Racial and ethnic associations with comprehensive cancer center access and clinical trial enrollment for acute leukemia.

BACKGROUND: Clinical trial participation at Comprehensive Cancer Centers (CCC) is inequitable for minoritized racial and ethnic groups with acute leukemia. CCCs care for a high proportion of adults with acute leukemia. It is unclear if participation inequities are due to CCC access, post-access enrollment, or both. METHODS: We conducted a retrospective cohort study of adults with acute leukemia (2010-2019) residing within Massachusetts, the designated catchment area of the Dana-Farber/Harvard Cancer Center (DF/HCC). Individuals were categorized as non-Hispanic Asian (NHA), Black (NHB), White (NHW), Hispanic White (HW), or Other. Decomposition analyses assessed covariate contributions to disparities in (1) access to DF/HCC care and (2) post-access enrollment. RESULTS: Of 3698 individuals with acute leukemia, 85.9% were NHW, 4.5% HW, 4.3% NHB, 3.7% NHA, and 1.3% Other. Access was lower for HW (age- and sex-adjusted OR = 0.64, 95% CI = 0.45 to 0.90) and reduced post-access enrollment for HW (aOR = 0.54, 95% CI =0.34 to 0.86) and NHB (aOR = 0.60, 95% CI = 0.39 to 0.92) compared to NHW. Payor and socioeconomic status (SES) accounted for 25.2% and 21.2% of the +1.1% absolute difference in HW access. Marital status and SES accounted for 8.0% and 7.0% of the -8.8% absolute disparity in HW enrollment; 76.4% of the disparity was unexplained. SES and marital status accounted for 8.2% and 7.1% of the -9.1% absolute disparity in NHB enrollment; 73.0% of the disparity was unexplained. CONCLUSIONS: A substantial proportion of racial and ethnic inequities in acute leukemia trial enrollment at CCCs are from post-access enrollment, the majority of which was not explained by sociodemographic factors.

Inequities in Alliance Acute Leukemia Clinical Trial and Biobank Participation: Defining Targets for Intervention.

PURPOSE: Representativeness in acute leukemia clinical research is essential for achieving health equity. The National Cancer Institute's mandate for Comprehensive Cancer Centers (CCCs) to define and assume responsibility for cancer control and treatment across a geographic catchment area provides an enforceable mechanism to target and potentially remediate participatory inequities. METHODS: We examined enrollee characteristics across 15 Cancer and Leukemia Group B/Alliance cooperative group adult acute leukemia clinical trials (N = 3,734) from 1998 to 2013, including participation in optional companion biobanks. We determined enrollment odds by race-ethnicity for all participants adjusted for national incidence, and for those enrolled at CCCs adjusted for catchment area incidence. We modeled biobank participation by sociodemographics using logistic regression. RESULTS: Non-Hispanic (NH)-White patients were more likely to be enrolled than NH-Black, NH-Asian, or Hispanic patients (odds ratio [OR], 0.75, 0.48, and 0.44, respectively; all P < .001), but less likely than NH-Native American patients (OR, 1.91; P < .001), adjusted for national incidence. Enrollment odds were lower for NH-Black, NH-Asian, and Hispanic patients at CCCs adjusted for catchment area incidence (OR, 0.57, 0.26, and 0.32, respectively; P < .001); differences were driven by overenrollment of NH-White patients from outside self-defined catchment areas (18.1% v 12.3%; χ2 P = .01) and by CCCs with less absolute enrollee diversity (rank sum P = .03). Among all enrollees, NH-White race-ethnicity and lower neighborhood deprivation correlated with biobank participation (OR, 1.81 and 1.45, respectively; P = .01 and .03). For CCC enrollees, the correlation of race-ethnicity with biobank participation was attenuated by a measure accounting for their site's degree of enrollment disparity but not neighborhood deprivation. CONCLUSION: Acute leukemia clinical research disparities are substantial and driven by structural trial enrollment barriers at CCCs. Real-time CCC access and enrollment monitoring is needed to better align research participation with local populations.

Gait speed, survival, and recommended treatment intensity in older adults with blood cancer requiring treatment.

BACKGROUND: Brief measures of physical function such as gait speed may be useful to optimize treatment intensity for older adults who have blood cancer; however, little is known about whether such assessments are already captured within oncologists' "gestalt" assessments. METHODS: Gait speed was assessed in 782 patients ≥75 years of age who had blood cancer, with results reported to providers after treatment decisions were made; 408 patients required treatment when different intensities were available per National Comprehensive Cancer Network (NCCN) guidelines. We performed structured abstractions of treatment intensity recommendations into standard intensity, reduced intensity, or supportive care, based on NCCN guidelines. We modeled gait speed and survival using Cox regression and performed ordinal logistic regression to assess predictors of NCCN-based categorizations of oncologists' treatment intensity recommendations, including gait speed. RESULTS: The median survival by gait speed category was 10.8 months (<0.4 m/s), 18.6 months (0.4-0.6 m/s), 34.0 months (0.6-0.8 m/s), and unreached (>0.8 m/s). Univariable hazard ratios (HRs) for death increased for each lower category compared with ≥0.8 m/s (0.6-0.8 m/s: HR, 1.76; 0.4-0.6 m/s: HR, 2.30; <0.4 m/s: HR, 3.31). Gait speed predicted survival in multivariable Cox regression (all P < .05). In multivariable models including age, sex, and Eastern Cooperative Oncology Group performance status, gait speed did not predict oncologists' recommended treatment intensity (all P > .05) and did not add to a base model predicting recommended treatment intensity. CONCLUSION: In older adults with blood cancer who presented for treatment, gait speed predicted survival but not treatment intensity recommendation. Incorporating gait speed into decision making may improve optimal treatment selection.

US State Government Crisis Standards of Care Guidelines: Implications for Patients With Cancer.

Importance: State crisis standards of care (CSC) guidelines in the US allocate scarce health care resources among patients. Anecdotal reports suggest that guidelines may disproportionately allocate resources away from patients with cancer, but no comprehensive evaluation has been performed. Objective: To examine the implications of US state CSC guidelines for patients with cancer, including allocation methods, cancer-related categorical exclusions and deprioritizations, and provisions for blood products and palliative care. Design, Setting, and Participants: This cross-sectional population-based analysis examined state-endorsed CSC guidelines published before May 20, 2020, that included health care resource allocation recommendations. Main Outcomes and Measures: Guideline publication before or within 120 days after the first documented US case of coronavirus disease 2019 (COVID-19), inclusion of cancer-related categorical exclusions and/or deprioritizations, provisions for blood products and/or palliative care, and associations between these outcomes and state-based cancer demographics. Results: Thirty-one states had health care resource allocation guidelines that met inclusion criteria, of which 17 had been published or updated since the first US case of COVID-19. States whose available hospital bed capacity was predicted to exceed 100% at 6 months (χ2 = 3.82; P = .05) or that had a National Cancer Institute-designated Comprehensive Cancer Center (CCC; χ2 = 6.21; P = .01) were more likely to have publicly available guidelines. The most frequent primary methods of prioritization were the Sequential Organ Failure Assessment score (27 states [87%]) and deprioritizing persons with worse long-term prognoses (22 states [71%]). Seventeen states' (55%) allocation methods included cancer-related deprioritizations, and 8 states (26%) included cancer-related categorical exclusions. The presence of an in-state CCC was associated with lower likelihood of cancer-related categorical exclusions (multivariable odds ratio, 0.06 [95% CI, 0.004-0.87]). Guidelines with disability rights statements were associated with specific provisions to allocate blood products (multivariable odds ratio, 7.44 [95% CI, 1.28-43.24). Both the presence of an in-state CCC and having an oncologist and/or palliative care specialist on the state CSC task force were associated with the inclusion of palliative care provisions. Conclusions and Relevance: Among states with CSC guidelines, most deprioritized some patients with cancer during resource allocation, and one-fourth categorically excluded them. The presence of an in-state CCC was associated with guideline availability, palliative care provisions, and lower odds of cancer-related exclusions. These data suggest that equitable state-level CSC considerations for patients with cancer benefit from the input of oncology stakeholders.

Practical allocation system for the distribution of specialised care during cellular therapy access scarcity.

Novel cellular therapy techniques promise to cure many haematology patients refractory to other treatment modalities. These therapies are intensive and require referral to and care from specialised providers. In the USA, this pool of providers is not expanding at a rate necessary to meet expected demand; therefore, access scarcity appears forthcoming and is likely to be widespread. To maintain fair access to these scarce and curative therapies, we must prospectively create a just and practical system to distribute care. In this article, we first review previously implemented medical product and personnel allocation systems, examining their applicability to cellular therapy provider shortages to demonstrate that this problem requires a novel approach. We then present an innovative system for allocating cellular therapy access, which accounts for the constraints of distribution during real-world oncology practice by using a combination of the following principles: (1) maximising life-years per personnel time, (2) youngest and robust first, (3) sickest first, (4) first come/first served and (5) instrumental value. We conclude with justifications for the incorporation of these principles and the omission of others, discuss how access can be distributed using this combination, consider cost and review fundamental factors necessary for the practical implementation and maintenance of this system.

Novel Data Sharing Between a Comprehensive Cancer Center and a Private Payer to Better Understand Care at the End of Life.

CONTEXT: Understanding end-of-life (EOL) care patterns is a prerequisite to improving the experience for cancer patients. EOL measures endorsed by the National Quality Forum (NQF) have been examined in older patients using Medicare claims. OBJECTIVES: To evaluate EOL care for patients treated at a comprehensive cancer center, using private payer claims data. METHODS: A retrospective cohort study was conducted of Dana-Farber Cancer Institute (DFCI) patients who died between July 2010 and December 2012, and were insured by Blue Cross Blue Shield of Massachusetts. Primary data sources included Blue Cross Blue Shield of Massachusetts claims information and DFCI administrative data. We assessed NQF-endorsed measures of EOL care related to emergency department visits, hospitalizations, and intensive care unit admissions in the last 30 days, chemotherapy in the last 14 days, hospice stay, and death in an acute care setting. Patterns of care by cancer type and service location were determined. RESULTS: Among 674 patients (mean age 58 years), event rates for NQF-endorsed EOL measures were similar to those reported using Medicare claims. Decedents with hematologic malignancies received significantly more intensive care and were less likely to have enrolled in hospice, compared to decedents with solid tumors. Thirty to 45% of EOL events occurred outside of DFCI and its affiliated hospitals. CONCLUSION: Data sharing between a private payer and a large cancer center proved feasible and informative. High rates of hospital service use outside of our sites of care were unexpected. The findings suggest opportunities to better manage care at the end of life.

Radiation for diffuse large B-cell lymphoma in the rituximab era: analysis of the National Comprehensive Cancer Network lymphoma outcomes project.

BACKGROUND: The role of consolidation radiotherapy was examined for patients with diffuse large B-cell lymphoma who were treated at institutions of the National Comprehensive Cancer Network during the rituximab era. METHODS: Failure-free survival (FFS) and overall survival (OS) were analyzed in terms of patient and treatment characteristics. Potential associations were investigated with univariate and multivariate survival analysis and matched pair analysis. RESULTS: There were 841 patients, and most (710 or 84%) received 6 to 8 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP); 293 (35%) received consolidation radiation therapy (RT). Failure occurred for 181 patients: 126 patients (70%) who did not receive RT and 55 patients (30%) who did. At 5 years, both OS and FFS rates were better for patients who had received RT versus those who did not (OS, 91% vs 83% [P = .01]; FFS, 83% vs 76% [P = .05]). A matched pair analysis (217 pairs matched by age, stage, International Prognostic Index [IPI] score, B symptoms, disease bulk, and response to chemotherapy) showed that the receipt of RT improved OS (hazard ratio [HR], 0.53 [P = .07]) and FFS (HR, 0.77 [P = .34]) for patients with stage III/IV disease, but too few events took place among those with stage I/II disease for meaningful comparisons (HR for OS, 0.94 [P = .89]; HR for FFS, 1.81 [P = .15]). A multivariate analysis suggested that the IPI score and the response to chemotherapy had the greatest influence on outcomes. CONCLUSIONS: There was a trend of higher OS and FFS rates for patients who had received consolidation RT after R-CHOP (especially for patients with stage III/IV disease), but the difference did not reach statistical significance.

Comparison of referring and final pathology for patients with T-cell lymphoma in the National Comprehensive Cancer Network.

BACKGROUND: T-cell lymphomas (TCLs) are uncommon in the United States. The accurate diagnosis of TCL is challenging and requires morphologic interpretation, immunophenotyping, and molecular techniques. The authors compared pathologic diagnoses at referring centers with diagnoses from expert hematopathology review to determine concordance rates and to characterize the usefulness of second-opinion pathology review for TCL. METHODS: Patients in the National Comprehensive Cancer Network non-Hodgkin lymphoma database with peripheral TCL, not otherwise specified (PTCL-NOS), angioimmunoblastic TCL (AITL), and anaplastic lymphoma kinase (ALK)-positive and ALK-negative anaplastic large cell lymphoma (ALCL) were eligible if they had prior tissue specimens examined at a referring institution. Pathologic concordance was evaluated using available pathology and diagnostic testing reports and provider progress notes. The etiology of discordance and the potential impact on treatment were examined. RESULTS: Among 131 eligible patients, 57 (44%) had concordant results, totaling 64% of the 89 patients who were referred with a final diagnosis. Thirty-two patients (24%) had discordant results, representing 36% of those who were referred with a final diagnosis. The rates of discordance among patients with of PTCL-NOS, AITL, ALK-negative ALCL, and ALK-positive ALCL were 19%, 33%, 34%, and 6%, respectively. In 14 patients (44% of discordant results), pathologic reclassification could have resulted in a different therapeutic strategy. Forty-two patients (32%) were referred for classification with a provisional diagnosis. CONCLUSIONS: In a large cohort of patients with TCL who were referred to National Comprehensive Cancer Network centers, the likelihood of a concordant final diagnosis at a referring institution was low. As current and future therapies target TCL subsets, these data suggest that patients with suspected TCLs would benefit from evaluation by an expert hematopathologist.

An enhanced International Prognostic Index (NCCN-IPI) for patients with diffuse large B-cell lymphoma treated in the rituximab era.

The International Prognostic Index (IPI) has been the basis for determining prognosis in patients with aggressive non-Hodgkin lymphoma (NHL) for the past 20 years. Using raw clinical data from the National Comprehensive Cancer Network (NCCN) database collected during the rituximab era, we built an enhanced IPI with the goal of improving risk stratification. Clinical features from 1650 adults with de novo diffuse large B-cell lymphoma (DLBCL) diagnosed from 2000-2010 at 7 NCCN cancer centers were assessed for their prognostic significance, with statistical efforts to further refine the categorization of age and normalized LDH. Five predictors (age, lactate dehydrogenase (LDH), sites of involvement, Ann Arbor stage, ECOG performance status) were identified and a maximum of 8 points assigned. Four risk groups were formed: low (0-1), low-intermediate (2-3), high-intermediate (4-5), and high (6-8). Compared with the IPI, the NCCN-IPI better discriminated low- and high-risk subgroups (5-year overall survival [OS]: 96% vs 33%) than the IPI (5 year OS: 90% vs 54%), respectively. When validated using an independent cohort from the British Columbia Cancer Agency (n = 1138), it also demonstrated enhanced discrimination for both low- and high-risk patients. The NCCN-IPI is easy to apply and more powerful than the IPI for predicting survival in the rituximab era.

Stem cell transplantation for follicular lymphoma relapsed/refractory after prior rituximab: a comprehensive analysis from the NCCN lymphoma outcomes project.

BACKGROUND: Stem cell transplant (SCT)-related outcomes and prognostication for relapsed/refractory follicular lymphoma (FL) are not well-defined in the post-rituximab era. METHODS: Through the National Comprehensive Cancer Network (NCCN) lymphoma outcomes study, 184 patients with relapsed/refractory FL who underwent autologous SCT (autoSCT) or allogenic SCT (alloSCT) following disease relapse after prior rituximab-based therapy were examined. RESULTS: Patients who underwent autoSCT (N=136) were older compared with patients who underwent alloSCT (N=48) (54 versus 51 years, respectively, P=.01) and more frequently had grade 3 FL (35% versus 8%, respectively, P=.006). Patients who underwent alloSCT received more prior therapies (4 versus 3, respectively, P<.0001) and more often had resistant disease at SCT (19% versus 6%, respectively, P=.008). Cumulative 100-day nonrelapse mortality (NRM) for autoSCT and alloSCT were 1% and 6%, respectively (P<.0001), whereas 3-year NRM rates were 3% versus 24%, respectively (P<.0001). For autoSCT and alloSCT, cumulative rates of relapse, progression, and/or transformation were 32% versus 16%, respectively (P=.03), whereas 3-year overall survival rates were 87% versus 61% (P<.0001); there were no differences in failure-free survival. AlloSCT was associated with increased risk of death on multivariate analysis (hazard ratio=2.77, 95% confidence interval=1.46-5.26, P=.002). This finding persisted on propensity scoring/matching. Multivariate analysis for autoSCT patients identified age>60 years and>3 prior therapies as adverse factors. Furthermore, a survival model was created for the autoSCT cohort based on number of factors present (0, 1, 2); 3-year failure-free survival was 72%, 47%, and 20%, respectively (P=.0003), and 3-year overall survival was 96%, 82%, and 62%, respectively (P<.0001). CONCLUSIONS: AutoSCT remains an effective therapy for patients with FL. For alloSCT, continued strategies to reduce NRM are needed.

Patterns of use of 18-fluoro-2-deoxy-D-glucose positron emission tomography for initial staging of grade 1-2 follicular lymphoma and its impact on initial treatment strategy in the National Comprehensive Cancer Network Non-Hodgkin Lymphoma Outcomes database.

We describe the patterns of use of 18-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for the initial staging of patients with newly diagnosed grade 1-2 follicular lymphoma (FL) and its potential impact on treatment. Data were obtained from the National Comprehensive Cancer Network Non-Hodgkin Lymphoma Outcomes database. Patients who presented between 1 January 2001 and 30 September 2009 with newly diagnosed grade 1-2 FL, with at least 6 months of follow-up, were included. We identified 953 eligible patients and 532 (56%) underwent FDG-PET as part of initial staging. Among patients who underwent FDG-PET for initial staging, 438 (82%) received early treatment compared to 259 (61.5%) of those staged without FDG-PET (p < 0.0001). Of all patients with stage I FL (n = 100), 47% were treated with radiotherapy (RT) alone, and the choice of initial treatment strategy for stage I FL did not vary significantly by use of FDG-PET (p = 0.22). The use of FDG-PET for staging of FL is widespread and is associated with a greater proportion of patients receiving early therapy. Given the widespread use and high cost of FDG-PET, its clinical utility in stage I FL should be further evaluated.

Comparative outcome of initial therapy for younger patients with mantle cell lymphoma: an analysis from the NCCN NHL Database.

Few randomized trials have compared therapies in mantle cell lymphoma (MCL), and the role of aggressive induction is unclear. The National Comprehensive Cancer Network (NCCN) Non-Hodgkin Lymphoma (NHL) Database, a prospective cohort study collecting clinical, treatment, and outcome data at 7 NCCN centers, provides a unique opportunity to compare the effectiveness of initial therapies in MCL. Patients younger than 65 diagnosed between 2000 and 2008 were included if they received RHCVAD (rituximab fractionated cyclophosphamide, vincristine, adriamycin, and dexamethasone), RCHOP+HDT/ASCR (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone + high-dose therapy/autologous stem cell rescue), RHCVAD+HDT/ASCR, or RCHOP. Clinical parameters were similar for patients treated with RHCVAD (n = 83, 50%), RCHOP+HDT/ASCR (n = 34, 20%), RCHOP (n = 29, 17%), or RHCVAD+HDT/ASCR (n = 21, 13%). Overall, 70 (42%) of the 167 patients progressed and 25 (15%) expired with a median follow-up of 33 months. There was no difference in progression-free survival (PFS) between aggressive regimens (P > .57), which all demonstrated superior PFS compared with RCHOP (P < .004). There was no difference in overall survival (OS) between the RHCVAD and RCHOP+HDT/ASCR (P = .98). RCHOP was inferior to RHCVAD and RCHOP+HDT/ASCR, which had similar PFS and OS. Despite aggressive regimens, the median PFS was 3 to 4 years. Future trials should focus on novel agents rather than comparing current approaches.

Lack of benefit of central nervous system prophylaxis for diffuse large B-cell lymphoma in the rituximab era: findings from a large national database.

BACKGROUND: Little is known about the utility of central nervous system (CNS) prophylaxis for diffuse large B-cell lymphoma (DLBCL) in the rituximab era. The objective of this study was to characterize patterns of CNS prophylaxis for patients who received combined rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy using the National Comprehensive Cancer Network Non-Hodgkin Lymphoma Outcomes Database, a prospective cohort study that collects clinical and outcomes data for patients at 7 participating centers. METHODS: Patients who were eligible for this analysis presented with newly diagnosed DLBCL between January 2001 and July 2008, had no evidence of baseline CNS disease, and had received R-CHOP within 180 days of diagnosis. The authors assessed incidence and covariates of prophylaxis, prophylaxis modality, and, using propensity score analysis, outcomes such as overall survival. RESULTS: Of 989 eligible patients, 117 received CNS prophylaxis (11.8%), most intrathecally (71.8%). Involvement of bone marrow, other high-risk site, >1 extranodal site, higher International Prognostic Index score, and higher stage were associated individually with the receipt of prophylaxis (all P < .0001). At a median follow-up of 2.5 years, there were 20 CNS recurrences (2% [95% confidence interval, 1.1%-2.9%]) among all patients, and overall survival was not affected by prophylaxis. CONCLUSIONS: Given the overall low rate of CNS recurrence and lack of prophylaxis-associated survival benefit, the current data called into question the practice of CNS prophylaxis in the rituximab era.

High rates of surveillance imaging for treated diffuse large B-cell lymphoma: findings from a large national database.

We aimed to characterize surveillance imaging and circumstances of relapse for patients with diffuse large B-cell lymphoma (DLBCL) in the National Comprehensive Cancer Network Non-Hodgkin's Lymphoma Outcomes Database, a prospective cohort study collecting clinical and outcome data at seven comprehensive cancer centers. Patients presenting with newly diagnosed DLBCL in remission ≥3 months after initial therapy and who had accrued 2 years of follow-up were eligible for analysis (n = 625). The median number of imaging studies was 2.5/year (institutional range 0.5-3.5, p < 0.0001); 48.4% received only dedicated computed tomography (CT) scans, 14.6% received only positron emission tomography (PET)-inclusive modalities, 32.8% received a combination and 4.2% received no imaging. Among all eligible patients, 50 (8.0%) experienced relapse, and approximately one-quarter of subclinical relapses were detected through routine imaging. Our results suggest that despite limited data regarding its effect on outcomes, surveillance imaging is prevalent in DLBCL, and a majority of patients receive PET scans at some point during follow-up.

Sunlight exposure, vitamin D, and risk of non-Hodgkin lymphoma in the Nurses' Health Study.

PURPOSE: Case-control studies suggest increased sun exposure reduces non-Hodgkin lymphoma (NHL) risk. Evidence from prospective cohort studies, however, is limited and inconsistent. We evaluated the association between ambient ultraviolet radiation (UV) exposure and NHL in a nationwide cohort of women, the Nurses' Health Study (NHS). METHODS: Between 1976 and 2006, we identified 1064 incident NHL cases among 115,482 women in the prospective NHS. Exposures assessed included average annual UV-B flux based on residence at various times during life, vitamin D intake, and predicted plasma 25-hydroxyvitamin D levels. We estimated incidence rate ratios (RRs) and 95% confidence intervals (CIs) for risk of all NHL and histologic subtypes using Cox proportional hazards models. RESULTS: NHL risk was increased for women residing in areas of high ambient UV radiation (UV-B flux >113 R-B count × 10(-4)) compared to those with lower exposure (<113), with positive linear trends at all time points. The multivariable-adjusted RR for high UV area at age 15 was 1.21 (95% CI: 1.00, 1.47; p-trend < 0.01). There was no evidence of statistical heterogeneity by subtype, although power was limited for subtype analyses. We observed no association between vitamin D measures and risk of NHL overall or by subtype. CONCLUSIONS: Our findings do not support the hypothesis of a protective effect of UV radiation exposure on NHL risk. We found no association between vitamin D and NHL risk.

Comparison of referring and final pathology for patients with non-Hodgkin's lymphoma in the National Comprehensive Cancer Network.

PURPOSE: Before the implementation of the WHO lymphoma classification system, disagreement about pathologic diagnosis was common. We sought to estimate the impact of expert review in the modern era by comparing final pathologic diagnoses at five comprehensive cancer centers with diagnoses assigned at referring centers. PATIENTS AND METHODS: Patients in the National Comprehensive Cancer Network (NCCN) non-Hodgkin's lymphoma (NHL) database with a documented pathologic diagnosis before presentation and a final pathologic diagnosis of any of five common B-cell NHLs were eligible. After central review of discordant cases, we estimated the rate of pathologic concordance, then investigated the etiology of discordance as well its potential impact on prognosis and treatment. RESULTS: The overall pathologic discordance rate was 6% (43 of 731 patients; 95% CI, 4% to 8%). For the majority of cases in which the referring diagnosis was apparently final, no additional studies were conducted at the NCCN center, and the change in diagnosis reflected a different interpretation of existing data. Concordance was highest for diffuse large B-cell lymphoma (95%) and follicular lymphoma (FL; grades 1, 2, and not otherwise specified, 95%) and lowest for grade 3 FL (88%). Of the 43 pathologically discordant cases, 81% (35 patients) might have experienced a change in treatment as a result of the pathologic reclassification. CONCLUSION: In the era of the WHO lymphoma classification system, the majority of common B-cell NHLs diagnosed in the community were unchanged by second opinion review by an expert hematopathologist. However, for one patient in 20, there was a discordance in diagnosis that could have altered therapy.