[Helical tomotherapy in the treatment of malignant pleural mesothelioma: The impact of low doses on pulmonary and oesophageal toxicity]

PURPOSE

To evaluate the adjuvant treatment of malignant pleural mesothelioma by helical tomotherapy and the impact of low doses on esophageal and pulmonary toxicity.

PATIENTS AND METHODS

Between June 2007 and May 2011, 29 patients diagnosed with malignant pleural mesothelioma received adjuvant radiotherapy by helical tomotherapy. The median age was 63 years (34-72). Histologically, 83 % of patients had epithelioid malignant pleural mesothelioma. Clinically, 45 % of patients were T3 and 55 % N0. Eighty six percent of the patients were treated by extrapleural pneumonectomy and 35 % received neoadjuvant chemotherapy with platinum and pemetrexed. The median dose in the pneumonectomy cavity was 50Gy at 2Gy/fraction.

RESULTS

The mean follow-up was 2.3 years after diagnosis. Overall survival at 1 and 2 years was 65 and 36 % respectively. The median survival from diagnosis was 18 months. Median lung volumes receiving 2, 5, 10, 13, 15 and 20Gy (V2, V5, V10, V13, V15 and V20) were 100, 98, 52, 36, 19 and 5 %. The median of the mean remaining lung dose was 11Gy. Two patients died of pulmonary complications, three patients had grade 3 lung toxicity, while esophageal grade 3-4 toxicity was observed in three other patients. No significant impact of clinical characteristics and dosimetric parameters were found on pulmonary toxicity, however a V10≥50 %, a V15≥15 % and mean lung dose of 10Gy or more had a tendency to be predictive of pulmonary toxicity (P<0.1). Moreover, in our analysis, the mean lung dose seems to have a significant impact on esophageal toxicity (P=0.03) as well as low doses to the controlateral lung: V5, V10 and V13 (P<0.05).

CONCLUSION

Helical tomotherapy is a promising technique in the multimodality treatment of malignant pleural mesothelioma. Low doses received by the contralateral lung appear to be the limiting factor. A dosimetric comparison with volumetric modulated arctherapy techniques would be interesting in this setting.

Using custom protein microarrays to identify autoantibody biomarkers for the early detection of breast cancer

Abstract #2003

Background: Cancer patients make antibodies to tumor-derived proteins that are potential biomarkers for early detection. To detect autoantibodies to tumor antigens in patient sera, we have adapted novel high-density custom protein microarrays (NAPPA) expressing 6,500 candidate tumor antigens for biomarker detection. These arrays are probed with sera from patients with early stage breast cancer and healthy women. Using this approach, we identified antibodies in the sera of breast cancer patients.&#x2028; Methods: 6,500 full-length human antigens were expressed using mammalian reticulocyte lysate and captured onto NAPPA protein microarrays. Protein expression (&gt;90%) was confirmed with anti-GST antibodies. Patient sera were added, and bound IgG detected with secondary antibodies. Serum samples were obtained from 103 patients with stages I-III breast cancer, and 103 age-matched control women, all undergoing routine mammography.&#x2028; Results: Using high-density protein microarrays, sera from breast cancer patients (n=53) and healthy donor sera (n=53) were screened for autoantibodies to 6,500 protein antigens. Antigens were selected for further analysis if the 95th percentile of signal of cases and controls were significantly different (p&lt;0.05) and if the number of cases with signals above the 95th percentile of controls was larger than the number expected due to random chance (p&lt;0.05). Known tumor antigens, such as p53, were detected, as well as novel antigens such as DCC1, Rab7L and USP44. In total, 768 unique antigens were selected for further analysis with an independent set of breast cancer patient (n=50) and healthy donor sera (n=50).&#x2028; Conclusions: Custom in-situ protein microarrays can be used to detect serum tumor antigen-specific antibodies and enables the rapid, simultaneous detection of immunogenic tumor antigens from patient sera. These autoantibodies are being evaluated as potential biomarkers for the early diagnosis of breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2003.

Trends in the prevalence of adolescent births in Antigua and Barbuda over 35 years

A retrospective study was undertaken to determine trends in teenage births in Antigua and Barbuda from 1969 to 2003. Maternity Ward records were reviewed at Holberton Hospital, site of over 90% of deliveries in Antigua and Barbuda. Maternal age for all births were included. The estimated population in Antigua and Barbuda increased from 60,159 in 1969 to 69,866 in 1998, with no suspected change in age-group or gender distribution. Births to mothers 12-13, 14-15, 16-17 and 18-19 years old were analyzed separately. Yearly birth totals for the 10-year period from 1969 to 1973 and 1999 to 2003 were compared using student t test analysis. The total number of births averaged 1075 per year with no change in trend. For females aged 12 and 13 years, there was no change in births from 1969 to 1978 compared with 1994 to 2003. For females aged 14 years, there was a 54% drop; for females aged 15 years, a 59% drop; for females aged 16 years, a 53% drop; for females aged 17 years, a 51% drop; for females 18 years, a 37% drop and for females aged 19 years, a 30% drop, while births to mothers > or = 20 years increased 25%. The decrease for all teen births was 42% from 1969-1978 to 1994-2003. Teen births accounted for 29% of all births at Holberton in 1969 to 1973 but only 16% of births in 1999 to 2003. In conclusion, Antigua and Barbuda has seen a marked drop of 42% in teenage deliveries, including a 53% drop in school-aged teens from 1969 to 2003. Explanations include factors such as economic, social, educational and medical developments.

Spinal cord stimulation for relief of abdominal pain in two patients with familial Mediterranean fever

Familial Mediterranean fever is a hereditary disease characterized by recurrent attacks of fever and serosal inflammation that commonly presents as severe abdominal pain. Though colchicine remains the mainstay of treatment, a significant proportion of patients are partially responsive, unresponsive or intolerant to it. We present two such cases where spinal cord stimulation (SCS) was used to manage the paroxysmal abdominal pain associated with this disease. Abdominal visceral pain pathways and the application of SCS techniques in its management are discussed.

Isoflurane-induced myocardial preconditioning is dependent on phosphatidylinositol-3-kinase/Akt signalling

BACKGROUND

Isoflurane and other volatile anaesthetics have a cardioprotective effect and limit myocardial infarct size to the same extent as ischaemic preconditioning. Phosphatidylinositol-3-kinase (PI3K) was found to play a key role in myocardial protection by ischaemic preconditioning. The aim of the present investigation was to evaluate whether isoflurane-induced myocardial preconditioning is dependent on PI3K signalling.

METHODS

Using a model of regional myocardial ischaemia and reperfusion, New Zealand White rabbits were subjected to 40 min of regional myocardial ischaemia followed by 120 min of reperfusion. The rabbits were randomly assigned to one of the following six experimental groups: sham-operated controls (n=5); ischaemia and reperfusion controls (n=8); isoflurane preconditioning (n=8); a PI3K inhibitor, wortmannin (0.6 mg kg(-1) i.v.) + isoflurane (n=8); and wortmannin+ischaemia and reperfusion (n=8). An additional control group of sham operation+ wortmannin (n=5) was also included. Myocardial injury was assessed by measuring the serum concentration of the MB fraction of creatine kinase (CK-MB) and infarct size was assessed by 2,3,5-triphenyl tetrazolium chloride staining. Phosphorylation of Akt, a downstream target of PI3K, was assessed by western blotting.

RESULTS

Isoflurane preconditioning was seen as reduced infarct size compared with control animals: 24 (4) and 41 (5)% respectively (P<0.05). Wortmannin inhibited this cardioprotective effect with myocardial infarct size at 44 (3)% (not significant). Akt phosphorylation was increased after isoflurane preconditioning, but administration of wortmannin blocked this effect.

CONCLUSIONS

Our data demonstrate that isoflurane protects the heart against ischaemia and decreases myocardial infarction by activation of PI3K.

Isoflurane does not mimic ischaemic preconditioning in decreasing hydroxyl radical production in the rabbit

BACKGROUND

Reactive oxygen species are an important mediator in isoflurane-induced myocardial preconditioning. However, hydroxyl radicals are also released during reperfusion after regional ischaemia. The purpose of the present study was to test whether ischaemic preconditioning and isoflurane would influence the production of hydroxyl radicals during reperfusion.

METHODS

After i.v. administration of salicylate 100 mg kg(-1) and a 30 min stabilization period, New Zealand White rabbits were subjected to 40 min of regional myocardial ischaemia and 2 h of reperfusion. Ischaemic preconditioning was elicited by 5 min ischaemia followed by 10 min reperfusion (before the 40 min ischaemia). In another group, isoflurane (2.1%) was administered for 30 min, followed by 15 min washout, before the long ischaemia. Area at risk and infarct size were assessed by blue dye injection and tetrazolium chloride staining. We quantified the level of OH-mediated conversion of salicylate to its dihydrobenzoate derivatives (2,3- and 2,5-DHBAs). Normalized values of the DHBAs (ng DHBA per mg salicylate) were calculated.

RESULTS

Mean (se) infarct size was 57 (6)% of the risk area in the untreated controls. This was significantly smaller in the ischaemic preconditioning and isoflurane groups: 22 (5) and 23 (6)% respectively. At 10 min of reperfusion, ischaemic preconditioning limited the mean increase in 2,3-DHBA to 24% from baseline, compared with 81% in control and 74% in the isoflurane group. Normalized 2,5-DHBA was maximally increased by 75% in the untreated group, 4 min after reperfusion. Ischaemic preconditioning significantly inhibited this increase (24% increase from baseline, P<0.01). However, the increase observed in the isoflurane group was not different from control (71%).

CONCLUSIONS

As already known, ischaemic preconditioning and isoflurane markedly reduced infarct size. However, only ischaemic preconditioning decreased postischaemic production of hydroxyl radicals. These different effects suggest different protective mechanisms at the cellular level.

Halofuginone--an inhibitor of collagen type I synthesis--prevents postoperative formation of abdominal adhesions

OBJECTIVE

To evaluate the effects of halofuginone, a specific inhibitor of collagen type I synthesis, on the postoperative formation of abdominal adhesions in rats.

SUMMARY BACKGROUND DATA

Postoperative adhesions remain the leading cause of small bowel obstruction in the Western world. Surgical trauma causes the release of a serosanguineous exudate that forms a fibrinous bridge between two organs. This becomes ingrown with fibroblasts, and subsequent collagen deposition leads to the formation of a permanent adhesion. Most of the drugs used have been clinically ineffective, and none has been specific to a particular extracellular matrix molecule. Therefore, there are serious concerns about the toxic consequences of interfering with the biosynthesis of other collagens, other matrix proteins, or vital collagen-like molecules.

METHODS

Adhesions were induced by scraping the cecum until capillary bleeding occurred. The adhesions were scored 21 days later. Halofuginone was either injected intraperitoneally (1 microg/25 g body weight) every day, starting on the day of operation, or added orally at concentrations of 5 or 10 mg/kg, starting 4 days before the operation. Collagen alpha1(I) gene expression was evaluated by in situ hybridization, total collagen was estimated by Sirius red staining, and collagen type III was detected by immunohistochemistry.

RESULTS

The adhesions formed between the intestinal walls were composed of collagen and were populated with cells expressing the collagen alpha1(I) gene. Regardless of the administration procedure, halofuginone significantly reduced the number and severity of the adhesions. Halofuginone prevented the increase in collagen alpha1(I) gene expression observed in the operated rats, thus reducing collagen content to the control level. In fibroblasts derived from abdominal adhesions, halofuginone induced dose-dependent inhibition of collagen alpha1(I) gene expression and collagen synthesis. Collagen type III levels were not altered by adhesion induction or by halofuginone treatment.

CONCLUSIONS

Upregulation of collagen synthesis appears to have a critical role in the pathophysiology of postoperative adhesions. Halofuginone, an inhibitor of collagen type I synthesis, could be used as an important tool in understanding the role of collagen in adhesion formation, and it may become a novel and promising antifibrotic agent for preventing postoperative adhesion formation.

Metaphyseal dissociation fractures of the proximal tibia. An analysis of treatment and complications

A study was done of 44 metaphyseal dissociation fractures of the proximal tibia in 42 patients (27 men and 15 women, aged 22 to 77 years; mean, 42 years). Follow-up ranged from 6 months to 4 years. There were 2 study groups: a retrospective group (group 1, 22 fractures) given a variety of treatments ranging from casts to dual plates, and a prospective group (group 2, 22 fractures) treated by combining external fixation and optional minimal internal fixation. There were 12 comminuted fractures in group 1 and 20 in group 2 (P < 0.01). All fractures eventually healed, with an average healing time in group 1 of 3.8 months, and 5.3 months in group 2. There was one delayed union in group 2. Results were graded from poor to excellent, based on pain, range-of-motion, and malunion. There were 6 poor and 4 fair results in group 1, and no poor and 3 fair results in group 2. Complications included 6 deep infections, 5 in group 1 (1 requiring a free-flap procedure); and 1 pin-tract infection resulting in septic arthritis in group 2. There were 7 gastrocnemius flaps required in group 1, and 1 in group 2. The results of this study suggest that patients treated with external fixation had better results with less infection and soft-tissue complications than those treated with conventional internal fixation.

Arthroscopic resection of dorsal ganglion of the wrist

In summary, arthroscopic resection is a reasonable approach for operative treatment of the dorsal ganglion. Arthroscopy is safe and addresses the key anatomic pathology. Recurrences to date have been equal to or less than with the open technique. Arthroscopic resection minimizes the surgical scar. Arthroscopy also permits evaluation of any intra-articular pathologic condition of either midcarpal or radiocarpal joints. In our series, 42% of patients had intra-articular pathologic conditions. In this study, these findings were recorded but not treated. Symptom resolution, therefore, correlated with ganglion resection and not with intra-articular pathologic conditions. We look forward to publishing our data in full at the completion of our study.