Neuroendocrine prostate cancer (NEPCa) is the most aggressive type of prostate cancer. However, energy metabolism, one of the hallmarks of cancer, in NEPCa has not been well studied. Pyruvate kinase M (PKM), which catalyzes the final step of glycolysis, has two main splicing isoforms, PKM1 and PKM2. PKM2 is known to be upregulated in various cancers, including prostate adenocarcinoma (AdPCa). In this study, we used immunohistochemistry, immunofluorescence staining, and bioinformatic analysis to examine the expression of PKM1 and PKM2 in mouse and human prostatic tissues, including developing, benign and cancerous prostate. We found that PKM2 was the predominant isoform expressed throughout prostate development and PCa progression, with slightly reduced expression in some NEPCa samples. PKM1 was mostly expressed in stromal cells but low-level PKM1 was also detected in prostate basal epithelial cells. Its expression was absent in the majority of PCa specimens but present in a subset of NEPCa. Additionally, we evaluated the mRNA levels of ten PKM isoforms that express exon 9 (PKM1-like) or exon 10 (PKM2-like). Some of these isoforms showed notable expression levels in PCa cell lines and human PCa specimens. These findings lay the groundwork for understanding PKMs' role in PCa carcinogenesis and NEPCa progression. The distinct expression pattern of PKM isoforms in different PCa subtypes may offer insights into potential therapeutic strategies for treating PCa.

Background: Malignant histiocytosis, also known as the M-group per the Histiocyte Society classification, represents a rare, aggressive malignant group of histiocytic neoplasms. It includes histiocytic neoplasms that occur de novo (pMHN) and those that develop in association with other malignant diseases (aMHN). However, little is known about factors that impact MHN clinical outcomes. We conducted this pooled database analysis to delineate key clinicopathological characteristics, prognostic indicators, and treatment modalities that affect survival in this rare histiocytic group. Methods: To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, survival, and prognostic factors, we compiled a pooled database of 270 cases of MHN. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS). Results: A total of 270 patients with confirmed MHN were identified, with 77% pMHN and 23% aMHN. The median age was 45, with bimodal peaks between 13-26 and 52-65. There was a male preponderance with M:F of 1.6. The most common primary sites of involvement were liver (15%), CNS and spleen (13% each), thoracic, GI, and soft tissues (12% each), bones (11%), skin (10%), and H&N (8%). Lymphadenopathy and bone marrow (BM) were involved in 28% and 18%, respectively. Constitutional symptoms occurred in 12% and hemophagocytic syndrome (HPS) in 6%. The median time of MHN onset in aMHN was 12 months. The median OS of the whole group was 12 months. BM involvement had a worse median OS (p = 0.003). Stage 1 disease had better median OS than higher stages (p = 0.01). Furthermore, unifocal had better median OS than multifocal/multicentric disease (p = 0.0005). The presence of inflammatory background positively impacted OS (p = 0.01). The occurrence of HPS adversely affected OS (p < 0.0001). Compared to no treatment, localized therapies such as surgery (S) and/or radiation therapy (RT) and systemic combination chemotherapy (CT) were statistically superior, with a median OS of 3, 24, and 18 months, respectively (p = 0.02). When MHN was not amenable to complete resection, CT and CT+/-S+/-RT were superior to RT+S (p = 0.03). Having CNS or splenic-lymphatic primary involvement tended to have a numerical but non-significant worse median OS than soft tissue or visceral disease. While female sex, size<10cm, and pMHN seemed to have numerically better OS, they did not reach statistical significance. There was no difference in median OS for age. Conclusions: This study presents updated clinicopathologic data from a pooled cohort of patients with MHN. It identifies BM involvement, stage, extent of the disease, the inflammatory background status, occurrence of HPS, and treatment approach as critical determinants of OS.

Background: Fluid overload-associated large B-cell lymphoma (FOLBCL) is a new WHO lymphoma entity previously known as PEL-like lymphoma or HHV8-unrelated PEL-like lymphoma. It is a rare lymphoma that arises within fluid-filled body cavities without a solid component. FOLBCL occurs in the absence of immunodeficiency and is commonly associated with conditions associated with fluid overload. It expresses mature B-cell phenotype and occasional EBV infection markers. We conducted this study to delineate key clinicopathological characteristics, prognostic indicators, and treatment modalities that affect outcomes in this rare and newly-defined lymphoma subtype. Methods: To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, survival, and prognostic factors, we compiled a pooled database of 115 cases that fit the diagnostic criteria for FOLBCL. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS). Results: A total of 115 patients with confirmed FOLBCL were identified. The median age was 74, with a peak incidence between 72 and 82 years. There was a male preponderance with M:F of 2. The pleural, pericardial, and peritoneal cavities were involved in 75%, 34%, and 27%, respectively. The median duration of symptoms before diagnosis was 1 month. Patients presented with constitutional symptoms and hepatosplenomegaly in 13% and 1%, respectively-no patients presented with lymph node and bone marrow involvement. The median OS of the whole group was 16 months. Patients younger than 70 had better median OS than 70 and older (24 vs. 10 months, p=0.008). The presence of any malignant peritoneal effusion was associated with worse OS when compared to effusion limited to the thoracic cavity (7 vs. 24 months, p=0.005). LDH≥500 was also associated with worse OS (p=0.02). Sex, the presence of fluid overload-causing conditions, and serum IL2R levels did not seem to impact OS. Compared to no treatment, chemotherapy had a numerically superior OS but did not reach statistical significance (19 vs. 10 months, p=0.11). However, patients that attained CR as their best response had a superior median OS (p<0.0001). Conclusions: This study presents updated clinicopathologic data from a pooled cohort of patients with FOLBCL. It identifies the age, the primary location of cavitary disease, LDH, active therapy, and quality of response to treatment as key determinants of OS.

Background: While PEL is a well-established distinct WHO entity, PEL-LL is poorly defined and has been characterized differently by different researchers. Over the years, it encompassed PEL that expressed mature B-cell markers, extra-cavitary solid PEL, and recently the HHV8-unrelated PEL-like lymphomas. For this study, we defined PEL-LL as PEL-like lymphomas expressing mature B-cell phenotype. We conducted this study to compare the clinicopathological characteristics of PEL and PEL-LL and their impact on clinical outcomes. Methods: To study the clinicopathologic characteristics, therapeutic interventions, overall survival (OS), disease-free survival (DFS), and prognostic factors, we compiled a pooled database of 381 cases of PEL and PEL-LL. Chi-square and t-test were used to test the statistical significance of differences in parameters. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of clinicopathologic factors on OS and DFS. Results: A total of 381 (268 PEL, 113 PEL-LL) patients were identified. PEL and PEL-LL median ages were 51 and 74 (p < 0.0001), respectively. There was a male preponderance with M:F of 7 with PEL versus 2 with PEL-LL (p < 0.0001). The median OS was 6 months for PEL and 16 months for PEL-LL (p = 0.006). Compared to the thoracic cavity, involvement of the peritoneal cavity was associated with worse OS in both PEL and PEL-LL. Still, PEL-LL maintained better outcomes for each risk group (24 and 7 vs. 11 and 4 months, p < 0.0001). In the absence of HIV infection, PEL-LL has a superior OS to PEL (19 vs. 6 months, p = 0.002). However, HIV infection erases this survival advantage (6 vs. 6.5 months). In both entities, active treatment was associated with better OS (19 vs. 10 and 9 vs. 2 months, p < 0.0001). However, the untreated PEL-LL arm did as well as the treated PEL arm. Achieving CR as the best response to therapy in both PEL-LL and PEL was associated with superior OS (108 vs. 7 and 70 vs. 2 months, p < 0.0001). While dose-intense chemotherapy regimens did not impact OS in PEL-LL, they were associated with better OS in PEL (22 vs. 18 and 15 vs. 8 months, p = 0.03). Conclusions: This is the first study to compare PEL and PEL-LL expressing mature B-cell phenotype. It identifies key factors that impact OS that vary between the two entities. It also supports that PEL and PEL-LL represent two different disease entities regardless of their similar presentation.

Background B-cell lymphoma with MYC, BCL2, and/or BCL6 rearrangements is classified as double/triple-hit lymphoma (DTHL). They usually, but not always, tend to be high-grade aggressive B-cell lymphoma with a worse prognosis. Despite this classification, DTHL remains a heterogeneous group with varied molecular profiles, biological behaviors, and prognoses. Therefore, we conducted this pooled database analysis to identify the prognostic factors, clinicopathological characteristics, and therapeutic strategies influencing survival in this rare disease. Methods To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, survival, and prognostic factors, we compiled a pooled database of 161 cases that fit the diagnostic criteria for DTHL. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS) and disease-free survival (DFS). Results We compiled a dataset of 161 patients with confirmed DTHL. The median age was 62, with an F:M of 1.08. The median duration of symptoms before diagnosis was 2 months. DTHL involved the lymph nodes (41%), bone marrow (31%), bone (14%), CNS (5%), skin (4%), liver (3%), and spleen (2%). Constitutional symptoms were reported in 20% of cases. The cohort consisted of primary (50%), secondary/transformed (16%), and follicular DTHL (34%). The median OS and DFS of the cohort were 69 and 27 months, respectively. Bone marrow and extra-lymphatic organ involvement were associated with worse DFS and non-significant numerically worse OS. LDH>500 (p=0.006), PAX5-negative (p=0.01), CD79a-negative (p=0.02), and Ki67>80% (p<0.0001) were associated with worse OS. Similarly, CD5+, CD10+, and MUM1+ had worse OS but did not reach statistical significance. Follicular DTHL was associated with the best median OS and DFS, followed by primary, then secondary/transformed in decreasing order. Advanced stage and high IPI were also associated with worse non-significant numerical OS. Age and sex did not impact OS. Compared to no treatment, chemotherapy and stem cell transplant had incrementally superior median OS (3 vs. 55 vs. NR months, p=0.008). Frontline intensive chemotherapy yielded similar DFS and OS to CHOP-like regimens. Patients who attained CR as their best response also had a superior median OS (p<0.0001). Conclusion This study presents clinicopathologic data from a cohort of patients with primary, secondary, and follicular DTHL. It identifies the type of DTHL, IHC profile, LDH levels, type of therapy, and quality of response to treatment as critical determinants of OS. Depending on the type (de novo, secondary, or follicular), DTHL seems to behave like 3 different disease entities.

Background Mast cell leukemia (MstCL) is a rare but aggressive variant of systemic mastocytosis (SM), defined by the presence of >20% atypical mast cells in the bone marrow. It is further classified into leukemic and aleukemic variants based on the presence or absence of >10% atypical mast cells in the peripheral blood, respectively. There is a wide variation in treatment regimens used to treat MstCL. Despite this, prognosis remains poor. While MstCL often follows an aggressive course, its outcomes vary considerably. We conducted this study to develop a provisional MstCL prognostic score (MCLPS) for this rare disease. Methods We used our constructed MstCL database, which contains retrospective data on 144 cases. Such data included demographics such as sex, age, and race. It also included disease presentation symptoms, duration of symptoms before diagnosis, site(s) of the disease, blood counts, coexisting comorbidities, disease immunohistochemical and molecular phenotype, types of treatment, and survival outcomes. Of the 144 cases, only 104 had complete survival and outcomes data, the sample chosen for this study. Cox proportional-hazards model and Log-rank tests were used to assess the influence of clinicopathologic factors on overall survival (OS). We included factors that statistically impacted OS and scored them by the impact of their hazard ratios. Results The median OS of the cohort was 9 months. The following dichotomous variables were identified as impactful prognostic factors in this cohort: Age<55 (6 vs. 15 months), Hgb<10g/dl (3 vs. 29 months), Platelets<100K (3 vs. 23 months), leukemic phase (7 vs. 18 months), and complex cytogenetics (2.3 vs. 23 months). A prognostic model was devised using these variables to identify different levels of risk. Each variable was assigned a score of 1 when present for a maximum score of 5. In this exploratory cohort, low risk was assigned a score of 0, intermediate risk a score of 1-2, and high risk a score of 3-5. This prognostic score system led to our cohort's most optimal risk discriminatory model, where low, intermediate, and high risk had a median OS of 29, 8, and 2.4 months, respectively (p=0.0006). Conclusion This MCLPS is a promising new tool for risk-stratifying patients with MstCL. However, it still requires prospective validation.

Background Plasmablastic Lymphoma (PBL) is a rare and aggressive subtype of non-Hodgkin's lymphoma. It tends to be associated with immunosuppressive clinical contexts, such as HIV infection and immunosuppressive therapies for autoimmune disorders and organ transplants. However, due to the rarity of the disease, which is poorly understood, varied treatment approaches have been implemented, and no optimal data or guidelines for managing PBL are available. Furthermore, a few small case series reported conflicting prognosticators. Therefore, we conducted this pooled database analysis to identify the prognostic factors, clinicopathological characteristics, and therapeutic strategies influencing survival in this rare disease. Methods To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, survival, and prognostic factors, we compiled a pooled database of 300 cases that fit the diagnostic criteria for PBL. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS). Results A total of 300 patients with confirmed PBL were identified. The median age was 49. There was a male preponderance with M:F of 2.7. The median duration of symptoms before diagnosis was 1 month. PBL involved the H&N (39%), Lymph nodes (LN) (33%), GI tract (31%), bone marrow (17%), bones (14%), lungs and pleura (10%), skin (9%), spleen (7%), liver (6%), CNS (6%), and testes (2%). Constitutional symptoms were reported in 35%. Stage III/IV accounted for 51% of the cohort. Sixty-two percent were immunosuppressed, 47% due to HIV. While 58% were Kappa restricted, 40% were Lambda, and 2% null. The median OS and DFS of the whole group were 25 and 15 months, respectively. The involvement of BM (p<0.0001), liver (p=0.003), lungs/pleura (p<0.0001), and upper GI tract (0.001) was associated with worse OS. Moreover, CD4<100 (p=0.006), HHV8+ (p=0.02), EBER-negative (p=0.01), LDH>500 (p=0.04), and stage>2 (p<0.0001) were also associated with worse OS. PBL involving the H&N had better OS (p=0.0001). Though CNS involvement, presence of constitutional symptoms, and MYC+ had numerically worse OS, it did not reach statistical significance. Age, sex, light chain restriction, type of immunosuppression, other organ involvement, and other IHC phenotype did not impact OS. Compared to no treatment, chemotherapy and stem cell transplant had incrementally superior median OS (2 vs. 27 vs. NR months, p<0.0001). Frontline intensive chemotherapy yielded better OS than CHOP-like and myeloma regimens in decreasing order (p<0.0001). Patients who attained CR as their best response also had a superior median OS (p<0.0001). Conclusion This study presents clinicopathologic data from the largest pooled cohort of patients with PBL. It identifies the type of organ involvement, CD4 counts, EBER and HHV8 status, LDH levels, stage, type of therapy, and quality of response to treatment as critical determinants of OS.

Background Primary Cutaneous Diffuse Large B-cell Lymphoma-Leg Type (PCDLBCL-LT) is a rare but non-indolent subtype of B-cell lymphoma. While most of PCDLBCL-LT starts over the lower extremities, some cases may present at other cutaneous sites. The determinants of survival outcomes in this disease are not very well defined. Therefore, we conducted this pooled database analysis to identify the prognostic factors, clinicopathological characteristics, and therapeutic strategies that influence survival in this disease. Methods To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, survival, and prognostic factors, we compiled a pooled database of 122 cases that fit the diagnostic criteria for PCDLBCL-LT. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS) and disease-free survival (DFS). Results A total of 122 patients with confirmed PCDLBCL-LT were identified. The median age was 76. There was a male preponderance with M:F of 2.4. Seventy-three percent involved the extremities. The median duration of symptoms before diagnosis was 3.5 months. Involvement of lymph nodes, bone marrow, bone, and CNS occurred in 11%, 3%, 4%, and 3%, respectively. Constitutional symptoms were reported in 5%. The median OS and DFS of the whole group were 39 and 32 months, respectively. Patients younger than 70 had better median DFS (NR vs. 24 months, p=0.02) with a non-significant better median OS. Lymph node involvement (18 vs. 45 months, p=0.006) and stage T3 compared to T1/T2 (16 vs. 41 months, p=0.006) were associated with worse OS. Sex, constitutional symptoms, IHC phenotype, extra-lymphatic/extra-cutaneous organ involvement, and histologic cutaneous patterns did not impact OS. Compared to no treatment, chemotherapy, XRT+/-surgery, and stem cell transplant had numerically better OS without reaching statistical significance (5 vs. 39 vs. 41 vs. NR months, p=0.15). Patients who attained CR as their best response also had a superior median OS compared to responses less than CR and non-responders (61 vs. 23 vs. 11 months, p<0.0001). Conclusion This study presents updated clinicopathologic data from a large, pooled cohort of patients with PCDLBCL-LT. It identifies age, lymph node involvement, T stage, type of therapy, and quality of response to treatment as critical determinants of OS.

Background: Double and triple hit lymphomas (DTHL) are aggressive high-grade lymphomas that harbor translocations of MYC and BCL2 and/or BCL6. They constitute 6-14% of all aggressive B-cell lymphoma and have been associated with poor clinical outcomes. Though there is no established standard therapy for DTHL, induction chemotherapy vacillates between R-CHOP-like regimens, R-EPOCH, or more dose-intense regimens (DI) such as R-hyperCVAD/MA and CODOX-M/IVAC with or without consolidation with stem cell transplant. Currently, there are no randomized trials establishing a standard induction regimen. Furthermore, several retrospective studies reported conflicting results regarding the comparative benefits of these various induction approaches. Therefore, we conducted this meta-analysis to evaluate the impact of induction chemotherapy regimens on the clinical outcomes of DTHL. Methods: A review of the medical literature was conducted using online databases. Inclusion criteria consisted of English language, diagnosis of DTHL, comparative studies of induction chemotherapy regimens, and studies that reported overall (OS) and progression-free (PFS) survival. Studies that reported the aggregate outcome of mixed samples of DTHL and other lymphomas were excluded. A meta-analysis using the fixed effects and random effects models was conducted. Results: Seven retrospective comparative studies with a total of 1433 patients were included. The median age was 62 years, and the median follow-up was 27.5 months. DI regimens were associated with better PFS than R-CHOP-like regimens (HR = 0.81, 95%CI 0.66-0.99, p = 0.039) but without improved OS. R-EPOCH, including R-DA-EPOCH, regimens were associated with better PFS than R-CHOP-like regimens (HR = 0.62, 95%CI 0.43-0.91, p = 0.013) but without improved OS. R-HyperCVAD/MA regimen was associated with better PFS compared to R-CHOP-like regimens (HR = 0.64, 95%CI 0.47-0.87, p = 0.005) but without improved OS. Conclusions: This is the first and largest meta-analysis to show that induction DI regimens, in general, and R-EPOCH and R-HyperCVAD/MA regimens, in particular, are associated with better PFS than R-CHOP-like regimens in patients with DTHL. However, this advantage did not translate into a survival benefit.

Background: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy with a propensity for cutaneous involvement. This disorder has gone through many reiterations over the years, being classified initially as a blastic NK-cell lymphoma, then a subset of AML, and finally recognized as a unique myeloid neoplasm. However, due to the poor understanding and the rarity of the disease, varied treatment approaches have historically been implemented, and no optimal data or guidelines for managing BPDCN are available. Therefore, we conducted this pooled database analysis to identify the prognostic factors, clinicopathological characteristics, and therapeutic strategies that influence survival in this disease. Methods: To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, survival, and prognostic factors, we compiled a pooled database of 273 cases that fit the diagnostic criteria for BPDCN. Kaplan-Meier survival curves were constructed. Cox proportional hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS). Results: A total of 273 patients with confirmed BPDCN were identified. The median age was 61.5. There was a male preponderance with M:F of 2.4. The median duration of symptoms before diagnosis was 5 months. Eighty-one percent of patients presented with skin lesions, 65% of which were disseminated. Involvement of Lymph nodes (LN), bone marrow (BM), spleen, peripheral blood, and CNS occurred in 62%, 73%, 55%, 71%, and 57%. Constitutional symptoms were reported in 13%. The median OS and DFS of the whole group were 16 and 13 months, respectively. Patients younger than 60 had better median OS (30 vs. 10 months, p < 0.0001). The involvement of LN (p = 0.03), BM (p = 0.007), spleen (p = 0.02), and peripheral blood (p = 0.01) was associated with worse OS. Furthermore, disseminated skin involvement had worse OS than focal (p = 0.001). Though CNS involvement, presence of constitutional symptoms, elevated LDH, and TdT negative status had numerically worse OS, it did not reach statistical significance. Sex did not impact OS. Compared to no treatment, non-dose-intense chemotherapy, dose-intense chemotherapy, and stem cell transplant had incrementally superior OS (3 vs. 10 vs. 22 vs. 66 months, p < 0.0001). Patients who attained CR as their best response also had a superior median OS (26 vs. 5 months, p < 0.0001). Conclusions: This study presents updated clinicopathologic data from a large, pooled cohort of patients with BPDCN. It identifies age, organ involvement, type of therapy, and quality of response to treatment as critical determinants of OS.