Abemaciclib plus trastuzumab with or without fulvestrant versus trastuzumab plus standard-of-care chemotherapy in women with HR+, HER2+ advanced breast cancer: plain language summary of the monarcHER study

WHAT IS THIS SUMMARY ABOUT?

This article summarizes the results of a study called monarcHER. The study included participants with a certain type of aggressive breast cancer called HR+, HER2+ advanced breast cancer (ABC) that had their disease worsen or return after multiple previous therapies. This summary intends to help you understand the impact of a non-chemotherapy treatment called abemaciclib in people with HR+, HER2+ ABC. When the study was planned, HER2-targeted therapy (ie trastuzumab) was standard treatment and was typically combined with chemotherapy and endocrine therapy (ie fulvestrant). However drug resistance can develop when HER2+ targeted therapy is used for a long time, making it less effective and allowing cancer to grow or spread to other parts of the body. When this happens, few chemotherapy-free options are available. Because of the chemotherapy side effects, this is not desirable. There is an urgent need to develop new, effective, safe, and tolerable treatment options for patients with HR+, HER2+ ABC. The monarcHER study compared the effects of abemaciclib plus trastuzumab with or without fulvestrant compared to the standard of care treatment.

WHAT WERE THE RESULTS?

Participants were randomly assigned to 1 of 3 groups: Group A (abemaciclib, trastuzumab and fulvestrant), Group B (abemaciclib and trastuzumab), or Group C (trastuzumab and standard of care chemotherapy). The study compared the length of time patients took study treatments without worsening or dying from their breast cancer. This is called the progression free survival (PFS). Participants in Group A had a longer median PFS than those in groups B and C (8.3 months, 5.7 months and 5.7 months respectively). There was no notable difference in PFS between participants in Groups B and C. Additionally, the study looked at the side effects with each treatment group. The most common side effect which is considered severe or lifethreatening was neutropenia, defined as decreased white blood cell levels. Neutropenia may lead to an increased risk of getting infections. However, the percentage of patients experiencing neutropenia was similar in all groups A, B and C (27%, 22% and 26%, respectively). Patients in groups A (79%) and B (78%) who received abemaciclib experienced similar rates of diarrhea.

WHAT DO THE RESULTS MEAN?

The data from the monarcHER study suggest that the combination of abemaciclib, trastuzumab, and fulvestrant may offer a chemotherapy-free option for patients with HR+, HER2+ ABC who have experienced worsening of disease despite multiple prior therapies.

Lobar versus sublobar resection for atypical lung carcinoid: An analysis from the National Cancer Database

BACKGROUND

There is a knowledge gap regarding lobar versus sublobar resection for atypical carcinoid (AC) of the lung. As such, the authors sought to understand and analyze the outcomes of sublobar resection versus lobectomy in this patient population.

METHODS

A retrospective analysis using the National Cancer Database was performed to compare overall survival (OS) between patients treated with lobectomy and patients treated with sublobar resection for AC of the lung between the years 2004 and 2016. Patient characteristics were compared with χ² tests. The Kaplan-Meier method was used to estimate OS distributions, and the log-rank test was used to compare distributions by treatment strategy. A multivariable Cox regression model was used to assess associations between the treatment strategy and OS. A propensity score matching method was also implemented to further eliminate treatment selection bias in the study sample.

RESULTS

The database identified 669 patients with T1-T4 and N0-N3 lung ACs that were surgically resected. Unadjusted Kaplan-Meier survival curves did not demonstrate an OS difference between lobectomy and sublobar resection (p = .094). After propensity score matching, curves demonstrated a numerical improvement in OS with lobectomy; however, it was not statistically significant (p = .5). In a subgroup analysis, lobectomy and node-negative disease were associated with the best OS, whereas sublobar resection and node-positive disease were associated with the worst OS (p < .0001). Nodal involvement was associated with worse survival, regardless of surgical treatment (p < .0001).

CONCLUSIONS

In patients with T1-T4 and N0-N3 ACs of the lung, lobectomy was not associated with an improvement in OS in comparison with sublobar resection.

Financial relationships between industry and principal investigators of US cooperative group randomized cancer clinical trials

Financial conflicts of interest (FCOIs) could bias the potentially practice-changing oncologic randomized clinical trials (RCTs) of tomorrow. This investigation characterized the FCOIs of the principal investigators (PIs) of all currently accruing trials of the four (adult) cooperative groups of the National Clinical Trials Network. For our study, the PI list was first compiled, and each name was then searched in the CMS Open Payments database. For each transaction (general payments (GPs) or research funding (RF)), the amount/number/source of payments was recorded. Results showed that from 2014 to 2019, the 91 PIs collectively accepted nearly one-third of a billion dollars ($10 477 023 GPs and $320 096 233 RF). The mean and median GP was $6505 and $945, respectively, and $301 693 and $49 824 RF, respectively. Multivariable Gamma regression analysis revealed that higher GP sums were associated with RCTs involving any type of systemic therapy, and higher RF sums with medical oncologist PIs, trials with phase III components, and RCTs involving radiotherapy (P < .05 for all). Both higher-volume GPs and RF were predicted by PIs having accepted payment(s) from the manufacturer of the drug utilized in their RCT (P < .001 GP, P = .008 RF). Taken together, the main message of this investigation is that FCOIs may be particularly high in PIs of phase III systemic therapy trials, especially if the PI accepted payments from the manufacturer of the drug utilized in their trial. Such RCTs should be thoroughly scrutinized by medical journals, the FDA, and insurance companies for potential "industry bias" that could influence the integrity of their conclusions.

US adults with diabetes mellitus: Variability in oral healthcare utilization

BACKGROUND

Diabetic patients are advised to have at least one dental examination per year. It is unclear to what extent different subgroups of US diabetic adults closely follow this recommendation. Thus, we assessed dental care utilization and related factors in a representative sample of US diabetic adults from rural and urban counties.

METHODS

Cross-sectional data were from the 2018 Behavioral Risk Factor Surveillance System (BRFSS). Survey logistic regression was used to account for the complex sampling design.

RESULTS

Among 40,585 eligible participants, 24,887 (60% of the population) had at least one dental visit for any reason within the past year. The lowest compliance was observed among edentulous participants (27%, adjusted OR = 0.26, 95% CI = 0.22-0.31 vs. fully dentate). Dental compliance was also negatively associated with having a lower income or education, ever being a smoker, or having barriers to access to care. Rural residents had lower dental compliance compared to urban residents, particularly those without healthcare coverage.

CONCLUSIONS

Dental compliance among US adult diabetic individuals was low, particularly among rural residents, and as compared to other recommended diabetic care practices. Future public health interventions may target rural individuals without healthcare coverage, smokers and edentulous individuals. There is a need to integrate dental and medical care to facilitate cross-talks among different health professionals, so that educational preventive messages are reinforced at every healthcare visit.

Variability in preventive care practices among US adults with diabetes mellitus

INTRODUCTION

Patients with diabetes are advised to follow standard medical care including daily blood glucose and foot checks, eye examinations with pupil dilation, and cholesterol checks to prevent diabetes-related complications. It is unclear how these practices currently vary across different US population subgroups. The objective of this study was to assess variation in overall and individual diabetes care practices and identify specific factors associated with differences in these practices in a representative sample of US diabetic adults.

RESEARCH DESIGN AND METHODS

Cross-sectional data were from the 2017 Behavioral Risk Factor Surveillance System. Survey logistic regression was used to account for the complex sampling design.

RESULTS

Among 30 780 eligible participants, 8957 (equivalent to 28% of the target population) followed all four diabetes care practices. Insulin-dependent participants had higher adjusted odds (adjusted OR=2.95; 95% CI 2.62 to 3.31) of following all four diabetic care practices compared with those who did not. Cost-related variables (having healthcare coverage and/or a personal doctor) were positively associated with diabetes care practices, with the strongest association observed for adherence to more costly practices (annual eye examination and cholesterol check) versus less costly ones (daily blood glucose check, daily foot check).

CONCLUSIONS

Our findings suggest the need for diabetes care practice-specific and population subgroup-specific public health interventions to encourage early adherence to diabetic care practices and reduce complications.

The impact of histology in the outcomes of patients with early-stage non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT) and adjuvant chemotherapy

INTRODUCTION

Stereotactic body radiation therapy (SBRT) is the standard of care treatment for nonsurgical patients with early-stage non-small cell lung cancer (NSCLC). A recent report has indicated an improvement in overall survival (OS) with adjuvant chemotherapy in patients with tumors ≥ 4 cm treated with SBRT. We present a retrospective study evaluating the impact of histology in patients treated with SBRT and adjuvant chemotherapy.

MATERIALS AND METHODS

Patients (≥18 years) diagnosed with clinical stages I-II NSCLC from 2004 to 2013 were identified using the National Cancer Database (n = 12,055). The Kaplan-Meier method was used to estimate overall survival (OS) distributions and the log-rank test was used to compare distributions by treatment strategy. Clinical stages I and II were subdivided according to the TNM staging and log-rank tests was used to compare survival distributions by treatment strategy within each subgroup. We performed subgroup analysis for the three main NSCLC histologies (i.e., adenocarcinoma, squamous cell carcinoma (SCC), and large cell).

RESULTS

In patients with adenocarcinoma, SCC and, large cell carcinoma; adjuvant chemotherapy was associated with worse OS in tumors < 4 cm (P<.0001, P<.0099, and P=.0082, respectively). In patients with adenocarcinoma and tumor ≥ 4 cm, adjuvant chemotherapy was not associated with improved OS (P=.262); however, in patients with SCC and large cell, adjuvant chemotherapy improved OS (P<.0001, and P=.0129, respectively).

CONCLUSION

In patients with NSCLC ≥ 4 cm treated with SBRT, adjuvant chemotherapy was associated with improved OS in patients with SCC and large cell histologies.

Association Between Treatment Facility Volume, Therapy Types, and Overall Survival in Patients With Stage IIIA Non-Small Cell Lung Cancer

BACKGROUND

There is significant heterogeneity in the treatment of stage IIIA non-small cell lung cancer (NSCLC). This study evaluated the therapeutic and survival disparities in patients with stage IIIA NSCLC based on the facility volume using the National Cancer Database.

METHODS

Patients with stage IIIA NSCLC diagnosed from 2004 through 2015 were included. Facilities were classified by tertiles based on mean patients treated per year, with low-volume facilities treating ≤8 patients, intermediate-volume treating 9 to 14 patients, and high-volume treating ≥15 patients. Cox multivariate analysis was used to determine the volume-outcome relationship.

RESULTS

Analysis included 83,673 patients treated at 1,319 facilities. Compared with patients treated at low-volume facilities, those treated at high-volume centers were more likely to be treated with surgical (25% vs 18%) and trimodality (12% vs 9%) therapies. In multivariate analysis, facility volume was independently associated with all-cause mortality (P<.0001). Median overall survival by facility volume was 15, 16, and 19 months for low-, intermediate-, and high-volume facilities, respectively (P<.001). Compared with patients treated at high-volume facilities, those treated at intermediate- and low-volume facilities had a significantly higher risk of death (hazard ratio, 1.09 [95% CI, 1.07-1.11] and 1.11 [95% CI, 1.09-1.13], respectively).

CONCLUSIONS

Patients treated for stage IIIA NSCLC at high-volume facilities were more likely to receive surgical and trimodality therapies and had a significant improvement in survival.

Adjuvant chemotherapy following SBRT for early stage non-small cell lung cancer (NSCLC) in older patients

Adjuvant chemotherapy improves overall survival (OS) following stereotactic body radiotherapy (SBRT) in patients with early stage non-small cell lung cancer and tumors ≥four cm. Here, we aim to evaluate its role following SBRT in older patients. Patients >70 years diagnosed with clinical stages I-II NSCLC, (N0 disease), who received SBRT, were identified using the National Cancer Database (n = 7042). The Kaplan-Meier method was used to estimate OS, and the log-rank test was used to compare distributions by treatment strategy overall and within clinical stages I and II. There were 3533 female patients (50.2%), and 6074 (86.3%) had stage I disease. Among stage I patients, 643 (10.6%) received adjuvant chemotherapy, compared to 372 stage II patients (38.4%). Median OS was better with SBRT in patients with stage I disease (25.4 vs. 20.3 months; p < .001); while patients with stage II NSCLC had better OS with SBRT + chemotherapy (20.2 vs. 14.2 months; p < .001). On multivariate analysis, patients with stage I NSCLC who received SBRT alone had better overall survival (HR: 0.79; 95% CI, 0.73, 0.87). SBRT alone was associated with an increased risk of death in patients with stage II disease (HR: 1.34; 95% CI, 1.15, 1.55). Patients with tumors ≥4 cm had better OS with SBRT + chemotherapy (18.5 vs. 15.5 months; p = .003), while patients with tumors <4 cm did better with SBRT (median OS of 24.1 vs. 20.3 months; p < .001). In >70 years old patients with tumors ≥4 cm, adjuvant chemotherapy following SBRT was associated with improved OS.

n-3 Docosapentaenoic Acid Intake and Relationship with Plasma Long-Chain n-3 Fatty Acid Concentrations in the United States: NHANES 2003-2014

The long-chain n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), play a crucial role in health, but previous National Health and Nutrition Examination Survey (NHANES) analyses have shown that EPA and DHA intake in the United States is far below recommendations (~250-500 mg/day EPA + DHA). Less is known about docosapentaenoic acid (DPA), the metabolic intermediate of EPA and DHA; however, evidence suggests DPA may be an important contributor to long-chain n-3 fatty acid intake and impart unique benefits. We used NHANES 2003-2014 data (n = 45,347) to assess DPA intake and plasma concentrations, as well as the relationship between intake and plasma concentrations of EPA, DPA, and DHA. Mean DPA intake was 22.3 ± 0.8 mg/day from 2013 to 2014, and increased significantly over time (p < 0.001), with the lowest values from 2003 to 2004 (16.2 ± 1.2 mg/day). DPA intake was higher in adults (20-55 years) and seniors (55+ years) compared to younger individuals. In regression analyses, DPA intake was a significant predictor of plasma EPA (β = 138.5; p < 0.001) and DHA (β = 318.9; p < 0.001). Plasma DPA was predicted by EPA and DHA intake (β = 13.15; p = 0.001 and β = 7.4; p = 0.002), but not dietary DPA (p = 0.3). This indicates that DPA intake is not a good marker of plasma DPA status (or vice versa), and further research is needed to understand the factors that affect the interconversion of EPA and DPA. These findings have implications for future long-chain n-3 fatty acids dietary recommendations.

HPV Status and Survival in Non-Oropharyngeal Squamous Cell Carcinoma of the Head and Neck

BACKGROUND/AIM

HPV-mediated oropharyngeal squamous cell carcinoma is associated with an increased survival. The prognostic value of HPV status for other primary sites is unclear. We aimed to assess the effect of HPV status on overall survival in patients with non-oropharyngeal head and neck squamous cell carcinoma (non-OPSCC) using the National Cancer Database (NCDB).

PATIENTS AND METHODS

Adults with non-OPSCC [gum, lip, floor of mouth, tongue (excluding base), hypopharynx, nasopharynx, other pharynx] and known HPV status were included in our study. Associations between HPV status, primary site, patient characteristics and overall survival (OS) were assessed.

RESULTS

HPV positivity was associated with a better OS compared to HPV-negative patients (HR=0.83, 95%CI=0.74-0.93, p<0.001). Female gender, gum, lip, nasopharynx primaries, and private insurance predicted for improved OS.

CONCLUSION

HPV positivity and female gender are good prognostic factors in non-OPSCC. Routine HPV testing should be considered for HPV positive non-OPSCC, as well as studies evaluating de-escalation of treatment if this association is confirmed.

National practice patterns of proton versus photon therapy in the treatment of adult patients with primary brain tumors in the United States

OBJECTIVES

To examine patterns of care associated with the administration of proton versus photon therapy for adult patients with primary brain tumors in a large national cohort from the United States.

METHODS

The National Cancer Database (NCDB) was queried for newly diagnosed primary brain tumors (2004-2014) in adult patients aged 18 and older receiving proton or photon radiotherapy. Clinical features, patient demographics and treatment parameters were extracted. Differences between groups were assessed using multivariable logistic regression analysis.

RESULTS

In total, 73,073 patients were analyzed (n = 72,635 [99.4%] photon therapy, n = 438 [0.6%] proton therapy). On multivariable analysis of photon versus proton therapy, several factors predicted for receipt of proton therapy, including younger age (p = .041), highest income quartile (p = .007), treatment at academic institutions (p < .001), in regional facilities outside the Midwest/South (p < .001), diagnosis in more recent years (p = .003), fewer comorbidities (p < .001) and non-glioblastoma histology (p < .001).

CONCLUSIONS

There are several significant socioeconomic variables that influence receipt of proton therapy for primary brain tumors. Although not implying causation, the socioeconomic findings discovered herein should be taken into account when delivering cancer care to all patients.

Adjuvant Systemic Therapy in Patients With Early-Stage NSCLC Treated With Stereotactic Body Radiation Therapy

INTRODUCTION

Stereotactic body radiation therapy (SBRT) is commonly used to treat nonsurgical patients with early-stage NSCLC. There are no prospective data on the role of adjuvant chemotherapy in this setting.

METHODS

Patients (≥18 years) diagnosed with clinical stages I-II NSCLC from 2004 to 2013 were identified using the National Cancer Database (n = 11,836). The Kaplan-Meier method was used to estimate overall survival (OS) distributions and the log-rank test was used to compare distributions by treatment strategy. Clinical stages I and II were subdivided according to the TNM staging and log-rank tests was used to compare survival distributions by treatment strategy within each subgroup.

RESULTS

In patients with T2bN0, median OS in the SBRT alone and SBRT plus adjuvant chemotherapy groups were 16.5 months versus 24.2 months, respectively (95% confidence interval [CI]: 14.1-20.1 months and 18.8-33.3 months, respectively; p < .001); whereas for T3N0, median OS times were 13 months and 20.1 months, respectively (95% CI: 11.7-14.5 mohths and 17.7-21.9 months, respectively; p < .001). For tumors 4 cm or larger and node-negative disease, median OS was 15.9 months in the SBRT-alone group, and 19 months in the SBRT-plus-chemotherapy group (95% CI: 15.1-16.8 months and 17.9-20.8 months, respectively; p < .001). For patients with tumors less than 4 cm and node-negative disease, the median OS was 28.5 months in the SBRT-alone group and 24.3 months in the SBRT-plus-chemotherapy group (95% CI: 27.4-29.4 months and 22.8-26.1 months, respectively; p < .001).

CONCLUSIONS

SBRT followed by adjuvant chemotherapy was associated with improved OS in comparison with SBRT alone in patients with T greater than or equal to 4 cm, similar to that seen after surgery.

Chemoradiotherapy versus chemotherapy alone for unresected intrahepatic cholangiocarcinoma: practice patterns and outcomes from the national cancer data base

Background

Current guidelines recommend chemotherapy (CT) with or without radiotherapy (RT) for unresected intrahepatic cholangiocarcinoma (IC). Although there is currently lack of consensus, previous smaller studies have illustrated the efficacy of local therapy for this population. This investigation evaluated outcomes of chemoradiotherapy (CRT) versus CT alone in unresected IC using a large, contemporary national database.

Methods

The National Cancer Data Base (NCDB) was queried for primary IC cases (2004-2013) receiving CT alone or CRT. Patients undergoing resection or not receiving CT were excluded, as were those with M1 disease or unknown M classification. Logistic regression analysis ascertained factors associated with CRT administration. Kaplan-Meier analysis evaluated overall survival (OS) between both groups. Cox proportional hazards modeling assessed variables associated with OS.

Results

In total, 2,842 patients were analyzed [n=666 (23%) CRT, n=2,176 (77%) CT]. CRT was less likely delivered at community centers, in more recent time periods (2009-2013), to older patients, and in certain geographic locations. Median OS in the CRT and CT groups were 13.6 vs. 10.5 months, respectively (P<0.001). On multivariate analysis, poorer OS was associated with age, male gender, increased comorbidities, treatment at a community center, and treatment at earlier time periods (2004-2008) (P<0.05 for all). Notably, receipt of CRT independently predicted for improved OS (P<0.001).

Conclusions

As compared to CT alone, CRT was independently associated with improved survival in unresected IC. These findings support a randomized trial evaluating this question that is currently accruing.

Clinical behavior of stage IVC squamous cell carcinoma of the head and neck

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Background: Squamous cell carcinoma of the head and neck (HNSCC) with distant metastasis at diagnosis (stage IVC) is rare, and outcomes are often lumped together with those of patients who relapse following initial treatment. We evaluated prognostic factors in patients presenting with stage IVC HNSCC. Methods: Data was extracted from the National Cancer Database to determine prevalence, overall survival (OS), and prognostic factors of stage IVC HNSCC (oral cavity, gum, lip, oropharynx, tongue, tonsil and hypopharynx) in adults, using SAS software for analysis. OS curves were estimated using the Kaplan-Meier method and differences were compared using a log-rank test. Significant parameters in the univariate Cox proportional hazards regression model analyses were included in the multivariate model, and hazard ratios, p-values and 95% confidence intervals were presented. Results: Of 226,302 patients with HNSCC, 5458 had distant metastases at diagnosis (2.40%); 5238 had complete data and were included in further analyses. Median survival of the entire cohort was 9.07 months, and one-year survival was 41%. Age > 70 years, Black race and higher Charlson-Deyo comorbidity score were associated with worse OS, while HPV positive status, tonsil and tongue (not including base) primary, private insurance and receipt of any treatment were associated with improved OS on univariate analysis. In multivariate analysis, HPV positive tumors were associated with improved OS compared to HPV negative tumors (HR 0.63, 95% CI 0.48-0.82; p= 0.001), even after adjusting for site of tumor origin. Only patients with a Charlson-Deyo score of ≥2 had worse OS compared to those without comorbidities. Hypopharynx, lip, tonsil and base of tongue primaries had significantly worse OS compared to gum and other mouth. Except for radiation alone and radiation with surgery, treatment demonstrated significant improvement in OS compared to no treatment, a combination of chemotherapy, radiation and surgery provided the largest survival benefit (HR 0.23, 95% CI 0.20-0.28). Conclusions: HPV positivity seems to predict for better prognosis, regardless of site of origin. Patients with metastatic HNSCC should be offered multimodality therapy in order to improve outcomes.

HPV status and survival in non-oropharyngeal squamous cell carcinoma of the head and neck

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Background: HPV positive squamous cell carcinoma of the oropharynx and tonsil has been associated with increased survival. However, the prognostic value of HPV status for other primary sites is unclear. We assessed the effect of HPV status on survival in patients with non-oropharyngeal head and neck squamous cell carcinoma at all stages. Methods: Data was obtained from the National Cancer Database (NCDB) to determine the effect of HPV status on overall survival (OS) in adults with non-oropharyngeal head and neck squamous cell carcinoma (gum, lip, floor of mouth, tongue (excluding base), hypopharynx and nasopharynx) using SAS software. Pearson’s Chi square test was used for comparisons by HPV status. The Kaplan-Meier method was used to estimate OS and differences were compared using a log-rank test. A multivariate Cox proportional hazards regression model analysis was performed to determine effects of individual variables on outcomes. Results: Patients with all stages of squamous cell carcinoma of the gum, lip, floor of mouth, tongue (excluding base), hypopharynx and nasopharynx diagnosed from 2010 to 2013 with complete HPV data were included (n = 13,908). In univariate analysis, HPV positivity, female gender, Asian race, primary site (lip, tongue, nasopharynx and hypopharynx), private insurance and any treatment (except for chemotherapy alone) were associated with increased OS, whereas increased age, Black race, higher Charlson-Deyo comorbidity score, hypopharynx primary, and higher AJCC stage were associated with worse OS. After adjustment for covariates, HPV positivity was associated with improved OS (HR 0.83, 95% CI 0.74-0.93; p < 0.001). Female gender, gum, lip, nasopharynx primaries, and private insurance on multivariate analysis predicted for improved OS, while age > 70, higher Charlson-Deyo score and higher AJCC stage were associated with worse OS. Conclusions: HPV positivity and female gender are good prognostic factors in squamous cell carcinoma of the head and neck, independent of primary site. Trials evaluating de-escalation of treatment should be considered for HPV positive tumors from non-oropharyngeal sites in the head and neck region.

Loss of Dnmt3a induces CLL and PTCL with distinct methylomes and transcriptomes in mice

Cytosine methylation of DNA is an epigenetic modification involved in the repression of genes that affect biological processes including hematopoiesis. It is catalyzed by DNA methyltransferases, one of which -DNMT3A- is frequently mutated in human hematologic malignancies. We have previously reported that Dnmt3a inactivation in hematopoietic stem cells results in chronic lymphocytic leukemia (CLL) and CD8-positive peripheral T cell lymphomas (PTCL) in EμSRα-tTA;Teto-Cre;Dnmt3a^fl/fl; Rosa26LOXP^EGFP/EGFP (Dnmt3a^Δ/Δ) mice. The extent to which molecular changes overlap between these diseases is not clear. Using high resolution global methylation and expression analysis we show that whereas patterns of methylation and transcription in normal B-1a cells and CD8-positive T cells are similar, methylomes and transcriptomes in malignant B-1a and CD8+ T cells are remarkably distinct, suggesting a cell-type specific function for Dnmt3a in cellular transformation. Promoter hypomethylation in tumors was 10 times more frequent than hypermethylation, three times more frequent in CLL than PTCL and correlated better with gene expression than hypermethylation. Cross-species molecular comparison of mouse and human CLL and PTCL reveals significant overlaps and identifies putative oncogenic drivers of disease. Thus, Dnmt3a^Δ/Δ mice can serve as a new mouse model to study CLL and PTCL in relevant physiological settings.