Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards

ASCO University
Mar 09, 2016 9:36 AM

User Instructions: Welcome to the Molecular Oncology Tumor Board Series! This educational initiative is a collaboration between the American Society of Clinical Oncology (ASCO), College of American Pathologists (CAP), and Association for Molecular Pathology (AMP).

A new case will be presented each month with discussions led by an expert pathologist and medical oncologist. Have an interesting case in mind? Submit your hypothetical patient cases for consideration in an upcoming Molecular Oncology Tumor Board discussion forum.

This month’s topic is led by Drs. Joseph Khoury (MD Anderson Cancer Center) and Grzegorz Nowakowski (Mayo Clinic). 

Users are encouraged to leave comments and post questions about the case in order to generate a wide discussion among the cancer care community. You can also receive email notifications when new comments are posted by clicking the “Follow this Conversation” option located at the bottom of this page.

When posting, please abide by the terms and conditions of this website

Please see attached for supplemental resources related to the case. 

Comments

12286

ASCO University
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 09, 2016 9:41 AM

Patient Case

Age/Sex:  55 year old female 

Medical History: The patient presented with several weeks history of progressive left cervical adenopathy. The patient FNA suggested high grade neoplasm and excisional biopsy was recommended. The patient denied night sweats, fevers or weight loss. She reports several weeks of vague, mild lateral left pelvic discomfort. She is able to perform all daily living activities, ECOG performance status 1.  

A left cervical LN excision was performed. 
 
Biopsy: The left cervical LN excisional biopsy showed a lymphoid malignancy comprised of large cells with moderate amounts of cytoplasm. The neoplastic cells had vesicular chromatin and prominent nucleoli. Mitotic figures were numerous. [Figure 1] By immunohistochemistry, the neoplastic cells were positive for CD20 and MUM1, and they were negative for CD10, BCL2 and BCL6. [Figure 2] On the basis of this immunophenotype, this neoplasm was classified as non-germinal center B-cell-like (non-GCB). Fluorescence in situ hybridization (FISH) using a breakapart probe set specific for the MYC gene locus was negative for rearrangement or copy number variation. [Figure 3]

Additional studies: The staging PET scan is shown. [Figure 4] Bone marrow biopsy showed no evidence of involvement by lymphoma.  LDH was elevated - 506 u/L with upper limit of normal of 222 u/L in local laboratory. Vitamin D level was 21 ng/mL (normal 21-50 ng/mL).  CBC, liver function tests and routine serum chemistry were unremarkable.

Type of Tumor: Diffuse large B-cell lymphoma. 

Relevant Markers:  CD20, MYC FISH

Prior Treatment History/Response: None.

Co-morbidities: Type 2 diabetes, diet controlled and hyperlipidemia. Echocardiography showed normal EF of 65%. Hepatitis B, C and HIV serology were negative. 

Images/Scans/Pathology: PET (PET 0) scan at initial diagnosis 

*The course faculty would like to acknowledge the contributions of Dr. Rebecca King with providing pathology images and Dr. William Sukov in providing the FISH image used in this post*

12291

ASCO University
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 09, 2016 9:43 AM

Discussion Questions

  1. What molecular testing on tissue should be performed in newly diagnosed DLBCL? 
  2. How does the need for molecular testing affect tissue requirements and biopsy size? 
  3. What staging studies and serum biomarkers would you obtain?  

12296

Anis Toumeh, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 09, 2016 3:44 PM

It is important to run the molecular studies which help identify those with higher risk disease (double hit lymphomas, double expressors and non germinal center) as the bullk of evidence suggests that their prognosis is less favorable with standard R-CHOP chemotherapy. FISH studies for c-MYC, BCL-2 and BCL-6, IHC for c-MYC, BCL-2, BCL-6 and MUM1 help identifying those patients (although the differentiation between germinal and non-germinal types can be best done through GEP). Having said that, and with the increased number of studies done on biopsy material, it is important to obtain enough tissue through preferably an excisional biopsy (or core biopsy if excision is not feasible) rather than FNA. 

I normally obtain a PET-CT for staging and a bone marrow biopsy especially in the context of possible stage I,II disease. CBC with differential and serum creatinine, liver function tests and electrolytes. Serum LDH aids in calculating the IPI score for risk stratification. 

 

12301

Gita Thanarajasingam, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 10, 2016 2:10 AM

In a patient with non-GCB DLBCL via IHC I would definitely obtain GEP and consider a clinical trial of R(X)-CHOP.  Two questions: (1) the incidence of double hit in non GCB patients is low - is it low enough to justify not performing FISH in patients who are non GCB by GEP? (2) After initial immunochemotherapy, would you consider radiating the site of bulky disease in the neck?

Thanks!

12306

Grzegorz S. Nowakowski, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 10, 2016 4:24 PM

Course Faculty Response

I agree with Dr. Toumeh's plan. We usually would perform IHC for myc as well. Unfortunately at present, there is very little evidence  what else can be done with patients identified as having high risk features.

To comment on Dr. Thanarajasingam’s questions, although most of double hit lymphoma appears to be of GCB subtype, the data in this regard is still emerging, and we routinely perform FISH for myc/bcl2/bcl6 regardless of molecular subtype at our institution. Radiation therapy to sites of bulky disease is somewhat controversial (as is definition of bulk).  If PET is negative post therapy (PET6), we typically would not consolidate with RT in our practice. If PET is positive, RT could be considered,  however, due to limited specificity, we usually favor biopsy and if indeed residual lymphoma is seen, we would use salvage therapy followed by HDC and ASCT. RT can be given then on day 60 post-transplant. The practice at other centers may vary in this regard.

 

12311

Daniel Oscar Persky, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 10, 2016 6:56 PM

I also agree with Dr. Toumeh's plan.

 

At our center we also obtain cell of origin designation and Myc/Bcl2 by immunohistochemistry, and FISH for MYC/BCL2/BCL6. We would not typically use radiation if PET6 was negative. 

12316

Jason R. Westin, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 11, 2016 9:41 AM

Excellent discussion of a common scenario - what to do to fully work up a patient with IPI 2 (LDH, stage) non-GCB DLBCL.

I agree with the need to determine cell of origin for all DLBCL patients, although the clinically utilized immunohistochemistry markers ("the Hans algorithm") is not ideal and gene expression profiling is not available as a standard of care assay. I agree with Dr. Thanarajasingam that true FISH defined 'double hit' is primarily a disease of GC origin, but the failings of immunohistochemistry cell of origin classification warrant FISH testing in all DLBCL patients due to the implications in clinical management and prognosis of a positive result. In order to obtain these tests, an FNA is not a sufficent method to diagnose DLBCL, and a core or ideally excional biopsy are required.

I agree with the discussion regarding use of PET, especially the need to biopsy an FDG postiive post therapy lesion to rule out a false positive. Regarding biomarkers, the use of blood based disease monitioring technologies are not yet ready for standard of care, but could be available in the next few years. These tools will require large clinical trials, some of which are ongoing now, to validate and determine how they should be used in clinical practice. 

At MD Anderson, we would strongly recommend a clinical trial to this patient due to the non-GCB phenotype. R-CHOP + X trials are necessary from a drug approval standpoint, but are sub-optimal long term as they further cement the ancient regimen of CHOP. Will we be managing DLBCL patients with R-CHOP based therapy 30 years from now? I certainly hope not.

 

12321

Anis Toumeh, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 11, 2016 12:19 PM

I certainly hope not too. We understand much more today about the heterogeniety of this disease, yet we don't seem to know how to best tackle down different subtypes optimally. Hopefully, ongoing trials will give some answers in the near future. 

12326

Catherine Lai, MD, MPH
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 11, 2016 4:41 PM

Great case and discussion. I also agree with Dr. Toumeh's plan. GEP is ideal but unfortunately the turn around time prohibits the results being used prior to starting treatment. I think excisional lymph node biopsies are preferred to adequately evaluate lymph node architecture. If the PET scan is negative at the end of treatment, I would not give radiation. In terms of treatment, hopefully the results of the CALGB randomized phase III of R-CHOP vs. R-EPOCH will be out soon and will give us more information. Also, I think clinical trials with R-CHOP + a targeted agent makes sense.

12331

Joseph Khoury
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 14, 2016 8:42 AM

Course Faculty Response

The scope of molecular testing for DLBCL is currently evolving. While no specific molecular tests are necessarily needed for diagnostic purposes, there is an increased emphasis to use molecular testing for subtyping DLBCL as was done in this case or to identify targetable mutations in patients with relapsed or refractory disease. Beyond molecular testing, FISH is an important testing modality that allows assessment of rearrangements and copy number alterations involving genes that are important in DLBCL such as MYC, BCL2, and BCL6.  

The need for molecular testing necessitates close communication between the oncologist, surgeon or interventional radiologist, and pathologist. Most molecular tests may be done on formalin-fixed paraffin-embedded tissue material, but assays that require high-quality RNA continue to yield best results using fresh samples.

 

12336

Grzegorz S. Nowakowski, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 14, 2016 8:44 AM

Course Faculty Response

I could not agree more with Dr. Khoury - the molecular classification of DLBCL is rapidly evolving and increasingly clinically important. As of now, several, sometimes overlapping subtypes can be identified. I would highlight ABC vs GCB  molecular subtypes and double hit lymphoma.  

For over 15 years now we know that gene expression profiling (GEP) of DLBCL identifies two major DLBCL subtypes: germinal center B-cell-like (GCB) subtype and activated B-cell (ABC) type. The ABC subtype is also referred to as non-GCB in immunohistochemistry (IHC) based classification and is associated with a significantly worse outcome when treated with R-CHOP. Until recently, there was a limited interest outside of researchers in identifying patients with ABC DLBCL clinically, since not much could have been done about the worse outcome of these patients and the assays were technically challenging and took a long time to elicit results. This has changed for two reasons. First, we now have drugs specifically active in the ABC subtype of DLBCL.  These include bortezomib, lenalidomide and ibrutinib. These agents are now combined with RCHOP (XRCHOP, where X is a targeted agent) in front line therapy of DLBCL. Second, the development of rapid immunohistochemistry techniques and GEP from paraffin tissue (Lymph 2Cx using Nanostring platform) allow for the identification of patients with non-GCB/ABC DLBCL at diagnosis. 

The other important subtype is “double hit” lymphoma – DLBCL with c-myc and bcl2 or bcl6 translocations. These are detected by FISH, in contrast to “double protein expression” patients where c-myc and bcl-2 overexpression is detected by IHC. Double hit lymphoma as defined by FISH, is associated with a poor outcome. Interestingly, double hit lymphoma is typically referred to as GCB DLBCL in molecular classification, and double hit DLBCL accounts for significant proportions of GCB DLBCL patients failing RCHOP. While the optimal management of double hit lymphoma is unknown, most experts recommend dose intensified chemotherapy. Venitoclax or ABT199 appears to be particularly promising in this space because of bcl2 inhibition. Several early ongoing and planned clinical trials are addressing patients with double hit lymphoma.

 

12341

ASCO University
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 14, 2016 8:47 AM

Patient Case Update

How tissue was acquired/preserved: FFPE

Testing Platform/Molecular Profiling: 

Nanostring: The patient was classified as ABC DLBCL by Lymph2Cx using Nanostring platform, as a part of E1412, a clinical trial. 

The patient was an overall stage IVA (extranodal bone involvement by PET, BM biopsy negative), IPI 2 (stage 3/4, elevated LDH).  

The patient elected to enter clinical study E1412 (NCT 01856192) , a NCI sponsored, multicenter, US inter-group study led by ECOG randomizing patients with newly diagnosed DLBCL to lenalidomide RCHOP (R2CHOP) vs RCHOP. The patient was randomized to experimental arm (R2CHOP).

The follow PET scan after 3 cycles of therapy (PET3) showed complete response (Figure 5).  PET scan at the end of therapy (PET6) showed no evidence of disease.  The patient is currently 24 months post completion of therapy and has no evidence of recurrence. 

12346

ASCO University
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 14, 2016 8:48 AM

Discussion Questions

  1. What are the prognostic implications of findings in this patient? 
  2. What are the differences between molecular classification methods? 
  3. What is the expected outcome?
  4. What are therapeutic options? 
  5. What is the impact of EFS24 (event-free survival at 24 months) on OS in DLBCL?

 

12356

Joseph Khoury
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 18, 2016 9:11 AM

Course Faculty Response

As Dr. Nowakowski elegantly described previously, subtyping of DLBCL has gained increased importance in the past few years with divergent therapeutic approaches for patients within each of the subtypes. The NanoString platform offers a subtyping assay, the Lymph2Cx, which relies on measurement of the expression status of 20 genes permitting subtyping DLBCL into GCB and ABC subtypes. Of note, the assay may be done using RNA derived from formalin-fixed paraffin-embedded tissue. In essence, the assay measures mRNA transcripts of 15 genes known to be significantly differentially expressed in the two DLBCL subtypes, as well as transcripts of 5 housekeeping genes. In a recent study by Scott DW et al, the assay was reported to have good and reproducible performance characteristics. How the Lymph2Cx will compare to IHC-based subtyping remains to be determined. 

 

12361

Grzegorz S. Nowakowski, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 18, 2016 9:16 AM

Course Faculty Response

This patient has high IPI and ABC DLBCL. This subtype of DLBCL is associated with a poor outcome, with expected PFS of 30-40% at 2 years. The impact of IPI on the outcome of patients with ABC DLBCL is less defined; patients with ABC DLBCL usually present with high IPI. The low vitamin level has been associated with a poor outcome in DLBCL. At present it is unknown if replacement of vitamin D can overcome the negative prognostic impact of low vitamin D.  The impact of vitamin D and its replacement is currently being evaluated in clinical trials. 

The ABC DLBCL in this patient is identified using Nanostring platform by Lymph2Cx from paraffin tissue. The patient entered a clinical study of R2CHOP vs RCHOP, E1412. 

The basis for these trials came from a phase 2 study of 64 patients with newly diagnosed DLBC.  Lenalidomide combined with RCHOP (R2CHOP) was well tolerated and resulted in a high complete response rate and encouraging progression- free and overall survival. Importantly, the addition of lenalidomide to RCHOP appeared to be particularly beneficial in a non-GCB subtype of DLBCL when results were compared to historical controls, essentially overcoming the negative prognostic impact of the ABC phenotype. Similar results were seen in an independent study conducted by an Italian group. These promising results led to the development of two currently ongoing randomized front line studies in DLBCL, E1412 and a ROBUST trial. 

E1412 (NCT 01856192) is an NCI sponsored, multicenter, US inter-group study led by ECOG, randomizing patients with newly diagnosed stage 2-4 DLBCL to R2CHOP vs RCHOP. In this study, patients with DLBCL are eligible, regardless of molecular subtype. Cell of origin by gene expression profiling is analyzed in all subjects from paraffin tissue using Nanostring platform and Lymph2Cx algorithm. The study is powered to analyze outcomes based on molecular subtype of DLBCL.

A second study, DLC002 or ROBUST study (NCT02285062), a multicenter global study supported by Celgene, focuses specifically on newly diagnosed ABC DLBCL. Eligible patients with stage 2-4 DLBCL, are identified by real time GEP using Nanostring platform (5 calendar days turnaround time) and ABC DLBCL patients are then randomized to R2CHOP plus RCHOP plus placebo.  

The fact that patients are now 24 months from diagnosis is an excellent prognostic factor, as patients without relapse in 24 months after diagnosis (EFS24) are at a low risk of relapse and have normal expected survival as compared with the normal population.

12376

Joseph Khoury
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 23, 2016 9:56 AM

Course Faculty Summary

This case is that of a patient with DLBCL, ABC subtype, determined with GEP profiling on the NanoString platform Lymph2Cx assay, an example of one of the emerging techniques of rapid GEP classification of DLBCL using paraffin embedded tissue. Immunohistochemistry also demonstrated a non-GCB immunophenotype, positive for CD20 and MUM1 with absence of CD10 expression. The tumor was negative for MYC rearrangement by FISH. 

 

12381

Grzegorz S. Nowakowski, MD
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 23, 2016 9:57 AM

Course Faculty Summary

The patient presented with typical features of ABC DLBCL including high LDL and extranodal disease. The patient entered clinical trial E1412, and was randomized to R2CHOP. R2CHOP is one of the XRCHOP combinations that showed promise in ABC DLBCL. Ongoing clinical trials will demonstrate if (and if so, which of) XRCHOP overcomes the negative prognostic impact of ABC DLBCL. Patients with different molecular subtypes of DLBCL should be encouraged to participate in clinical trials.

 

12386

ASCO University
Re: Diffuse Large B-Cell Lymphoma (March 2016): Molecular Oncology Tumor Boards
Mar 23, 2016 9:59 AM

Thank you to Drs. Khoury and Nowakowski for leading the discussion of this case and also to all of those who contributed to the conversation! The forum is now closed to further comments but participants can claim credit through ASCO University.

Please check back in mid-April for a new case in this series related to lung cancer.   

Have an interesting case in mind? Submit your hypothetical patient cases for consideration in an upcoming Molecular Oncology Tumor Board discussion forum.


Advertisement