Apar Kishor Ganti

Endothelium and the lipid metabolism: the current understanding

The endothelium is a dynamic organ and responds to various physical and humoral conditions. The endothelium secretes several biologically active substances, both vasoconstrictors and vasodilators, which control these processes. Endothelial function is most commonly assessed as the vasodilatory response to stimuli. Several endothelium-dependent agonists have been identified, each of which acts through a membrane receptor. Nitric oxide which is continuously synthesized by the endothelium has a wide range of biological properties that maintain vascular homeostasis. It is a potent vasodilator and inhibitor of platelet aggregation and thus has an important protective role. Endothelial dysfunction in hypercholesterolemic patients is in large part due to a reduced bioavailability of NO. Traditional coronary risk factors, especially hypercholesterolemia, produce endothelial dysfunction even in patients with normal blood vessels. The underlying mechanisms involve a local inflammatory response, release of cytokines and growth factors, activation of oxidation-sensitive mechanisms in the arterial wall, modulation of intracellular signaling pathways, increased oxidation of low-density lipoprotein cholesterol, and quenching of nitric oxide. Clinical studies have shown a significant improvement in endothelial dysfunction following lowering of serum cholesterol levels, infusion of nitric oxide donors like L-arginine and exercise training. Clinical trials are underway examining the role of endothelin-1 receptor antagonists like bosentan in the prevention of graft atherosclerosis.

Predictive role of HER-2/neu overexpression and clinical features at initial presentation in patients with extensive stage small cell lung carcinoma

Although recent advances in therapy have improved the quality of life in patients with extensive stage small cell lung cancer (ESSCLC), prolonged survival is still uncommon. To determine the role of HER-2/neu overexpression and other clinical predictors (symptoms at presentation) of adverse outcome in ESSCLC, we performed a retrospective study on subjects with a biopsy-proven diagnosis of ESSCLC. HER-2/neu overexpression was evaluated using immunohistochemistry (IHC) performed on paraffin-embedded specimens. An IHC score of > or = 2+ was considered positive for overexpression. Between 1991 and 2000, 223 patients with ESSCLC were identified, of whom 193 patients (84 females, 109 males) with a mean age of 68.5 years (range: 42-90 years) had adequate tissue specimens for HER-2/neu testing. The symptoms at initial presentation and proportionate number of patients were: weight loss 61 (31.6%), cough 53 (27.5%), dyspnea 33 (17.1%), mass on chest radiograph 18 (9.3%), chest pain 15 (7.7%), asymptomatic 14 (7.2%) and others (weakness, lymphadenopathy, hoarseness and paraneoplastic syndromes) 29 (15.0%). Of the 193 specimens, 57 (29.5%) revealed HER-2/neu overexpression. The median survival for patients with ESSCLC who were HER-2/neu positive was 8 months (range: 1-25.5 months) while that in the HER-2/neu negative group was 16 months (range: 2-34 months). Interestingly, after adjusting for age, performance status and type of therapy, subset analysis revealed that the survival was significantly lower in HER-2/neu positive individuals (P<0.001; Mann-Whitney U-test). In our study, weight loss and cough were the two most common (59%) presenting complaints in patients with ESSCLC. Also, since HER-2/neu positivity was a marker for poor prognosis in ESSCLC, testing for overexpression may play a role in identifying patients at risk for shortened survival. Further studies would delineate whether HER-2/neu overexpression renders SCLC chemoresistant and thus, adversely affects outcome. There exists a need for randomized controlled trials to assess the role of Herceptin (alone or in combination with standard chemotherapy) in patients with ESSCLC.

Predictive value of clinical features at initial presentation in pancreatic adenocarcinoma: a series of 308 cases.

Pancreatic cancer is the fourth leading cause of cancer death in both men and women with a mortality: incidence ratio of 0.99. In an effort to describe the role of clinical features at initial presentation, we conducted a retrospective observational study in patients with a biopsy-proven diagnosis of adenocarcinoma of the pancreas. Between 1986 and 2001, 308 patients (160 males, 148 females) were diagnosed with pancreatic adenocarcinoma. The mean age at diagnosis was 70.1 yr (range: 34–96 yr). The mean survival was 7.6 mo (range: 0–97 mo). Statistical analysis was performed using log-rank tests and analysis of variance. As expected, age at diagnosis was a significant factor affecting survival, with older patients doing relatively poorly (p<0.05). Patients with a good performance status performed significantly better than those with a poor performance status (p<0.01). In addition, the presence of the tumor in the head of the pancreas was a predictor for improved survival (p<0.01). Although smoking increased the chances of detection at an earlier age, neither diabetes mellitus nor a positive smoking history had a statistically significant effect on the survival. Pancreatic adenocarcinoma is a disease of the elderly associated with a poorer outcome. Knowledge of possible clinical predictors of survival may lead to better patient counseling regarding prognosis.

Angiosarcoma of the Small Intestine: A Possible Role for Thalidomide?

An 85-yr-old male presented with complaints of a 40-lb weight loss and a dull left upper quadrant abdominal pain. He also complained of decreased appetite, generalized weakness, generally not feeling well, and a dull left upper quadrant abdominal pain that was not relieved by food. He had a ventral and a left-sided inguinal hernia. Laboratory investigations revealed iron deficiency anemia, the cause of which was not apparent despite extensive investigation including computerized tomographic scans, esophagogastroduodenoscopy, and small-bowel follow-through examination. Surgical exploration for possible angiodysplasia, malignancy, and/or mesenteric ischemia revealed an incarcerated hernia, and the histopathological examination of the surgical specimen revealed high-grade angiosarcoma. The tumor showed strong positivity for vimentin and CD31 and a focal positivity for Factor VIII and CD34. At that time he was found to have hepatic metastases. He was started on thalidomide as an experimental measure with no change in the performance status and increasing evidence of necrosis in the metastatic lesion.

Identification of HER-2/neu overexpression and the clinical course of lung carcinoma in non-smokers with chronic lymphocytic leukemia

Patients with CLL have an excess risk of developing second primary malignancies. The etiology of this excess risk is unclear, and has been thought to be related to smoking. HER-2/neu overexpression has evolved as a prognostic/predictive factor in some solid tumors. We reviewed our experience with non-smokers who had CLL and subsequently developed lung carcinoma, in an effort to better understand the clinical course of these patients, and to evaluate the role of HER-2/neu overexpression. We reviewed the records of all patients who had a diagnosis of both CLL and lung carcinoma between 1986 and 2000. HER-2/neu overexpression was estimated by immunohistochemistry (IHC) using the Hercep test (DAKO). An IHC score of 2+ or greater was considered positive. Overall survival was calculated from the date of diagnosis of lung carcinoma by the Kaplan-Meier product limit method. Fourteen non-smokers in whom a diagnosis of CLL was made at least 6 months prior to the diagnosis of lung carcinoma were identified. The median age for diagnosis of CLL in this group was 67 years while that for lung carcinoma was 70 years. The lung carcinomas included 10 non-small cell (NSCLC) and four small cell (SCLC) carcinomas. Nine specimens (six NSCLC and three SCLC) showed HER-2/neu overexpression. Interestingly, 90% of patients with advanced stage cancer (stage IIIB/IV NSCLC or extensive SCLC) overexpressed HER-2/neu. The presence of CLL did not alter outcome in patients with early stage lung cancer. However, after adjustment for age and performance status, patients with advanced stage NSCLC and CLL had a worse than expected outcome. HER-2/neu overexpression (independent of smoking) may be involved in the development/progression of lung cancer in patients with CLL, and has an associated worse outcome. It is appropriate to consider heightened surveillance of CLL patients for lung carcinoma.

HER-2/neu overexpression detected by immunohistochemistry in soft tissue sarcomas.

&NA; Sarcomas currently represent 1% of adult malignancies and 15% of pediatric malignancies. To determine the prevalence of HER‐2/neu overexpression by the histologic type and to identify a possible predictive role in patients with sarcoma, we performed a retrospective study on subjects with a biopsyproven diagnosis of a soft tissue sarcoma. HER‐2/neu overexpression was evaluated using immunohistochemistry (IHC) performed on paraffin‐embedded specimens. An IHC score of 2+ or greater was considered positive for overexpression. Two hundred seventy‐three patients with soft tissue sarcoma were identified (164 females, 109 males) with a mean age of 56 (range: 1–93). The most common tumors identified were malignant fibrous histiocytoma (MFH) (18.3%), dermatofibrosarcoma (DFS) (16.1%), leiomyosarcoma (13.2%) and carcinosarcomas (CS) (7.3%). Of the 273 specimens, 29 (10.6%) revealed HER‐2/neu overexpression. CS, MFH, and DFS specimens showed the highest incidence of HER‐2/neu overexpression (40%, 26%, and 18.2%, respectively). The incidence of HER‐2/neu overexpression was found to be significantly higher in patients with a survival of less than 8 months (p = 0.035). This demonstrates that HER‐2/neu overexpression is preferentially seen in certain soft tissue sarcomas, and when present is associated with a poorer prognosis in patients with sarcoma. Further studies would delineate whether HER‐2/neu overexpression renders sarcomas chemoresistant and thus adversely affects outcome. In addition, there may be a role for Herceptin (trastuzumab) alone, or in combination with conventional therapy, in patients with CS, MHF, and DFS.

Immunohistochemical identification of HER-2/neu overexpression and CD117 (c-kit) expression in multiple myeloma

Multiple myeloma (MM) is the most common plasma cell dyscrasia. Conventional therapy results in a median survival of 3-5 years. Patients with B-cell disorders and coexistent HER-2/ neu overexpression in solid tumors have a poorer prognosis than those without an underlying B-cell disorder. This, and the recent success of the tyrosine kinase inhibitor, imatinib mesylate in chronic myelogenous leukemia, led us to evaluate the incidence and role of c-kit (CD117) and HER-2/ neu overexpression in MM. We conducted a retrospective study to determine the incidence of HER-2/ neu and c-kit overexpression in MM. HER-2/ neu overexpression was evaluated using the DAKO Hercep test and c-kit overexpression was assessed using conventional immunohistochemistry (IHC); 69 patients with a diagnosis of MM were identified, of whom, 31 patients (19 males and 12 females) had an adequate pathological specimen available for IHC testing; 4 out of 31 patients (12.9%) showed HER-2/ neu overexpression, while 5/31 (16.13%) showed CD117 expression. Two patients (6.45%) showed both HER-2/ neu and c-kit overexpression. Although both HER-2/ neu and c-kit are not expressed very frequently in patients with MM, there appears to be a subgroup of patients in whom, either one or both these oncogenes is overexpressed. Given our small sample size, it is difficult to comment on the effect of CD117 and/or HER-2/ neu overexpression on survival. Future larger studies are needed to define the association in MM and to determine if the presence of one (CD117 or HER-2/ neu ) has an effect on overexpression of the other oncoprotein. Furthermore, it would be beneficial to identify the molecular nature of the interplay between HER-2/ neu and c-kit, if any. Target-directed signal transduction inhibition therapy using tyrosine kinase inhibitors, may be a distinct possibility in a select group of patients with MM.

Myeloproliferative syndromes and the associated risk of coronary artery disease

INTRODUCTION Of the major myeloproliferative syndromes (MPS) [polycythemia vera (PV), essential thrombocythemia (ET), chronic myeloid leukemia (CML) and myelofibrosis (MF)], PV and ET are reported to be associated with increased thrombotic complications. However, the relationship between these myeloproliferative syndromes and coronary artery disease (CAD) is unclear. METHODS We performed a retrospective chart review to evaluate the prevalence of CAD in patients with diagnosed with MPS between 1991 and 2001. RESULTS One hundred and eighty-one patients (100 males, 81 females) with a mean age of 72.5 years were included. Twenty-nine patients, 19 males and 10 females (16%, 95% CI: 12.0-24.0) had CAD. These included 6/53 (11.3%, 95% CI: 1.5-20.2) patients with CML, 1/26 (3.8%, 95% CI: -4.4 to 12.8) patients with PV, 5/30 (16.7%, 95% CI: 2.5-30.8) patients with ET, 3/7 (42.9%, 95% CI: 12.3-87.7) patients with MF and 14/65 (21.5%, 95% CI: 13.1-37.8) patients with co-existent MPS. Comparing the risk of CAD with CML as a baseline, MF had an OR of 8.2 (p < 0.01, 95% CI: 1.7-39), PV-0.4 (p = 0.4, 95% CI: 0.04-3.2), ET-1.6 (p = 0.7, 95% CI: 0.43-6.2) and patients with co-existent MPS-2.8 (p=0.07, 95% CI: 0.91-8.6). However, after adjusting for age, sex, dyslipidemia, diabetes, hypertension and tobacco use, the difference in the prevalence of CAD between the various categories of MPS was not significant. CONCLUSION Contrary to conventional belief, we did not find an increased prevalence of CAD in patients with either PV or ET. In fact, patients with MF had a significantly higher prevalence of CAD. However, this difference appears to be due to the increased age at diagnosis of MF. The conventional risk factors for CAD appear to be the major determinants of CAD among patients with MPS.

Chromosomal anomalies in two coexistent myeloproliferative disorders

A 58-year-old male presented with fatigue, tiredness, and pruritus after hot showers and an elevated white blood cell count (20000/mm(3)). A diagnosis of polycythemia vera (PV) was made after investigation revealed a low erythropoietin and elevated leukocyte alkaline phosphatase (LAP) score; he was treated with repeated phlebotomies. Two years later he developed elevated white counts again and investigation revealed Philadelphia chromosome positive (19/20 cells) chronic myelocytic leukemia (CML). The karyotype also revealed trisomy 9 in 1 of 20 cells. He was treated with imatinib mesylate and went into clinical, hematologic, cytogenetic, and molecular remission. Repeat chromosomal analysis revealed absence of Philadelphia chromosome and BCR/ABL translocation but presence of trisomy 9. To our knowledge, this is the first reported case of coexisting PV and CML both associated with separate chromosomal abnormalities. This also raises an interesting therapeutic consideration of using concomitant imatinib mesylate and hydroxyurea.

Plasma tissue plasminogen activator and plasminogen activator inhibitor-1 levels in acute myocardial infarction

The cause of the circadian variation in the incidence of acute myocardial infarction (AMI) has not been identified. Tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) have opposing effects on thrombi. Hence, the extent of the clot, the size of the infarct and outcome of patients could depend on t-PA and PAI-1 levels. In an effort to elucidate the pathophysiologic basis of circadian variation of AMI, we investigated the presence of a possible corresponding circadian variation in the levels of endogenous t-PA and PAI-1 in patients diagnosed to have AMI and the effects of hypertension, diabetes and site of the infarct on these levels. We estimated the levels of t-PA and PAI-1 in platelet-poor plasma of 42 patients with AMI on admission, using the enzyme-linked immunosorbant assay. Although not statistically significant, patients having an AMI in the morning hours had the highest t-PA:PAI-1 ratio. The normal circadian variation in PAI-1 levels was lost in patients with AMI, probably due to the disease process. Also, the t-PA levels in hypertensive patients were significantly lower than in nonhypertensives. PAI-1 levels were also significantly lower in patients with anteroseptal than in inferior and anterolateral AMI. This relationship between the fibrinolytic potential and the site of infarction needs further study. Furthermore, t-PA levels on admission were significantly lower in survivors and may have a predictive value in determining the outcome.