techniques.

METHODS

Retrospective laboratory data review of BMBs in adult lymphoma patients from 2005 to 2010 to determine subtypes, rates of bone marrow involvement (BMI), human immunodeficiency virus (HIV) seroprevalence and CD4 counts, trephine length and additional findings.

RESULTS

A total of 1215 BMBs reported in lymphoma included 759 newly diagnosed patients, with BMI in 43.6% of non-Hodgkin lymphoma (NHL) overall, 28.9% of high-grade B subtypes and 35.7% of Hodgkin lymphoma (HL). HIV seroprevalence was 38.8%, 53.0% and 33.9% in the 3 respective groups. There was a statistical association between BMI and HIV seropositivity in Burkitt lymphoma and HL, and BMI and CD4 count in HIV-related HL. Over 10% (n = 79) of new lymphoma cases were diagnosed by BMB with ancillary tests. Occasional histological discordance and transformation were reported in NHL. Focal/unilateral BMI was uncommon. Bilateral BMB and biopsy length exceeding 26 mm did not improve BMI detection.

CONCLUSION

In the South African public sector, high HIV prevalence leads to a different lymphoma pathology profile from the developed world. High BMI rates are encountered. Here, and in similar resource-constrained settings, international lymphoma staging guidelines can be logistically challenging and unaffordable. BMB remains useful in the staging and diagnosis of lymphoma. Unilateral sampling with a processed trephine length of at least 26 mm is recommended.