Laparoscopic splenectomy in patients with hematologic malignancies.

BACKGROUND: Although laparoscopic splenectomy (LS) for benign hematologic disease is well accepted, its role in hematologic malignancies is not clearly defined. This study examined the efficacy and feasibility of LS for hematologic malignancies. METHODS: Records were reviewed from patients who underwent LS at two university hospitals. Charts from 77 open splenectomies for malignancy (OM) during the same period were also reviewed. RESULTS: Fifty-three patients underwent LS, 22 for hematologic malignancies (LM) and 31 for benign hematologic disorders (LB). Median splenic weight was greater in the LM group (930 g) than in the LB group (164 g, P = 0.001). LM was associated with longer operations and greater blood loss than was LB. LM had a 41% conversion rate. Morbidity, mortality, and transfusion rates were similar. Median hospital stay was shorter for LM (4 days) than for OM (6 days, P = 0.001). CONCLUSIONS: LS is feasible in hematologic malignancies but is associated with increased operative time and blood loss and a high conversion rate. Morbidity and mortality, however, was similar. Shorter hospital stays for LM compared with OM may translate into earlier recovery and initiation of antineoplastic therapy.

Is mammography useful in screening for local recurrences in patients with TRAM flap breast reconstruction after mastectomy for multifocal DCIS?

BACKGROUND: Skin-sparing mastectomy with immediate transverse rectus abdominis musculocutaneous (TRAM) flap reconstruction is being used more often for the treatment of breast cancer. Mammography is not used routinely to evaluate TRAM flaps in women who have undergone mastectomy. We have identified the potential value of its use in selected patients. METHODS AND RESULTS: We report on four women who manifested local recurrences in TRAM flaps after initial treatment for ductal carcinoma in situ (DCIS) or DCIS with microinvasion undergoing skin-sparing mastectomy and immediate reconstruction. All four patients presented with extensive, high-grade, multifocal DCIS that precluded breast conservation. Three of four mastectomy specimens demonstrated tumor close to the surgical margin. Three of the four recurrences were detected by physical examination; the remaining local recurrence was documented by screening mammography. The recurrences had features suggestive of malignancy on mammography. CONCLUSION: We conclude that all patients undergoing mastectomy and TRAM reconstruction for extensive, multifocal DCIS should undergo regular routine mammography of the reconstructed breast. Our experience with this subgroup of patients raises concern about the value of skin-sparing mastectomy with immediate reconstruction for therapy. Adjuvant radiation therapy should be recommended for those patients with negative but close surgical margins.

Advances in melanoma therapy.

This review discusses several advances in melanoma therapy that have recently occurred or are presently in a developmental stage. We discuss the history and present dogma regarding assessment of the regional lymph nodes and adjuvant therapy for melanoma. Of special interest is radiolymphatic sentinel node mapping of the lymph nodes and adjuvant interferon alfa-2b for thick primary lesions and stage III disease. We also discuss several evolving novel and innovative genetic immunotherapy approaches for patients with stage IV disease.

Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation.

The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403 amino acid dual specificity phosphatase (protein tyrosine phosphatase; PTPase), was shown recently to play a broad role in human malignancy. Somatic PTEN deletions and mutations were observed in sporadic breast, brain, prostate and kidney cancer cell lines and in several primary tumours such as endometrial carcinomas, malignant melanoma and thyroid tumours. In addition, PTEN was identified as the susceptibility gene for two hamartoma syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD families and seven BZS families was screened for germline PTEN mutations. PTEN mutations were identified in 30 of 37 (81%) CD families, including missense and nonsense point mutations, deletions, insertions, a deletion/insertion and splice site mutations. These mutations were scattered over the entire length of PTEN , with the exception of the first, fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD mutations identified in this exon. Seven of 30 (23%) were within the core motif, the majority (five of seven) of which were missense mutations, possibly pointing to the functional significance of this region. Germline PTEN mutations were identified in four of seven (57%) BZS families studied. Interestingly, none of these mutations was observed in the PTPase core motif. It is also worthy of note that a single nonsense point mutation, R233X, was observed in the germline DNA from two unrelated CD families and one BZS family. Genotype-phenotype studies were not performed on this small group of BZS families. However, genotype-phenotype analysis inthe group of CD families revealed two possible associations worthy of follow-up in independent analyses. The first was an association noted in the group of CD families with breast disease. A correlation was observed between the presence/absence of a PTEN mutation and the type of breast involvement (unaffected versus benign versus malignant). Specifically and more directly, an association was also observed between the presence of a PTEN mutation and malignant breast disease. Secondly, there appeared to be an interdependent association between mutations upstream and within the PTPase core motif, the core motif containing the majority of missense mutations, and the involvement of all major organ systems (central nervous system, thyroid, breast, skin and gastrointestinal tract). However, these observations would need to be confirmed by studying a larger number of CD families.

Astrocytes derived from p53-deficient mice provide a multistep in vitro model for development of malignant gliomas.

Loss or mutation of p53 is thought to be an early event in the malignant transformation of many human astrocytic tumors. To better understand the role of p53 in their growth and transformation, we developed a model employing cultured neonatal astrocytes derived from mice deficient in one (p53 +/-) or both (p53 -/-) p53 alleles, comparing them with wild-type (p53 +/+) cells. Studies of in vitro and in vivo growth and transformation were performed, and flow cytometry and karyotyping were used to correlate changes in growth with genomic instability. Early-passage (EP) p53 -/- astrocytes achieved higher saturation densities and had more rapid growth than EP p53 +/- and +/+ cells. The EP p53 -/- cells were not transformed, as they were unable to grow in serum-free medium or in nude mice. With continued passaging, p53 -/- cells exhibited a multistep progression to a transformed phenotype. Late-passage p53 -/- cells achieved saturation densities 50 times higher than those of p53 +/+ cells and formed large, well-vascularized tumors in nude mice. p53 +/- astrocytes exhibited early loss of the remaining wild-type p53 allele and then evolved in a manner phenotypically similar to p53 -/- astrocytes. In marked contrast, astrocytes retaining both wild-type p53 alleles never exhibited a transformed phenotype and usually senesced after 7 to 10 passages. Dramatic alterations in ploidy and karyotype occurred and were restricted to cells deficient in wild-type p53 following repeated passaging. The results of these studies suggest that loss of wild-type p53 function promotes genomic instability, accelerated growth, and malignant transformation in astrocytes.

Basic fibroblast growth factor and fibroblast growth factor receptor I are implicated in the growth of human astrocytomas.

Malignant astrocytomas are highly invasive, vascular neoplasms that comprise the majority of nervous system tumors in humans. A strong association has previously been made between malignancy in human astrocytic tumors and increased expression of certain fibroblast growth factor (FGF) family members, including basic and acidic FGF. The influence of endogenous basic FGF on glioblastoma cell growth in vitro was evaluated using basic FGF-specific antisense oligonucleotides. These studies indicated that human glioblastoma cell growth in vitro, can be inhibited by suppressing basic FGF expression. Human astrocytomas also exhibited changes in FGF receptor (FGFR) expression during the course of their progression from a benign to a malignant phenotype. FGFR2 (bek) expression was abundant in normal white matter and in all low grade astrocytomas, but was not observed in glioblastomas. Conversely, FGFR1 (flg) expression was absent or barely detectable in normal white matter, but was significantly elevated in glioblastomas. Glioblastomas also expressed an alternatively spliced form of FGFR1 containing two immunoglobulin-like disulfide loops (FGFR1 beta), whereas normal human adult and fetal brain expressed a form of the receptor containing three immunoglobulin-like disulfide loops (FGFR1 alpha). Intermediate grades of astrocytic tumors exhibited a gradual loss of FGFR2 and a shift in expression from FGFR1 alpha to FGFR1 beta as they progressed from a benign to a malignant phenotype. The underlying cytogenetic changes that contribute to these alterations are not entirely understood, but abnormalities in the p53 tumor suppressor gene may influence expression of bFGF as well as the FGFR. These results suggest that alterations in FGFR signal transduction pathways may play a critical role in the malignant progression of astrocytic tumors.

Clinical trials of modulation of multidrug resistance. Pharmacokinetic and pharmacodynamic considerations.

A growing body of evidence indicates that expression of the mdr1 gene, which encodes the multidrug transporter, P-glycoprotein, contributes to chemotherapeutic resistance of human cancers. Expression of this protein in normal tissues such as the biliary tract, intestines, and renal tubules suggests a role in the excretion of toxins. Modulation of P-glycoprotein function in normal tissues may lead to decreased excretion of drugs and enhanced toxicities. A clinical trial of etoposide with escalating doses of cyclosporine (CsA) as a modulator of multidrug resistance was performed. CsA was delivered as a 2-hour loading dose followed by a 60-hour intravenous infusion, together with etoposide administered as a short infusion daily for 3 days. Patients received one or more courses of etoposide alone before the combined therapy to establish their clinical resistance to etoposide and to study etoposide pharmacokinetics without and then with CsA. Plasma and urinary etoposide was measured by high-performance liquid chromatography and plasma CsA by a nonspecific immunoassay. Conclusions from the initial phase I trial with the use of CsA as a modulator of etoposide are: (1) Serum CsA steady-state levels of up to 4800 ng/ml (4 microM) could be achieved with acceptable toxicity. (2) Toxicities caused by the combined treatment included increased nausea and vomiting, increased myelosuppression, and hyperbilirubinemia, consistent with modulation of P-glycoprotein function in the blood-brain barrier, hematopoietic stem cell, and biliary tract. Renal toxicity was uncommon, but severe in two patients with steady-state plasma CsA levels above 6000 ng/ml. (3) CsA administration had a marked effect on the pharmacokinetics of etoposide, with a doubling of the area under the concentration-time curve as a result of both decreased renal and nonrenal clearance, necessitating a 50% dose reduction in patients with normal renal function and hepatic function. (4) The recommended dose of CsA is a 6-7 mg/kg loading dose administered as a 2-hour intravenous infusion followed by a continuous infusion of 18-21 mg/kg/day for 60 hours with adjustments in the infusion rate to maintain steady-state serum levels of 3000-4800 ng/ml (2.5-4.0 M). We are performing additional phase I trials combining CsA with single-agent doxorubicin and taxol, and the CsA analog PSC-833 with various multidrug-resistant-related cytotoxins.

Phase I trial of etoposide with cyclosporine as a modulator of multidrug resistance.

PURPOSE: To determine the maximum-tolerated dose (MTD) of cyclosporine (CsA) infusion administered with etoposide for 3 days in patients with cancer. PATIENTS AND METHODS: Of the 72 registered patients, 26 were treated initially with CsA and etoposide. Forty-six received etoposide alone until disease progression, and 31 of these proceeded to CsA and etoposide. CsA was administered as a 2-hour loading dose (LD) and as a 3-day continuous infusion (CI); doses were escalated from 2 to 8 mg/kg LD and 5 to 24 mg/kg/d CI. RESULTS: Fifty-seven patients were treated with 113 cycles of CsA with etoposide. Steady-state serum CsA levels (nonspecific immunoassay) more than 2,000 ng/mL were achieved in 91% of the cycles at CsA doses > or = 5 mg/kg LD and > or = 15 mg/kg/d CI. The major dose-related toxicity of CsA was reversible hyperbilirubinemia, which occurred in 78% of the courses with CsA levels > 2,000 ng/mL. Myelosuppression and nausea were more severe with CsA and etoposide. Other CsA toxicities included hypomagnesemia, 60%; hypertension, 29%; and headache, 21%. Nephrotoxicity was mild in 12% and severe in 2% of the cycles. Tumor regressions occurred in four patients after the addition of CsA (one non-Hodgkin's lymphoma, one Hodgkin's disease, and two ovarian carcinomas). Biopsy procedures for tumors from three of the four patients who responded were performed, and the results were positive for mdr1 expression. CONCLUSIONS: Serum CsA levels of up to 4 mumol/L (4,800 ng/mL) are achievable during a short-term administration with acceptable toxicities when administered in combination with etoposide. The CsA dose that is recommended in adults is a LD of 5 to 6 mg/kg, followed by a CI of 15 to 18 mg/kg/d for 60 hours. CsA blood levels should be monitored and the doses should be adjusted to achieve CsA levels of 2.5 to 4 mumol/L (3,000 to 4,800 ng/mL). Reversible hyperbilirubinemia may be a useful marker of inhibition by CsA of P-glycoprotein function. When used with high-dose CsA, etoposide doses should be reduced by approximately 50% to compensate for the pharmacokinetic effects of CsA on etoposide (Lum et al, J Clin Oncol, 10:1635-1642, 1992).

Alteration of etoposide pharmacokinetics and pharmacodynamics by cyclosporine in a phase I trial to modulate multidrug resistance.

PURPOSE: To determine the effects of high-dose cyclosporine (CsA) infusion on the pharmacokinetics of etoposide in patients with cancer. PATIENTS AND METHODS: Sixteen patients were administered 20 paired courses of etoposide and CsA/etoposide. Etoposide was administered daily for three days, alone or with CsA, which was delivered by a loading dose and 3-day infusion. Etoposide was measured by high-performance liquid chromatography (HPLC) and serum CsA by nonspecific immunoassay. Etoposide pharmacokinetics included area under the concentration-time curve (AUC), total and renal clearance (CL), half-life (T1/2), and volume of distribution at steady state (Vss). RESULTS: CsA concentrations more than 2,000 ng/mL produced an increase in etoposide AUC of 80% (P less than .001), a 38% decrease in total CL (P < .01), a > twofold increase in T1/2 (P < .01), and a 46% larger Vss (P = .01) compared with etoposide alone. CsA levels ranged from 297 to 5,073 ng/mL. Higher CsA levels (< 2,000 ng/mL v > 2,000 ng/mL) resulted in greater changes in etoposide kinetics: Vss (1.4% v 46%) and T1/2 (40% v 108%). CsA produced a 38% decrease in renal and a 52% decrease in nonrenal CL of etoposide. Etoposide with CsA levels > 2,000 ng/mL produced a lower WBC count nadir (900/mm3 v 1,600/mm3) compared with baseline etoposide cycles. CONCLUSIONS: High-dose CsA produces significant increases in etoposide systemic exposure and leukopenia. These pharmacokinetic changes are consistent with inhibition by CsA of the multidrug transporter P-glycoprotein in normal tissues. Etoposide doses should be reduced by 50% when used with high-dose CsA in patients with normal renal and liver function. Alterations in the disposition of other multidrug resistance (MDR)-related drugs should be expected to occur with modulation of P-glycoprotein function in clinical trials.

Conjugated desferoxamine attenuates hepatic microvascular injury following ischemia/reperfusion.

Iron-dependent oxy radicals have been implicated in reperfusion injury. Although the iron chelator desferoxamine (DFO) is beneficial, its hemodynamic effects and short vascular retention limit its use in vivo. We tested whether DFO conjugated to a high-molecular-weight starch might ameliorate in vivo hepatic microvascular injury without adverse side effects following 120 min of ischemia. Prior to reperfusion, conjugated DFO (100 mg/kg), vehicle (Veh), or saline (I/R) was administered. After 90 min of reperfusion, blood was collected for serum transaminase determination (ALT; U/liter), and fluorescein-albumin was injected to label perfused microvessels, which were quantified in frozen sections by a point-count technique. Tissue edema was estimated by wet to dry weight ratios (W/D). Reperfusion results in hepatocyte injury (rise in ALT and W/D) and a 30% loss of perfused microvessels. Intravenous administration of conjugated DFO produces no significant change in systemic hemodynamics, whereas both ALT and tissue edema were decreased by approximately 50%. Moreover, perfused microvessels were restored virtually to nonischemic control levels. Enhanced perfusion and attenuated cell injury with DFO suggest that microvascular failure and resultant cell death are mediated, at least in part, by iron-dependent mechanisms in reperfusion.

Susceptibility of hepatic microcirculation to reperfusion injury: a comparison of adult and suckling rats.

Primary graft failure and vascular thromboses are frequent complications of liver transplantation, yet the mechanisms responsible remain unclear. Previous work from our laboratory has shown that hepatic reperfusion injury results in damage at the microvessel level. The present study was performed to determine whether an increased susceptibility of immature animals to microvascular injury during reperfusion might be a contributing factor in these complications. Suckling (35 to 50 g) or adult (250 to 400 g) rats were subjected to 30 or 60 minutes of hepatic ischemia to the left and median lobes followed by 90 minutes of reperfusion. Control animals were sham-operated, time-matched rats. At the end of reperfusion, fluorescein-labeled albumin was injected systemically to mark perfused sinusoids. Frozen sections of liver biopsies were viewed under fluorescence microscopy. The perfused sinusoid density was determined by point count analysis and expressed as the number of intersections of perfused sinusoids with 25 randomly oriented points superimposed on the sinusoid field. In sham-operated rats, at both 30 and 60 minutes, there were no differences between sucklings and adults. After 30 minutes of ischemia and 90 minutes of reperfusion, adults showed a significantly decreased density of perfused sinusoids (4.5 +/- 0.1 intersections per field) when compared with suckling rats (6.0 +/- 0.3 intersections per field, P less than .001). However, in rats subjected to 60 minutes of ischemia followed by 90 minutes of reperfusion, the microvascular injury was more severe in suckling rats (2.7 +/- 0.2 intersections per field) than in adults (4.7 +/- 0.2 intersections per field, P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)