Hypofractionated Radiotherapy for Hematologic Malignancies during the COVID-19 Pandemic and Beyond

PURPOSE

Radiotherapy is integral in the management of hematological malignancies (HM). Standard radiotherapy dose fractionation regimens range between 20 and 50 Gy in 10-25 fractions over 2-5 weeks. This study presents the outcomes of patients with HM treated with hypofractionation radiotherapy (HFRT) during the COVID-19 pandemic.

METHODS

Patients (n = 36) were treated with HFRT between January 2020 and September 2022. The outcomes measured were the overall response rate (ORR), freedom from local progression (FFLP), and overall survival (OS).

RESULTS

The median follow-up was 13.2 months. Thirty-three patients (92%) had non-Hodgkin (NHL) or Hodgkin lymphoma (HL). Eighteen patients (50%) had aggressive and nine (25%) had indolent NHL. Nineteen patients (53%) presented with stage I/II and fifteen (42%) with stage III/IV disease. Twenty-five (69.4%) and eleven (30%) received consolidative and definitive RT, respectively. Twenty patients (56%) received treatment to the neck and/or thorax and nine (25%) to the abdomen or pelvis. The total dose ranged from 18 to 42.5 Gy in 6-17 fractions/2.67-5 Gy per fraction. The median dose in 2 Gy fractions for an alpha/beta (α/β) ratio of 10 amounted to 39 Gy (SD ± 13.86) and 43.6 Gy (SD ± 12) for an α/β of 3. The most commonly used fractionation scheme was 39 Gy in 13 fractions. ORR was 94.4% for the entire cohort, and 100, 94.4, and 83.3% for indolent NHL, aggressive NHL, and HL patients. The two-year FFLP was 76% (95% CI: 34-93%) for the entire cohort and 100, 87 (95% CI: 56.4-96.5%), and 42% (95% CI: 1.1-84.3%) for the indolent NHL, aggressive NHL, and HL patients. Two-year OS for the entire cohort was 80% (95% CI: 59.9-90.5%) and 100, 66.1 (95% CI: 36.4-84.4%), and 100% for the indolent NHL, aggressive NHL, and HL patients. Only one patient presented with grade two pulmonary toxicity.

CONCLUSIONS

HFRT in HM provides excellent local control to be validated in a larger prospective study.

Steroid-Induced Hyperglycemia and Its Effect on Outcomes of R-CHOP Chemotherapy for Diffuse Large B-Cell Lymphoma

Large doses of steroids are integral to R-CHOP, a first-line systemic therapy for diffuse large B-cell lymphoma (DLBCL), an aggressive form of non-Hodgkin Lymphoma (NHL). Patients on R-CHOP often develop clinically significant hyperglycemia from steroids. There is evidence of harms from steroid-induced hyperglycemia in the context of chemotherapy which are associated with a reduction in overall survival. The objective of our study was to characterize the effect of steroid-induced hyperglycemia on the outcomes of R-CHOP chemotherapy for DLBCL.

METHODS

We performed a retrospective chart review of 188 patients with DLBCL treated with R-CHOP through CancerCare Manitoba (CCMB) from 1 January 2010 to 31 December 2014. Patients diagnosed with DLBCL were identified using the Manitoba Cancer Registry. The CCMB electronic medical record was reviewed to examine the association between steroid-induced hyperglycemia and subsequent infection, including febrile neutropenic events and overall survival (OS).

RESULTS

Patients who developed hyperglycemia with steroid exposure became hyperglycemic during their first R-CHOP cycle. No significant differences in OS or rates of infection were found between euglycemic and hyperglycemic subjects.

CONCLUSIONS

Patients destined to develop steroid-induced hyperglycemia declare themselves early in the course of steroid exposure. No statistically significant reduction in overall survival attributable to steroid-induced hyperglycemia was found.

Hypofractionated Radiotherapy for Hematological Malignancies during COVID-19 Pandemic and Beyond

PURPOSE/OBJECTIVE(S)

Conventionally fractionated radiotherapy (RT) has shown to have excellent local control in hematological malignancies (HM). Up to date there is none or scant literature about the use of hypofractionated radiotherapy (HFRT) for the treatment of HM, this single institution study analyzed the efficacy of HFRT in HM. We hypothesized that HFRT in HM will result in a similar local tumor control that has been reported with standard fractionated RT.

MATERIALS/METHODS

In this retrospective study, we analyzed the data from patients within the provincial cancer registry diagnosed with HM treated with a curative intent using HFRT regimens suggested by International Lymphoma Radiation Oncology Group between 2020-2022 during the COVID-19 pandemic. Primary outcome of the study was overall response rate (ORR), measured as complete response (CR), partial response (PR) or stable disease (SD) within the irradiated field determined radiologically or clinically post completion of RT. Secondary end point was freedom from local progression (FFLP), calculated from the date of initiation of RT to the first date among in-field progression, death, and last follow-up. Summary statistics were used to describe cohort and treatment characteristics. FFLP was calculated by 1 minus cumulative incidence accounting for competing risk (i.e., death).

RESULTS

Of the 36 patients included for analysis, 18 were aggressive non-Hodgkin lymphoma (NHL), 9 were indolent NHL, 6 were Hodgkin lymphoma (HL) and 3 were other HM. Among them 25 had consolidation RT and 11 had definitive RT. HFRT daily dose per fraction ranged from 2.67 Gy to 5 Gy and total dose regimens ranged from 18 Gy to 42.5 Gy in 6 - 17 fractions and median equivalent dose in 2 Gy fractions (EQD2) for alpha/beta = 10Gy was 36 Gy (±7.5). ORR for the entire cohort was 94.4%. With a median follow up of 13.2 months, FFLP at one year for the entire cohort was 91.5% and death without infield progression was 8.7%. Among the 4 patients who had in radiation field recurrence, 2 had aggressive NHL and 2 had HL. No grade 3 or 4 acute toxicities were reported.

CONCLUSION

This retrospective study using HFRT showed an ORR and FFLP comparable to historical studies using standard fractionation. Further long-term follow-up is warranted to confirm these findings.

Low T-cell proportion in the tumor microenvironment is associated with immune escape and poor survival in diffuse large B-cell lymphoma

The tumor microenvironment (TME) is important in the pathogenesis and prognosis of lymphoma. Previous studies have demonstrated that features of the diffuse large B-cell lymphoma (DLBCL) TME can be associated with prognosis, but questions remain about the mechanisms underlying these TME features and the interplay between tumor cells and the local TME. Therefore, we performed multispectral immunofluorescence (mIF) using two 6-color panels to interrogate the cellular proportions of T-cell subsets, macrophages, and NK-cells in 57 cases of de novo DLBCL treated with R-CHOP chemotherapy. We found that very low CD3+ T-cell proportion and low CD4+PD1+ and CD8+PD1+ T-cells have poor survival compared to those with a high T-cell proportion. Also, cases with concurrently low TIM3 and PD1 have a poor prognosis. This poor prognosis with low T-cell proportion was validated using immune deconvolution of gene expression profiling data from 351 cases of DLBCL and an additional cohort of 53 cases of DLBCL using routine immunohistochemistry. In addition, cases with loss of B2M, HLA I and/or HLA II protein expression on the tumor cells also had a low T-cell proportion, providing evidence that lack of these proteins allows for immune evasion. Overall, our results show that patients with DLBCL with a low T-cell proportion in the TME have a poor survival when treated with R-CHOP and exhibit mechanisms of immune escape.

Relative frequency and clinicopathologic characteristics of MYC-rearranged follicular lymphoma

MYC rearrangement is a relatively rare genetic abnormality in follicular lymphoma (FL). In this study, we evaluated the relative frequency of MYC rearrangement in 522 cases of FL and studied their clinicopathologic, cytogenetic, and molecular characteristics. Fluorescence in situ hybridization studies for MYC (break-apart probe), MYC/IGH, IGH/BCL2, and BCL6 rearrangements were performed on tissue microarrays. Immunohistochemical stains for CD10, BCL2, BCL6, and MYC were performed and scored on MYC-rearranged cases. On 4 FL cases, a custom targeted panel of 356 genes was used for mutation analysis. Ten cases (1.9%) were positive for MYC rearrangement. Histologically, 6 of 10 cases were grade 1-2, and 4 cases were grade 3A. By immunohistochemistry, 9 of 9 tested cases were CD10+, all cases were BCL6+, and 9/10 cases were BCL2+. MYC protein staining was low in all cases tested. IGH/BCL2 rearrangement was detected in 5 of 9 cases, whereas BCL6 rearrangement was detected in 3 of 7 tested cases and 4 of 10 cases showed MYC/IGH rearrangement. The most commonly detected mutations in the MYC-positive cases included HLA-B, TNFRSF14, and KMT2D. MYC and/or B2M abnormalities were detected in 2 cases. In conclusion, MYC rearrangement is uncommon in FL and these cases do not appear to have specific histologic characteristics. Molecular analysis showed abnormalities in genes associated with transformation, namely MYC and B2M. Larger studies are needed to evaluate if MYC-rearrangement in FL has prognostic significance.

Validation of the Double-Hit Gene Expression Signature (DLBCL90) in an Independent Cohort of Patients with Diffuse Large B-Cell Lymphoma of Germinal Center Origin

The prognosis of diffuse large B-cell lymphoma (DLBCL) has been associated with clinical parameters, cell of origin, and various genetic aberrations. Recently, a NanoString gene expression assay (DLBCL90) was developed, which identifies DLBCL cases with an outcome similar to those with double- or triple-hit DLBCL with both MYC and BCL2 rearrangements. This study validates the predictive ability of the DLBCL90 assay in an independent cohort of patients with the germinal center B-cell subtype DLBCL. A customized targeted sequencing panel was used to analyze the mutational profile in these patients. Cases with a double or triple hit by conventional fluorescence in situ hybridization cytogenetic analysis are known to have a poor prognosis, and the DLBCL90 gene expression signature identified these cases, as well as additional cases that would have otherwise been missed by fluorescence in situ hybridization analysis. Our findings validate use of the DLBCL90 assay for identifying high-risk patients for new and innovative therapies.

Double-hit Signature with TP53 Abnormalities Predicts Poor Survival in Patients with Germinal Center Type Diffuse Large B-cell Lymphoma Treated with R-CHOP

PURPOSE

We performed detailed genomic analysis on 87 cases of de novo diffuse large B-cell lymphoma of germinal center type (GCB DLBCL) to identify characteristics that are associated with survival in those treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone).

EXPERIMENTAL DESIGN

The cases were extensively characterized by combining the results of IHC, cell-of-origin gene expression profiling (GEP; NanoString), double-hit GEP (DLBCL90), FISH cytogenetic analysis for double/triple-hit lymphoma, copy-number analysis, and targeted deep sequencing using a custom mutation panel of 334 genes.

RESULTS

We identified four distinct biologic subgroups with different survivals, and with similarities to the genomic classifications from two large retrospective studies of DLBCL. Patients with the double-hit signature, but no abnormalities of TP53, and those lacking EZH2 mutation and/or BCL2 translocation, had an excellent prognosis. However, patients with an EZB-like profile had an intermediate prognosis, whereas those with TP53 inactivation combined with the double-hit signature had an extremely poor prognosis. This latter finding was validated using two independent cohorts.

CONCLUSIONS

We propose a practical schema to use genomic variables to risk-stratify patients with GCB DLBCL. This schema provides a promising new approach to identify high-risk patients for new and innovative therapies.

Emerging therapies for the treatment of relapsed or refractory diffuse large B cell lymphoma

Diffuse large B cell lymphoma (dlbcl) is an aggressive non-Hodgkin lymphoma, accounting for approximately 30% of lymphoma cases in Canada. Although most patients will achieve a cure, up to 40% will experience refractory disease after initial treatment, or relapse after a period of remission. In eligible patients, salvage therapy followed by high-dose therapy and autologous stem-cell transplantation (asct) is the standard of care. However, many patients are transplant-ineligible, and more than half of those undergoing asct will subsequently relapse. For those patients, outcomes are dismal, and novel treatment approaches are a critical unmet need. In this paper, we present available data about emerging treatment approaches in the latter setting and provide a perspective about the potential use of those approaches in Canada.

Long-term time trends in incidence, survival and mortality of lymphomas by subtype among adults in Manitoba, Canada: a population-based study using cancer registry data

OBJECTIVE

To examine 30-year time trends in incidence, survival and mortality of lymphomas by subtype in Manitoba, Canada.

METHODS

Lymphoma cases diagnosed between 1984 and 2013 were classified according to the 2008 WHO classification system for lymphoid neoplasms. Death data (1984-2014) were obtained from the Manitoba Vital Statistics Agency. To examine time trends in incidence and mortality, we used joinpoint regression to estimate annual percentage change and average annual percentage change. Age-period-cohort modelling was conducted to measure the effects of age, period and cohort on incidence and mortality time trends. We estimated age-specific and standardised 5-year relative survival and used Poisson regression model to test time trends in relative survival.

RESULTS

Total Hodgkin lymphoma (HL) incidence in men and women was stable during the study period. Age-standardised total non-Hodgkin lymphoma (NHL) incidence increased by 4% annually until around 2000, and the trend varied by sex and NHL subtype. Total HL mortality continuously declined (by 2.5% annually in men and by 2.7% annually in women), while total NHL mortality increased (by 4.4% annually in men until 1998 and by 3.2% annually in women until 2001) and then declined (by 3.6% annually in men and by 2.5% annually in women). Age-standardised 5-year relative survival for HL improved from 72.6% in 1984-1993 to 85.8% in 2004-2013, and for NHL from 57.0% in 1984-1993 to 67.5% in 2004-2013. Survival improvement was also noted for NHL subtypes, although the extent varied, with the greatest improvement for follicular lymphoma (from 65.3% in 1984-1993 to 87.6% in 2004-2013).

CONCLUSIONS

Time trends were generally consistent with those reported in other jurisdictions in total HL and NHL incidence, but were unique in incidence for HL and for NHL subtypes chronic/small lymphocytic leukaemia/lymphoma, diffuse large B cell lymphoma and follicular lymphoma. Survival improvements and mortality reductions were seen for HL and NHL in both sexes.

Importance of accessible cancer care

Accessibility is a fundamental principle of government run health systems. Despite this, many factors impair access to care including geography, language, socioeconomic status and gender. Waiting for health care is a barrier to access that can result in significant anxiety and stress, deterioration in functional status and loss of income. Prompt access to diagnosis and treatment are key requirements to improving survival and quality of life for patients with cancer. This review will focus on studies, programs and policies aimed at improving access to care, applicability to patients with lymphoma, and potential impact. There is a growing burden on health care systems due to increasing cancer incidence and escalating health expenditures. Accordingly, initiatives and programs must be evaluated for effectiveness and efficiency.

Epidemiology of non-Hodgkin lymphoma

Non-Hodgkin Lymphoma (NHL) occurs worldwide although there is notable geographical variation in incidence and subtype distribution. These differences are due to a combination of demographic, environmental and other unidentified factors. A dramatic increase in NHL incidence was seen starting around 1970, with subsequent stabilization 10 years ago. Despite this plateau, the number of new cases in many countries will increase significantly in coming years due primarily to aging populations. In the majority of cases, strong risk factors are not identifiable. There is significant epidemiological heterogeneity between NHL subtypes, yet cancer registries have tended to consider NHL as a single entity. This is one of several epidemiological obstacles discussed.