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Dive into the research topics where Samuel Rotstein is active.

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Featured researches published by Samuel Rotstein.


Gut | 2003

Prevalence and incidence of hyperplastic polyps and adenomas in familial colorectal cancer: correlation between the two types of colon polyps

Annelie Liljegren; Annika Lindblom; Samuel Rotstein; Bo Nilsson; Carlos A. Rubio; E Jaramillo

Background and aims: Colorectal adenomas are recognised as precursors of colorectal carcinomas. The significance of hyperplastic (metaplastic) colorectal polyps is unknown. The relationship between hyperplastic polyps and adenomas, and the prevalence and incidence of these lesions were evaluated in individuals predisposed to familial colorectal cancer. Methods: A total of 299 individuals participating in our surveillance programme during 1990–2000 were retrospectively evaluated. Subjects were classified into three groups: hereditary non-polyposis syndrome (HNPCC) (n=108), hereditary colorectal cancer (HCRC) (n=127), and individuals with empirical risk estimates—two close relatives (TCR) (n=64). Findings from 780 colonoscopies were evaluated regarding prevalence and incidence of hyperplastic polyps and adenomas. Correlations between hyperplastic polyps and adenomas were calculated by Pearson correlation. Results: In total, 292 hyperplastic polyps and 186 adenomas were observed in 98 and 90 individuals, respectively. A positive correlation was found between the numbers of hyperplastic polyps and adenomas (r=0.40; p<0.001). Correlations between adenomas and hyperplastic polyps were similar in the three groups. The risk of detecting new hyperplastic polyps (odds ratio 5.41) or adenomas (OR 2.56) increased significantly when there was a positive finding at first colonoscopy. Conclusion: Hyperplastic polyps as well as adenomas may identify individuals with a high risk of colorectal cancer. This information is important when these individuals are selected and included in tailored surveillance programmes.


International Journal of Radiation Oncology Biology Physics | 1990

Influence of radiation therapy on the lung-tissue in breast cancer patients: CT-assessed density changes and associated symptoms

Samuel Rotstein; Ingmar Lax; Gunilla Svane

The relative electron density of lung tissue was measured from computer tomography (CT) slices in 33 breast cancer patients treated by various techniques of adjuvant radiotherapy. The measurements were made before radiotherapy, 3 months and 9 months after completion of radiation therapy. The changes in lung densities at 3 months and 9 months were compared to radiation induced radiological (CT) findings. In addition, subjective symptoms such as cough and dyspnoea were assessed before and after radiotherapy. It was observed that the mean of the relative electron density of lung tissue varied from 0.25 when the whole lung was considered to 0.17 when only the anterior lateral quarter of the lung was taken into account. In patients with positive radiological (CT) findings the mean lung density of the anterior lateral quarter increased 2.1 times 3 months after radiotherapy and was still increased 1.6 times 6 months later. For those patients without findings, in the CT pictures the corresponding values were 1.2 and 1.1, respectively. The standard deviation of the pixel values within the anterior lateral quarter of the lung increased 3.8 times and 3.2 times at 3 months and 9 months, respectively, in the former group, as opposed to 1.2 and 1.1 in the latter group. Thirteen patients had an increase in either cough or dyspnoea as observed 3 months after completion of radiotherapy. In eleven patients these symptoms persisted 6 months later. No significant correlation was found between radiological findings and subjective symptoms. However, when three different treatment techniques were compared among 29 patients the highest rate of radiological findings was observed in patients in which the largest lung volumes received the target dose. A tendency towards an increased rate of subjective symptoms was also found in this group.


Biomedical Engineering Online | 2005

Influence of electrical and thermal properties on RF ablation of breast cancer: is the tumour preferentially heated?

Vilhelm Ekstrand; Hans Wiksell; Inkeri Schultz; Bengt Sandstedt; Samuel Rotstein; Anders Eriksson

BackgroundTechniques based on radio frequency (RF) energy have many applications in medicine, in particular tumour ablation. Today, mammography screening detects many breast cancers at an early stage, facilitating treatment by minimally invasive techniques such as radio frequency ablation (RFA). The breast cancer is mostly surrounded by fat, which during RFA-treatment could result in preferential heating of the tumour due to the substantial differences in electrical parameters. The object of this study was to investigate if this preferential heating existed during experimental in vitro protocols and during computer simulations.MethodsExcised breast material from four patients with morphologically diagnosed breast cancers were treated with our newly developed RFA equipment. Subsequently, two finite element method (FEM) models were developed; one with only fat and one with fat and an incorporated breast cancer of varying size. The FEM models were solved using temperature dependent electrical conductivity versus constant conductivity, and transient versus steady-state analyses.ResultsOur experimental study performed on excised breast tissue showed a preferential heating of the tumour, even if associated with long tumour strands. The fat between these tumour strands was surprisingly unaffected. Furthermore, the computer simulations demonstrated that the difference in electrical and thermal parameters between fat and tumour tissue can cause preferential heating of the tumour. The specific absorption rate (SAR) distribution changed significantly when a tumour was present in fatty tissue. The degree of preferential heating depended on tissue properties, tumour shape, and placement relative to the electrode. Temperature dependent electrical conductivity increased the thermal lesion volume, but did not change the preferential heating. Transient solutions decreased the thermal lesion volume but increased the preferential heating of the tumour.ConclusionBoth the computer model and the in vitro study confirmed that preferential heating of the tumour during RFA exists in breast tissue. However, the observed preferential heating in the in vitro studies were more pronounced, indicating that additional effects other than the difference in tissue parameters might be involved. The existing septa layers between the cancer tissue and the fatty tissue could have an additional electrical or thermal insulating effect, explaining the discrepancy between the in vitro study and the computer model.


Breast Cancer Research | 2009

Human antimicrobial protein hCAP18/LL-37 promotes a metastatic phenotype in breast cancer

Günther Weber; Clara Ibel Chamorro; Fredrik Granath; Annelie Liljegren; Sami Zreika; Zuzana Saidak; Bengt Sandstedt; Samuel Rotstein; Romuald Mentaverri; Fabio Sánchez; Andor Pivarcsi; Mona Ståhle

IntroductionHuman cathelicidin antimicrobial protein, hCAP18, and its C-terminal peptide LL-37 is a multifunctional protein. In addition to being important in antimicrobial defense, it induces chemotaxis, stimulates angiogenesis and promotes tissue repair. We previously showed that human breast cancer cells express high amounts of hCAP18, and hypothesised that hCAP18/LL-37 may be involved in tumour progression.MethodshCAP18 mRNA was quantified in 109 primary breast cancers and compared with clinical findings and ERBB2 mRNA expression. Effects of exogenous LL-37 and transgenic overexpression of hCAP18 on ErbB2 signalling were investigated by immunoblotting using extracts from breast cancer cell lines ZR75-1 and derivatives of MCF7. We further analysed the impact of hCAP18/LL-37 on the morphology of breast cancer cells grown in soft agar, on cell migration and on tumour development in severe combined immunodeficiency (SCID) mice.ResultsThe expression of hCAP18 correlated closely with that of ERBB2 and with the presence of lymph node metastases in oestrogen receptor-positive tumours. hCAP18/LL-37 amplified Heregulin-induced mitogen-activated protein kinase (MAPK) signalling through ErbB2, identifying a functional association between hCAP18/LL-37 and ErbB2 in breast cancer. Treatment with LL-37 peptide significantly stimulated the migration of breast cancer cells and their colonies acquired a dispersed morphology indicative of increased metastatic potential. A truncated version of LL-37 competitively inhibited LL-37 induced MAPK phosphorylation and significantly reduced the number of altered cancer cell colonies induced by LL-37 as well as suppressed their migration. Transgenic overexpression of hCAP18 in a low malignant breast cancer cell line promoted the development of metastases in SCID mice, and analysis of hCAP18 transgenic tumours showed enhanced activation of MAPK signalling.ConclusionsOur results provide evidence that hCAP18/LL-37 contributes to breast cancer metastasis.


Journal of Clinical Oncology | 2004

Individuals with an increased risk of colorectal cancer: perceived benefits and psychological aspects of surveillance by means of regular colonoscopies.

Annelie Liljegren; G. Lindgren; Yvonne Brandberg; Samuel Rotstein; Bo Nilsson; T. Hatschek; E. Jaramillo; Annika Lindblom

PURPOSE To evaluate the psychological consequences of genetic counseling followed by a surveillance program using colonoscopy among individuals with increased risk of colorectal cancer. PATIENTS AND METHODS Two hundred sixty-five individuals, participating in a surveillance program with colonoscopy, were mailed a survey questionnaire that assessed their experience of the surveillance program and their perception of the risk of colorectal cancer. The Hospital Anxiety and Depression scale and the Swedish Short Form-36 Health Survey was also included. RESULTS Two hundred forty individuals completed the questionnaire and were divided into the following risk groups: risk group 1, an individual with a mutation in hMLH1 or hMSH2 and a lifetime colorectal cancer risk of 80% (n = 28); risk group 2, a lifetime colorectal cancer risk of 40% (n = 129); and risk group 3, a lifetime colorectal cancer risk of 20% (n = 83). Among all individuals, the mean for perceived benefit was 8.0, and the perception of discomfort was 3.3 on the visual analog scale (1-10). In risk group 1, 61% underestimated personal risks as being 40% or less. Approximately 50% of the subjects in risk groups 2 and 3 either under- or overestimated their lifetime risk. According to the Swedish Short Form-36 Health Survey and the Hospital Anxiety and Depression scale, the study sample resembled the reference population. CONCLUSION A majority of the study sample understood why they were under surveillance, and regular colonoscopies were well-tolerated. The wide range of risk perception as well as low-risk perception in mutation positive subjects is acceptable, as long as these individuals adhere to surveillance programs and do not demonstrate increased levels of anxiety or depression.


The Breast | 2010

Feasibility study on the treatment of small breast carcinoma using percutaneous US-guided preferential radiofrequency ablation (PRFA)

Hans Wiksell; Lars Löfgren; Kai-Uwe Schässburger; Helene Grundström; Marina Janicijevic; Ulla Lagerstedt; Karin Leifland; Rolf Nybom; Samuel Rotstein; Ariel Saracco; Inkeri Schultz; Karin Thorneman; Carl Wadström; Lars Westman; Hans Wigzell; Brigitte Wilczek; Gert Auer; Bengt Sandstedt

The purpose of this study was to determine the safety and efficacy of percutaneous ultrasound (US) guided preferential radiofrequency ablation (PRFA) of unifocal human invasive breast carcinoma with largest radiological diameters of up to 16 mm. Thirty-three patients were enrolled in a study to be treated prior to scheduled partial mastectomy. A needle-shaped treatment electrode, successively developed in two different sizes, was placed into the center of the lesions using ultrasound guidance. A temperature of 85 degrees C was maintained for 10 min. The analysis of the resected specimen was performed using conventional histopathological methods with the aim to determine the size of the lesion as well as the potential viability of tumor cells. Of the 33 patients enrolled 31 were treated. In 26 (84%) patients a complete ablation of the tumor was achieved. Ultrasound guided preferential radiofrequency ablation of small breast carcinoma is feasible and patient friendly. The success rate depends on accurate preoperative diagnostic imaging as well as an exact position of the needle electrode.


Breast Cancer Research and Treatment | 1988

Influence of adjuvant tamoxifen on blood lymphocytes

Samuel Rotstein; Henric Blomgren; Björn Petrini; Jerzy Wasserman; Lars-Victor von Stedingk

SummaryThe blood lymphocyte population was studied in 23 breast cancer patients treated with adjuvant tamoxifen for 1.5–2 years, and in an equal number of control patients. The size and cellular composition of the blood lymphocyte population, as assessed by monoclonal antibodies directed against various subsets, did not differ between the two patient groups. However, lymphocytes from the tamoxifen-treated patients exhibited a significantly lower NK activity against K562 cells. In contrast, the proliferative response of lymphocytes to ConA was significantly higher. These results indicate that tamoxifen may modulate the immune system.


British Journal of Cancer | 2010

Prevention of tumour cell dissemination in diagnostic needle procedures

Hans Wiksell; Kai-Uwe Schässburger; Janicijevic M; Karin Leifland; Lars Löfgren; Samuel Rotstein; Sandberg Po; Wadström C; Gert Auer

Background:A side effect of diagnostic needle biopsies is the possibility to disseminate tumour cells into the needle track, which may cause concern in certain malignant tumour types.Methods:In order to prevent tumour cell dissemination we developed a technology that uses radiofrequency (RF) pulses to sterilise the needle track and denaturate tumour cells. To determine feasibility, we applied this technology to fine needle aspiration biopsy (FNAB) and used breast cancer as a model tumour. Routine FNAB was performed in 88 patients with adenocarcinoma and blood droplets passing the skin orifice were cytomorphologically analysed for the presence of tumour cells.Results:The analysis showed the presence of tumour cells in 65/88 cases (74%). When using an experimental anti-seeding device in a subset of patients viable tumour cells were found in 0/31 cases (P<0.001). In all 31 patients blood passing the skin orifice was sparse. No degrading effect on the cytological sample inside the needle was detected and pain caused by the RF pulses was comparable to that of the biopsy procedure itself.Conclusion:The herein presented method has the potential to prevent the dissemination of viable tumour cells in the needle track and minimize bleeding without additional pain or degradation of the aspirate.


Acta Oncologica | 1996

Social Support and Immune Status During and after Chemotherapy for Breast Cancer

Mats Lekander; Carl Johan Fürst; Samuel Rotstein; Henric Blomgren; Mats Fredrikson

Social support and immune status were assessed in women treated with adjuvant chemotherapy for breast cancer. Perception of enhanced attachment was associated with an increased number of white blood cell levels three months after, but not during, chemotherapy. After treatment, patients with high attachment ratings had higher numbers and proportions of granulocytes, and lower proportions of lymphocytes and monocytes. It is concluded that the support experienced by a cancer patient can be associated with counts and proportions of leukocytes, but that this effect, if present during chemotherapy, is overridden by the biological factor that affects the haematopoetic process.


Acta Oncologica | 1995

Influence of radiation therapy on lung tissue in breast cancer patients : CT-assessed density changes 4 years after completion of radiotherapy

Gunilla Svane; Samuel Rotstein; Ingmar Lax

CT-assessed density changes in lung tissues were measured in 22 disease-free breast cancer patients 4 years after completion of radiation therapy. All patients had previously undergone similar CT-examinations before treatment, 3 months, and 9 months after radiotherapy. In patients with visible areas of increased lung density at earlier CT-examinations a decrease of focal findings was observed at 4 years. In patients without focal findings, an increase in density relative to that before therapy was observed. The difference between the mean lung density values among those with visible radiological findings and those without was statistically significant both at 3 and 9 months after therapy. However, this difference did not persist at 4 years. These results may indicate a 2-phase development of radiation-induced lung damages--an acute phase and a late phase; the late phase emerging slowly, and in this study detectable 4 years after completion of radiation therapy.

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Henric Blomgren

Karolinska University Hospital

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Annelie Liljegren

Karolinska University Hospital

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Björn Petrini

Stockholm County Council

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Evi Gustavson-Kadaka

Karolinska University Hospital

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