Surgical complications in abdominal tumor surgery in children. Experiences at a single oncological center

INTRODUCTION

Surgical complications after tumor operations are frequent in children, with rates of up to 30% cited in the literature. Various approaches to reduce these complication rates have been attempted, with preoperative chemotherapy holding pride of place. One approach to minimize surgical complications is better preoperative preparation. In a retrospective analysis, we evaluated the complications associated with tumor surgery.

MATERIAL AND METHODS

We retrospectively analyzed patient data from 1991 to 2007. The distribution of the various tumors, the type of surgery, and complications were evaluated. For neuroblastomas a differentiated analysis of complications was performed, which included staging and radiologically defined surgical risk factors (SRFs). Patients were divided into two groups: A and B. Intensified surgical planning with 3D visualization was used in patients of group B.

RESULTS

A total of 145 operations for abdominal tumors were performed in 123 patients. The three most common diseases were neuroblastoma (36%), nephroblastoma (26%), and ovarian tumor (19%). In 68% of patients complete resection and in 19% of cases partial resection of the tumor was carried out; open biopsy was performed in 13%. A total of 15 (10.3%) complications developed: the incidence of complications for group A was 11.8% and 7.7% for group B (p=0.5). For nephroblastoma these figures were 27.9% and 21.2% (p=1.0). In the group of patients with neuroblastoma, six complications developed in patients from group A (21.4%) and one in a group B patient (4.2%) (p=0.107). 54% of neuroblastomas were completely and 33% partially resected; these figures and the distribution of SRFs were similar in the two groups. A significant increase in the risk of complications could be seen with an increase in SRFs (p=0.0267) and with disease stages 2 and 3 (p=0.016). Tumor reduction surgery was also associated with an increase in complications (p=0.086).

CONCLUSIONS

In summary, tumor surgery is associated with considerable risks in children. Therefore it is very important to look for new approaches that could potentially minimize these risks. As the causes of surgical complications are multifactorial, we are of the opinion that intensified surgical planning can contribute to reducing risks. Particularly neuroblastoma surgery could profit from an increased use of 3D visualization and improved preoperative planning.

[The clinical application of intensity-modulated radiation therapy]

Intensity-modulated radiation therapy (IMRT) represents one of the greatest technical innovations in modern radiotherapy. Its capacity of achieving treatments with the dose conforming largely to the irradiated area makes it possible to treat volumes close to organs at risk with great safety These characteristics make it an ideal technique for studies, whether for reducing toxicity in organs at risk, or for intensifying dosages to improve the control of the disease. The first part of the article considers what is understood by IMRT and its peculiar dosimetric characteristics, as well the types of IMRT; the second part deals with the clinical evidence in some localisations such as tumours of the head and neck, prostate and breast.

The EORTC Quality of Life Questionnaire for patients with prostate cancer: EORTC QLQ-PR25. Validation study for Spanish patients

OBJECTIVES

The EORTC Quality of Life (QL) Group has developed a questionnaire, the EORTC QLQ-PR25, for evaluating QL in prostate cancer. The aim of this study is to assess the psychometric properties of the EORTC QLQPR25 when applied to a sample of Spanish patients.

MATERIALS AND METHODS

One hundred and thirty-seven prostate cancer patients with localised disease who started radiotherapy with radical intention combined with or without hormonotherapy prospectively completed the EORTC QLQ-C30 and EORTC QLQ-PR25 questionnaires three times: on the first and last day of radiotherapy and in the follow-up period. Psychometric evaluation of the questionnaires' structure, reliability and validity was conducted.

RESULTS

Multitrait scaling analysis showed that many of the item-scale correlation coefficients met the standards of convergent and discriminant validity. Exceptions appeared mainly in the scales for bowel symptoms and for hormonal- treatment-related symptoms. Cronbach's coefficients of the scales were good (0.72-0.86) for the urinary symptoms and sexual function scales but they were lower (<0.70) for the bowel and hormonal treatment scales. Most scales of the EORTC QLQ-PR25 had low to moderate intercorrelations. Correlations between the scales of the QLQ-C30 and the module were generally low. Group comparison analyses showed better QL in patients with higher Performance Status. Changes in QL appeared throughout the measurements. These were in line with the treatment process.

CONCLUSIONS

The EORTC QLQ-PR25 was a reliable and valid instrument when applied to a sample of Spanish prostate cancer patients. These results are in line with those of the EORTC validation study.

[Clinical impact of image guided radiotherapy]

Image guided radiotherapy (IGR) is a concept that encompasses the most modern way of administering radiotherapy treatment. The aim is to maximise the dose deposited in the target volume, minimising the dose in healthy organs. This would not be possible without the continuous development of technology and software, above all in the following areas: deformable image registration, replanning new treatments, real time image and calculation of accumulated dose. While the clinical impact is evident, little is said about the impact on the reorganisation of the Radiotherapy Oncology services. IGR supposes training all team members involved, with a training and a starting period. With the experience acquired, the time dedicated to each patient (in all stages of treatment: simulation, planning, starting out, systems for verifying position, on-line, off-line corrections, replanning, periodic clinical controls) is far higher than that required in conventional radiotherapy, which gives rise to new responsibilities and roles.

[Image-guided brachytherapy]

Brachytherapy consists in the administration of radiation in intimate contact with the tumour, with a low exposure of neighbouring healthy tissues. Its use began in the early XX century and it has developed since then: different radioisotopes, systems of remote treatment, computer programs making individual dose calculation possible. In recent years there have been changes affecting two aspects of brachytherapy. In the first place, the incorporation of imaging techniques such as echography, computerised tomography (CT) and magnetic resonance (MR), indispensable for diagnosis and tumoural staging. Their use when the implant is being done helps in guiding and carrying out the operation with greater precision. In the second place, the use of CT, MR and echography makes better coverage of the tumour possible, or reduces the dose to healthy organs. They are used in inverse planning systems, which carry out dose calculation on the basis of the doses to be administered to the tumour and healthy organs. In these planning programs it is possible to make calculations more rapidly, taking account of the placement of the source at each moment in time. This technique, called real-time planning, is starting to show advantages in the treatment of prostate cancer. Incorporation of imaging techniques and improvements in calculation systems mean that brachytherapy is currently playing an important role in treating cancer of the prostate, cervix, breast, head and neck tumours, bronchial tubes or oesophagus.

[Radiotherapy of mobile tumors]

In this article we detail some questions related to managing the treatment of mobile tumors, that is, those tumors that shift with respiratory movements, integrating movement into the plan of treatment. This fact complicates the administration of high doses of radiotherapy since, in such cases, the radiation margin must be wider than that required by the tumor itself, representing a greater risk to surrounding healthy tissue. However, the new technologies offer an alternative in these cases, such as tracking and respiratory gating in radiotherapy (RT), that is, the synchronization of treatment with respiratory movement. In gating we capture the tumor and other organs at risk at a specific moment in the breathing cycle, while in tracking we trace the tumor and the organs at risk throughout the breathing cycle. It is therefore essential to obtain good images and to correlate them with each phase of the breathing cycle. The tumors with which these strategies have been most employed are those of the lung, breast and lymphomas, and less frequently with some abdominal tumors such as pancreas, liver and prostate.

[New developments in cancer immunotherapy]

Recent progress unveiling the cellular and molecular basis of the immune response allows nowadays the design of novel therapies for tumor immunotherapy. These recent approaches translate into response rates that often surpass what can be obtained by conventional chemotherapies or targeted therapies. Here we present the main current developments with an accent on the Lausanne experience in the treatment of melanoma. First, the new developments of peptide-based vaccination are presented. Second, approaches related to adoptive transfer are illustrated with a particular attention for the patient conditioning using lymphodepletion. Finally, the Lausanne project of rational lymphocyte TCR optimization is described.

Anticipation in familial lattice corneal dystrophy type I with R124C mutation in the TGFBI (BIGH3) gene

PURPOSE

To report the clinical, ophthalmic, and genetic characteristics for lattice corneal dystrophy type I (LCDI) in a Chilean family.

METHODS

Six affected family members were examined clinically including visual acuity, color cornea photography, applanation tonography, and fundoscopy. Genomic DNA was extracted from peripheral leukocytes from six affected and three unaffected members of a family with lattice corneal dystrophy type I. Exon 4 of the transforming growth factor-induced gene (TGFBI) was screened for the most frequent mutation, R124C, in the proband by sequencing. We also designed a rapid polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to analyze the same mutation, amplifying exon 4 and digesting with PstI restriction enzyme. Using this strategy, we analyzed the mutation in six affected and three healthy family members.

RESULTS

Three generations of family members were positively diagnosed with lattice corneal dystrophy. Six participants demonstrated LCD1 in both eyes, most of whom were symmetric. Age at onset of symptoms was variable (3-42 years old). Moreover, in this family, the age of onset of the disease decreased in succeeding generations, which could be interpreted as anticipation. Visual acuity varied from 1.0 to 0.13. Two patients, ages 69 and 44 years old, demonstrated a degree of severity "Bad" according to best-corrected vision and corneal commitment. The exon 4 sequence of TGFBI of the proband exhibits the heterozygous single-nucleotide mutation, C417T, leading to amino acid substitution (R124C) in the encoded TGF-induced protein. Using PCR-RFLP, we confirmed the heterozygous mutation in six affected family members and excluded it in three healthy members.

CONCLUSIONS

The R124C mutation in TGFBI cosegregated with LCD type I in the investigated family. This is the first report of a molecular analysis of LCD type I in Chilean patients. The early onset affected persons in the fourth generation raises the possibility of anticipation.

A methodology for the capture and analysis of hybrid data: a case study of program debugging

This article describes a methodology for the capture and analysis of hybrid data. A case study in the field of reasoning with multiple representations--specifically, in computer programming--is presented to exemplify the use of the methodology. The hybrid data considered comprise computer interaction logs, audio recordings, and data about visual attention focus. The capture of the focus of visual attention data is performed with software. The software employed tracks the user's visual attention by blurring parts of the stimuli presented on the screen and allowing the participant to see only a small region of it at any one time. These hybrid data are analyzed via a methodology that combines qualitative and quantitative approaches. The article describes the software tool employed and the analytic methodology, and also discusses data capture issues and limitations of the approach.

Potential target antigens for immunotherapy in human pancreatic cancer

BACKGROUND

To be effective and selective, immunotherapy ideally targets specifically tumor cells and spares normal tissues. Identification of tumor specific antigens is a prerequisite to establish an effective immunotherapy. Still very little is known about the expression of tumor-related antigens in pancreatic neoplasms. Cancer Testis antigens (CT) are antigens shared by a variety of malignant tumors, but not by normal tissues with the exception of germ cells in testis. Restricted expression in neoplastic tissues and inherent immunogenic features make CT antigens ideal for use in immunotherapy. We analyzed the expression of a selected panel of nine CT antigens that have been proven to elicit an efficient immunogenic response in other malignancies. In addition we analyzed the expression of HERV-K-MEL, an immunogenic antigen of viral origin.

METHODS

Pancreatic adenocarcinoma tumor samples (n=130) were obtained intraoperatively, control tissues (n=23) were collected from cadaveric donor and from patients with chronic pancreatitis. Tumor-associated antigen expression of MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, LAGE-1, NY-ESO-1, SCP-1, SSX-2, SSX-4 and HERV-K-MEL was assessed by PCR. Sequencing of PCR products were performed to assess the expression of SSX-4 in neoplastic and normal pancreatic tissues.

RESULTS

Three of 10 tested antigens were expressed in over 10% of malignant pancreatic tissue samples. SSX-4 was found positive in 30% of cases, SCP-1 in 19% and HERV-K-MEL in 23% of cases. No expression of CT antigens was found in non-malignant pancreatic tissue with the exception of SSX-4 and and SSX-2.

CONCLUSIONS

Fifty two percentage of the analyzed tissues expressed at least one CT antigen. The concomitant expression of SSX-4 in both malignant and non-malignant pancreatic tissue is a new finding which may raise concerns for immunotherapy. However, HERV-K-MEL is expressed with a relatively high prevalence and may be a candidate for specific immunotherapy in a large subgroup of pancreatic cancer patients. This study advocates the analysis of patients with regard to their immunogenic profile before the onset of antigen-specific immunotherapy.

G2 checkpoint-dependent DNA repair and its response to catalase in Down syndrome and control lymphocyte cultures

The amount of DNA lesions repaired in G2 and also G2 timing are controlled by the DNA damage-dependent checkpoint. Down syndrome (DS) lymphocytes showed twice as much constitutive DNA damage in G2 than control ones, when recording it as chromosomal aberrations in metaphase, after caffeine-induced checkpoint abrogation. During G2, DS lymphocytes repaired 1.5 times more DNA lesions than control ones. However the DS cells displayed a decreased threshold for checkpoint adaptation, as the spontaneous override of the G2 to mitosis transition block induced by the checkpoint took place in the DS cells when they had three times more DNA lesions than controls. Catalase addition to cultures scavenges hydrogen peroxide diffused from cells, resulting in subsequent intracellular depletion (Antunes and Cadenas, 2000). The intracellular H2O2 level seemed to regulate the G2 checkpoint. Thus, in controls, H2O2 depletion (induced by 3.2-50 microg/mL catalase) prevented its functioning: chromosomal damage increased while G2 shortened. Conversely, in the DS lymphocytes, 12.5 microg/mL catalase lengthened G2 and decreased chromosomal damage, in spite that the amount of DNA repaired in G2 was half of that repaired in the catalase-free DS lymphocytes.

Deficit irrigation and rootstock: their effects on water relations, vegetative development, yield, fruit quality and mineral nutrition of Clemenules mandarin

Differences between rootstocks, 'Cleopatra' mandarin and 'Carrizo' citrange, in soil-plant water relations and the influence of these factors on vigor, crop yield, fruit quality and mineral nutrition were evaluated in field-grown Clemenules mandarin trees irrigated at 100% of potential seasonal evaporation (ET(c)) (control treatment), or irrigated at 100% ET(c), except during Phases I and III of fruit growth and post-harvest when no irrigation was applied (deficit irrigation (DI) treatment), for 3 years. Differences between rootstocks in plant-soil water relations were the primary cause of differences among trees in vegetative development and fruit yield. After 3 years of DI treatment, trees on 'Cleopatra' showed more efficient soil water extraction than trees on 'Carrizo', and maintained a higher plant water status, a higher gas exchange rate during periods of water stress and achieved faster recovery in gas exchange following irrigation after water stress. The DI treatment reduced vegetative development more in trees on 'Carrizo' than in trees on 'Cleopatra'. Cumulative fruit yield decreased more in DI trees on 'Carrizo' (40%) than on 'Cleopatra' (27%). The yield component most affected by DI in 'Cleopatra' was the number of fruit, whereas in 'Carrizo' it depended on the severity of water stress reached in each phase (severe water stress in Phase I affected mainly the number of fruit, whereas it affected fruit size the most in Phase III). In the third year of DI treatment, water-use efficiency decreased sharply in trees on 'Carrizo' (70%) compared to trees on 'Cleopatra' (30%). Thus, trees on 'Cleopatra' were able to tolerate moderate water stress, whereas trees on 'Carrizo' were more sensitive to changes in soil water content.