Rafal Suwinski
UCLA Medical Center
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Rafal Suwinski.
Radiotherapy and Oncology | 1996
B. Maciejewski; K. Składowski; B. Pilecki; Jeremy M. G. Taylor; Rodney Withers; Leszek Miszczyk; Aleksander Zajusz; Rafal Suwinski
PURPOSE Toxicity of an accelerated 7 days per week fractionation schedule (arm A) was evaluated and compared with a conventional 5 days per week treatment (arm B) in a randomized trial. MATERIALS AND METHODS Forty-four patients with squamous cell carcinoma of the head and neck in stage T2-4Nzero-1Mzero were included in the study. Total dose and dose per fraction of 2.0 Gy given once-a-day at 24 h intervals were the same in both arms of the trial. The only difference was the overall treatment time being 5 weeks in arm A and 7 weeks in arm B. RESULTS Analysis of severe mucosal reactions shows significant difference between arm A and B, with regard to both maximum score and duration of severe mucositis. Confluent mucositis (score > 15 according to the Dische system) lasting longer than 3 weeks developed in 48% of patients in arm A and only in 5% in arm B. In group A seven (30%) late effects (osteo- and soft tissue necrosis) occurred during 7-12 month follow-up with two reactions (10%) in group B being suspected as late effects. There was significant association between acute reactions and late effects in arm A, suggesting that the late effects are consequential. CONCLUSION The high incidence of severe acute reactions and consequential late effects suggests that the accelerated treatment in arm A (using daily fractions of 2.0 Gy, 7 days per week) gives unacceptable toxicity.
International Journal of Radiation Oncology Biology Physics | 2002
Rafal Tarnawski; Jack F. Fowler; K. Składowski; Andrzej Świerniak; Rafal Suwinski; B. Maciejewski; A. Wygoda
PURPOSE/OBJECTIVE Our goal was to analyze the repopulation of surviving tumor cells during a treatment gap in radiotherapy for head-and-neck cancer. METHODS AND MATERIALS Clinical material is based on the records of 1502 patients treated by radiotherapy alone in Maria Sklodowska-Curie Memorial Institute in Gliwice during the period between1980 and 1989. All patients had histologically confirmed squamous cell carcinoma of the larynx or pharynx. The mean gap duration was 9 days. Only 10% of patients were treated without gaps. The dose per fraction was in the range of 1.5 to 2.5 Gy. Patient data were fitted directly to the mixed linear-quadratic model using maximum-likelihood estimation. Tumor stage or tumor localization was introduced into the equation as a categorical variable. Tumor proliferation was estimated by dividing the treatment gaps into three groups: the first 2 weeks, second 2 weeks, and the period after 4 weeks of irradiation. RESULTS Tumor control probability was significantly correlated with radiation dose, tumor progression (according to TNM), overall treatment time, and gap duration. Laryngeal cancers had a better prognosis than cancers of the oro- and nasopharynx. Significant tumor repopulation was found after the first 2 weeks of radiotherapy. During the treatment gap, the proliferation rate was equal to 0.75 Gy/day. During the days with irradiation, repopulation was slower and equal to 0.2 Gy/day. CONCLUSION The repopulation of tumor cells is faster during a gap than during the normal days of irradiation. Accelerated repopulation probably starts soon after 2 weeks of irradiation.
International Journal of Radiation Oncology Biology Physics | 1998
Rafal Suwinski; Jeremy M. G. Taylor; H. Rodney Withers
PURPOSE To quantify the dose-time fractionation factors in preoperative radiation therapy for microscopic pelvic deposits of rectal cancer. This provides a biologic basis for understanding and improving the results of adjuvant therapies for this disease. METHODS The reduction in incidence of pelvic relapses as a function of radiation dose and overall treatment time was determined from the literature. The displacement of dose-response curves to higher doses reflects the growth during radiation treatment of subclinical pelvic deposits which are beyond the future surgical margins. RESULTS Dose-response curves are steep if the effect of overall duration of radiation therapy is accounted for. The time-related displacement of these steep dose-response curves is consistent with a median doubling time for malignant clonogenic cells of about 4 or 5 days, much faster than the growth rate of the average primary tumor at diagnosis. This rapid growth is evident within the first few days of irradiation, implying that the natural growth rate of these microscopic deposits if fast, and/or that an acceleration of growth follows initiation of radiation injury with a very short lag time. CONCLUSION Subclinical pelvic deposits of rectal cancer grow rapidly during preoperative radiation therapy with an adverse influence on the rate of pelvic tumor control from protracting the duration of adjuvant treatment. Low doses only offer clinically relevant reduction in risk of pelvic relapses if the overall radiation treatment time is short. For a given overall treatment duration there is a relatively steep dose-response curve, predicting that significant improvements in tumor control are possible.
Seminars in Radiation Oncology | 1998
H. Rodney Withers; Rafal Suwinski
The development of adjuvant therapies for subclinical metastases has been empiric. Decades of experience showed that 45 to 50 Gy resulted in high control rates for subclinical lymph node involvement.1 By analogy with the response of macroscopic tumors, in which doses below a threshold yield no benefit, it was commonly believed that doses lower than 40 to 50 Gy would not be useful in elective treatment of subclinical disease. Biological phenomena, such as presumed metastatic tumor cell burden and growth rate of micrometastases, which could guide the oncologist, had little or no role in the empirical development of adjuvant cytotoxic therapies. In this article, some assumptions regarding the biology of subclinical metastases are discussed and examined in the light of treatment responses reported from clinical experience. In particular, the importance of early initiation of adjuvant therapy can be appreciated as well as the significant reductions in the incidence of metastases that can be achieved even when doses less than 45 to 50 Gy have to be accepted if necessitated by normal tissue tolerance.
Radiotherapy and Oncology | 2007
Rafal Suwinski; Magdalena Bańkowska-Woźniak; Wojciech Majewski; Adam Idasiak; Adam Maciejewski; Ewa Ziółkowska; Wiesława Windorbska; K. Składowski; Leszek Miszczyk; B. Maciejewski
PURPOSE To evaluate the normal tissue reactions and loco-regional control rates (LRC) in patients treated with 7-days-a-week postoperative continuous irradiation (p-CAIR) compared to conventionally fractionated 5-days-a-week postoperative radiotherapy (CF). MATERIALS/METHODS Between 2001 and 2004, 279 patients with high-risk squamous cell cancer of the larynx (158 pts.) or cancer of the oral cavity/oropharynx (121 pts.) were enrolled. They were stratified according to the primary cancer site (larynx vs. others) and the treating center and randomized to receive 63 Gy in fractions of 1.8 Gy given 5-days-a-week (140 pts: CF) or 7-days-a-week (139 pts: p-CAIR). RESULTS The acute and late toxicity was considered acceptable, although the proportion of patients with confluent mucositis was higher in p-CAIR compared to CF (60.0 vs. 33.3%). The actuarial 3-year LRC were 64 vs. 70% for CF and p-CAIR, respectively, p=0.32. A statistically significant improvement in 3-year LRC in p-CAIR arm appeared in a subset of the patients with cancer of the oropharynx/oral cavity (74% p-CAIR vs. 53% CF, p=0.02). By contrast, there was no improvement in LRC in a subset of the patients with cancer of the larynx (p=0.46). CONCLUSION An improvement in LRC attributable to acceleration of postoperative radiotherapy appeared restricted to the patients with cancer of the oropharynx/oral cavity. In patients with cancer of the larynx acceleration of postoperative radiotherapy did not have any beneficial effect.
International Journal of Cancer | 2012
Dorota Butkiewicz; Anna Drosik; Rafal Suwinski; Małgorzata Krześniak; Marek Rusin; Agata Kosarewicz; Jadwiga Rachtan; Iwona Matuszczyk; Marzena Gawkowska-Suwińska
Polymorphisms in DNA repair genes may modulate not only an individual DNA repair capacity, DNA damage levels and cancer risk but also clinical outcome after DNA damage‐inducing anticancer therapy. In this study, we analyzed the association between the XPA ‐4G>A, XPD Asp312Asn, hOGG1 Ser326Cys, XRCC1 Arg399Gln, XRCC2 ‐4234G>C, XRCC3 ‐4541A>G and Thr241Met polymorphisms and prognosis in 250 inoperable non‐small cell lung cancer (NSCLC) patients treated with radiotherapy and platinum‐based chemotherapy. In univariate model, the XPA‐4A and XRCC1 399Gln alleles alone and in combination influenced survival only in stage III group. In multivariate analysis, the XPA‐4 GA/AA was associated with poor survival (HR 1.55, p = 0.011 overall and HR 1.72, p = 0.008 in stage III). In chemoradiotherapy group, the XPA‐4A carriers were at increased risk of death and progression (HR 1.73, p = 0.013 and HR 1.65, p = 0.016, respectively), especially in stage III (p = 0.008). Moreover, individuals with ≥ 2 XPA/XRCC1 adverse alleles showed a higher risk of death (HR 1.46, p = 0.036 overall; HR 1.85, p = 0.004 in stage III and HR 1.71, p = 0.022 in chemoradiotherapy group) and progression (HR 1.75, p = 0.011 overall and HR 1.93, p = 0.005 in stage III). The XPA‐4 GA/AA genotype individually and together with the XRCC1 399Gln was an independent unfavorable prognostic factor in our study. Thus, our findings indicate a prognostic potential of the XPA‐4G>A in unresected NSCLC treated with radiotherapy and chemoradiotherapy. The results require validation in an independent population.
PLOS ONE | 2012
Miroslaw Snietura; Magdalena Jaworska; Joanna Młynarczyk-Liszka; Aleksandra Goraj-Zajac; Wojciech Piglowski; Dariusz Lange; Grzegorz Wozniak; Elżbieta Nowara; Rafal Suwinski
Background Tumor suppressor PTEN is known to control a variety of processes related to cell survival, proliferation, and growth. PTEN expression is considered as a prognostic factor in some human neoplasms like breast, prostate, and thyroid cancer. Methodology/Principal Findings In this study we analyzed the influence of PTEN expression on the outcome of a randomized clinical trial of conventional versus 7-days-a-week postoperative radiotherapy for squamous cell cancer of the head and neck. The patients with cancer of the oral cavity, oropharynx, and larynx were randomized to receive 63 Gy in fractions of 1.8 Gy given 5 days a week (CF) or 7 days a week (p-CAIR). Out of 279 patients enrolled in the study, 147 paraffin blocks were available for an immunohistochemical assessment of PTEN. To evaluate the prognostic value of PTEN expression and the effect of fractionation relative to PTEN, the data on the outcome of a randomized clinical trial were analyzed. Tumors with a high intensity of PTEN staining had significant gain in the loco-regional control (LRC) from p-CAIR (5-year LRC 92.7% vs. 70.8%, for p-CAIR vs. CF, p = 0.016, RR = 0.26). By contrast, tumors with low intensity of PTEN did not gain from p-CAIR (5-year LRC 56.2% vs. 47.2%, p = 0.49, RR = 0.94). The intensity of PTEN highly affected the LRC in a whole group of 147 patients (5-year LRC 80.9% vs. 52.3% for high vs. low PTEN, p = 0.0007, RR = 0.32). In multivariate Cox analysis, including neck node involvement, EGFR, nm23, Ki-67, p53, cyclin D1, tumor site and margins, PTEN remained an independent predictor of LRC (RR = 2.8 p = 0.004). Conclusions/Significance These results suggest that PTEN may serve as a potent prognostic and predictive marker in postoperative radiotherapy for high-risk squamous cell cancer of the head and neck.
International Journal of Oncology | 2011
Monika Pietrowska; Joanna Polanska; Rafal Suwinski; Maciej Wideł; T. Rutkowski; Michal Marczyk; Iwona Domińczyk; Lucyna Ponge; Łukasz Marczak; Andrzej Polanski; Piotr Widlak
Mass spectrometry-based analyses of the low-molecular-weight fraction of serum proteome allow identifying proteome profiles (signatures) that are potentially useful in detection and diagnostics of cancer. Here we compared serum proteome profiles of healthy donors and patients with three different types of cancer aiming to identify peptide signatures that were either common for all cancer samples or specific for cancer type. Blood samples were collected before start of the therapy from patients with head and neck squamous cell cancer, colorectal adenocarcinoma and non-small cell lung cancer, and from a corresponding group of healthy volunteers. Mass profiles of the serum proteome were recorded in the range between 2 and 13 kDa using MALDI-ToF spectrometry and 131 identified peptide ions were used for statistical analyses. Similar degrees of overall similarities were observed in all intra-group and inter-group analyses when general features of serum proteome profiles were compared between individual samples. However, classifiers built of selected spectral components allowed differentiation between healthy donors and three groups of cancer patients with 69-74% sensitivity and 82-84% specificity. There were two common peptide species (3766 and 5867 Da) with increased levels in all cancer samples. Several spectral components permitted differentiation between lung cancer samples and either head and neck cancer or colorectal cancer samples, but two latter types of samples could not be properly discriminated. Abundance of spectral components that putatively corresponded to fragments of serum amyloid A (11511 and 11667 Da) was highest in lung cancer samples, yet increased levels of these peptides appeared to generally associate with more advanced cancer cases. We concluded that certain components of serum peptide signatures are common for different cancer signatures and putatively reflect general response of organism to the disease, yet other components of such signatures are more specific and most likely correspond to clinical stage of the malignancy.
International Journal of Radiation Oncology Biology Physics | 2010
Rafal Suwinski; Magdalena Jaworska; Barbara Nikiel; Wozniak Grzegorz; M. Bankowska-Wozniak; Majewski Wojciech; Skladowski Krzysztof; Lange Dariusz
PURPOSE To determine the prognostic and predictive values of molecular marker expression profiles based on data from a randomized clinical trial of postoperative conventional fractionation (p-CF) therapy versus 7-day-per-week postoperative continuous accelerated irradiation (p-CAIR) therapy for squamous cell cancer of the head and neck. METHODS AND MATERIALS Tumor samples from 148 patients (72 p-CF and 76 p-CAIR patients) were available for molecular studies. Immunohistochemistry was used to assess levels of EGFR, nm23, Ki-67, p-53, and cyclin D1 expression. To evaluate the effect of fractionation relative to the expression profiles, data for locoregional tumor control (LRC) were analyzed using the Cox proportional hazard regression model. Survival curves were compared using the Cox f test. RESULTS Patients who had tumors with low Ki-67, low p-53, and high EGFR expression levels and oral cavity/oropharyngeal primary cancer sites tended to benefit from p-CAIR. A joint score for the gain in LRC from p-CAIR based of these features was used to separate the patients into two groups: those who benefited significantly from p-CAIR with respect to LRC (n = 49 patients; 5-year LRC of 28% vs. 68%; p = 0.01) and those who did not benefit from p-CAIR (n = 99 patients; 5-year LRC of 72% vs. 66%; p = 0.38). The nm23 expression level appeared useful as a prognostic factor but not as a predictor of fractionation effect. CONCLUSIONS These results support the studies that demonstrate the potential of molecular profiles to predict the benefit from accelerated radiotherapy. The molecular profile that favored accelerated treatment (low Ki-67, low p-53, and high EGFR expression) was in a good accordance with results provided by other investigators. Combining individual predictors in a joint score may improve their predictive potential.
Pediatric Neurosurgery | 1999
Jorge A. Lazareff; Rafal Suwinski; Roberto De Rosa; Charles E. Olmstead
Pediatric low grade gliomas evidence a tendency towards quiescent growth, thus complicating the clinical management of nonresected tumors whose clinical behavior may be difficult to predict. We decided to explore the hypothesis of possible correlation in pediatric low grade glioma between tumor volume and growth rate. We identified 6 children with hypothalamic chiasmatic lesions. Five of these patients were treated only with biopsy and 1 with repeated partial tumor resection. All of 6 patients had 10–15 sequential brain MRI over a time span of 3–8 years. Tumor volume was determined using Sigma Scan Image® software. The results were analyzed utilizing two equations for modeling tumor growth: exponential and Gompertz. In 4 patients whose tumor volume was approximately 80–100 cm3 at the time of diagnosis, slow spontaneous partial regression was observed. In the other patients deceleratory or exponential tumor growth was volume-dependent. Our results suggest that growth of pediatric low grade glioma decelerates as tumor becomes large and that the Gompertz model for tumor growth is useful for understanding the growth kinetics of pediatric low grade glioma.