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Biomedical subjects

I L Atahan

Publications and source records attributed to I L Atahan.

At least 19 recordsLinked to original sources
PubMed2005

1,25-Dihydroxy vitamin D3: can it be an effective therapeutic option for aggressive fibromatosis.

Aggressive fibromatosis (AF), also known as desmoid tumor is a monoclonal fibroblastic proliferation in a collagen matrix that arises in musculoaponeurotic structures. Though considered as benign, they are locally invasive and their propensity for recurrence after conservative surgery is well documented. Addition of postoperative adjuvant radiotherapy produces higher local control rates, although recurrence rates are still high in patients with positive margins. The antineoplastic activity of vitamin D has been demonstrated both in vitro and in vivo models of several cancers. The proposed mechanisms for antineoplastic activity include inhibition of proliferation associated with cell cycle arrest, induction of apoptosis and reduction in invasiveness and angiogenesis. It has also been shown that vitamin D has a negative impact on collagen homeostasis by inhibiting the formation and increasing its degradation. Since vitamin D has an antineoplastic activity and negative effect on collagen synthesis and deposition, it is proposed that 1,25-dihydroxy vitamin D3 can be a right therapeutic option for the management of desmoid tumors.

Antineoplastic Agents↗
PubMed2005

Importance of timing of antiaggregant treatment in the prevention of radiation induced enteropathy.

Chronic radiation enteropathy (CRE) is an undesirable radiation-induced toxicity and a common health problem in patients with pelvic or abdominal malignancies. Damage to microvascular endothelial cells and connective tissue is blamed to cause this adverse effect. It is shown that platelets are the first cellular elements that initiate the homeostatic and inflammatory responses and release of several proinflammatory and fibrinogenic mediators. Antiplatelet agents such as ticlopidine and clopidogrel were shown to prevent CRE and this effect is believed to be directed by their activities against thrombocytes. However, recent studies have shown that these drugs also induce apoptosis in endothelial cells and may lead to decreased expression of endothelial prostacyclin and thrombomodulin (TM) and increased release of von Willebrand factor which are shown to be major contributors of coagulation process. Assuming that radiation induced apoptosis occur 6-10h after irradiation, we think that timing of these antiaggregant drugs with irradiation is important and a 6-10h interval between these may be beneficial to avoid this adverse interaction.

Apoptosis↗
PubMed2001

Acute phase response during radiotherapy.

PURPOSE: The acute phase response is characterized by changes in the plasma concentrations of a number of liver-synthesized proteins, one of which is C-reactive protein (CRP). The existence of these changes in the plasma profile underlies the change in erythrocyte sedimentation rate (ESR). Acute phase response itself is an illness and may result from immunologic reactions and inflammatory processes. This study is designed to determine whether the CRP level and ESR increase during radiotherapy and whether their rise correlates with acute and late radiation morbidity. METHODS AND MATERIALS: Between April 1997 and October 1998, 51 patients with the diagnosis of endometrium and cervical cancer were treated with surgery and postoperative radiotherapy. Median age at the time of radiotherapy was 52 (range, 26-73) years. Thirty patients received pelvic radiotherapy, and 21 patients were treated by pelvic-paraaortic irradiation. A total dose of 50.4 Gy to the pelvis and 45 Gy to the paraaortic field were delivered in conventional fraction. Erythrocyte sedimentation rates and CRP levels were studied before, during, and at the end of radiotherapy. RESULTS: The mean ESR measurements before and after radiotherapy were 40 (8-100) and 52 (10-120), and mean CRP levels were 1.4 (0.12-9.8) and 2.7 (0.12-32.2), respectively. The statistical analysis yielded significant rise in ESR and CRP levels at the end of radiotherapy (p < 0.001). The increase was more prominent in patients who were irradiated through pelvic-paraaortic field than in patients with pelvic radiation (p = 0.005 and 0.028 respectively). CONCLUSION: Acute phase response was present during radiotherapy. Radiotherapy should be considered as a cause of increase in CRP level and ESR especially in clinical conditions where acute phase response is important.

Acute-Phase Reaction↗
PubMed2001

Malignancy in Behçet's disease: a report of 13 cases and a review of the literature.

Behçet's disease (BD) has rarely been reported in association with malignant diseases. In most cases the autoimmune nature of the disease itself or immunosuppressive drug use has been blamed for malignant transformation. We report 13 cases of BD concurrent with neoplastic disease as well as treatment-related morbidities in this particular patient group. Between 1986 and 1999, 400 patients were diagnosed as having BD in Hacettepe University Hospitals. Of these 13 patients, 3.25% developed malignant diseases within a median follow-up time of 9.8 years. Solid tumors were diagnosed in 10 patients and haematological or lymphoid malignancies in three. Surgery was performed in seven patients, whereas radiotherapy was applied in six and chemotherapy in eight. A literature review revealed 27 cases of BD associated with malignancies, mostly lymphoid or haematological. Ten of our cases were solid tumors, and to our knowledge most of these are the first reported cases of specific malignancies concurrent with BD. Treatment-related morbidities were wound infection as surgical morbidity in one patient (1/7) and radiotherapy-related morbidity in three (3/6) patients in a median follow-up time of 2 years. Solid tumors in addition to lymphoid and haematological malignancies are also seen during the course of BD. Radiation therapy may cause severe late toxicities in the presence of BD. Chemotherapy and surgery are fairly safe for the treatment of malignancies in BD patients.

Adult↗
PubMed2001

Dermatofibrosarcoma protuberans metastasizing to cavernous sinuses and lungs: a case report.

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive tumor with a low potential for distant metastases. We report a 22-year-old female patient with a typical cutaneous DFSP who developed five local recurrences followed by left cavernous sinus metastasis at the eighth year and right cavernous sinus and lung metastases at the ninth year. In each local recurrence the tumor showed histological signs of progression as being more cellular, having higher mitotic index and being aggressively invasive through the underlying soft tissues. The histopathological evaluation of the metastatic tumor resected from the left cavernous sinus revealed dedifferentiation from low-grade DFSP to higher grade fibrosarcomatous morphology. Immunohistochemical studies of the primary tumor and also the recurrent and metastatic tumors showed diffuse CD34 positivity in all specimens and p53 positivity was detected in the metastatic tumor resected from left cavernous sinus.

Adult↗
PubMed2000

Conventional external radiotherapy in the management of clivus chordomas with overt residual disease.

Cranial chordomas are uncommon tumors accounting for less than 1% of all intracranial neoplasms. Although they are slowly growing, rarely metastasizing tumors, cranial chordomas are challenging to treat due to their critical location, invasive nature and aggressive recurrence. The aim of this retrospective study was to evaluate the role of conventional irradiation in the treatment of clival chordomas with overt residual disease after incomplete surgery. Between January 1979 and December 1997, 18 patients with histologically confirmed clival chordoma were treated with radiotherapy. Median age at the time of diagnosis was 32 years. The mean duration of the symptoms before diagnosis was 33.9 months. Median tumor diameter at initial presentation was 5 cm (range, 3-7 cm). The type of surgical procedure was subtotal excision in 11 patients and biopsy in 7. Radiation treatment was delivered with megavoltage units, and total doses between 50 Gy and 64 Gy (median, 60 Gy) were administered with conventional daily fractions. One patient received additional 12.50 Gy with linear accelerator-based stereotactic radiosurgery after subtotal excision and external irradiation. The mean follow-up time was 43.2 months. Overall survival at 5 years was 35%. Eleven patients showed progression after radiotherapy. The median time to progression after radiotherapy was 40.8 months (38.4-43.2) with a 5-year progression-free survival of 23%. Five patients (29.4%) showed symptomatic relief after radiotherapy while persistent symptoms were recorded for 6 patients. Incomplete surgery and conventional external radiotherapy with a dose of around 60 Gy seem to be inadequate in the treatment of clival chordomas.

Adult↗
PubMed2000

Accelerated hyperfractionated radiotherapy in supratentorial malignant astrocytomas.

PURPOSE: To determine the safety and effectiveness of accelerated hyperfractionated radiotherapy in the treatment of supratentorial malignant astrocytomas. MATERIALS AND METHODS: Between June 1995-July 1997, 75 patients were enrolled to a prospective phase II study. A total dose of 60 Gy was delivered in 2 Gy b.i.d. fractions with an interval of 6-8 h, 5 days per week, in an overall time of 3 weeks. The treatment protocol was planned to give 40 Gy to a treatment volume covering the contrast-enhancing lesion and oedema (+ 3-cm margin) and additional 20 Gy to the volume encompassing the contrast-enhancing lesion alone with a 1-cm margin based on preoperative magnetic resonance imaging and/or CT findings. The patients had a median age of 46 years and a median Karnofsky performance status score of 80. Histology consisted of anaplastic astrocytoma (AA) in 16 (21%) and glioblastoma multiforme (GBM) in 59 (79%) patients. RESULTS: Median survival was 11 months for all patients; 10 months for GBM patients and 40 months for AA patients. Survival rates at 1 and 3 years were 41%, 11% for all patients; 62, 37% for AA patients and 35, 6% for GBM patients, respectively. Multivariate analysis revealed significant impact of age, histology and neurological functional class on survival. The incidence of grade 3 or worse late neurological toxicity was 5.3%. CONCLUSIONS: Although accelerated hyperfractionated radiotherapy showed no significant advantage on survival, it shortened the treatment period from 6 to 3 weeks. Radiotherapy was well tolerated and the incidence of late toxicity is acceptable.

Adolescent↗
PubMed2000

Primary breast lymphomas--a retrospective analysis of twelve cases.

This study was undertaken to define the natural history and treatment results of patients with primary breast non-Hodgkin's lymphoma (NHL). Twelve female patients who had been followed at Hacettepe University Hospital between 1973 and 1997 were retrospectively evaluated. All patients presented with breast masses (6 in the right breast and 6 in the left) that had recently enlarged. The most common histologic subtype was diffuse, small cleaved-cell lymphoma. Chemotherapy regimens were employed in 9 patients. Radiotherapy was delivered to the breast and its lymphatics in 8 patients. Lumpectomy, simple or modified radical mastectomy was performed in 5 cases. An objective response was attained with surgery, chemotherapy, or radiotherapy alone in 2, 1, and 1 cases, respectively. Combined modality treatment including either two or three modalities was successful in 7 cases. The median progression-free and overall survival times were 49 and 56 months, respectively. Although primary NHL of the breast is a rare disease compared to carcinoma, it should be considered in the differential diagnosis of breast masses.

Adolescent↗
PubMed1999

Comparison of AJCC 1988 and 1997 classifications for nasopharyngeal carcinoma. American Joint Committee on Cancer.

PURPOSE: A comparison of American Joint Committee on Cancer (AJCC) 1988 and 1997 nasopharyngeal carcinoma (NPC) classifications was made in terms of patient distribution and efficacy in predicting prognosis. METHODS AND MATERIALS: Between 1993-1997, 90 patients (64 M, 26 F) with non-metastatic NPC were treated. The mean age was 42.02 (range: 9-82) years old. Histopathological diagnosis was WHO 2 and 3 in 83 (92.2%) patients. All patients were prospectively staged using AJCC 1988 and modified Ho's classifications (1989) and these data were stored in a computer database. Retrieval of this information enabled us to restage patients according to the AJCC 1997. Median follow-up was 38 months. RESULTS: According to the AJCC 1988 there were 2 (2.2%), 6 (6.7%), 13 (14.4%), and 69 (76.7%) patients in Stage I, II, III and IV, respectively. Same figures were 8 (8.8%), 21 (23.3%), 26 (28.9%), and 35 (38.8%), according to AJCC 1997. Three year overall survival (OS) rates were 100%, 100%, 67%, and 62% for patients Stage I, II, III, and IV according to the AJCC 1988 and 100%, 72%, 65%, and 55%, (I vs. IV; p = 0.03, I vs. III; p = 0.05) respectively, according to the AJCC 1997. Three year loco-regional relapse free survival (LRRFS) rates were 50%, 100%, 100%, and 83% (I vs. III; p = 0.03) for patients in Stage I, II, III, and IV according to the AJCC 1988. Same figures were 88%, 90%, 89%, and 85% according to the AJCC 1997. Three year distant metastasis free survival (DMFS) rates were 100%, 100%, 82%, and 67% for patients in Stage I, II, III, and IV according to the AJCC 1988. Same figures were 100%, 74%, 80%, and 57% (I vs. IV; p = 0.03) according to the AJCC 1997. We did not observe any significant difference in LRRFS among T stages for both staging system and the N stage was the primary determinant for DMFS in both systems. CONCLUSIONS: We observed a better patient distribution with AJCC 1997 comparing to AJCC 1988. The new classification also attained better statistical significances among stages in the OS and DMFS rates.

Adolescent↗
PubMed1999

The effect of verapamil in the prevention of radiation-induced cataract.

PURPOSE: Cataract is an unavoidable complication when radiation therapy includes the lens, even in small doses. Alterations in the ion content of the lens were considered to play an essential role in cataract formation. In this experimental study, the effect of verapamil on ion concentrations within the irradiated lenses was investigated in rats. METHODS AND MATERIALS: Forty female Wistar albino rats, each weighing 180-250 g, were divided into three groups: (a) radiation treated (n = 10); (b) no treatment (n = 10); (c) or a combination of radiation and verapamil (n = 20). Both the radiation group and verapamil-treated group received 5 Gy radiation to the cranium in a single fraction, including the eyes, within the irradiation volume. All animals were sacrificed by bleeding, 7.5 weeks posttreatment. Calcium, sodium, and potassium levels were measured in blood and in lens homogenates. However, for technical reasons, magnesium levels could only be studied in lens homogenates. RESULTS: Potassium and sodium concentrations in lens homogenates did not differ in the control and radiation groups, but both were significantly lower in the verapamil-treated group (p = 0.001, p = 0.009, respectively). Calcium levels were higher in the radiation group and lower in the verapamil-treated group compared to the controls (p < 0.0001); magnesium levels did not differ (p = 0.37). CONCLUSION: Verapamil effectively decreased the lens calcium concentration, which is accepted as the key element in radiation cataractogenesis. It is therefore concluded that verapamil may reduce the risk of radiation-induced cataract formation.

Animals↗
PubMed1999

High-dose-rate mold brachytherapy of early gingival carcinoma: a clinical report.

Two elderly edentulous patients with the diagnosis of early stage cancer of the upper gingiva were treated by customized dental mold brachytherapy. Locoregional tumor control was achieved in both patients. One patient is alive without any evidence of disease 36 months after treatment, the other patient died of distant metastasis shortly after brachytherapy. Brachytherapy, being easy to apply with short treatment time and good acute tolerance, is a good choice and effective modality for the management of early stage gingival cancer, particularly in elderly patients.

Aged↗
PubMed1999

Sucralfate in the prevention of radiation-induced oral mucositis.

Radiotherapy-induced mucositis decreases the quality of life by impairing eating, swallowing, and talking and by disturbing sleep. Mucositis may also predispose to local and systemic infections and may cause interruption of radiotherapy course. We studied the efficacy of sucralfate suspension in the prevention and management of oral mucositis and pain during radiotherapy in a double-blind, placebo-controlled, randomized, prospective trial. Twenty-eight patients with head and neck cancer were included in the study. The patients were randomized to use either sucralfate mouth washing (n = 18) or placebo washing (n = 10) during irradiation. Oral mucositis and symptoms were assessed by the same physician using Radiation Therapy Oncology Group Acute Radiation Morbidity Scoring criteria. All patients developed varying degrees of radiation-induced mucositis. Grade 4 mucositis was not encountered in any patient. One patient had grade 1, seven patients grade 2, and two patients grade 3 mucositis in placebo group. In sucralfate group, nine patients each had grade 1 and grade 2 with no grade 3 mucositis. Patients in the sucralfate group experienced significantly lower degree of mucositis than placebo group (p < 0.05). Sucralfate mouth washing is beneficial in decreasing the intensity of radiation-induced mucositis and oral discomfort. It is cheap, easy to administer with no serious side effect, and may be routinely used in patients receiving head and neck radiotherapy.

Double-Blind Method↗
PubMed1998

The influence of dose per fraction on the pathogenesis of radiation nephropathy.

Both kidneys of male Wistar rats were irradiated with either a 10-Gy single dose or 26 Gy at a rate of 2 Gy per fraction per day. Serum blood urea nitrogen (BUN), creatinine and blood haematocrit levels were assessed prior to radiotherapy and at intervals of 8 weeks thereafter. A subset of animals from each dose group were killed at 4, 8, 16 and 24 weeks and both kidneys of each animal were examined by electron microscopy. In both dose groups a significant increase in BUN and creatinine levels, together with a decrease in haematocrit level, was observed at 16 weeks, and this was followed by an apparent improvement at 24 weeks. There was no statistical difference in these responses between the two groups. The morphological changes in both dose groups were essentially similar, but differed in severity. At 4 weeks after irradiation glomerular and proximal tubular injury were observed in both groups. A marked increase of glomerular and tubular injury in the 10-Gy dose group, without any apparent progression in the 26-Gy dose group, was detected at 8 weeks. By 16 weeks a noticeable improvement in both tubular and glomerular lesions (especially in the 10-Gy dose group) was observed. No apparent difference from the 16th week of evaluation was found at 24 weeks. These findings indicate that there is some recovery in kidney after irradiation, but the extent of the recovery process is somewhat limited.

Analysis of Variance↗
PubMed1997

Kaposi's sarcoma: the efficacy of a single fraction of 800 cGy.

BACKGROUND: Although Kaposi's sarcoma is the most common neoplasm in association with AIDS, classic Kaposi's sarcoma is rare. The best treatment modality is still unclear. METHODS: Between December 1993 and December 1995, 42 fields in 12 patients with Kaposi's sarcoma were treated at our department. Only 3 patients had a history of renal transplantation and immunosuppressive treatment. A single dose of 800 cGy with 4-6 MeV electron beams was delivered to all patients. RESULTS: Complete response rates at the 1st, 6th and 12th months after treatment were 45.2, 62 and 89.7%, respectively. Side effects included various degrees of hyperpigmentation and mild edema and fibrosis in 1 patient. CONCLUSION: Our results suggest that a single application of 800 cGy is as effective as a more protracted course of radiotherapy with a comparable complication rate.

Adult↗
PubMed1996

Factors influencing the distribution of metastases and survival in metastatic breast carcinoma.

A total of 370 patients with metastatic breast, carcinoma who had been followed at Hacettepe Oncology Department between 1980 and 1991 were retrospectively analyzed for the factors influencing the distribution of metastases and survival. Median age was 47 years. Radical or modified radical mastectomies were performed in 199 (53.8%). Infiltrative ductal carcinoma was the most common pathologic subtype (69.4%). In 191 patients who were evaluated for estrogen receptor (ER) status, 101 (52.9%) were positive and 90 (47.1%) were negative. The distribution of first metastases did not differ between the soft tissue, bone, and visceral sites. The second, third, and fourth metastases were more common in visceral sites (p < 0.05). ER and menopausal status did not affect distribution. Mortality rate was significantly lower in the group having the first metastasis to the bone (p < 0.05). Of interest, first metastases were predominantly found in visceral sites in patients having radical or modified radical mastectomies (p < 0.05). Response to therapy, presence of initial metastases, axillary status, and age were the important factors influencing the overall survival in univariate analysis, whereas response to therapy, ER status, age, and presence of initial metastases were the important factors according to the multivariate analysis.

Adult↗
PubMed1993

Does gastric adenocarcinoma develop after the treatment of gastric lymphoma?

Two adult patients with the diagnosis of gastric lymphoma who developed adenocarcinoma of the stomach 8 years after the treatment are presented. Both patients were treated by subtotal gastrectomy followed by irradiation of 4,000-4,500 cGy to the epigastric region and six courses of chemotherapy (vincristine, cyclophosphamide, prednisolone). In our review of the literature, 16 cases of gastric adenocarcinoma following the treatment of gastric lymphoma were found and listed with details. The factors influencing the development of this secondary carcinoma, mainly those treatment related are discussed. The possible role of both radiotherapy and chemotherapy in shortening the latent period for the development of stump carcinoma is emphasized.

Adenocarcinoma↗