Is watch and wait still acceptable for patients with low-grade follicular lymphoma? Blood. 2016;127:2804-2808. [PMID: 26994147 DOI: 10.1182/blood-2015-11-632745]

Baseline 18F-FDG PET/CT may contribute to the determination of initial treatment strategy for newly diagnosed follicular lymphoma

BACKGROUND

"Watch-and-wait" approach is an important management option in asymptomatic follicular lymphoma (FL) patients with low tumor burden. Since most FL lesions are FDG-avid, we wonder if 18F-FDG PET/CT at baseline can help to better choose the patients who can benefit from early chemotherapy. This study aimed to investigate the prognostic value of baseline 18F-FDG PET/CT in newly diagnosed FL patients treated with either watch-and-wait approach or chemotherapy.

RESULTS

Patients received chemotherapy as initial treatment had higher Ann Arbor stage, higher incidence of extranodal involvement and bulky disease, more involved lymph nodes larger than 3 cm, and higher SUVmax, MTV, and TLG than those managed with watch-and-wait approach (p < 0.05). The median PFS and TTNT in patients received chemotherapy and under watch-and-wait did not show significant difference, however patients with MTV<111.66 mL or TLG<141.50 SUVbw*mL had significantly longer PFS and TTNT than those patients with MTV≥111.66 mL or TLG≥141.50 SUVbw*mL (p < 0.05). Further analysis revealed that for patients with TLG≥141.50 SUVbw*mL or MTV≥111.66 mL, those who received chemotherapy as initial treatment had a significantly longer PFS and TTNT than those managed with initial watch-and-wait approach (p < 0.05). However, for patients with MTV<111.66 mL or TLG<141.50 SUVbw*mL in baseline PET/CT, there was no significant difference in PFS or TTNT between patients who received chemotherapy and those under watch-and-wait.

CONCLUSION

Baseline 18F-FDG PET/CT may provide prognostic value and help to improve the decision-making of initial treatment plans for newly diagnosed FL patients.

B-cell non-Hodgkin lymphomas

B-cell lymphomas occur with an incidence of 20 new cases per 100 000 people per year in high-income countries. They can affect any organ and are characterised by heterogeneous clinical presentations and courses, varying from asymptomatic, to indolent, to very aggressive cases. Since the topic of B-cell non-Hodgkin lymphomas was last reviewed in The Lancet in 2017, a deeper understanding of the biological background of this heterogeneous group of malignancies, the availability of new diagnostic methods, and the development and implementation of new targeted and immunotherapeutic approaches have improved our ability to treat patients. This Seminar provides an overview of the pathobiology, classification, and prognostication of B-cell non-Hodgkin lymphomas and summarises the current knowledge and standard of care regarding biology and clinical management of the most common subtypes of mature B-cell non-Hodgkin lymphomas. It also highlights new findings in deciphering the molecular background of disease development and the implementation of new therapeutic approaches, particularly those targeting the immune system.

Starting and stopping cancer drugs: The need for randomized trials

Precision oncology has gained widespread popularity over the past decade, and increasingly oncologists strive to provide the right treatment to the right patient. To date, precision efforts have focused on the specific mutational target(s), food/ drug interactions, functional oncology, or dose of drug given. Moreover, the tumor and blood samples of hundreds of thousands of patients with cancer have been sequenced in the United States alone with the goal of identifying and prescribing the most precise treatment. Despite this broad consideration of precision oncology, one neglected aspect of precision oncology is identifying the optimal start time and stopping point for cancer therapies. Is it possible to improve overall survival (OS) or quality of life for patients with more precise initiation and discontinuation of therapy? In this commentary, we review the historical basis to initiate, discontinue or switch therapies. We emphasize that largely these time points were selected arbitrarily, and subsequently constrained by historical accident. We highlight randomized efforts to better elucidate the time points in starting or stopping therapy. Finally, we provide suggestions for a research agenda on precision timing of anti-cancer drugs.

Managing Follicular Lymphoma in the Elderly Population

Follicular lymphoma (FL) is one of the most commonly diagnosed types of indolent non-Hodgkin lymphoma (NHL). The median age of diagnosis for FL is 65 years old. Although the median life expectancy after diagnosis is approximately 10 years, the incurable disease has a high risk of transformation. This case report focuses on an 80-year-old patient diagnosed with low-grade follicular lymphoma which subsequently transformed leading to the patient's eventual demise as the patient took on the palliative intent. This case report aims to highlight the importance of clinical markers or prognostic factors to identify patients, specifically the elderly population who are at risk of transformation to aggressive forms when their FL remains at stage I-II phases. Currently, elderly patients with FL tend to be quickly dismissed with curative intent with chemotherapy, given their age and comorbidities, despite forming the majority of the population with follicular lymphoma. Age more than 60 years old has been shown to be one of the most powerful yet poor prognostic features in follicular lymphoma international prognostic index (FLIPI)-the main scoring system used for FL. Hence, further studies are required to look into the tailoring treatment for elderly patients with follicular lymphoma after risk stratifying them with appropriate clinical and prognostic markers.

Bruton’s Tyrosine Kinase Inhibitor Zanubrutinib Effectively Modulates Cancer Resistance by Inhibiting Anthracycline Metabolism and Efflux

Zanubrutinib (ZAN) is a Bruton’s tyrosine kinase inhibitor recently approved for the treatment of some non-Hodgkin lymphomas. In clinical trials, ZAN is often combined with standard anthracycline (ANT) chemotherapy. Although ANTs are generally effective, drug resistance is a crucial obstacle that leads to treatment discontinuation. This study showed that ZAN counteracts ANT resistance by targeting aldo-keto reductase 1C3 (AKR1C3) and ATP-binding cassette (ABC) transporters. AKR1C3 catalyses the transformation of ANTs to less potent hydroxy-metabolites, whereas transporters decrease the ANT-effective concentrations by pumping them out of the cancer cells. In our experiments, ZAN inhibited the AKR1C3-mediated inactivation of daunorubicin (DAUN) at both the recombinant and cellular levels. In the drug combination experiments, ZAN synergistically sensitised AKR1C3-expressing HCT116 and A549 cells to DAUN treatment. Gene induction studies further confirmed that ZAN did not increase the intracellular level of AKR1C3 mRNA; thus, the drug combination effect is not abolished by enzyme induction. Finally, in accumulation assays, ZAN was found to interfere with the DAUN efflux mediated by the ABCB1, ABCG2, and ABCC1 transporters, which might further contribute to the reversal of ANT resistance. In summary, our data provide the rationale for ZAN inclusion in ANT-based therapy and suggest its potential for the treatment of tumours expressing AKR1C3 and/or the above-mentioned ABC transporters.

Routine Pathologic Examination of Femoral Head Specimens from Total Hip Arthroplasty May Not Be Indicated or Cost-effective: A Systematic Review

Background

There is considerable disparity in institutional practices surrounding routine pathologic examination of femoral heads removed during total hip arthroplasty (THA). Multiple groups have studied the merits of routine femoral head pathology in THA, without clear consensus. We sought to further investigate the existing evidence on routine pathologic examination of femoral heads retrieved during THA to determine if this practice provides additional clinical value and is cost-effective.

Material and methods

To conduct a systematic review of the literature, a medical librarian was consulted to develop and perform comprehensive searches in PubMed (1809-present), Embase (embase.com 1974-present), CINAHL (EBSCO, 1937-present), and the Cochrane Central Register of Controlled Trials (Wiley). Final searches resulted in 727 references. Through multiple reviewer screenings and assessments of eligible full-text articles, we included 14 articles for review.

Results

Our systematic review yielded pathologic examination results from 17,388 femoral head specimens collected during THA. In 0.85% of cases, the pathologic diagnosis differed in a meaningful way from the preoperative clinical diagnosis. Routine pathology changed patient management in approximately 0.0058% of cases. The average cost for pathologic examination of each specimen was $126.38.

Conclusion

Routine pathologic examination of femoral heads retrieved during THA has limited impact on patient management. With an estimated 500,000 THAs performed in 2019, the economic feasibility of routine femoral head pathology is limited at an annual cost of up to $63,000,000 and cost per quality-adjusted life-year approaching infinity. However, surgeon discretion on a patient-specific or practice-specific basis should be used to make the final determination on the need for femoral head pathology.

Follicular Lymphoma in China: Systematic Evaluation of Follicular Lymphoma Prognostic Models

Objects

To systematically evaluate the baseline characteristics, tumour microenvironment indicators such as the lymphocyte/monocyte ratio (LMR) and treatment response (POD24) as prognostic predictors of follicular lymphoma (FL) among Chinese patients.

Methods

We retrospectively analysed 112 FL patients from 2000 to 2017, whose pathology grading included 1-3a. Absolute lymphocyte and monocyte counts were determined by cell blood counting. The Kaplan-Meier method was used to analyse the influence of prognostic predictors on progression-free survival (PFS) and overall survival (OS). Multivariate analysis was conducted using the Cox proportional risk model.

Results

The long-term survival of Chinese FL patients (median PFS, 74.8 months) was slightly better than that of patients in foreign countries. Among several prognostic models, the Follicular Lymphoma International Prognostic Index (FLIPI) score had a significant effect on both PFS and OS, while there were no independent prognostic predictors. Patients with LMR ≤3.6, ALC ≤0.6*109/L and AMC >0.6*109/L had worse OS, among which LMR was an independent indicator of OS. The POD24 subgroup had a higher frequency of high-risk patients according to FLIPI and FLIPI2 scores (63.0% vs 35.1%, P = 0.013 and 18.5% vs 3.9%, P = 0.003) and had an markedly shorter OS (P < 0.0001).

Conclusion

This study is a systematic prognostic evaluation based on Chinese clinical data. We found a new factor, the LMR, that could independently predict prognosis compared with FLIPI or FLIPI2.

Baseline [18F]FDG PET/CT may predict the outcome of newly diagnosed follicular lymphoma in patients managed with initial "watch-and-wait" approach

OBJECTIVES

To investigate if baseline [¹⁸F]FDG PET/CT can predict the outcome of follicular lymphoma (FL) in patients managed with an initial "watch-and-wait" approach.

METHODS

Thirty-eight newly diagnosed FL patients who were managed with an initial "watch-and-wait" approach and undergone baseline [¹⁸F]FDG PET/CT were retrospectively enrolled. The standard uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of FL lesions were measured on PET/CT. Patients were followed up for at least 24 months or until initiation of FL therapy. The endpoint was the time to initiation of lymphoma treatment (TLT).

RESULTS

After a median follow-up of 28 months (range 3-94 months), lymphoma treatment was initiated in 21/38 (55.3%) patients (median 15 months, range 3-51 months). Patients with TLT < 24 months showed SUVmax and TLG values significantly higher than those with TLT ≥ 24 months (p < 0.05). Receiver operating characteristic analysis demonstrated cutoff values of SUVmax > 9.5, MTV > 90.62 ml, and TLG > 144.96 SUVbw*ml were optimal for predicting TLT < 24 months. Kaplan-Meier analysis showed SUVmax > 9.5, MTV > 90.62 ml, and TLG > 144.96 SUVbw*ml had statistically significant correlations with shorter TLT (p < 0.01). Lymph node regions ≥ 3 and lymph nodes > 3 cm had almost significance (p < 0.1). In multivariate analysis, SUVmax > 9.5 (HR 3.2 [95% CI 1.1-9.2], p = 0.033) and TLG > 144.96 SUVbw*ml (HR 9.3 [95% CI 1.8-47.7], p = 0.008) were demonstrated to be independent predictive factors for shorter TLT.

CONCLUSIONS

Metabolic indices (SUVmax and TLG) of baseline [¹⁸F]FDG PET/CT could predict the outcome independently in FL patients under an initial "watch-and-wait" approach.

KEY POINTS

• "Watch-and-wait" approach is part of the overall treatment plan in asymptomatic patients with low tumor burden FL. However, the time to initiation of active treatment varies from months to years. • In our retrospective study of 38 patients with FL managed with an initial "watch-and-wait" approach, the SUVmax and TLG were demonstrated to be independent predictive factors for time to initiation of FL treatment. • Baseline [¹⁸F]FDG PET/CT may help to better select patients with FL who are most likely to benefit from "watch-and-wait" management.

Whole-Body Magnetic Resonance Imaging: Current Role in Patients with Lymphoma

Imaging of lymphoma is based on the use of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) and/or contrast-enhanced CT, but concerns have been raised regarding radiation exposure related to imaging scans in patients with cancer, and its association with increased risk of secondary tumors in patients with lymphoma has been established. To date, lymphoproliferative disorders are among the most common indications to perform whole-body magnetic resonance imaging (MRI). Whole-body MRI is superior to contrast-enhanced CT for staging the disease, also being less dependent on histology if compared to ¹⁸F-FDG-PET/CT. As well, it does not require exposure to ionizing radiation and could be used for the surveillance of lymphoma. The current role of whole-body MRI in the diagnostic workup in lymphoma is examined in the present review along with the diagnostic performance in staging, response assessment and surveillance of different lymphoma subtypes.

Obinutuzumab-related adverse events: A systematic review and meta-analysis

Rituximab, the first anti-CD20 monoclonal antibody, has dramatically improved outcomes for patients with B-cell lymphoproliferative disorders. Obinutuzumab was developed to potentiate activity and overcome resistance to rituximab. Clinical data suggest that obinutuzumab is superior to rituximab in follicular lymphoma (FL) and chronic lymphocytic leukemia (CLL). Yet, it has increased toxicity. This systematic review and meta-analysis compiled all randomized controlled trials (RCTs) comparing obinutuzumab-based regimens with rituximab-based regimens to better assess their toxicity profile. Primary outcome was grade 3-4 infections; secondary outcomes included any adverse events (AE), grade 3-4 AE, drug discontinuation rate, and 3-years mortality. Relative risks (RRs) were estimated and pooled using a fixed-effect model, unless there was significant heterogeneity, in which case a random-effects model was used. Our comprehensive search yielded five RCTs conducted between 2009 and 2014, including 4247 patients. The trials included FL patients, CLL and diffuse large B cell lymphoma. Monoclonal antibodies were given with different chemotherapy regimens (in four trials) or as monotherapy (in one trial). The point estimate favored increase in both grade 3-4 infections rate (RR 1.17 [95% CI, 1.0-1.36]) and any AE rate (RR 1.05 [95% 1-1.1]) with obinutuzumab, although this was not statistically significant. There was a significantly increased rate of grade 3-4 AE (RR 1.15 [95% CI, 1.09-1.2]), as well as grade 3-4 toxicities including thrombocytopenia (RR 2.8 [95% CI, 1.92-4.06]), infusion related reactions (RR 2.8 [95% CI, 2.16-3.64]) and cardiac events (RR 1.65 [95% CI, 1.11-2.46]). There was no significant difference in grade 3-4 anemia and neutropenia nor in the 3-year mortality rate. The point estimate favored increase in discontinuation rate due to AE with obinutuzumab, although without statistical significance (RR 1.24 [95% CI, 1.0-1.54]). In conclusion, physicians need to weigh the clinical benefits of this agent against higher toxicity.

Population-based epidemiological data of follicular lymphoma in Poland: 15 years of observation

Available epidemiological reports on follicular lymphoma (FL) often highlight a significant discrepancy between its high and low incidence rates in Western and Eastern Europe, respectively. The reasons behind that difference are not fully understood, but underreporting is typically presumed as one of the main factors. This study aimed to assess FL epidemiology in Poland based on 2000-2014 data from the Polish National Cancer Registry, which has 100% population coverage and over 90% completeness of the registration. All cases were coded according to ICD-10 and ICD-O-3 recommendations. The total number of registered FL cases was 3,928 with crude (CR) and standardized (SR) incidence rates of 0.72/10⁵ and 0.87/10⁵, respectively. The median age of FL diagnosis was 61 years, with the male to female incidence ratio of 1.06. The distribution of morphological types of FL: not otherwise specified (NOS), grades 1, 2, or 3 were 72.58, 4.81, 12.88, and 9.73%, respectively. Among all reported mature B-cell non-Hodgkin lymphomas, FL was ranked the fourth in incidence, just after chronic lymphocytic leukemia/small lymphocytic lymphoma (CR 3.62/10⁵, SR 4.99/10⁵), plasma cell neoplasms (CR 3.78/10⁵, SR 4.97/10⁵) and diffuse B-cell lymphoma, NOS (CR 2.13/10⁵, SR 2.65/10⁵). The systematic increase in FL incidence among females was observed. Our study confirms a lower FL incidence rate in Poland as compared to other European countries. Moreover, as our analysis was based on a registry with high data completeness, it provides evidence that reasons other than underreporting are responsible for FL incidence discrepancies between Eastern and Western Europe.

Relevance on the diagnosis of malignant lymphoma of the salivary gland

Malignant lymphoma originates from the lymphohematopoietic system. It can occur in any lymphoid tissue. Malignant lymphoma of the salivary gland is rare, but its incidence has increased in recent years. Its clinical- presentations are non-specific, and it is often manifested as a painless mass in a salivary gland, which can be accompanied by multiple swollen cervical lymph nodes. Confirmation of the diagnosis before an invasive procedure is difficult. Clinically, malignant lymphoma of the salivary gland tends to be misdiagnosed, leading to an inappropriate treatment plan and the ultimate delay in the optimal treatment of the disease. This article reviews the pathogenesis, clinical features, imaging findings, diagnosis, treatment and prognosis of malignant lymphoma of the salivary gland.

Costs associated with follicular lymphoma among individuals diagnosed with non-Hodgkin lymphoma: a longitudinal analysis using SEER-Medicare data

There is limited information on the cost burden associated with follicular lymphoma (FL) and how it compares to other non-Hodgkin lymphoma (NHL) subtypes. We examined the direct medical costs associated with FL and estimated the incremental 3-year cost of FL compared to other NHL subtypes. Using the linked Surveillance, Epidemiology and End Results-Medicare dataset, we identified 16,691 NHL patients aged 66 years or older who were diagnosed with NHL between 2007 and 2013. The mean 3-year cost among the full NHL sample was $120,120 (standard error (SE) 839). The mean 3-year cost per patient was $114,443 (SE 1738) for FL and $121,402 (SE 950) for non-FL subtypes. The incremental 3-year cost of FL compared to non-FL was US$-5458 (95% confidence interval: US$-9325 to US$-1590). Longitudinally, FL was less costly than other NHL subtypes in the first year only, and became more expensive in the second and third years.

Short regimen of rituximab plus lenalidomide in follicular lymphoma patients in need of first-line therapy

The SAKK 35/10 phase 2 trial, developed by the Swiss Group for Clinical Cancer Research and the Nordic Lymphoma Group, compared the activity of rituximab vs rituximab plus lenalidomide in untreated follicular lymphoma patients in need of systemic therapy. Patients were randomized to rituximab (375 mg/m² IV on day 1 of weeks 1-4 and repeated during weeks 12-15 in responding patients) or rituximab (same schedule) in combination with lenalidomide (15 mg orally daily for 18 weeks). Primary end point was complete response (CR)/unconfirmed CR (CRu) rate at 6 months. In total, 77 patients were allocated to rituximab monotherapy and 77 to the combination (47% poor-risk Follicular Lymphoma International Prognostic Index score in each arm). A significantly higher CR/CRu rate at 6 months was documented in the combination arm by the investigators (36%; 95% confidence interval [CI], 26%-48% vs 25%; 95% CI, 16%-36%) and confirmed by an independent response review of computed tomography scans only (61%; 95% CI, 49%-72% vs 36%; 95% CI, 26%-48%). After a median follow-up of 4 years, significantly higher 30-month CR/CRu rates and longer progression-free survival (PFS) and time to next treatment (TTNT) were observed for the combination. Overall survival (OS) rates were similar in both arms (≥90%). Toxicity grade ≥3 was more common in the combination arm (56% vs 22% of patients), mainly represented by neutropenia (23% vs 7%). Addition of lenalidomide to rituximab significantly improved CR/CRu rates, PFS, and TTNT, with expected higher, but manageable toxicity. The excellent OS in both arms suggests that chemotherapy-free strategies should be further explored. This trial was registered at www.clinicaltrials.gov as #NCT01307605.

Transformed follicular lymphoma in the rituximab era: A report from the Spanish Lymphoma Oncology Group

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma (NHL) subtype. The histological transformation (HT) of FL is an event considered frequent in the natural history of this tumor. We studied the transformation rates, predictive factors, and treatment characteristics that may impact in the survival of patients with FL and HT. A total of 1074 patients diagnosed with FL were prospectively enrolled from 1990 to 2016 in a Spanish registry. Sixty-four HTs were recorded based on clinical criteria (55%) or histological confirmation (45%). The cumulative incidence rate of transformation at 5 years is 7.3%. The 5-year overall survival (OS) without HT was 85% (95% confidence interval [CI], 70%-90%) vs 66% (95% CI, 51%-76%; P = 0.0012) with HT. Factors associated with HT were elevated lactate dehydrogenase (LDH) (odds ratio [OR] 1.83), intermediate-high Follicular lymphoma international prognostic index (FLIPI) (OR 2.16-OR 3.21), B symptoms (OR 2.46), or Eastern Cooperative Oncology Group (ECOG) 1 (OR 2.35). Treatment options related to HT were "watch and wait" or no rituximab or anthracyclines initially. A 5-year OS for patients treated with chemotherapy before HT was 55% (95% CI, 38%-69%) versus 81% (95% CI, 53%-93%; P = 0.009) for those who had not received it. The HT rate has decreased after the introduction of rituximab, as has been previously described. The timing of this treatment had an impact on the survival of these patients.

One Size Does Not Fit All: Who Benefits From Maintenance After Frontline Therapy for Follicular Lymphoma?

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma and the most common indolent B-cell malignancy. The disease often presents in advanced stage and can often be observed before initiation of therapy. Although the incidence is only approximately 15,000 new cases per year, the prevalence is substantially higher owing to the favorable overall survival (OS) of most patients. The most impactful advance responsible for the improvement of OS in FL was the introduction of the anti-CD20 monoclonal antibody (mAb) rituximab over 20 years ago. Phase III trials demonstrate that rituximab improves the OS in FL when combined with chemotherapy. However, unlike aggressive B-cell lymphomas, advanced stage FL is generally incurable and often displays a pattern of progressively shorter remissions with subsequent lines of therapy. Hence, maintenance strategies have been developed to prolong remissions achieved with frontline therapy. The value of maintenance after frontline therapy has been most extensively studied with extended treatment of anti-CD20 mAb, but recent approaches include chemotherapy-free combinations and targeted therapies given for extended durations. Here, we review relevant data that provide rationale in support of maintenance therapy in FL as well as the risks and limitations of a "one-size-fits-all" approach. Importantly, we note the biologic and clinical heterogeneity across patients with FL that must be considered when making clinical decisions. Finally, we highlight ongoing research that explores response-adapted approaches based on the depth of response as defined by PET scans and assays for minimal residual disease (MRD) that aim to better personalize individual management strategies.

R-CHOP, radioimmunotherapy, and maintenance rituximab in untreated follicular lymphoma (SWOG S0801): a single-arm, phase 2, multicentre study

BACKGROUND

Despite an abundance of therapeutic options, advanced-stage follicular lymphoma remains incurable. Furthermore, the ideal sequence and absolute benefit of post-induction therapy is unclear. We designed SWOG S0801 to assess the efficacy and safety of consolidative radioimmunotherapy and sequential maintenance rituximab following chemoimmunotherapy.

METHODS

For this single-arm, phase 2, multicentre study, we enrolled patients aged 18 years and older with a diagnosis of stage III, IV, or bulky stage II follicular lymphoma, grades 1, 2, or 3a, who had not received previous therapy, from from 20 institutions within the United States National Cancer Institute Clinical Trials Network. Patients were assigned to a 5-year treatment plan consisting of R-CHOP (rituximab plus cyclophosphamide [750 mg/m2], doxorubicin [50 mg/m2], vincristine [1·4 mg/m2], and prednisone or prednisolone [100 mg]) every 21 days for up to six cycles, with rituximab 375 mg/m2 given on day 1 of cycles 1-4, followed by 131iodine tositumomab radioimmunotherapy and subsequent maintenance rituximab 375 mg/m2 within 12 weeks after the sixth cycle of R-CHOP, every 3 months for up to 4 years. The primary endpoint was 3-year progression-free survival in the intention-to-treat population. Efficacy and safety analyses were done in the intention-to-treat population and the per-protocol population. This trial was registered with ClinicalTrials.gov, number NCT00770224.

FINDINGS

Between April 1, 2009, and Dec 15, 2010, we enrolled 84 evaluable patients, of whom 73 completed R-CHOP and radioimmunotherapy. Of 69 patients who registered to maintenance therapy, only 41 completed the 4-year rituximab maintenance treatment. Progression-free survival at 3 years was 90% (95% CI 82-95). The most common grade 3 or worse adverse events included neutropenia in 48 (57%) patients, leucopenia in 34 (40%) patients, thrombocytopenia in 17 (20%) patients, and febrile neutropenia in 14 (17%) patients. Nine patients had possible treatment-related deaths during the study from secondary or unknown causes (n=3), cirrhosis (n=1), cardiac arrest (n=1), and secondary malignancies (n=4). Secondary malignancies occurred in seven patients, including two sarcomas, two colorectal carcinomas, two acute myelogenous leukaemias, and one case of renal-cell carcinoma.

INTERPRETATION

SWOG S0801 showed near universal responses following chemoimmunotherapy and radioimmunotherapy. However, most discontinuations occurred during maintenance therapy, suggesting that rituximab over a 4-year span is not feasible for many patients. Nonetheless, this sequential therapeutic strategy resulted in good overall outcomes for patients, including a low incidence of early disease progression.

FUNDING

The National Cancer Institute and GlaxoSmithKline.

Whole body magnetic resonance in indolent lymphomas under watchful waiting: The time is now

ᅟ: The indolent non-Hodgkin lymphomas (i-NHLs) are characterised by 'indolent' clinical behaviour with slow growth and prolonged natural history. The watchful waiting (WW) strategy is a frequently employed treatment option in these patients. This implies a strict monitoring by imaging examinations, including 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) and CT. A major concern is radiation exposure due to regularly monitoring by conventional imaging procedures. Several studies have demonstrated the reliability of whole-body magnetic resonance imaging (WB-MRI) for lymphoma staging. WB-MRI could be useful for active surveillance in i-NHLs providing the suspect of disease progression that can be then confirmed by additional diagnostic procedures, including 18F-FDG-PET/CT. The directive 2013/59 by the European Union claims that if a radiation-free imaging technique allows obtaining the same diagnostic results, it should be invariably used. In this setting, WB-MRI may be considered a reasonable option in i-NHLs under WW, replacing imaging modalities that cause exposure to ionising radiations. This will help to reduce the cancer risk in i-NHL patients for whom chemo-/radiotherapy remain the usual treatment options following the usually long WW phase. The scientific community should raise the awareness of the risk of ionising radiations in i-NHLs and the emphasise the need for establishing the proper place of WB-MRI in lymphoma imaging.

KEY POINTS

• Watchful waiting is a reasonable option in patients with indolent non-Hodgkin lymphomas. • Imaging is crucial to monitor patients with indolent non-Hodgkin lymphomas. • CT and ¹⁸ F-FDG-PET/CT are commonly used, implying a substantial radiation exposure. • WB-MRI is highly reliable in lymphoma staging. • WB-MRI may be considered to monitor indolent non-Hodgkin lymphomas under watchful waiting.

Rituximab in B-Cell Hematologic Malignancies: A Review of 20 Years of Clinical Experience

Rituximab is a human/murine, chimeric anti-CD20 monoclonal antibody with established efficacy, and a favorable and well-defined safety profile in patients with various CD20-expressing lymphoid malignancies, including indolent and aggressive forms of B-cell non-Hodgkin lymphoma. Since its first approval 20 years ago, intravenously administered rituximab has revolutionized the treatment of B-cell malignancies and has become a standard component of care for follicular lymphoma, diffuse large B-cell lymphoma, chronic lymphocytic leukemia, and mantle cell lymphoma. For all of these diseases, clinical trials have demonstrated that rituximab not only prolongs the time to disease progression but also extends overall survival. Efficacy benefits have also been shown in patients with marginal zone lymphoma and in more aggressive diseases such as Burkitt lymphoma. Although the proven clinical efficacy and success of rituximab has led to the development of other anti-CD20 monoclonal antibodies in recent years (e.g., obinutuzumab, ofatumumab, veltuzumab, and ocrelizumab), rituximab is likely to maintain a position within the therapeutic armamentarium because it is well established with a long history of successful clinical use. Furthermore, a subcutaneous formulation of the drug has been approved both in the EU and in the USA for the treatment of B-cell malignancies. Using the wealth of data published on rituximab during the last two decades, we review the preclinical development of rituximab and the clinical experience gained in the treatment of hematologic B-cell malignancies, with a focus on the well-established intravenous route of administration. This article is a companion paper to A. Davies, et al., which is also published in this issue.

FUNDING

F. Hoffmann-La Roche Ltd., Basel, Switzerland.

Non-Hodgkin lymphoma

Lymphomas can affect any organ in the body, present with a wide range of symptoms, and be seen by primary care physicians and physicians from most specialties. They are traditionally divided into Hodgkin's lymphoma (which accounts for about 10% of all lymphomas) and non-Hodgkin lymphoma, which is the topic of this Seminar. Non-Hodgkin lymphoma represents a wide spectrum of illnesses that vary from the most indolent to the most aggressive malignancies. They arise from lymphocytes that are at various stages of development, and the characteristics of the specific lymphoma subtype reflect those of the cell from which they originated. Since this topic was last reviewed in The Lancet in 2012, advances in understanding the biology and genetics of non-Hodgkin lymphoma and the availability of new diagnostic methods and therapies have improved our ability to manage patients with this disorder.

Imaging of Early Response to Predict Prognosis in the First-Line Management of Follicular Non-Hodgkin Lymphoma with Iodine-131-Rituximab Radioimmunotherapy

The purpose of this study was to evaluate prediction of prognosis after first-line radioimmunotherapy (RIT) of advanced follicular non-Hodgkin lymphoma (FL), by imaging with fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography (¹⁸F-FDG-PET/CT) three months after induction treatment by Iodine-131-rituximab (¹³¹I-rituximab). Objective response was determined using the Deauville 5-point scale in 68 prospective clinical trial patients. Baseline ¹⁸F-FDG-PET/CT studies were used to calculate total-metabolic-tumor-volume (TMTV). Non-imaging studies included the Follicular lymphoma international prognostic index (FLIPI) and absolute baseline monocyte and lymphocyte counts. Patients were monitored for over ten years (median follow-up 59 months), and no patient was lost to follow-up. Complete response (CR) of 88% predicted excellent prognosis with median time-to-next-treatment (TTNT) not yet reached. Those patients (12%) who failed to achieve CR (Deauville ≤ 3) on ¹⁸F-FDG-PET/CT at three months had significantly poorer outcomes (p < 0.0001) with a median TTNT of 41 months. Requirement for re-treatment was predicted by FLIPI and absolute baseline monocyte count but not lymphocyte count. The TTNT was accurately predicted by ¹⁸F-FDG-PET/CT Deauville response at three months following first-line therapy of FL with RIT. Early response demonstrated by imaging does, therefore, foretell prognosis in the individual FL patients.

Systemic Front Line Therapy of Follicular Lymphoma: When, to Whom and How

The natural history of follicular lymphoma is usually characterized by an indolent course with a high response rate to the first line therapy followed by recurrent relapses, with a time to next treatment becoming shorter after each subsequent treatment line. More than 80% of patients have advanced stage disease at diagnosis. The time of initiation and the nature of the treatment is mainly conditioned by symptoms, tumor burden, lymphoma grading, co-morbidities and patients preference. A number of clinical and biological factors have been determined to be prognostic in this disease, but the majority of them could not show to be predictive of response to treatment, and therefore can’t be used to guide the treatment choice. CD20 expression is the only predictive factor recognized in the treatment of FL and justifies the use of “naked” or “conjugated” anti-CD20 monoclonal antibodies as a single agent or in combination with chemo- or targeted therapy. Nevertheless, as this marker is almost universally found in FL, it has little role in the choice of treatment. The outcome of patients with FL improved significantly in the last years, mainly due to the widespread use of rituximab, autologous and allogeneic transplantation in young and fit relapsed patients, the introduction of new drugs and the improvement in diagnostic accuracy and management of side effects. Agents as new monoclonal antibodies, immuno-modulating drugs, and target therapy have recently been developed and approved for the relapsed setting, while studies to evaluate their role in first line treatment are still ongoing. Here we report our considerations on first line treatment approach and on the potential factors which could help in the choice of therapy.