Germline mutations of the p53 tumor-suppressor gene in children and young adults with second malignant neoplasms.

BACKGROUND. Acquired mutations in the p53 tumor-suppressor gene have been detected in several human cancers, including colon, breast, and lung cancer. Inherited mutations (transmitted through the germline) of this gene can underlie the Li-Fraumeni syndrome, a rare familial association of breast cancer in young women, childhood sarcomas, and other malignant neoplasms. We investigated the possibility that p53 mutations in the germline are associated with second primary cancers that arise in children and young adults who would not be considered as belonging to Li-Fraumeni families. METHODS. Genomic DNA was extracted from the blood leukocytes of 59 children and young adults with a second primary cancer. The polymerase chain reaction, in combination with denaturant-gel electrophoresis and sequencing, was used to identify p53 gene mutations. RESULTS. Mutations of p53 that changed the predicted amino acid sequence were identified in leukocyte DNA from 4 of the 59 patients (6.8 percent). In three cases, the mutations were identical to ones previously found in the p53 gene. The fourth mutation was the first germline mutation to be identified in exon 9, at codon 325. Analysis of leukocyte DNA from close relatives of three of the patients indicated that the mutations were inherited, but cancer had developed in only one parent at the start of the study. CONCLUSIONS. These findings identify an important subgroup of young patients with cancer who carry germline mutations in the p53 tumor-suppressor gene but whose family histories are not indicative of the Li-Fraumeni syndrome. The early detection of such mutations would be useful not only in treating these patients, but also in identifying family members who may be at high risk for the development of tumors.     

The efficacy of postoperative pain management with ketorolac for day case oral surgery

The efficacy of the non-steroidal anti-inflammatory analgesic, ketorolac (Toradol), was investigated in 52 day case patients undergoing removal of impacted third molar teeth under intravenous sedation and local analgesia. The study was double-blind, randomized and placebo-controlled. A single 30 mg dose of ketorolac was administered intravenously just prior to induction of sedation with midazolam. Ketorolac was well tolerated and provided good postoperative analgesia. It is suggested that ketorolac is a useful addition to the analgesic armamentarium and appropriately prescribed, provides good pain relief following day case oral surgery.     

Urinary C-peptide creatinine ratio to detect absolute insulin deficiency in type 2 diabetes

BackgroundNational Institute for Health and Clinical Excellence guidelines (CG87) recommend neutral protamine hagedorn (NPH) insulin for the provision of basal insulin in type 2 diabetes, but use of analogue insulin is as much as 40%. Where residual endogenous insulin secretory capacity is present there is no evidence that analogue insulins provide any additional benefit over human insulins, and they come at an expensive premium. Anecdotally, however, there is a reluctance to switch people back to NPH insulin, partly because of a perceived risk of pancreatic failure and potential ketosis. Urinary C-peptide creatinine ratio (UCPCR) has been validated as a method for evaluating residual endogenous insulin secretion in type 1 and type 2 diabetes, with a UCPCR of no more than 0·2 nmol/mmol suggestive of absolute insulin deficiency. We aimed to evaluate the prevalence of true insulin deficiency among patients with type 2 diabetes with UCPCR, and confirm findings with the gold standard mixed meal tolerance test (MMTT).Methods191 insulin-treated patients with a clinical diagnosis of type 2 diabetes (diagnosed at or after age 45 years and who did not start insulin within the first year of diagnosis) collected a 2-h post-prandial urine sample for UCPCR measurement. Nine patients from two subgroups (UCPCR ≤0·2 nmol/mmol and UCPCR >0·2) completed a standard MMTT.Findings11 (5·8%) of 191 patients had two consistent UCPCRs of less than or equal to 0·2 nmol/mmol. Nine were able to do the MMTT, of whom five were confirmed to have absolute insulin deficiency (stimulated serum c-peptide <0·2 nmol/L). Three of these five patients were glutamic acid decarboxylase antibody-negative. Nine of nine patients with UCPCR of more than 0·2 nmol/L had confirmed endogenous insulin secretion in their MMTT. Those with insulin deficiency had a shorter time to starting insulin (median 2·5 years [IQR 1·5–3·0] vs 6·0 [3·0–10·75], p=0·005) and lower body-mass index (25 kg/m² vs 29, p=0·04) but no other significant differences in clinical characteristics.InterpretationWe have demonstrated a very low prevalence of true pancreatic failure in this population of insulin-treated patients with type 2 diabetes. This requires further exploration by comparison of a population being treated with NPH insulin with one on analogue insulin, and then determining whether UCPCR could act as a clinical decision support tool to safely switch from analogue insulin to NPH insulin.FundingNational Institute for Health Research.     

MicroRNA-30c expression level is an independent predictor of clinical benefit of endocrine therapy in advanced estrogen receptor positive breast cancer

MicroRNAs (miRNAs) are small RNA molecules that modulate gene expression and which have been implicated in cancer. We evaluated whether five candidate predictive miRNAs, derived from a pilot study in which 249 miRNAs were assayed, were associated with clinical benefit of tamoxifen therapy in advanced breast cancer. These five miRNAs were measured in an independent series of 246 estrogen receptor (ER)-positive primary breast tumors of patients who received tamoxifen for advanced disease by quantitative Real Time PCR. Univariate analysis showed that higher expression levels of hsa-miR-30a-3p, hsa-miR-30c, and hsa-miR-182 were significantly associated with benefit of tamoxifen treatment and with longer PFS (all P-values <0.01). In multivariate analysis, corrected for the traditional predictive factors, only hsa-miRNA-30c was an independent predictor (P-value <0.01). Finally, in an attempt to understand the biology connected to this miRNA, Global testing pathway analysis showed an association of hsa-miRNA-30c expression with HER and RAC1 signaling pathways. We identified hsa-miRNA-30c as an independent predictor for clinical benefit of tamoxifen therapy in patients with advanced breast cancer. Assessment of tumor levels and connected pathways could be helpful to improve treatment strategies.     

Association of an extracellular matrix gene cluster with breast cancer prognosis and endocrine therapy response

PURPOSE: We previously discovered an extracellular matrix (ECM) gene cluster associated with resistance to first-line tamoxifen therapy of patients with metastatic breast cancer. In this study, we determined whether the six individual ECM genes [collagen 1A1 (COL1A1), fibronectin 1 (FN1), lysyl oxidase (LOX), secreted protein acidic cysteine-rich (SPARC), tissue inhibitor of metalloproteinase 3 (TIMP3), and tenascin C (TNC)] were associated with treatment response, prognosis, or both. EXPERIMENTAL DESIGN: In 1,286 primary breast tumors, mRNA expression (quantitative real-time PCR) was related to clinicopathologic factors and disease outcome in univariate and multivariate analysis including traditional factors. RESULTS: TIMP3, FN1, LOX, and SPARC expression levels (continuous variables) were significantly associated with distant metastasis-free survival (MFS) in 680 lymph node-negative untreated patients (P<0.03). Using a calculated linear prognostic score, these patients were evenly divided into five prognostic groups with a significant difference in 10-year MFS of approximately 40% between the two extreme prognostic groups. Furthermore, high TNC expression as continuous variable was associated with (a) shorter MFS in 139 estrogen receptor-positive and lymph node-positive patients who received adjuvant tamoxifen therapy (hazard ratio, 1.53; P=0.001), and (b) no clinical benefit (odds ratio, 0.81; P=0.035) and shorter progression-free survival (hazard ratio, 1.19; P=0.002) in 240 patients in whom recurrence was treated with tamoxifen as first-line monotherapy. These results were also significant in multivariate analyses. CONCLUSION: FN1, LOX, SPARC, and TIMP3 expression levels are associated with the prognosis of patients with breast cancers, whereas TNC is associated with resistance to tamoxifen therapy. Further validation and functional studies are necessary to determine the use of these ECM genes in decisions regarding treatment and whether they can serve as targets for therapy.     

Randomized controlled trial of dexamethasone treatment in very-low-birth-weight infants with ventilator-dependent chronic lung disease

This randomized controlled trial was designed to answer the question: does administration of dexamethasone to neonates with bronchopulmonary dysplasia decrease the need for assisted ventilation? Twenty-five infants with a birth weight < 1501 g, requiring mechanical ventilation and FiO₂ of ± 0.30 at 21-35 days of age, were randomized to treatment with iv dexamethasone or to sham injections for 12 days. The primary outcome criterion was extubation within seven days after study entry. Treatment (n= 12) and control (n= 13) groups were well matched at entry. Dexamethasone facilitated weaning from assisted ventilation (p= 0.0154). There was no increased incidence of infection. Dexamethasone treatment resulted in a significant increase in glucosuria (p= 0.0002) and in systolic blood pressure (p= 0.0034). There was a significant decrease in heart rate (p= 0.0001) and a significant weight loss (p= 0.0002) following dexamethasone treatment. Dexamethasone treatment facilitated weaning from assisted ventilation but several systemic effects were noted that deserve further evaluation before dexamethasone becomes routine treatment.     

Phase I escalation of gemcitabine combined with protracted oral etoposide in gynecologic malignancies: A Gynecologic Oncology Group study

Objective: Although improvementshave been made in the management ofpatients with advanced ovarian cancer,long-term survivors are still uncommon. Gemcitabine and prolonged oral etoposidehave shown reproducible single-agentactivity in patients withplatinum/paclitaxel-resistant ovariancancer. This, combined with preclinicalsynergism, prompted the GynecologicOncology Group to determine the maximumtolerated dose (MTD) of this combination. Methods: Eligible patients hadrecurrent epithelial ovarian cancer,primary papillary peritoneal, or fallopiantube carcinoma. All had received priorplatinum/paclitaxel-based chemotherapy andhad adequate hepatic, renal and bone marrowfunction. Oral etoposide was administeredat 50 mg/m² for ten days, with threeproposed dose levels for gemcitabine ondays 1 and 8: 400, 550 and 700 mg/m². Cycles were to be repeated every 28 days. Three patients were to enter at each doselevel. Results: Patients were enrolled onlyto dose level 1 as this dose exceeded MTD. Of six patients initially enrolled, one wasremoved after three days with fever,ascites and decreased albumin believed notto be treatment related. Five patientswere evaluable for toxicity and response. One of the first three patients developeddose limiting toxicity (DLT) manifested asgrade 4 neutropenia. A second DLT(neutropenic fever and thrombocytopeniaassociated with bleeding) occurred amongthe next three patients; therefore, MTD wasreached at dose level 1. Grade 4toxicities included episodes of neutropenia(4) and thrombocytopenia (3). No objectiveresponse was observed. Conclusions: Oral etoposide andgemcitabine at this dose and schedule wasassociated with substantial toxicity inthis population. Patients who are previously treated withplatinum/paclitaxel-based chemotherapy maybe at particular risk for toxicity.     

Higher expression of human kallikrein 10 in breast cancer tissue predicts tamoxifen resistance

The human tissue kallikreins are secreted serine proteases, encoded by a group of homologous genes clustered in tandem on chromosome 19q13.3-4. Human kallikrein 6 and human kallikrein 10 are two new members of this family. Recently, we developed highly sensitive and specific immunofluorometric assays for human kallikrein 6 and human kallikrein 10, which allow for their quantification in tissue extracts and biological fluids. Both human kallikrein 6 and human kallikrein 10 are found to be down-regulated in breast cancer cell lines, suggesting that they may be involved in breast cancer pathogenesis and progression. In this study, we investigated the potential value of human kallikrein 6 and human kallikrein 10 as prognostic and predictive factors in breast cancer. We quantified human kallikrein 6 and human kallikrein 10 protein levels in 749 breast tumour cytosolic extracts and correlated this data with various clinicopathological variables and patient outcomes. Human kallikrein 6 and human kallikrein 10 are positively correlated with each other. Higher human kallikrein 6 and human kallikrein 10 protein levels are associated with younger age, pre-menopausal, status and tumours which are negative for oestrogen and progesterone receptors. No correlation was found between human kallikrein 6 and human kallikrein 10 levels and tumour size, grade, and nodal status. Survival analysis showed that neither human kallikrein 6 nor human kallikrein 10 are related to the rate of relapse-free and overall survival. In the analysis with respect to response to tamoxifen therapy, although human kallikrein 6 levels were not associated with tamoxifen responsiveness, higher levels of human kallikrein 10 were significantly associated with a poor response rate. This association remained significant in the multivariate analysis. Furthermore, higher human kallikrein 10 levels were significantly related with a short progression-free and post-relapse overall survival after start of tamoxifen treatment for advanced disease. Taken together, our results suggest that although human kallikrein 6 and human kallikrein 10 are not prognostic markers for breast cancer, human kallikrein 10 is an independent predictive marker for response of tamoxifen therapy.