Prognostic significance of bone marrow fibrosis in diffuse large B-cell lymphoma.

INTRODUCTION: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphomas. The aim of this study is to determine the relationship between the increase in the degree of fibrosis in the bone marrow and prognosis and mortality in newly diagnosed DLBCL. METHODS: Bone marrow biopsy of 153 newly diagnosed DLBCL patients was determined by staining with reticulin, Masson's trichrome histochemical stain, and the degree of fibrosis was determined. RESULTS: In the bone marrow biopsy performed at the time of diagnosis, bone marrow fibrosis (BMF) was observed in 70 patients. While BMF-1 was detected in 42 patients (60%), BMF-2 was detected in 25 patients (35%) and BMF-3 was detected in 3 patients (4%). As the degree of BMF increased, the median overall survival and median progression-free survival times were significantly shorter (p: 0.008), (p < 0.001). In patients with an increased degree of BMF, a significant decrease in leukocyte and neutrophil counts was observed after chemotherapy (p: 0.004). According to the results of the multivariate Cox regression model, it was determined that high NCCN-IPI risk (HR: 8.25; %95 CI: 1.09-62.52; p = 0.041) and being BMF ≥ 2 (HR: 3.75; %95 CI: 1.65-8.51; p = 0.002), increased the risk of death (p = 0.002, -2 loglikelihood = 392,553). CONCLUSION: When the literature was reviewed, it was seen that this study was the first to define that bone marrow fibrosis grade 2 and above in DLBCL is a prognostic marker associated with worse survival. In the bone marrow pathology, which is examined to detect advanced disease in DLBCL, besides lymphomatous involvement, the detection of fibrosis grade is very important.

Diagnosis Rates Through Cancer Screening Programs in Patients with Breast Carcinoma.

AIM: This study investigated whether breast cancer patients had ever applied for Cancer Early Diagnosis Screening and Training Centers (KETEM). METHOD: This study, conducted from November 2020 to April 2021, adopts a cross-sectional research design and is planned as a survey study. The "Diagnosis Rates with Screening Programs in Breast Cancer Patients" survey was conducted on women over 45 who were diagnosed with breast cancer in the Medical Oncology Clinic of Izmir Katip Çelebi University Atatürk Education and Research Hospital. Further information about the cancer stage was gathered from the Medical Oncology outpatient clinic file records. Data obtained in the study were evaluated using the the Statistical Package for Social Sciences version 26.0 software (IBM Corp.; Armonk, NY, USA), using the number, percentage distribution, arithmetic mean, and chi-square test methods. RESULTS: It has been determined that most patients diagnosed did not receive a diagnosis through screening programs, were not aware of KETEM, and did not apply to KETEM. A positive relationship was found between the level of education and participation in screening programs. It was observed that women who knew about the KETEM's participated more often in the scans. CONCLUSION: The study discovered a lack of knowledge and inadequacy in screening programs for patients with breast cancer. We believe that it is essential to introduce and disseminate KETEMs so that cancers can be detected early through screening.

Clinicopathological features of mammary Paget's disease: a single-center experience in Turkey

Background/aim: Paget's disease (PD) of the breast is a very rare presentation of breast malignancy, accounting for 1%­3% of all primary breast tumors. We aimed to evaluate and compare the clinicopathological features and clinical outcome of PD accompanied by in situ carcinoma and invasive cancer. Materials and methods: We used the archive of our pathology laboratory retrospectively for age, sex, history of surgery, histopathological findings, treatment modalities, and follow-up information. We used the Kaplan­Meier method for survival analysis. Results: There were 46 female patients diagnosed with PD. In 39 (84.7%) patients, invasive carcinoma accompanied PD, while 7 (15.3%) patients had ductal carcinoma in situ. The median age at diagnosis was 53.5 years. The median follow-up period was 47 months. Of the 39 invasive carcinoma, 10 (25.6%) died during the follow-up period. Invasive ductal carcinoma group had a mean overall survival of rate of 57.8 ± 6.6 months. According to univariate analysis, only the tumor type was found to impact overall survival (p < 0.001). Conclusions: The current study displayed the tumor type as the only parameter affecting overall survival in the invasive carcinoma group. Although it was not statistically significant, breast cancers accompanied by PD were found to be predominantly advanced stage tumors, high grade, hormone receptor negative, and HER2 positive.

Clinicopathological analysis of invasive cribriform carcinoma of the breast, with review of the literature.

Invasive cribriform carcinoma (ICC) is a rare type of a primary breast carcinoma. It is subdivided into two groups as pure and mixed types. There are limited studies comparing the pure and mixed ICC at present. We aim to investigate the clinicopathological, radiological, prognostic features, and survival outcomes of two types with reviewing the published literature. 16 pure ICC and 26 mixed ICC cases were evaluated. The population consisted of 41 female and 1 male patients. The only male patient was a pure ICC case. The median age was for pure and mixed type, 46.5 and 54 years, respectively. All ICCs were ER positive. All ICCs except one mixed ICC, were positive for PR. Only one mixed ICC was accepted HER2 positive (3+). Pure ICCs showed more favorable features than mixed ICCs such as lesser axillary lymph node involvement, lower grade, and proliferation index. Twenty-five patients had one of the following imaging methods; ultrasonography (US), mammography (MG), and magnetic resonance imaging (MRI). Irregular shape, hypoechogenicity, and spiculated margins were the most common US findings. Similarly, irregular shape+spiculated margin is the most common MG findings. The median follow-up time for pure and mixed ICC was 88 and 56.5 months, respectively. One mixed ICC case developed bone metastasis. One death occurred in each group. Reasons of death were unknown. The 5-year OS for both ICC groups was 100%. 10-year OS for pure and mixed ICCs was 100% and 90%, respectively. 5-year DFS was 100% for pure ICC, and 94% for mixed ICC.

BCR-ABL1-Negative Chronic Myeloproliferative Neoplasms and Pulmonary Hypertension: A Prospective Long-Term Follow-up Study of the Impact of Pulmonary Hypertension on Survival.

PURPOSE: To assess the prevalence of PHT in patients with BCR-ABL1-negative CMPN and to evaluate impact of PHT on survival during long-term follow-up. PATIENTS AND METHODS: A total of 122 patients with BCR-ABL1-negative CMPN underwent transthoracic echocardiographic (TTE) evaluation at the beginning of study. Patients undergoing PHT on TTE examination were also evaluated by a pulmonologist. Patients were divided into 3 groups. Group A comprised patients with CMPN-related PHT; group B, patients with no PHT; and group C, patients with PHT due to secondary causes. Patients were evaluated again every 3 to 6 months. RESULTS: PHT was detected in 33 (27%) of 122 patients. Eight (6.5%) had CMPN-related PHT and the remaining 25 (20.5%) had non-CMPN-related PHT. Positivity for JAK2 V617F mutation in the study population was 72.9%. Groups were similar with respect to hematologic parameters and gender. Follow-up times were as follows: median (range) time from diagnosis to TTE and study end were 34 (1-158) months and 107 (16-251) months, respectively, and from TTE to study end was 88 (7-110) months. No significant differences found among the groups in terms of median time from diagnosis to TTE, follow-up, and overall survival. CONCLUSION: BCR-ABL1-negative CMPN patients had a lower prevalence of PHT compared to earlier studies. There was no statistically significant difference in median overall survival between patients with or without PHT. This may be because patients with PHT were asymptomatic and PHT was mild. The impact of PHT on survival was negligible.

Is adjuvant chemotherapy necessary for Luminal A-like breast cancer?

PURPOSE: Patients with breast cancer with Luminal-A subtype have a better prognosis but poor chemotherapy response. Chemotherapy is controversial in lymph node-positive patients with Luminal-A subtype. In this retrospective study, we aimed to evaluate the efficacy and benefit of chemotherapy in the Luminal A-like subtype of breast cancer. METHODS: Patients diagnosed with breast cancer within 2006 and 2011 were retrospectively evaluated. Patients with pathologically confirmed Luminal A-like breast cancer were analyzed , and were divided in those receiving taxane-based adjuvant chemotherapy and those who did not. RESULTS: A total of 136 patients with Luminal-A type were included in the study. The 10-year cumulative disease-free survival (DFS) was 85.6 vs 96.7% (p=0.230) for the chemotherapy and non-chemotherapy groups, and overall survival (OS) was 88.6 vs 100%, respectively (p=0.242). The 10-year cumulative DFS was 80 vs 98.1% for the taxane-based chemotherapy group and taxane-free chemotherapy group (p=0.501), while the OS was 87.5 vs 95.2%, respectively (p=0.391). There was a positive correlation between relapse status and lymph node involvement in the multivariate analysis (p=0.031). CONCLUSION: Adjuvant chemotherapy in Luminal-A showed no significant difference for DFS and OS. Taxane-based chemotherapy did not demonstrate any benefit for OS and DFS with relatively more advanced stage and lymph node involvement. We believe that adjuvant chemotherapy plays a minor role in a significant proportion of Luminal-A subtype of breast cancer.

Prognostic significance of androgen receptor expression in HER2-positive and triple-negative breast cancer.

Triple-negative breast cancer (TNBC) and HER2-positive breast cancer are more aggressive than other subtypes of breast cancer. Due to the limited number of treatment alternatives and the absence of target receptors in TNBC, and because of progression in the HER2-positive group despite targeted treatments, new treatment targets and therapeutic combinations are required. In this context, the present study aims to evaluate the prognostic importance of immunohistochemical androgen receptor (AR) expression in HER2-positive breast cancer and TNBC subtypes. AR nuclear staining density was evaluated immunohistochemically. A total of 111 operated patients with breast cancer were included in the study; 44 (39.6%) belonged to the HER2-positive breast cancer subgroup and 67 (60.4%) belonged to the TNBC subgroup. AR expression was 34.3% and 79.5% in TNBC and HER2-positive groups, respectively. The 5-year overall survival (OS) was 76% and 58% for the group with an AR-expression > 7.5% and AR-expression < 7.5%, respectively, in the TNBC subgroup (p = 0.042). In the HER2-positive patient group, the subgroups characterised by an AR-expression > 7.5% and AR-expression < 7.5% had 5-year OS rates of 57.6% and 63.5%, respectively (p = 0.91). Including the assessment of AR expression in the routine pathological examination will contribute to our understanding of the relevance of AR in the biology and prognosis of breast cancer.

Treatment choice in metaplastic breast cancer: A report of 5 cases.

Metaplastic breast carcinoma (MBC) is a general term defining a heterogeneous group that includes biphasic lesions, with both malignant epithelial and mesenchymal tissue components. Although its clinical findings are similar to those present in invasive ductal carcinoma, it rarely presents with the findings of inflammatory breast cancer. It is generally seen in the fifth decade. MBC spreads via lymph and blood circulation. Most common distant metastasis areas include lungs and the bone. Although the treatment generally relies on the same principles applied in invasive ductal carcinoma, a more aggressive treatment should be employed in at-risk groups due to higher rates of local recurrence. In this study, we aimed to discuss clinicopathological features and treatment approach in 5 women with MBC.

The prognostic significance of cyclin D1 expression in patients with triple-negative breast cancer.

PURPOSE: Breast cancer (BC) is the most common cancer and the second leading cause of cancer death among women. While receptor-targeted therapies are used for other subtypes due to the presence of such receptors, studies are still continuing on receptor expression in order to identify new therapeutic targets as the triple-negative breast cancer (TNBC) lacks a target receptor and its prognosis is worse than the other subtypes. Cyclin D1 (CycD1) is a cell cycle regulator protein. It is stated that its overexpression plays a role in carcinogenesis. With the present study, we aimed to evaluate the prognostic significance of immunohistochemical expression of CycD1 in patients with TNBC. METHODS: The study included 56 operated patients with TNBC who were diagnosed between 2006 and 2011 at Izmir Katip Celebi University, Ataturk Research and Training Hospital, Department of Pathology. In tumor paraffin-embedded sections, CycD1 was immunohistochemically (IHC) studied. Demographic and survival data of the patients were obtained from the Department of Medical Oncology follow-up files. ROC curve analysis was used to calculate the cutoff value for CycD1 staining density. Patients were divided into two groups using 11.5 cutoff value for the expression of CycD1, obtained by ROC analysis. Kaplan-Meier analysis was utilized for survival analyses, and log rank test for comparisons between the two groups. RESULTS: Of the patients, 62.5% had CycD1 expression (37.5% had not). In the whole group, the 5-year disease-free survival (DFS) was 51%, and the 5-year overall survival (OS) was 65%. No difference in DFS between the two groups was noticed (p=0.37). The 5-year DFS was 47% in the group with CycD1 expression below 11.5, while it was 57% in the group above the 11.5 value. The difference in OS between the groups was statistically significant (p=0.044). The 5-year OS was 55% in the group with a CycD1 expression below 11.5, while it was 79% in the group above the 11.5 value (p=0.044). CONCLUSION: OS differed significantly between the high and low-CycD1 expression. It was also demonstrated that CycD1 may have prognostic significance in TNBC. Further studies with larger populations are required to confirm the prognostic significance of CycD1.

PDGFRA and KIT Mutation Status and Its Association With Clinicopathological Properties, Including DOG1.

Most of the gastrointestinal stromal tumors (GISTs) have gain-of-function mutations in the KIT gene, which can be used as a prognostic marker for the biological behavior of tumors, predictive marker for the response of tyrosine kinase inhibitors, and diagnostic marker. Researchers have focused on PDGFRA mutations because of both their prognostic and predictive potential and DOG1 positivity for diagnosis on GISTs. The aim of this study is to investigate the effect DOG1, PDGFRA, and KIT mutations on the prediction of the outcome for GIST management. Polymerase chain reaction was performed for KIT gene exons 9, 11, 13, and 17 and PDGFRA gene exons 12 and 18 with the genomic DNA of 46 GIST patients, and amplicons were sequenced in both directions. Immunocytochemical stainings were done by using primary antibodies. Molecular analysis revealed that the KIT mutation was observed in 63% of all cases, while the PDGFRA mutation was observed in 23.9% of cases. Significant relationships were found between age and KIT mutation, tumor location and KIT mutations, and tumor location and PDGFRA mutations (p ≤ 0.05). DOG1 positivity was detected in 65.2% of all GISTs and DOG1-positive cells had a higher KIT mutation ratio than DOG1-negative cells (p ≤ 0.05). KIT gene exon 11 mutations in DOG1-positive cells was higher than DOG1-negative cells (p ≤ 0.05). Conversely, KIT gene exon 13 mutations were higher in DOG1-negative cells than DOG1-positive cells (p ≤ 0.05). In this study, KIT mutation frequency was found similar with the European population; conversely, PDGFRA mutation frequency was similar with an Asian-Chinese-based study. KIT/PDGFRA mutations and tumor location can be used for the prediction of tumor behavior and the management of disease in GISTs. DOG1 positivity might be a candidate marker to support KIT and PDGFRA mutations, due to the higher DOG1 positivity in KIT exon 11 mutant and stomach- and small intestine-localized GISTs.

Platelet-Rich Fibrin Improves the Viability of Diced Cartilage Grafts in a Rabbit Model.

BACKGROUND: Diced cartilage may be wrapped with synthetic or biological materials before grafting to a recipient site. These materials have unique advantages and disadvantages, and a gold standard is not available. OBJECTIVES: The authors investigated the effects of platelet-rich fibrin (PRF) on the survival of cartilage grafts in a rabbit model. METHODS: In this experimental study, diced cartilage pieces from the ears of 9 male rabbits were left unwrapped or were wrapped with PRF, oxidized regenerated cellulose, or fascia. Specimens then were placed into subcutaneous pockets prepared on the backs of the rabbits. The animals were sacrificed 2 months after the procedure, and the grafts were excised for macroscopic and histopathologic examination. RESULTS: The cartilage graft wrapped with PRF showed superior viability compared with the cartilage graft wrapped with oxidized regenerated cellulose. No significant differences were found among the other groups. The groups were not significantly different in terms of rates of inflammation, fibrosis, or vascularization. CONCLUSIONS: PRF enhances the viability of diced cartilage grafts and should be considered an appropriate biological wrapping material for cartilage grafting.

The Effects of Adjuvant Endocrine Treatment on Serum Leptin, Serum Adiponectin and Body Composition in Patients with Breast Cancer: The Izmir Oncology Group (IZOG) Study.

BACKGROUND: A limited number of studies have been conducted on the effects of hormonal therapy with tamoxifen (TMX) or aromatase inhibitors (AIs) on plasma levels of leptin and adiponectin, as well as body composition in breast cancer (BC) patients. Therefore, we aimed to analyze the relationship between adipocytokines and body composition as well as the effects of TMX and AIs on plasma adiponectin, leptin, leptin/adiponectin ratio (LAR) and body composition. METHODS: Patients were treated with either TMX or AI according to their menopausal status after adjuvant radiotherapy. Changes in body composition and serum leptin and adiponectin levels were evaluated. We recorded the type of hormonal therapy, BMI, waist/hip ratio (WHR), leptin and adiponectin levels at study entry, and after 6 and 12 months. RESULTS: From baseline to the 6- and 12-month follow-ups, there were statistically significant increases in WHR (p = 0.003), fat mass (p = 0.041), and serum leptin (p < 0.001) and adiponectin levels (p < 0.001). The changes in body composition and serum leptin and adiponectin levels were similar in TMX and AI groups. A statistically significant decrease was found in total body water and LAR (p < 0.001). Although weight and body fat percentage increased, such increases were not statistically significant. A positive correlation was found between baseline BMI and serum leptin levels. This correlation was maintained at 6 and 12 months. The negative correlation found between serum adiponectin levels at baseline and baseline BMI did not last throughout the study. CONCLUSION: In this study, increased leptin and adiponectin levels and a decreased LAR were found in both AI and TMX groups. These changes might have occurred through both mechanisms of hormonal therapy and body composition changes. Therefore, AIs and TMX may exert their protective effects for BC patients by decreasing LAR rather than affecting leptin or adiponectin alone.

Cytopathological features of matrix-producing carcinoma of the breast.

Matrix producing carcinoma (MPC) of the breast is a very rare subtype of metaplastic carcinoma with heterelogous elements, which comprises <0.1% of invasive breast carcinomas. There are very few reports describing the cytological features of MPC. In this article, we aimed to discuss cytological, histopathological and immunohistochemical features of this rare entity in a 59-year-old woman.

Prognostic value of mesothelin expression in patients with triple negative and HER2-positive breast cancers.

PURPOSE: Mesothelin is a cell surface glycoprotein that is overexpressed in various malignancies. Recent studies have revealed that mesothelin plays an oncogenic role in tumor growth and drug resistance through the Wnt/NF-κB/PI3K/Akt signaling pathways. Herein, the expression of mesothelin in HER2-positive and triple-negative breast cancer (TNBC) has been correlated with prognosis. METHODS: A total of 430 patients with breast cancer treated between 2006 and 2013 were retrospectively reviewed; of these, 123 cases were considered TNBC (n=71; 58%) or were positive for HER2 (n=52; 42%). Mesothelin expression was assessed by immunohistochemistry. RESULTS: Of the patients with TNBC, 30 (42.3%) were positive for mesothelin expression, compared to only two (3.8%) of the HER2-positive cases. As most HER2-positive tumors were negative for mesothelin staining, statistical analysis was not performed. Median overall survival (OS) was 70.1 months for patients with TNBC, whereas median OS was 70.1 months, in the mesothelin-positive group and 74.5 months in mesothelin-negative group, respectively. Strong correlation was seen between mesothelin expression and tumor grade in patients with TNBC (P<0.005). In a multivariable Cox proportional hazards model, mesothelin expression was not independently associated with OS in patients with TNBC. CONCLUSIONS: Expression of mesothelin was observed in 42.3% of patients with TNBC and demonstrated a strong association with tumor grade. However, its expression was not correlated with prognosis.

Do the derived neutrophil to lymphocyte ratio and the neutrophil to lymphocyte ratio predict prognosis in breast cancer?

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) is a strong predictor of mortality in patients with cancer. Similarly, a study in a large series has shown that the newly defined derived NLR (dNLR; neutrophil/leukocyte-lymphocyte ratio) also has prognostic value. The present study retrospectively evaluates the prognostic significance of NLR and dNLR in breast cancer. METHODS: Hematological parameters and clinicopathological data during diagnosis were retrospectively recorded for 1,527 patients diagnosed with breast cancer at Izmir Katip Celebi University Ataturk Research and Training Hospital from January 2006 to December 2011. The cut-off values were determined by calculating the NLR and dNLR of the patients. RESULTS: The cut-off values were determined as 4 and 2 for NLR and dNLR, respectively. The association between NLR and dNLR assessed by Spearman's rank correlation analysis was 0.935 (P < 0.001). There was a significant difference regarding disease free survival (DFS) and overall survival (OS) in patients with NLR <4 and NLR ≥4 (respectively, P < 0.00, P < 0.001). Similarly, there was a significant difference regarding DFS and OS in patients with dNLR <2 and dNLR ≥2 (respectively, P < 0.001, P < 0.001). Furthermore, NLR and dNLR demonstrated a significant association with the American Joint Committee on Cancer (AJCC) staging (P < 0.001). Assessment using the Cox proportional multivariate model showed that high NLR, pN, pT, luminal A-like, luminal B-like (HER2 positive), basal-like, and AJCC staging are independent prognostic factors. DISCUSSION: NLR was shown to be better than dNLR in terms of predicting prognosis in patients with breast cancer. However, large prospective studies are required to further demonstrate the prognostic significance of these two values.

The prognostic significance of bone marrow metastases: evaluation of 58 cases.

BACKGROUND: Bone marrow biopsy is widely used method for diagnosis, follow-up and staging of hemato-oncologic diseases. This procedure is also used for determining the bone marrow metastasis in patients with solid tumors. In this study, clinical, hematological, and pathological features of 58 patients with bone marrow metastases diagnosed by bone marrow biopsies were examined retrospectively MATERIALS AND METHODS: Among 3345 bone marrow biopsies performed in our hospital between January 2006 and August 2013, 58 cases with solid tumor metastasized to bone marrow were included in this study. RESULTS: Among 58 cases with solid organ carcinoma metastasis in bone marrow, mean age was 59.9. Thirty-nine cases were found to have a known primary tumor focus. The most common tumors metastasized to bone marrow were breast carcinomas (23 patients, 59%), gastric carcinomas (6 patients, 15.3%), prostate carcinomas (4 patients, 10,2%), and lung carcinomas (3 patients, 7.7%), respectively. Nineteen patients were firstly diagnosed from bone marrow biopsies as metastatic carcinomas. The median overall survival after bone marrow metastasis was 28 days (95% confidence interval: 7.5-48.4). The median overall survival difference was not statistically significant between patients with primary known and unknown tumor (P = 0.973). Statistically significant difference was observed between the survival of breast cancer and gastric cancer (P = 0.028). The most common hematologic symptom was the coexistence of anemia and thrombocytopenia (31%), thrombocytopenia (27.6%) and anemia (20.7%) alone. The median overall survival difference was statistically significant between patients who have anemia and thrombocytopenia (P < 0.005). CONCLUSION: Bone marrow biopsy is an easily accessible, easily applied, a useful procedure for diagnosing metastatic diseases in patients with hematologic symptoms such as anemia and thrombocytopenia besides being an uncomfortable procedure for patients. Furthermore, it is useful in predicting the prognosis and short survey after diagnosing bone marrow metastasis.

Primary mucinous cystadenocarcinoma of the breast with amplification of the HER2 gene confirmed by FISH - case report and review of the literature.

Fifty five-years-old woman was presented to the general surgery upon the palpation of a mass in her left breast. In the excisional biopsy performed, partially cystic tumor of 2 × 1 cm with solid areas was macroscopically observed. After through microscopic examination, the patient was diagnosed as invasive mucinous cystadenocarcinoma and the tumor was found to be ER- and PR-negative and C-erbB2 (2+). In the fluorescent in situ hybridization, HER2/neu gene amplification was observed. Here, we present the clinical, cytological, morphological and immunohistochemical features of a very rare type of breast carcinoma, mucinous cystadenocarcinoma of the breast, with the review of the relevant literature.

JAK2 V617F mutation status of 232 patients diagnosed with chronic myeloproliferative neoplasms.

INTRODUCTION/BACKGROUND: The aim of this study was to investigate the presence of Janus kinase 2 (JAK2) V617F mutation in patients with break point cluster region-abelson negative chronic myeloproliferative neoplasms (CMPNs) in our center. PATIENTS AND METHODS: We compared patients with and without the mutation, and also patients with the homozygous and heterozygous mutation, in terms of different clinical and laboratory features. RESULTS: The JAK2 V617F mutation was detected in 77 (95%), 88 (68%), and 17 (77%) of polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) patients, respectively. Among JAK2 V617F-positive patients, the homozygous genotype was found in 39 (50.6%) of the 77 PV, 23 (26.1%) of the 88 ET, and 11 (64.7%) of the 17 PMF patients. Bleeding was seen in 14 (6%) of all patients. Upper gastrointestinal bleeds were the most common, seen in 11 patients. Out of 232 CMPN patients, 44 (19%) had thrombosis. The most common thrombotic event was transient ischemic attack (52%). Progression to myelofibrosis was seen in 1 (1.2%) PV and 3 (2.3%) ET patients, and progression to acute leukemia was seen in 2 (2.5%) PV and 3 (2.3%) ET patients. Three patients with PV (3.7%), 3 with ET (2.7%), and 5 with PMF (2.7%) died during follow-up. CONCLUSION: JAK2 V617F mutation frequencies in our PV and ET patients were similar to those reported previously. JAK2 V617F mutation frequency in our PMF patients was greater than in previous reports. All of our PV patients with thrombosis and most of our ET patients with thrombosis (76.1%) were JAK2 V617F mutation-positive. This mutation seems to be correlated with thrombosis risk.