Overexpression of c-erbB-2 protein correlates with chromosomal gain at the c-erbB-2 locus and patient survival in advanced colorectal carcinomas

Overexpression of the c-erbB-2 protein (also called HER-2/neu) is observed in a variety of malignancies including colorectal cancer (CRC). In this study we aimed to evaluate the rate of c-erbB-2 overexpression in our tumor collection and to clarify its correlation with the chromosomal status at the c-erbB-2 locus in CRC. Additionally we correlated the c-erbB-2 overexpression and the chromosomal gain of 17q with patient survival. Seventy-four specimens were analyzed immunohistochemically using a polyclonal c-erbB-2 antibody (DAKO) and the staining was scored according to the Clinical Trial Assay recommendations (0-3+). Of these, 45 cases were analyzed by comparative genomic hybridization (CGH) and immunohistochemistry (IHC). Overexpression was observed in 51% of the cases (score > or = 2). Chromosomal gains at the c-erbB-2 locus were clearly correlated with overexpression of the gene (P = 0.0009). Furthermore Kaplan-Meier analysis showed that overexpression of c-erbB-2 was significantly associated with poor survival and thus could serve as a prognostic marker. We conclude that c-erbB-2 is related with tumor progression in CRC which can be observed on protein level and reflects chromosomal gain at the locus at 17q.

Surgical oncology in the interplay of surgical and nonsurgical disciplines

Advances in surgical tumor therapy are founded on a very close interaction between different surgical subspecialties as well as the inclusion of surgical into modern multimodality treatment concepts. The ongoing development of surgical techniques, e.g. microsurgical flap transfers or pouch reconstructions of intestinal reservoirs, has increasingly enabled organ- and function-preserving surgery. In addition, new materials (e.g. modular tumor endoprosthesis) has supported this development. The broad application of the sentinel node technique in melanoma and breast cancer and also in gastrointestinal tract cancers opens new concepts of diagnosis and therapy for lymphatic metastasized tumors. Locally advanced tumors can be treated in neoadjuvant protocols to increase the resectability rate and the probability for local control as a prerequisite for long-term survival. Especially for metastatic disease, interventional treatment techniques such as laser-induced thermotherapy (LITT) or photodynamic therapy have added valuable options to surgical treatment.

Sentinel lymphonodectomy in gastrointestinal cancer--where are we now?

Up to now, no reliable methods for the pre- or intraoperative prediction of the nodal status are available in gastrointestinal cancer patients. Therefore, after the successful application of the sentinel lymph node concept in melanoma and breast cancer, ongoing research on this field is extended to gastrointestinal tumor entities. According to recent experiences, the most promising tumor entities are colon, gastric and anal cancer. First results with these patients indicate that the method could be a reliable predictor of the nodal status and, thus, may have important future implications for adjuvant therapy and the extent of surgery. The dye method for colon cancer and the combined method (dye and radiocolloid) for gastric cancer seem to be appropriate approaches, even when the general experience is still low. In rectal cancer, however, current experience failed yet to yield satisfying results. Up to now, anal cancer has not been a focus of publication, even when the concept seems to be very attractive for the evaluation of the inguinal lymph node status.

Hyperthermia in combined treatment of cancer

Hyperthermia, the procedure of raising the temperature of tumour-loaded tissue to 40-43 degrees C, is applied as an adjunctive therapy with various established cancer treatments such as radiotherapy and chemotherapy. The potential to control power distributions in vivo has been significantly improved lately by the development of planning systems and other modelling tools. This increased understanding has led to the design of multiantenna applicators (including their transforming networks) and implementation of systems for monitoring of E-fields (eg, electro-optical sensors) and temperature (particularly, on-line magnetic resonance tomography). Several phase III trials comparing radiotherapy alone or with hyperthermia have shown a beneficial effect of hyperthermia (with existing standard equipment) in terms of local control (eg, recurrent breast cancer and malignant melanoma) and survival (eg, head and neck lymph-node metastases, glioblastoma, cervical carcinoma). Therefore, further development of existing technology and elucidation of molecular mechanisms are justified. In recent molecular and biological investigations there have been novel applications such as gene therapy or immunotherapy (vaccination) with temperature acting as an enhancer, to trigger or to switch mechanisms on and off. However, for every particular temperature-dependent interaction exploited for clinical purposes, sophisticated control of temperature, spatially as well as temporally, in deep body regions will further improve the potential.

[Laser-induced thermotherapy (LITT) for malignant liver tumours: the role of sonography in catheter placement and observation of the therapeutic procedure]

AIM

Evaluation of sonography in the placement of catheters for laser-induced thermotherapy (LITT) as well as for the observation of the therapeutic procedure in cases of malignant liver tumours.

METHODS

Following the placement of 1-4 LITT applicators, 18 patients with malignant liver tumours (recurrence of hepatocellular carcinoma n = 5, metachronous liver metastases n = 13) were examined by ultrasound to determine the position of the applicators as well as the sonographic visualisation of the respective lesion. The laser treatment procedure was also observed sonographically. As standard reference method for the documentation of thermally induced necroses we used magnetic resonance tomography 24-48 hours after the procedure.

RESULTS

The tip of the applicator could be localised in all cases, and the position of the applicator relative to the lesion could be directly visualised in 78% of cases. The hyperechogenic thermal effect during LITT had a median size of 4.5 cm, thus proving to be significantly larger than the actual necrosis induced (p < 0.01). The sonographic observation of the procedure identified 8/10 primarily incomplete ablations which were then treated again immediately after correction of the position of the applicators.

CONCLUSION

Continuous sonographic observation of the procedure of LITT can yield important additional information.

Resection and local therapy for liver metastases

In 30-50% of patients the liver is a preferred site of distant disease for many malignant tumours. Due to the high incidence, most of the available data relate to metastases arising from colorectal primaries. Surgical resection is at present the only treatment offering potential cure. The achievable 5-year survival rate is 30%. However, only 10-15% of patients with colorectal liver metastases can undergo potentially curative liver resection. Therefore, accurate staging is an important prerequisite in selecting patients who would benefit from surgery. Recurrence of hepatic metastases after potentially curative resection occurs in up to 60% of the cases. Results demonstrate that re-resection of liver metastases can provide long-term survival rates in a carefully selected group of patients without extrahepatic disease. Because of the high rate of recurrences following an apparently curative resection several authors investigated the use of adjuvant chemotherapy (systemic, intraportal, and hepatic arterial infusion). Until recently none had shown effectiveness. Pre-operative chemotherapy seems to be a promising approach in patients with liver metastases initially considered unsuitable for radical surgery. Recently, neoadjuvant chemotherapy has been proposed as an alternative approach to conventional surgery as initial management with the aim of improving the results in resectable liver metastases. Interventional strategies (ethanol injection, cryosurgery, laser-induced thermotherapy, radio-frequency ablation) and combined modalities (surgical/interventional) are additive methods which may help to improve treatment results in the future.

[T4 rectal carcinoma. Surgical and multimodal therapy]

BACKGROUND

In locally advanced rectal cancer with infiltration of neighbouring organs (uT4), resectability and local control are difficult to achieve. Combined preoperative radiochemotherapy may result in increased resectability and reduced local recurrence rates.

PATIENTS AND METHODS

Thirty-four patients with biopsy-proven locally advanced rectal cancer were treated by preoperative radiochemotherapy. All tumours had been staged as uT4 lesions by endorectal ultrasound or computed tomography. Radiotherapy was applied in standard blocks, 5 x 1.8 Gy up to 45 Gy. Chemotherapy consisted of two cycles of 5-fluorouracil (300-350 mg/m2/day) and leucovorin (50 mg). In 20 patients, additional thermotherapy was carried out using the Sigma 60 applicator BSD 2000 once a week prior to radiotherapy. Surgery was performed 4-6 weeks after radiochemotherapy. Postoperatively, all patients received four cycles of 5-fluorouracil and leucovorin.

RESULTS

Treatment-induced toxicity occurred in 26% of the patients (WHO grade III (n = 6) and IV (n = 3)). The resectability rate was 76% (26/34 patients) (R0 resectability n = 21; 62%). The pathological complete response rate was 6% (n = 2) and the partial response rate was 47% (n = 16). A local failure was observed in six patients after median time of 16 months (range 7-36 months). Patients with R0 resection achieved a 5-year disease-free survival rate of 55% and a survival rate of 71%. The overall 5-year survival rate for all patients with advanced uT4 rectal cancer was 49%.

CONCLUSIONS

Our data on preoperative combined treatment in locally advanced T4 rectal cancer revealed encouraging downstaging, local control, and survival rates.

Incidence of chromosomal imbalances in advanced colorectal carcinomas and their metastases

Comparative genomic hybridization (CGH) was used to screen 54 advanced colon carcinomas. i.e., 24 primary tumors and 30 metastases, for chromosomal alterations. Using a sensitive statistical method for the determination of DNA imbalances and histograms for analysis of the incidence of changes, we identified the DNA over-representation of chromosome 20q as the most common alteration being present in 100% of cases. High incidence deletions were observed on 18q21-18q23 (96%), 4q27-4q28 (96%), 4p14 (87%), 5q21 (81%), 1p21-1p22 (72%), 21q21 (74%), 6q16 (72%), 3p12 (66%), 8p24-8p21 (66%), 9p21 (64%), 11q22 (64%), and 14q13-14q21 (64%). Further frequent over-representation was found on 7q12-7q11.2 (75%), 16p11-16p12 (70%), 19p13 (70%), 9q34 (67%), 19q13 (67%), 13q34 (64%), 13q13 (64%), 17q21 (59%), 22q11 (61%), 8q24 (57%), and 1q21 (57%). Pronounced DNA gains and losses being defined as regions in which the ratio profiles exceeded the values of 1.5 and 0.5, respectively, frequently colocalized with peaks of incidence curve. The use of difference histograms for the comparison of tumor subgroups as well as case-by-case histogram for the analysis of 15 paired tumor samples identified several of the above alterations as relevant for tumor progression and metastasis formation. The study identified additional loci and delineates more precisely those that have been previously reported. For comparative purposes, we have made our primary data (ratio profiles, clinicopathological parameters, histograms) available at the interactive web site http://amba.charite.de/cgh, where the incidence of changes can be determined at individual loci and additional parameters can be applied for the analysis of our CGH results.

[Tumor downstaging through preoperative chemoradiotherapy in locally advanced rectal cancer]

OBJECTIVE

To evaluate the impact of preoperative chemoradiotherapy on patients with locally advanced rectal cancer by clinical and pathological characteristics.

METHODS

From July 1994 to May 1995, 36 patients with locally advanced rectal cancer were treated. Pathology: adenocarcinoma 27, mucinous adenocarcinoma 7 and ductal adenocarcinoma 6. The protocol was carried out in sequence of chemo-->radio-->surgery-->chemotherapy. The treatment began with preoperative chemotherapy with folinic acid 50 mg followed by 5-FU bolus of 300 mg/m2 given for two cycles on d1-5 and d22-26 before irradiation. Radiation therapy was delivered to a dose of 45 Gy, 1.8 Gy per fraction, 5 days a week. Surgery was done 4-6 weeks after this preoperative treatments. Another 2 to 4 cycles of chemotherapy were added 2 to 4 weeks after operation. Twenty-one patients were treated by Dixon's operation, 14 patients by Mile's operation and 1 by local tumorectomy through the rectum. Radical operation was performed in 29 patients and palliative resection was done in 7 patients.

RESULTS

Grade III hematological toxicity was observed in only 2(5.6%) patients. No patient had grade III or IV acute toxicity in the gastrointestinal, skin or urological systems. All patients underwent surgery. The perioperative morbidity rate was 13.8% with no mortality or late toxicity. As a result of this preoperative management, the tumor was reduced by an average of 28.0%, with a complete pathological response in 4(11.1%) patients. In 28 CR + PR (77.8%) patients, a downstaging in 19(52.8%) patients was observed. Sixty percent of positive lymph nodes as assessed by transrectal ultrasonography before therapy became pathologically negative postoperatively, with the frequency of lymph node metastasis decreased by 46.0%(83.0% to 37.0%).

CONCLUSION

Preoperative radiochemotherapy is proved as a safe method with a tolerable toxicity. Complete pathological response, shrinkage of the primary tumor and decrease in lymph node metastasis are observed after preoperative radiochemotherapeutic regimen. An overall benefit of downstaging the primary tumor and a greatly enhanced effect of surgery is enjoyed by the patients.

[Influence of positron emission tomography on surgical therapy planning in recurrent colorectal cancer]

The advantages of PET are high sensitivity and specificity for the detection of local tumor relapse, especially in comparison with conventional imaging techniques. Furthermore, there is an additional value of FDG-PET for the detection of tumor manifestations associated with a tumor marker (e.g. serum CEA) increase without suspicious findings in other diagnostic procedures. The methodological advantage of a whole-body examination further improves the detectability of distant metastases. Thus, FDG-PET may induce a change in the therapeutic concept in recurrent colorectal cancer in approximately 30% of cases, concerning the indication for surgery as well as the use of multimodal surgical concepts. By means of the metabolic functional approach FDG-PET offers the possibility of therapy monitoring. This enables very early and more specific indication of response to preoperative therapies or of the presence of residual disease after surgical tumor resection or interventional tumor ablation of metastases or recurrences. PET using new tracer molecules demonstrates an additional advantage of the technique regarding the determination of the micromilieu of a tumor (vascularity, proliferation) compared with all other non-invasive diagnostic methods. This opens up new possibilities to optimize surgical therapy planning and prognostic evaluation.

Regression of high-grade gastric B-cell lymphoma after eradication of Helicobacter pylori

Regression of high-grade gastric B-cell lymphoma after eradication of Helicobacter pylori with antibiotic therapy has recently been shown in a very small number of patients. We describe here a patient with a 5-cm polypoid gastric lymphoma, who received a 7-day course of triple therapy when the histopathology was unknown. A second endoscopic examination 4 weeks later showed partial tumor regression without biopsy evidence of malignancy. Endoscopic mucosectomy was performed 8 weeks after the initial diagnosis. Again, in the histological analysis of the specimen, no evidence of B-cell lymphoma could be found. To confirm that the original biopsies were from the same patient, DNA analyses were carried out which gave identical results. This case suggests that a subgroup of primary gastric B-cell lymphomas responds to eradication of H. pylori with antibiotic therapy.

[Value of laparoscopic ultrasound for staging of gastrointestinal tumors]

BACKGROUND

The objective of this study was to evaluate the impact of laparoscopic ultrasound on the staging of gastrointestinal tumors prospectively.

METHODS

Between 1993 and 2000 staging laparoscopy was performed on 668 patients with various neoplasms. Laparoscopy provided adequate information regarding resectability in 366 patients. Laparoscopic ultrasonography was performed in 302 patients (45%) using an intraoperative ultrasound unit (B & K) and a semiflexible ultrasound probe (5-7.5 MHz). The results of staging laparoscopy were compared to the preoperative staging and histopathology.

RESULTS

Compared to preoperative staging laparoscopic ultrasound provided additional information of therapeutic relevance in 46 of 302 cases (15%). In a group of 384 patients with tumors of the upper gastrointestinal tract, laparoscopic ultrasound was performed in 186 cases and showed occult liver metastases, M1-lymph nodes, or nonresectable disease in 26 patients. Overall, this technique improved the staging of esophageal, gastric and pancreatic cancer in 12%, 3%, and 12% of the patients, respectively. Laparoscopic ultrasound proved to be most useful in esophageal and pancreatic cancer with a rate of 52% and 20% information additional to laparoscopy. The relative contribution of laparoscopic ultrasound to the staging of gastric cancer was only 10%.

CONCLUSION

Laparoscopic ultrasound improves the diagnostic accuracy of staging laparoscopy. However, routine use of this technique is only justified, if neoadjuvant therapy--particularly in controlled trials--is considered in patients with advanced gastrointestinal cancer.

A rapid bioinformatic method identifies novel genes with direct clinical relevance to colon cancer

Identifying genes whose differential expression affect the survival of patients after primary tumor surgery is a major aim of clinical cancer research. To address this issue we combined rapid bioinformatic search algorithms with quantitative RT-PCR in a panel of clearly defined cases of colorectal carcinomas with detailed patient histories. Search algorithms were written that identified Expressed Sequence Tags (ESTs) from the Unigene EST collection of putative open reading frames (ORFs). Expression ratios of healthy to cancerous tissue of each Unigene ORF were calculated. The first 35 candidates arising from bioinformatic searches were examined for mRNA expression in a panel of 20 well documented cases of colon cancer. Four of these 35 genes showed significant correlations with histopathological parameters. Therefore, their expression was further analysed by quantitative RT-PCR in a larger patient cohort. Kaplan-Meier/log rank statistical tests of up to 49 patients in three of the four genes demonstrated significant association of gene expression with poor survival. All four genes demonstrated a strong association with metastatic tumor progression. Expression of the genes was localized to epithelial cells by in-situ hybridization.

Histopathological correlation to MRI findings during and after laser-induced thermotherapy in a pig pancreas model

RATIONALE AND OBJECTIVES

To investigate whether percutaneous laser-induced thermotherapy (LITT) with continuous magnetic resonance (MR) monitoring of thermal effects within the pancreas is feasible in a porcine model.

METHODS

Laser applicators were placed in the pancreas of 15 female pigs. A temperature-sensitive (thermo--fast low-angle shot) sequence was used for continuous monitoring of thermal effects during LITT at 1.5 T. Follow-up MR images were acquired, the pigs were observed for 7 days, and then a pathological examination was performed after sacrifice.

RESULTS

Continuous MR monitoring visualized thermal effects in pancreatic tissue and thermal damage of the spleen (n = 1), the left kidney (n = 1), and peripancreatic fat (n = 4) but missed the thermal damage of the duodenum (n = 2). Thermal-induced lesions (10--32-mm diameter) were clearly visualized on contrast-enhanced T1-weighted images.

CONCLUSIONS

Laser-induced thermotherapy of pancreatic tissue was feasible in this porcine model, and online monitoring was practicable. Further studies are necessary to increase the accuracy of online MR imaging of thermal effects.

Detailed deletion mapping in sporadic breast cancer at chromosomal region 17p13 distal to the TP53 gene: association with clinicopathological parameters

Chromosome 17p is among the most frequently deleted regions in a variety of human malignancies including breast cancer. This study has further refined the localization of a putative tumour suppressor gene (TSG) at 17p13 distal to the TP53 gene in breast carcinomas. It was found that 73% (37 of 51) of the breast tumours exhibited loss of heterozygosity (LOH) at one or more loci at 17p13. The allelic loss patterns of these tumours suggest the presence of at least seven commonly deleted regions on 17p13. The three most frequently deleted regions were mapped at chromosomal location 17p13.3-17p13.2 between the markers D17S831 and D17S1845 (56% LOH), at 17p13.1 between D17S1810 and D17S1832 (53% LOH), and at 17p13.1 between D17S938 and TP53 (55% LOH). A significant correlation was found between loss at 17p13 and tumour grade, size, proliferative activity, and oestrogen receptor (ER) status. Losses at 17p13 were seen more frequently in large and poorly differentiated tumours with high proliferative activity. These data support and extend previous reports on the presence of a putative TSG(s) at chromosomal region 17p13 distal to the TP53 gene and show that different subsets of LOH are associated with more aggressive tumour behaviour.

Overexpression of sialyltransferase CMP-sialic acid:Galbeta1,3GalNAc-R alpha6-Sialyltransferase is related to poor patient survival in human colorectal carcinomas

Thomsen-Friedenreich (TF)-related blood group antigens, such as TF, Tn, and their sialylated variants, belong to a family of tumor-associated carbohydrates. The aim of the present study was to examine tumor-associated alterations of glycosyltransferases involved in the biosynthesis of the TF glycotope in colorectal carcinomas. To this end, glycosyltransferase expression was examined in 40 cases of colorectal carcinoma specimens classified according to the WHO/Union International Contre Cancer guidelines and in "normal" mucosa of the same patients. Occurrence of TF glycotope was examined by immunohistochemistry with the monoclonal antibody A78-G/A7. Expression of sialyltransferases CMP-sialic acid:Galbeta1,3GalNAc-R alpha3-sialyltransferase I and II (ST3Gal-I and ST3Gal-II) and CMP-sialic acid:Galbeta1,3GalNAc-R alpha6-sialyltransferase (ST6GalNAc-II) and of core 2 beta1,6-N-acetylglucosaminyltransferase was determined by reverse transcription-PCR in the same cryostat sections used for immunohistochemistry. Additionally, alpha2,3-sialyltransferase enzyme activity was studied in each of these tissues. The TF glycotope was detected in 7% of the normal mucosa, but in 57% of the carcinoma samples. Expression of alpha2,3-sialyltransferases ST3Gal-I, ST3Gal-II, and enzyme activity of alpha2,3-sialyltransferase was significantly increased (P < 0.001) in carcinoma specimens compared with normal mucosa. ST3Gal-I mRNA expression was significantly increased (P = 0.05) in cases showing invasion of lymph vessels. Expression of ST6GalNAc-II was significantly increased (P = 0.04) in cases with metastases to lymph nodes along the vascular trunk. Moreover, ST6GalNAc-II expression provides an prognostic factor for patient survival (log rank, P = 0.02). In an attempt to study the functional relevance of the glycosyltransferases for TF biosynthesis, SW480 colorectal cells were transfected with each of the enzymes, and cell surface expression of the TF glycotope was examined by flow cytometry. The presence of TF was not altered by transfection of the cells with either sialyltransferase ST3Gal-I or ST3Gal-II. However, successful transfection with core 2 beta1,6-N-acetylglucosaminyltransferase led to reduced expression of TF. In contrast, increased cell surface expression of TF was found after ST6GalNAc-II transfection. Thus, expression of TF on the cell surface of SW480 colorectal carcinoma cells depends on the ratio of core 2 beta1,6-N-acetylglucosaminyltransferase and ST6GalNAc-II. Earlier immunohistological studies demonstrated that TF is a prognostic factor for patient survival. Our results suggest that sialyltransferase ST6GalNAc-II is of crucial relevance for the prognostic significance of TF.

Hyperthermia-induced nuclear translocation of transcription factor YB-1 leads to enhanced expression of multidrug resistance-related ABC transporters

Genotoxic stress leads to nuclear translocation of the Y-box transcription factor YB-1 and enhanced expression of the multidrug resistance gene MDR1. Because hyperthermia is used for the treatment of colon cancer in combination with chemoradiotherapy, we investigated the influence of hyperthermia on YB-1 activity and the expression of multidrug resistance-related genes. Here we report that hyperthermia causes YB-1 translocation from the cytoplasm into the nucleus of human colon carcinoma cells HCT15 and HCT116. Nuclear translocation of YB-1 was associated with increased MDR1 and MRP1 gene activity, which is reflected in strong efflux pump activity. However, a combination of hyperthermia and drug treatment effectively reduced cell survival of the HCT15 and HCT116 cells. These results demonstrate that activation of MDR1 and MRP1 gene expression and increased efflux pump activity after hyperthermia were insufficient to cause an increase in drug resistance in colon cancer cell lines. The ability of hyperthermia to abrogate drug resistance in the presence of an increase in functional MDR proteins may provide an explanation for the efficacious results seen in the clinic in colon cancer patients treated with a combination of hyperthermia and chemotherapy.

Prognostic significance of activated CD8(+) T cell infiltrations within esophageal carcinomas

The purpose of this study was to explore whether there is a linkage between the infiltration of CD8(+) T cells and the risk of death from esophageal cancer. Cases of 70 consecutive patients in whom esophageal squamous cell carcinomas ( n = 33) or adenocarcinomas (n = 37) were R0-resected between 1993 and 1999 were reviewed. The presence of activated CD8(+) T cells was evaluated by quantitative real-time PCR and immunohistochemistry and compared to clinical and pathological stages. The primary end point analyzed was overall survival, and a multivariate analysis was performed to distinguish any factors conferring an improved survivorship. Intratumoral (i.t.) CD8(+) T cells accumulating within the epithelial complexes were detected in 11 of all (16%) cases: in 9 of 25 (36%) patients with Union Internationale Contrele Cancer stage I or II versus 2 of 45 (4%) patients with Union Internationale Contrele Cancer stage III or IV (P = 0.001). Intratumoral CD8(+) T cell infiltrations showed proliferative activity and also IFN-gamma secretion. The presence of i.t. CD8(+) T cell infiltration more than peritumoral infiltration was associated with a good prognosis in both squamous cell and adenocarcinomas. Multivariate analysis showed that i.t. CD8(+) T cell infiltration was an independent prognostic factor (hazard ratio, 0.5; P = 0.0004) indicating favorable outcome. In conclusion, the presence of CD8(+) T cell infiltration in esophageal carcinomas is a favorable prognostic factor that should have diagnostic and therapeutic implications.

Perceptual phenomena after unilateral arm amputation: a pre-post-surgical comparison

Painful and non-painful phantom phenomena occur frequently after amputations but are rarely investigated in the perioperative stage. The goal of the present study was the assessment of phantom phenomena, pain and changes in primary somatosensory cortex prior to and after upper limb amputation. Two patients who suffered from metastatic carcinoma were examined 2 days prior to and 7 days after the amputation of an arm using comprehensive psychometric assessments and neuroelectric source imaging. Both patients reported phantom limb pain that was similar to their pre-amputation pain. In one patient, reorganization of the mouth area into the deafferented hand area took place immediately after the amputation. In the other patient reorganization had occurred prior to the amputation possibly related to non-use of the arm several years prior to the amputation.

[beta-Catenine as a genomic target of high-grade microsatellite instability in colorectal cancer]

AIMS

Various inherited and acquired alterations affecting the genes and gene products of the WNT pathway appear to be involved in the different molecular routes leading to colorectal cancer (CRC). This study was initiated to investigate the prevalence of somatic mutations in the beta-catenin gene (CTNNB1) and the associated pathology in CRC with defective DNA mismatch repair.

METHODS

Paraffin and/or frozen sections of 33 primary CRC (including any liver and lymph node metastases present) with high-grade microsatellite instability (MSI-H; i.e. with > or = 5 unstable microsatellite markers of 10 tested) were polytopically fractionated by microdissection. Genomic and c-DNA samples were sequenced across exons 2-4 of CTNNB1 and the expression patterns of beta-catenin (beta-C) analyzed by immunohistology and Western blotting.

RESULTS

Seven somatic mutations affecting phosphorylation sites of exon 3 (2 deletions also encompassing parts of either intron 2 or exon 4 [delta X2/3 bzw. delta X3/4] and 5 missense mutations [2 x T41A, 2 x S45F, S45P]) were identified. Two mutations (delta X3/4 and S45F) were concordantly present in CRC primaries and their respective metastases whereas the S45P mutation was restricted to a hepatic metastasis. In the delta X2/3 CRC primary only a shortened 66 kD CTNNB1 gene product was present while its associated liver metastasis showed a total loss of beta-C expression.

CONCLUSIONS

Both exon 3 and the entire locus coding for beta-C are somatically altered in approximately 20% of CRC with MSI-H at different stages of tumor progression. Thus CTNNB1 appears to be a genomic target for complex oncogenic mutations and deletional processes in a substantial fraction of this molecular subset of CRC.

[Radiochemotherapy plus hyperthermia in rectal carcinoma]

In locally advanced rectal cancer (uT3/uT4) resectability as well as local control is reduced. In the patients combined preoperative radiochemotherapy demonstrated an increase of resectability and a reduction of local recurrence. Radiotherapy was applied in standard blocks, 5 x 1.8 Gy up to 45 Gy. Chemotherapy consisted out of two cycles of 5-Fluorouracil (300-350 mg/m2/d) and Leucovorin (50 mg). Prior to radiotherapy additionally thermotherapy was carried out using the SIGMA 60 applicator BSD 2000 once a week. The hyperthermia method is based on heating up affected tissue compartments to temperature above 42 degrees Celsius without damaging surrounding tissue compartments. In regional hyperthermia tumors in the abdominal region are treated by emitting radio waves into the patient. 4-6 weeks after radiochemotherapy, surgery was performed. The therapeutic toxicity was acceptable and the resectability rate was up to 90%. Response rate to treatment was 60%. Our data with preoperative combined treatment in locally advanced rectal cancer revealed encouraging downstaging, local control, and survival rates.

Three-dimensional ultrasonography of bone and soft tissue lesions

BACKGROUND

The aim of this study was to investigate feasibility and potential applications of three-dimensional (3D) ultrasonography in the evaluation of musculoskeletal disorders.

METHODS

3D ultrasonography was performed in 83 patients with bone (n = 50) or soft tissue lesions (n = 33). Volume data were obtained using two volume probes (1-8.5 and 8.5-12 MHz) and a 3D ultrasound unit. The results of 3D ultrasonography were compared to two-dimensional ultrasound and radiological imaging.

RESULTS

The system enabled acquisition of 3D ultrasound data in diagnostic quality. 3D image-processing permits to analyse ultrasound data interactively in three orthogonal planes (section mode) or in realistic 3D views (rendering mode). Compared to conventional ultrasonography 3D image analysis improved assessment of details, provided better spatial orientation and facilitated image interpretation in 23, 44 and 49 cases, respectively. Additional findings that had significant influence on patient management were obtained in 16 of 83 patients (19%). Multiplanar reformating provided additional scan planes and increased the comparability of follow up examinations by standardized display and measurement. 3D surface reconstructions were very helpful to understand the morphology of bone lesions e.g. tortuous fracture lines.

CONCLUSION

Our preliminary experience shows that 3D ultrasonography of musculoskeletal disorders is feasible. The ability to assess previously unattainable scan planes and lifelike surface projections may be particularly valuable for imaging of bone lesions. Further studies will be required to assess the exact role of this new technique for the evaluation of musculoskeletal disorders.

Near-infrared fluorescent dyes for enhanced contrast in optical mammography: phantom experiments

Optical mammography with near-infrared (NIR) light using time-domain, frequency-domain, or continuous-wave techniques is a novel imaging modality to locate human breast tumors. By investigating excised specimens of normal and diseased mamma tissue we were able to demonstrate that differences in their scattering properties are a poor predictive parameter for normal and diseased mamma tissue. This paper describes the application of a NIR dye to improve the differentiation between breast tumors and normal tissue in a rat model. The NIR dye furnished a high tumor-to-tissue contrast ratio (6:1) in fluorescence images. Furthermore, this dye was used to develop liquid scattering phantoms with absorbing and fluorescent inhomogeneities. Using frequency-domain and time-domain instrumentation these inhomogeneities were localized at sufficient contrast by their increased absorption and fluorescence. Contrast between inhomogeneities and surrounding medium could be improved by combining fluorescence and transmittance images.