Natural history of follicular grade 3 non-Hodgkin's lymphoma

A Favorable Outcome of Grade 3 Follicular Lymphoma Treated With Surgery and Obinutuzumab Combined With Chemotherapy: A Case Report and Literature Review

Follicular lymphoma is the most common type of low-grade non-Hodgkin lymphoma and the second most common type of lymphoma. Primary extranodal follicular lymphoma is rare compared with nodular follicular lymphoma involving the gastrointestinal (GI) tract. There has been uncertainty regarding follicular lymphomas due to the heterogeneous presentation and severity in which they present. However, studies showed that patients diagnosed with primary gastrointestinal follicular lymphoma do not typically differ in their presentation from those diagnosed with nodular follicular lymphoma involving the GI tract. Furthermore, recent literature identifies that patients diagnosed with grade 3 follicular lymphoma tend to have similar genetic and molecular entities to those diagnosed with diffuse large B-cell lymphoma (DLBCL). Based on these results, current studies have shown that patients with grade 3 follicular lymphoma who are treated with anthracycline-based regimens have similar outcomes to those with diffuse large B-cell lymphoma. However, additional studies are warranted to demonstrate the benefit of managing grade 3 follicular lymphoma with more aggressive anthracycline/rituximab-based regimens. Here, we present a case of a 44-year-old male diagnosed with grade 3 follicular lymphoma involving the gastrointestinal tract, who demonstrated an excellent treatment response following therapy similar to the treatment of bulky diffuse large B-cell lymphoma despite a tumor burden size below 7.5 cm.

Limited benefit of additional contrast-enhanced CT to end-of-treatment PET/CT evaluation in patients with follicular lymphoma

Despite follicular lymphoma (FL) is frequently characterized by a moderate increase of glucose metabolism, PET/CT examinations provides valuable information for staging and response assessment of the disease. The aim of the study was to assess and compare the diagnostic performance of PET/ldCT and PET/ceCT, respectively, in evaluating FL patients at the end of treatment. Fifty FL consecutive patients who underwent end-of-therapy PET/CT with both ldCT and ceCT were analyzed. Two blinded observers independently assessed PET/ldCT and PET/ceCT applying the Deauville score (DS) and Lugano classification criteria. PET imaging obtained after the end-of-treatment (EoT) was classified as showing PET and ce-CT matched response (concordant imaging group, CIG) or PET and ce-CT unmatched response (discordant imaging group, DIG). Relapse rate and Event-Free Survival (EFS) were compared between CIG and DIG patients. Overall, no differences in metabolic response classification were observed between PET/ldCT and PET/ceCT. In 13 (26%) patients PET/ceCT identified additional FDG-negative nodal lesions in mesenteric, retroperitoneal and iliac regions. However, in all cases, final DS remained unchanged and the additional results did not modify the following therapeutic decision. Among patients, who obtained complete metabolic response a comparable rate of relapse was registered in DIG 3/13 (23%) and CIG subgroups 5/20 (25%) [p = 0.899]. In all 3 DIG cohort patients who relapsed the recurrent disease involved also, but not exclusively, PET negative lymph nodes detected by ceCT. In overall population metabolic response defined by PET/ldCT predicted EFS [76% (group of patients with metabolic response) vs 35% (group of patients with residual disease), p = 0.0013] significantly better than ceCT-Based response assessment [75% (group of patients with complete response) vs 53% (group of patients with residual disease), p = 0.06]. Our study demonstrates a negligible diagnostic and predictive value of ceCT performed in addition to standard ¹⁸FDG PET/ldCT for EoT response evaluation in FLs. PET/ldCT should be performed as first-line imaging procedure, also in patients with prevalent abdominal and pelvic involvement, limiting the acquisition of ceCT in selected cases. This tailored approach would contribute to avoid useless radiation exposure and preserve renal function of patients.

Pixantrone plus rituximab versus gemcitabine plus rituximab in patients with relapsed aggressive B-cell non-Hodgkin lymphoma not eligible for stem cell transplantation: a phase 3, randomized, multicentre trial (PIX306)

PIX306 was a phase 3, randomised, single-blind, multicentre trial conducted in adult patients with diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma (FL) grade 3 who relapsed after ≥1 rituximab-containing regimen and were not eligible for a stem cell transplant. Patients were randomised 1:1 to pixantrone 50 mg/m² or gemcitabine 1000 mg/m² on days 1, 8 and 15 of a 28-day cycle, combined with rituximab 375 mg/m² on day 1, for up to six cycles. Patients were followed for up to 96 weeks. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), complete response (CR) rate, overall response rate (ORR) and safety. Overall, 312 patients were randomised (median age 73·0 years). The study did not meet its primary endpoint. Median PFS [95% confidence interval (CI)] was 7·3 months (5·2-8·4) with pixantrone + rituximab (PIX + R) and 6·3 months (4·4-8·1) with gemcitabine + rituximab [GEM + R; hazard ratio (HR): 0·85; 95% CI 0·64-1·14; P = 0·28]. Median OS was 13·3 (10·1-19·8) months with PIX + R and 19·6 (12·4-31·9) months with GEM + R (HR: 1·13; 95% CI 0·83-1·53). ORR was 61·9% and 43·9% respectively and CR rate 35·5% and 21·7%. The incidence of adverse events, including cardiac events, was not statistically significant different between PIX + R and GEM + R.

Follicular lymphoma grade 3: review and updates

Follicular lymphoma (FL), Grade 3, is recognized as a distinct entity in the World Health Organization classification of lymphoma. It is further classified into Grade 3a and Grade 3b depending on the Bernard cell counting system and percentage of centroblasts. Grade 3 has molecular and genetic characteristics that distinguish it from other grades of FL. There is confusion and misunderstanding about the natural history and clinical course of Grade 3a and 3b because some studies indicate them as having indolent behavior and others describe more aggressive biology. The purpose of this article is to understand the concept of Grade 3 FL, especially the fundamental differences between Grade 3a and Grade 3b FL. Grade 3 FL is still an evolving subclass in FL and the practicing physician should understand the aggressive nature of Grade 3b, which typically requires timely attention, compared with Grade 3a. Grade 3a FL has more indolent characteristics but can possibly progress to Grade 3b and/or transform to diffuse large B-cell lymphoma at a future time. Nevertheless, large prospective studies are missing for an optimal evidence-based management approach for patients with Grade 3 FL at this time.

Inter-reader variability in follicular lymphoma grading: Conventional and digital reading

CONTEXT

Pathologists grade follicular lymphoma (FL) cases by selecting 10, random high power fields (HPFs), counting the number of centroblasts (CBs) in these HPFs under the microscope and then calculating the average CB count for the whole slide. Previous studies have demonstrated that there is high inter-reader variability among pathologists using this methodology in grading.

AIMS

The objective of this study was to explore if newly available digital reading technologies can reduce inter-reader variability.

SETTINGS AND DESIGN

IN THIS STUDY, WE CONSIDERED THREE DIFFERENT READING CONDITIONS (RCS) IN GRADING FL: (1) Conventional (glass-slide based) to establish the baseline, (2) digital whole slide viewing, (3) digital whole slide viewing with selected HPFs. Six board-certified pathologists from five different institutions read 17 FL slides in these three different RCs.

RESULTS

Although there was relative poor consensus in conventional reading, with lack of consensus in 41.2% of cases, which was similar to previously reported studies; we found that digital reading with pre-selected fields improved the inter-reader agreement, with only 5.9% lacking consensus among pathologists.

CONCLUSIONS

Digital whole slide RC resulted in the worst concordance among pathologists while digital whole slide reading selected HPFs improved the concordance. Further studies are underway to determine if this performance can be sustained with a larger dataset and our automated HPF and CB detection algorithms can be employed to further improve the concordance.

Immunomodulation therapy with lenalidomide in follicular, transformed and diffuse large B cell lymphoma: current data on safety and efficacy

Lenalidomide is an immunomodulatory agent which has been approved for multiple myeloma. Lenalidomide is also effective in and tolerated well by patients with follicular lymphoma, diffuse large B-cell lymphoma, and transformed large cell lymphoma. This review summarizes the results of current preclinical and clinical studies of lenalidomide, alone or in combination with the monoclonal antibody rituximab, as a therapeutic option for these three lymphoma types. This review will serve as a tool guiding future clinical investigations to improve survival rates for these three lymphomas.

FDG-PET in Follicular Lymphoma Management

18-Fluoro-deoxyglucose positron emission tomography/computerised tomography (FDG PET/CT) is commonly used in the management of patients with lymphomas and is recommended for both initial staging and response assessment after treatment in patients with diffuse large B-cell lymphoma and Hodgkin lymphoma. Despite the FDG avidity of follicular lymphoma (FL), FDG PET/CT is not yet applied in standard clinical practice for patients with FL. However, FDG PET/CT is more accurate than conventional imaging for initial staging, often prompting significant management change, and allows noninvasive characterization to guide assessment of high-grade transformation. For restaging, FDG PET/CT assists in distinguishing between scar tissue and viable tumors in residual masses and a positive PET after induction treatment would seem to predict a shorter progression-free survival.

Imaging in follicular NHL

Imaging contributes to management of follicular lymphoma (FL) through guiding biopsy, determining disease stage and assessing therapeutic response. Molecular imaging with positron emission tomography (PET), especially when combined with computer tomography (PET/CT), is more accurate than conventional imaging and extends the role of imaging to lesion characterisation, including non-invasive assessment of high-grade transformation. There is strong data to support the use of FDG PET/CT for primary staging, resulting in significant management change. In patients with early stage follicular lymphoma (stage I or II), there is a clear role for PET/CT to avoid futile involved-field radiotherapy in patients with widespread disease and to optimise the treatment field in patients with confirmed localised disease. For restaging, use of PET/CT allows discrimination between scar tissue and viable tumour in residual masses. Molecular imaging is likely to play an increasing role in selection of patients for specific treatments and in prognostic stratification.

Survival in non-Hodgkin's lymphoma by histology and family history

PURPOSE

Although survival has been studied for various subtypes of non-Hodgkin's lymphoma (NHL), there have been few comprehensive studies to quantify the prognosis, including all specific histologies. The effect of family history on survival in NHL has not been examined.

METHODS

We used the Swedish Family-Cancer Database to estimate hazard ratios in NHL by histology and family history.

RESULTS

Using diffuse centroblastic lymphoma as reference (HR 1.0), patients with Waldenström's macroglobulinemia and hairy-cell leukemia had the best survival. Survival advantage was also noted among patients with lymphoplasmacytic lymphoma and different kinds of follicular lymphomas. For T-cell lymphoma, mycosis fungoides showed a favorable prognosis. As for survival by family history, a total of 98 familial cases were noted in our Database with a similar prognosis compared to sporadic cases in both parental and offspring generations. A non-significant familial concordance of either good or poor survival was noted among family members when probands' prognosis was stratified by survival time.

CONCLUSIONS

Our results provide quantitative prognosis data for patients with NHL according to specific histologies. Patients with a familial NHL had a similar prognosis compared to patients with sporadic disease. The data suggest familial concordance in either good or poor survival among family members.

Prognostic significance of B-cell differentiation genes encoding proteins in diffuse large B-cell lymphoma and follicular lymphoma grade 3

AIM

To define prognostic significance of B-cell differentiation genes encoding proteins and BCL2 and BCL6 gene abnormalities in diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern.

METHODS

In 53 patients with diffuse large B-cell lymphoma and 20 patients with follicular lymphoma grade 3 with >75% follicular growth pattern the following was performed: 1) determination of protein expression of BCL6, CD10, MUM1/IRF4, CD138, and BCL2 by immunohistochemistry; 2) subclassification into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) groups according to the results of protein expression; 3) detection of t(14;18)(q32;q21)/IgH-BCL2 and BCL6 abnormalities by fluorescent in situ hybridization in diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern as well as in GCB and ABC groups; and 4) assessment of the influence of the analyzed characteristics and clinical prognostic factors on overall survival.

RESULTS

Only BCL6 expression was more frequently found in follicular lymphoma grade 3 with >75% follicular growth pattern than in diffuse large B-cell lymphoma (P=0.030). There were no differences in BCL2 and BCL6 gene abnormalities between diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern. Diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern patients were equally distributed in GCB and ABC groups. t(14;18)(q32;q21) was more frequently recorded in GCB group, and t(14;18)(q32;q21) with BCL2 additional signals or only BCL2 and IgH additional signals in ABC group (P=0.004). The GCB and ABC groups showed no difference in BCL6 gene abnormalities. There was no overall survival difference between the diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern patients, however, GCB group had longer overall survival than ABC group (P=0.047). Multivariate analysis showed that BCL6, CD10, and BCL2 expression, BCL2 and BCL6 abnormalities, and International Prognostic Index were not significantly related to overall survival.

CONCLUSION

Diffuse large B-cell lymphoma and follicular lymphoma grade 3 with >75% follicular growth pattern patients have very similar characteristics and their prognosis is more influenced by protein expression of B-cell differentiation stage genes than by tumor cells growth pattern, BCL2 and BCL6 abnormalities, and International Prognostic Index.