A prospective observational registry evaluating clinical outcomes of Radium-223 treatment in a nonstudy population.

The ALSYMPCA study established a 3.6 month Overall Survival (OS) benefit in metastatic Castration Resistant Prostate Cancer (mCRPC) patients treated with Radium-223 dichloride (Ra-223) over placebo. Here we report clinical outcomes of Ra-223 treatment in a nonstudy population. In this prospective registry, patients from 20 Dutch hospitals were included prior to Ra-223 treatment. Clinical parameters collected included previous treatments and Adverse Events. Primary outcome was 6 months Symptomatic Skeletal Event (SSE)-free survival, while secondary outcomes included Progression-Free Survival (PFS) and Overall Survival (OS). Of the 305 patients included, 300 were evaluable. The mean age was 73.6 years, 90% had ≥6 bone metastases and 74.1% were pretreated with Docetaxel, 19.5% with Cabazitaxel and 80.5% with Abiraterone and/or Enzalutamide. Of all patients, 96.7% were treated with Ra-223 and received a median of 5 cycles. After a median follow-up of 13.2 months, 6 months SSE-free survival rate was 83%, median PFS was 5.1 months and median OS was 15.2 months. Six months SSE-free survival rate and OS were comparable with those reported in ALSYMPCA. "Previous Cabazitaxel treatment" and "bone-only metastases" were independent predictors of a shorter and longer PFS, respectively, while above-median LDH and "bone-only metastases" were independent predictors of shorter and longer OS, respectively. Toxicity was similar as reported in the ALSYMPCA trial. These results suggest that in a nonstudy population, Ra-223 treatment is well-tolerated, equally effective as in the ALSYMPCA population and that patients not previously treated with Cabazitaxel benefit most from Ra-223.

Potential cost savings owing to the route of administration of oncology drugs: a microcosting study of intravenous and subcutaneous administration of trastuzumab and rituximab in the Netherlands.

There is little evidence on the costs associated with the route of administration of oncology drugs. We investigated time and resource use for hospitals and patients and compared healthcare and societal costs for intravenous (IV) and subcutaneous (SC) administration of trastuzumab and rituximab. Data for the preparation and administration of both drugs were collected at the hospital pharmacy and at the oncology day care unit. Patients completed a questionnaire for obtaining information on societal costs (productivity losses, informal care and traveling expenses). A total of 126 patients were recruited in six hospitals; 82 received trastuzumab (37 IV and 45 SC) and 44 received rituximab (23 IV and 21 SC). The costs per administration (including societal cost but excluding drug costs) were &OV0556;167 and &OV0556;264 for IV and &OV0556;76 and &OV0556;146 for SC trastuzumab and rituximab, respectively. The costs for SC administration were lower in all categories. The largest cost component was related to time spent at the day care unit (overhead costs). This resulted in savings of &OV0556;47 for SC trastuzumab and &OV0556;69 for SC rituximab. The costs related to time of healthcare professionals was &OV0556;9 lower for both drugs. The costs for consumables resulted in another &OV0556;12 savings. Societal costs were &OV0556;22 lower for SC trastuzumab and &OV0556;28 lower for SC rituximab. Although administration costs are relatively a small part of the total costs, important savings can be generated by switching to an SC route of administration especially because a large number of patients receive oncology drugs and patients receive more than one administration.

Prognostic parameters for response to enzalutamide after docetaxel and abiraterone treatment in metastatic castration-resistant prostate cancer patients; a possible time relation.

BACKGROUND: Abiraterone Acetate (AA) and Enzalutamide (Enz) are effective hormonal treatments in mCRPC patients. Retrospective studies suggested clinical cross-resistance between Enz and AA. However, 12.8-39.1% of patients previously treated with docetaxel (Doc) and AA do respond to Enz. These responders have not been characterized. METHODS: 102 Enz treated mCRPC patients after AA and Doc treatment were included in this study. Differences in patient characteristics and previous treatment outcomes between PSA responders and non-responders on Enz were evaluated. RESULTS: Median Progression-Free Survival was 12.2 weeks (95%CI 11.7-14.3) and Overall Survival 43.5 weeks (95%CI 37.4-61.2). There were 26 (25%) Enz-responders and 76 (75%) non-responders. Significant higher percentages of Gleason scores ≥ 8 and PSA doubling times (PSA-DT) <3 months were found in Enz responders than in non-responders. The interval between end of AA and start of Enz treatment (IAE) for responders was 24.6 weeks (IQR 4.0-48.1) and 8.9 weeks for non-responders (IQR 3.7-25.9) (P = 0.08). In an IAE <40 days subgroup (34 patients), Enz responses were related to AA non-responsiveness, while univariate and logistic regression analysis of baseline criteria of a subgroup of patients with an IAE ≥ 40 (68 patients) revealed significant differences in baseline PSA levels, PSA-DT <3 months, Gleason scores ≥ 8 and IAE's between Enz responders and non-responders. CONCLUSIONS: PSA response to Enz after previous AA and Doc treatment was associated with a longer IAE, a higher Gleason score and a PSA-DT <3 months. Identification of these patients might be of value for sequencing of treatment options.

Enzalutamide as a Fourth- or Fifth-Line Treatment Option for Metastatic Castration-Resistant Prostate Cancer.

OBJECTIVE: To evaluate the efficacy of enzalutamide (Enz) as fourth- or fifth-line treatment in men with metastasized castration-resistant prostate cancer (mCRPC), by analyzing a retrospective cohort of heavily pretreated patients. METHODS: We evaluated toxicity, overall survival (OS), progression-free survival (PFS) and time to prostate-specific antigen (PSA) progression data from 47 CRPC patients treated with fourth- or fifth-line Enz. RESULTS: All patients were treated with docetaxel and abiraterone acetate and 42 patients (89%) with cabazitaxel. The median age of the patients was 69 years (IQR, 63-73.5), 79% had bone metastases, 55% had lymph node metastases, and 17% had visceral metastases. The median duration of Enz treatment was 12.0 weeks (IQR, 8.3-20.4), and 11 patients (23%) responded to Enz (maximum PSA decline ≥50%). In general, Enz was well tolerated, with the most frequently reported adverse events being fatigue and nausea. The median OS was 40.1 weeks (95% CI, 25.4-61.4), the median PFS was 12.1 weeks (95% CI, 9.9-14.0) and the median time to PSA progression was 15.7 weeks (95% CI, 14.0-28.7). CONCLUSIONS: Analysis of this retrospective cohort suggests that Enz is well tolerated and that there is a 23% response rate in heavily pretreated CRPC patients, which is comparable with third-line treatment outcomes.

CAST: A retrospective analysis of cabazitaxel and abiraterone acetate sequential treatment in patients with metastatic castrate-resistant prostate cancer previously treated with docetaxel.

Cabazitaxel and abiraterone have both received approval for treating metastatic castrate-resistant prostate cancer (mCRPC) patients after first-line docetaxel therapy. In the cabazitaxel and abiraterone sequential treatment (CAST) study, the clinical outcome of docetaxel-treated mCRPC patients treated sequentially with both cabazitaxel and abiraterone was studied. Data were collected retrospectively from mCRPC patients at 12 hospitals across the Netherlands who initiated cabazitaxel and/or abiraterone before December 2012. Primary outcome measure was overall survival (OS); secondary measures were progression-free survival (PFS), biochemical PFS, and best clinical and PSA response. Hospital admission data during treatment were collected, as well as toxicities resulting in treatment discontinuation or patient death. Sixty-three and 69 patients received Cab→Abi (cabazitaxel prior to abiraterone) and Abi→Cab before July 10th, 2013, respectively. Median OS was 19.1 months and 17.0 months in Cab→Abi and Abi→Cab treated patients, respectively (p = 0.369). Median PFS and biochemical PFS were significantly longer in Cab→Abi treated patients: 8.1 versus 6.5 (p = 0.050) and 9.5 versus 7.7 months (p = 0.024), respectively. Although partial responses to cabazitaxel occurred in both groups, Abi→Cab treated patients had a significantly decreased antitumor response from cabazitaxel than Cab→Abi treated patients (median PFS 5.0 versus 2.6 months, p < 0.001). Minor differences in toxicities were observed based on therapy sequence; generally, toxicity from cabazitaxel could be severe, while abiraterone toxicity was milder. This retrospective analysis indicates that primary progression on cabazitaxel or abiraterone did not preclude a response to the other agent in mCRPC patients. However, tumor response of both agents, particularly cabazitaxel, was lower when administered as higher-line therapy in the selected study population.

Clinical activity and tolerability of enzalutamide (MDV3100) in patients with metastatic, castration-resistant prostate cancer who progress after docetaxel and abiraterone treatment.

BACKGROUND: Enzalutamide (Enz) and abiraterone acetate (AA) are hormone treatments that have a proven survival advantage in patients with metastatic, castration-resistant prostate cancer who previously received docetaxel (Doc). Recently, limited activity of AA after Enz and of Enz after AA was demonstrated in small cohort studies. Here, the authors present the activity and tolerability of Enz in patients who previously received AA and Doc in the largest cohort to date. METHODS: The efficacy and tolerability of Enz were investigated in men with progressive, metastatic, castrate-resistant prostate cancer who previously received Doc and AA. Toxicity, progression-free survival, time to prostate-specific antigen (PSA) progression, and overall survival were retrospectively evaluated. RESULTS: Sixty-one patients were included in the analysis. The median age was 69 years (interquartile range [IQR], 64-74 years), 57 patients (93%) had an Eastern Cooperative Oncology Group performance status from 0 to 2, 48 patients (79%) had bone metastases, 33 patients (54%) had lymph node metastases, and 13 patients (21%) had visceral metastases. The median duration of Enz treatment was 14.9 weeks (IQR, 11.1-20.0 weeks), and 13 patients (21%) had a maximum PSA decline ≥50%. The median progression-free survival was 12.0 weeks (95% confidence interval [CI], 11.1-16.0 weeks), the median time to PSA progression was 17.4 weeks (95% CI, >16.0 weeks), and the median overall survival was 31.6 weeks (95% CI, >28.7 weeks). Enz was well tolerated, and fatigue and musculoskeletal pain were the most frequent grade ≥2 adverse events. The PSA response to Doc and AA did not predict the PSA response to Enz. CONCLUSIONS: Enz has modest clinical activity in patients with metastatic, castrate-resistant prostate cancer who previously received Doc and AA. PSA response to Doc and AA does not predict for PSA response to ENz.

Integrated analysis of pain, health-related quality of life, and analgesic use in patients with metastatic castration-resistant prostate cancer treated with Radium-223.

BACKGROUND: Radium-223 (Ra-223), an alpha-emitting radiopharmaceutical, established an improved overall survival and health-related quality of life (HRQoL) in symptomatic metastatic castration-resistant prostate cancer (mCRPC) patients. However, effects on pain were not specifically evaluated. Here we assess integrated HRQoL, pain, and opioid use in a contemporary, more extensively pretreated, symptomatic and asymptomatic mCRPC population. METHODS: mCRPC patients scheduled for Ra-223 treatment were included and analyzed for HRQoL, pain, and opioid use, using Functional Assessment of Cancer Therapy-Prostate (FACT-P) and Brief Pain Inventory-Short Form (BPI-SF) questionnaires and recording of opioid use and dosage, respectively. Primary outcome measure was the percentage of patients experiencing a complete pain response (score of 0 on the BPI-SF Worst pain item and no increase in daily use of analgesics). A complete or partial pain response (better BPI-SF score and decrease in opioid use) and a better or no change in HRQoL was evaluated as an integrated overall clinical response (IOCR). Secondary endpoints included the time to pain progression (TPP) and Total FACT-P deterioration (TTFD), defined as time from first Ra-223 treatment to clinical meaningful increase in BPI-SF Worst pain item score and Total FACT-P score, respectively. RESULTS: This registry included 300 patients, of whom 105 (35%) were evaluable for FACT-P and BPI-SF during Ra-223 treatment. Forty-five (43%) patients had pain at baseline (PAB) (BPI-SF Worst pain score 5-10 points) and 60 (57%) had no pain at baseline (no-PAB) (BPI-SF Worst pain score 0-4 points). Complete pain response was achieved in 31.4% of the patients, while 58% had an IOCR. The median TTP and TTFD were 5.6 and 5.7 months, respectively, while the difference between PAB and no-PAB patients was not significant. CONCLUSIONS: In contemporary, extensively pretreated mCRPC patients, Ra-223 treatment induced complete pain responses while integrated analysis of HRQoL, pain response, and opioid use demonstrated that the majority of patients derive clinical benefit.

Third-line Life-prolonging Drug Treatment in a Real-world Metastatic Castration-resistant Prostate Cancer Population: Results from the Dutch Castration-resistant Prostate Cancer Registry.

BACKGROUND: Evidence concerning third-line life-prolonging drugs (LPDs) in the treatment of metastatic castration-resistant prostate cancer (mCRPC) patients is incomplete. OBJECTIVE: To evaluate third-line LPD outcomes in a real-world cohort of mCRPC patients, identify variables associated with overall survival (OS), and establish a prognostic model. DESIGN, SETTING, AND PARTICIPANTS: Patients with mCRPC who were progressive on second-line LPD before July 1, 2017 were retrospectively identified from the Dutch Castration-resistant Prostate Cancer Registry (CAPRI) and followed until December 31, 2017. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Association of potential risk factors with OS was tested by Cox proportional hazard models after multiple imputation of missing baseline characteristics. A predictive score was computed from the regression coefficient and used to classify patients into risk groups. RESULTS AND LIMITATIONS: Of 1011 mCRPC patients progressive on second-line LPD, 602 (60%) received third-line LPD. Patients receiving third-line LPD had a more favorable prognostic profile at baseline and longer median OS than patients with best supportive care (10.4 vs 2.4 mo, p < 0.001). Eastern Cooperative Oncology Group performance status 1 and ≥2 (hazard ratio [HR] 1.51, p < 0.007 and HR 3.08, p < 0.001, respectively), opioid use (HR 1.55, p = 0.019), visceral metastases (HR 2.09, p < 0.001), hemoglobin <7 mmol/l (HR 1.44, p < 0.002), prostate-specific antigen ≥130 µg/l (HR 1.48, p = 0.001), alkaline phosphatase ≥170 U/l (HR 1.52, p < 0.001), and lactate dehydrogenase ≥250 U/l (HR 1.44; p = 0.015) were associated with shorter survival. Harrell's C-index was 0.74. The median OS values for low-, low-intermediate-, high-intermediate-, and high-risk groups were 14, 7.7, 4.7, and 1.8 mo, respectively. Limitations include the retrospective design. CONCLUSIONS: We developed a prognostic model and identified a subgroup of patients in whom third-line LPD treatment has no meaningful benefit. Our results need to be confirmed by prospective clinical trials. PATIENT SUMMARY: We reported outcomes from third-line life-prolonging drugs in metastatic prostate cancer patients and developed a prognostic model that could be used to guide treatment decisions.

EBV-positive immunodeficiency lymphoma after alemtuzumab-CHOP therapy for peripheral T-cell lymphoma.

Chemotherapy with alemtuzumab and the combination of cyclophosphamide, adriamycin, oncovin, and prednisone (CHOP) has become experimental trial therapy for aggressive T-cell lymphoma. Several multicenter phase 3 trials will incorporate this scheme. As part of an ongoing phase 2 trial in which we recently treated 20 patients with 8 cycles of CHOP every 2 weeks with 3 additional doses of 30 mg alemtuzumab per cycle, we observed the development of Epstein-Barr virus (EBV)-positive lymphoproliferative disease, after completion of the immunochemotherapy in 3 patients with peripheral T-cell lymphoma. Because the occurrence of EBV-positive lymphoproliferative disease is rare after alemtuzumab monotherapy, such as is given for chronic lymphocytic leukemia, we think that early reporting of this potential side effect is warranted. It may be caused by intrinsic T-cell defects in patients with T-cell lymphoma, or by the combination of alemtuzumab with CHOP chemotherapy.

Health-related Quality of Life and Pain in a Real-world Castration-resistant Prostate Cancer Population: Results From the PRO-CAPRI Study in the Netherlands.

BACKGROUND: The purpose of this study was to determine generic, cancer-specific, and prostate cancer-specific health-related quality of life (HRQoL), pain and changes over time in patients with metastatic castration-resistant prostate cancer (mCRPC) in daily practice. PATIENTS AND METHODS: PRO-CAPRI is an observational, prospective study in 10 hospitals in the Netherlands. Patients with mCRPC completed the EQ-5D, European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), and Brief Pain Inventory-Short Form (BPI-SF) every 3 months and European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire-Prostate Cancer Module (EORTC QLQ-PR25) every 6 months for a maximum of 2 years. Subgroups were identified based on chemotherapy pretreatment. Outcomes were generic, cancer-specific, and prostate cancer-specific HRQoL and self-reported pain. Descriptive statistics were performed including changes over time and minimal important differences (MID) between subgroups. RESULTS: In total, 151 included patients answered 873 questionnaires. The median follow-up from the start of the study was 19.5 months, and 84% were treated with at least 1 life-prolonging agent. Overall, patients were in good clinical condition (Eatern Cooperative Oncology Group performance status 0-1 in 78%) with normal baseline hemoglobin, lactate dehydrogenase, and alkaline phosphatase. At inclusion, generic HRQoL was high with a mean EQ visual analog score of 73.2 out of 100. The lowest scores were reported on role and physical functioning (mean scores of 69 and 76 of 100, respectively), and fatigue, pain, and insomnia were the most impaired domains. These domains deteriorated in > 50% of patients. CONCLUSION: Although most patients were treated with new treatments during follow-up, mCRPC has a negative impact on HRQoL with deterioration in all domains over time, especially role and physical functioning. These domains need specific attention during follow-up to maintain HRQoL as long as possible by timely start of adequate supportive care management.

Differences in Trial and Real-world Populations in the Dutch Castration-resistant Prostate Cancer Registry.

BACKGROUND: Trials in castration-resistant prostate cancer (CRPC) treatment have shown improved outcomes, including survival. However, as trial populations are selected, results may not be representative for the real-world population. The aim of this study was to assess the differences between patients treated in a clinical trial versus standard care during the course of CRPC in a real-world CRPC population. DESIGN, SETTING, AND PARTICIPANTS: Castration-resistant Prostate Cancer Registry is a population-based, observational, retrospective registry. CRPC patients from 20 hospitals in the Netherlands have been included from 2010 to 2013. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Baseline characteristics, systemic treatment, and overall survival were the main outcomes. Descriptive statistics, multivariate Cox regression, and multiple imputations with the Monte Carlo Markov Chain method were used. RESULTS AND LIMITATIONS: In total, 1524 patients were enrolled of which 203 patients had participated in trials at any time. The median follow-up period was 23 mo. Patients in the trial group were significantly younger and had less comorbidities. Docetaxel treatment was more frequently used in trial patients (85% vs 40%). Despite an observed unadjusted median overall survival difference of 35 mo versus 24 mo between the trial and standard care group, this difference was not retained after adjustment for baseline characteristics and treatment effect. CONCLUSIONS: At CRPC diagnosis, the baseline characteristics of the patients who had been enrolled in trials notably differed from patients who received standard treatment options only. The survival difference between the trial and standard care group could be explained by baseline differences and treatment effects. These results indicate that trial results cannot easily be translated to real-world practice. PATIENT SUMMARY: We observed that patients treated in clinical trials differed from patients who were not. We concluded that this may lead to differential treatment and survival. Caution is warranted when real-world outcomes are compared with trial results.

Classification and occurrence of clinically significant drug interactions with irinotecan and oxaliplatin in patients with metastatic colorectal cancer.

BACKGROUND: Pharmacokinetic and pharmacodynamic drug interactions with cytotoxic drugs may significantly influence the efficacy and toxicity of chemotherapy. OBJECTIVE: The purpose of this study was to identify drug interactions with irinotecan and oxaliplatin reported in the literature, to assess their clinical significance, and to examine the occurrence of these interactions in patients with metastatic colorectal cancer treated with either irinotecan or oxaliplatin or both. METHODS: To obtain data on drug-drug interactions with irinotecan and oxaliplatin, a literature search of PubMed and EMBASE was conducted using the search terms irinotecan, oxaliplatin, and interactions (English-language studies only published between 1980 and August 2004). The interactions found were subsequently classified for documentation evidence and severity of clinical effect, according to a 5-level classification system of a standard reference text, by a study panel of medical oncologists and clinical pharmacists. Comedication of patients who were treated with irinotecan or oxaliplatin, or both, was then examined to determine the occurrence of clinically significant interactions. RESULTS: Ninety-eight patients (50 women, 48 men;mean age, 60 years) were included in the study. Seventeen interactions with irinotecan were found in the literature, and 11 were classified as clinically significant. Only 1 nonspecific, clinically significant interaction was identified for oxaliplatin. Irinotecan-treated patients received a mean of 8 different comedications and oxaliplatin-treated patients received a mean of 6. Apart from antiemetic and antidiarrheal drugs that were prescribed for treatment-related toxicities, only 1 patient appeared to be exposed to a possible clinically significant interaction (between irinotecan and phenytoin). CONCLUSIONS: Eleven of the 17 interactions with irinotecan that were found in the literature were classified as clinically significant versus 1 clinically significant interaction with oxaliplatin. The occurrence of these interactions in the study patients with metastatic colorectal cancer was low. For medication surveillance purposes, however, the significant interactions should be considered in clinical practice.

Relationship between pharmacokinetics of 5-FU in plasma and in saliva, and toxicity of 5-fluorouracil/folinic acid.

BACKGROUND: Dose adaptation based on pharmacokinetic parameters has been shown to decrease toxicity of some 5-fluorouracil(5-FU)-based continuous infusion regimens. PATIENTS AND METHODS: In the present study the relationship between 5-FU pharmacokinetics in plasma and in saliva, and toxicity was investigated in 40 patients receiving the combination of 5-FU 425 mg/m2 and folinic acid 20 mg/m2 daily during 5 consecutive days according to the Mayo-regimen. RESULTS: The overall non-hematological and hematological toxicity, as well as mucositis only, were not statistically significant related to the area-under-the-curve in plasma (AUCp) or in saliva (AUCs), nor to the maximum concentration measured in plasma (Cmaxp) or in saliva (Cmaxs). Although statistically significant, the correlation between the AUCp and AUCs was relatively low, implying that salivary pharmacokinetics are not accurately predictive of plasma pharmacokinetics. CONCLUSION: The conclusion of this study is that the application of pharmacokinetic parameters is not appropriate for identification of patients at risk for developing toxicity from treatment with 5-FU according to the Mayo-regimen.

Cabazitaxel in patients with metastatic castration-resistant prostate cancer: results of a compassionate use program in the Netherlands.

BACKGROUND: Cabazitaxel has been reimbursed as a second-line therapy for patients with metastatic castrate-resistant prostate cancer (mCRPC) in the Netherlands since 2011. Before reimbursement was available, cabazitaxel was provided through a Compassionate Use Program (CUP). We report the results of the Dutch CUP, detailing the safety and efficacy of cabazitaxel in a routine clinical practice setting. PATIENTS AND METHODS: Safety and efficacy data of all 5 Dutch centers participating in the cabazitaxel CUP were collected. Safety data were collected prospectively using the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 3.0. Overall survival (OS) and progression-free survival (PFS), time to PSA progression (TTPP), and best clinical response were evaluated retrospectively. RESULTS: Fifty-one patients were registered in the CUP; 49 received cabazitaxel. Forty-two of 49 patients [85.7%], 42 patients had ≥ 2 metastatic sites. Patients received on average 6 cabazitaxel cycles (range, 1-21). A dose reduction or dose delay occurred in 13 and 20 patients [26.5% and 40.9%] respectively. Prophylactic granulocyte colony-stimulating factor (G-CSF) was used in 8 patients [16.3%]. Grade ≥ 3 adverse events were observed in 25 patients [51.0%]; 16 patients [32.7%] discontinued treatment because of treatment-emergent adverse events (TEAEs). Serious adverse events (SAEs) occurred in 16 (32.7%) patients; the most frequent SAEs were hematuria (4 patients [8.3%]) and urosepsis (3 patients [6.3%]). Febrile neutropenia occurred twice; no patient had grade ≥ 3 neuropathy. No toxicity-related mortality occurred. Median follow-up was 24.1 months. Median OS was 8.7 months (interquartile range [IQR], 6.0-15.9 months); median TTPP was 2.8 months (IQR, 1.7-5.9 months). CONCLUSION: In the Dutch CUP, patients with advanced mCRPC had delayed tumor progression with acceptable toxicities using cabazitaxel treatment.

[Monoclonal B-cell lymphocytosis: physiological entity or preliminary stage of chronic lymphocytic leukaemia?]. / Monoklonale B-cellymfocytose: fysiologische bevinding of voorstadium van chronische lymfatische leukemie?

The criteria for the diagnosis of chronic lymphocytic leukaemia (CLL) have recently been changed, with the absolute number of monoclonal B cells instead of the total number of lymphocytes now important. CLL is diagnosed when the number of monoclonal B cells with the characteristic CLL phenotype in peripheral blood exceeds 5 x 10(9)/l; fewer than 5 x 10(9)/l of monoclonal B cells with the characteristic CLL phenotype present in peripheral blood leads to a diagnosis of monoclonal B-cell lymphocytosis (MBL): a new diagnostic entity. The prevalence of MBL is estimated to be 3% and has a relatively mild course with a progression rate from MBL to CLL of 1-2% per year. After a single evaluation by a haematologist to exclude lymphadenopathy, organomegaly and infection as causes of the lymphocytosis, patients with MBL need only be evaluated once annually by their general practitioner for measurement of the blood lymphocyte count and referral in case of progression.