PubMed Health⌕ Search

Biomedical subjects

C Scott

Publications and source records attributed to C Scott.

At least 55 records · Page 3Linked to original sources

Randomized phase III study comparing Best Supportive Care to Biafine as a prophylactic agent for radiation-induced skin toxicity for women undergoing breast irradiation: Radiation Therapy Oncology Group (RTOG) 97-13.

PURPOSE: To determine if Biafine compared to Best Supportive Care (BSC) is effective in minimizing or preventing radiation-induced dermatitis in women undergoing breast irradiation. METHODS AND MATERIALS: Patients were randomized between Biafine (n = 83) vs. BSC (n = 89). The institutions identified preference for BSC at the time of randomization. A no-treatment arm was allowed (16% received no treatment). Patients were instructed to apply randomized product three times a day, but not within 4 h of their daily RT session. Application began following their first radiation treatment and continued 2 weeks postradiation. Skin dermatitis was scored weekly utilizing the RTOG and ONS (Oncology Nursing Society) skin toxicity scales, a weekly patient satisfaction and quality-of-life questionnaire. RESULTS: Using the RTOG toxicity scale there was no overall difference for maximum dermatitis during RT between Biafine and BSC (p = 0.77). There was no difference in maximum toxicity by arm or breast size. There was an interaction between breast size and toxicity, with large-breasted women exhibiting more toxicity. Large-breasted women receiving Biafine were more likely to have no toxicity 6 weeks post RT. CONCLUSION: There was no overall difference between BSC and Biafine in the prevention, time to, or duration of radiation-induced dermatitis.

Adult↗

Recursive partitioning analysis of 1999 Radiation Therapy Oncology Group (RTOG) patients with locally-advanced non-small-cell lung cancer (LA-NSCLC): identification of five groups with different survival.

PURPOSE: Survival of patients with locally-advanced non-small-cell lung cancer (LA-NSCLC) is predicted by the stage of the disease and other characteristics. This analysis was undertaken to identify these characteristics in a large cooperative group patient population, as well as to define subgroups of the population with differing outcomes. PATIENTS AND METHODS: Analysis included 1,999 patients treated in 9 RTOG trials between 1983 and 1994 with thoracic irradiation (RT) with (n = 355) or without chemotherapy (CT). RESULTS: In univariate analysis, the following characteristics were significantly associated with an improved survival: use of CT, CT delivered without major deviation, abnormal pulmonary function tests, normal hemoglobin, protein, LDH and BUN, presence of dyspnea, hemoptysis, cough or hoarseness, uninvolved lymph nodes, T1 or T2 stage, no malignant pleural effusion (PE), weight loss of < 8%, Karnofsky performance status (KPS) of at least 90, adenocarcinoma histology, female gender, and age less than 70 years. Recursive partitioning analysis (RPA) was subsequently applied to identify 5 patient subgroups with significantly different median survival times (MST): Group I, KPS of > or = 90, who received chemotherapy (MST 16.2 months); Group II, KPS of > or = 90, who received no CT, but had no PE (MST 11.9 months); Group III, KPS < 90, younger than 70 years, with non-large cell histology (MST 9.6 months); Group IV, KPS > or = 90, but with PE, or KPS < 90, younger than 70 years, and with large cell histology, or older than 70 years, but without PE (MST 5.6-6.4 months); Group V, older than 70, with PE (MST 2.9 months). CONCLUSION: Cisplatinum-based CT improves survival, for excellent prognosis of LA-NSCLC patients, over RT alone. The presence of a malignant pleural effusion is a major negative prognostic factor for survival. The identification of RPA prognostic groups among patients with LA-NSCLC provides prognostic information and may serve as a basis of stratification in future trials.

Adenocarcinoma↗

Phase II, two-arm RTOG trial (94-11) of bischloroethyl-nitrosourea plus accelerated hyperfractionated radiotherapy (64.0 or 70.4 Gy) based on tumor volume (> 20 or < or = 20 cm(2), respectively) in the treatment of newly-diagnosed radiosurgery-ineligible glioblastoma multiforme patients.

PURPOSE: To compare survivorship, and acute and delayed toxicities following radiation therapy (RT) of radiosurgery-ineligible glioblastoma multiforme (GBM) patients treated with tumor volume-influenced, high-dose accelerated, hyperfractionated RT plus bischloroethyl-nitrosourea (BCNU), using prior RTOG malignant glioblastoma patients as historical controls. METHODS AND MATERIALS: One hundred four of 108 patients accrued from June 1994 through May 1995 from 26 institutions were analyzable. Patients were histologically confirmed with GBM, and previously untreated. Treatment assignment (52 patients/arm) was based on tumor mass (TM), defined as the product of the maximum diameter and greatest perpendicular dimension of the titanium-gadolinium-enhanced postoperative MRI: Arm A, 64 Gy, TM > 20 cm(2); or Arm B, 70.4 Gy, TM < or = 20 cm(2). Both Arms A and B received BCNU (80 mg/m(2), under hyperhydration) days 1-3, 56-58, then 4 cycles, each 8 weeks, for a total of 6 treatment series. RESULTS: During the 24 months immediately post-treatment, the overall median survival was 9.1 months in Arm A (64 Gy) and 11.0 months in Arm B (70.4 Gy). Median survival in recursive partitioning analysis (RPA) Class III/IV was 10.4 months in Arm A and 12.2 months in Arm B, while RPA Class V/VI was 7.6 months in Arm A and 6.1 months in Arm B. There were no grade 4 neurological toxicities in Arm A; 2 grade 4 neurological toxicities were observed in Arm B (1 motor deficit, 1 necrosis at 157 days post-treatment). CONCLUSION: This strategy of high-dose, accelerated hyperfractionated radiotherapy shortens overall RT treatment times while allowing dose escalation, and it provides the potential for combination with currently available, as well as newer, chemotherapy agents. Survival is comparable with previously published RTOG data, and toxicities are within acceptable limits.

Antineoplastic Agents, Alkylating↗

Zinc uptake, oxidative stress and the FNR-like proteins of Lactococcus lactis.

Lactococcus lactis ssp. cremoris MG1363 contains two FNR homologues, FlpA and FlpB, encoded by the distal genes of two paralogous operons (orfX(A/B)-orfY(A/B)-flpA/B). An flpA flpB double mutant strain is hypersensitive to hydrogen peroxide and has a depleted intracellular Zn(II) pool. The phenotypes of the flp mutant strains suggest that FlpA and FlpB control the expression of high and low affinity ATP-dependent Zn(II) uptake systems, respectively. Plate tests revealed that expression from a orfX(B)::lac reporter was activated by Cd(II), consistent with other Zn(II)-regulated systems. The link between a failure to acquire Zn(II) and hypersensitivity to oxidative stress suggests that Zn(II) may be required to protect vulnerable protein thiols from oxidation.

Adenosine Triphosphate↗

Genomic sequence and transcriptional profile of the boundary between pericentromeric satellites and genes on human chromosome arm 10q.

The organization of centromeric heterochromatin has been established in a number of eucaryotes but remains poorly defined in human. Here we present 1025 kb of contiguous human genomic sequence which links pericentromeric satellites to the RET proto-oncogene in 10q11.2 and is presumed to span the transition from centric heterochromatin to euchromatin on this chromosome arm. Two distinct domains can be defined within the sequence. The proximal approximately 240 kb consists of arrays of satellites and other tandem repeats separated by tracts of complex sequence which have evolved by pericentromeric-directed duplication. Analysis of 32 human paralogues of these sequences indicates that most terminate at or within repeat arrays, implicating these repeats in the interchromosomal duplication process. Corroborative PCR-based analyses establish a genome-wide correlation between the distribution of these paralogues and the distribution of satellite families present in 10q11. In contrast, the distal approximately 780 kb contains few tandem repeats and is largely chromosome specific. However, a minimum of three independent intrachromosomal duplication events have resulted in >370 kb of this sequence sharing >90% identity with sequences on 10p. Using computer-based analyses and RT-PCR we confirm the presence of three genes within the sequence, ZNF11/33B, KIAA0187 and RET, in addition to five transcripts of unknown structure. All of these transcribed sequences map distal to the satellite arrays. The boundary between satellite-rich interchromosomally duplicated DNA and chromosome-specific DNA therefore appears to define a transition from pericentromeric heterochromatin to euchromatin on the long arm of this chromosome.

Centromere↗

Importance of the mini-mental status examination in the treatment of patients with brain metastases: a report from the Radiation Therapy Oncology Group protocol 91-04.

PURPOSE: Little information is available on the importance of pretreatment Mini-Mental Status Exam (MMSE) on long-term survival and neurologic function following treatment for unresectable brain metastases. This study examines the importance of the MMSE in predicting outcome in a group of patients treated with an accelerated fractionation regimen of 30 Gy in 10 daily fractions in 2 weeks. MATERIALS AND METHODS: The Radiation Therapy Oncology Group (RTOG) accrued 445 patients to a Phase III comparison of accelerated hyperfractionated (AH) radiotherapy (1.6 Gy b.i.d.) to a total dose of 54.4 Gy vs. an accelerated fractionation (AF) of 30 Gy in 10 daily fractions from 1991 through 1995. All patients had histologic proof of malignancy at the primary site. Brain metastases were measurable by CT or MRI scan and all patients had a Karnofsky performance score (KPS) of at least 70 and a neurologic function classification of 1 or 2. Two hundred twenty-four patients were entered on the accelerated fractionated arm, and 182 were eligible for analysis (7 patients were judged ineligible, no MMSE information in 29, no survival data in 1, no forms submitted in 1). RESULTS: Average age was 60 years; 58% were male and 25% had a single intracranial lesion on their pretherapy evaluation. KPS was 70 in 32%, 80 in 31%, 90 in 29%, and 100 in 14%. The average MMSE was 26.5, which is the lower quartile for normal in the U.S. population. The range of the MMSE scores was 11-30 with 30 being the maximum. A score of less than 23 indicates possible dementia, which occurred in 16% of the patients prior to treatment. The median time from diagnosis to treatment was 5 days (range, 0-158 days). The median survival was 4.2 months with a 95% confidence interval of 3.7-5.1 months. Thirty-seven percent of the patients were alive at 6 months, and 17% were alive at 1 year. The following variables were examined in a Cox proportional-hazards model to determine their prognostic value for overall survival: age, gender, KPS, baseline MMSE, time until MMSE below 23, time since diagnosis, number of brain metastases, and radiosurgery eligibility. In all Cox model analyses, age, KPS, baseline MMSE, time until MMSE below 23, and time since diagnosis were treated as continuous variables. Statistically significant factors for survival were pretreatment MMSE (p = 0.0002), and KPS (p = 0.02). Age was of borderline significance (p = 0.065) as well as gender (p = 0.074). A poorer outcome is associated with an increasing age, male gender, lower MMSE, and shorter time until MMSE below 23. Improvement in MMSE over time was assessed; 62 patients died prior to obtaining follow-up MMSE, and 30 patients had a baseline MMSE of 30 (the maximum), and, therefore, no improvement could be expected. Of the remaining 88, 48 (54.5%) demonstrated an improvement in their MMSE at any follow-up visit. Lack of decline of MMSE below 23 was seen in long-term survivors, with 81% at 6 months and 66% at 1 year of patients maintaining a MMSE above 23. Analysis of time until death from brain metastases demonstrated that decreasing baseline MMSE (p = 0.003) and primary site (breast vs. lung vs. other p = 0.032) were highly associated with a terminal event. CONCLUSION: While gender and perhaps age remain significant predictors for survival, MMSE is also an important way of assessing a patient's outcome. Accelerated fractionation used in the treatment of brain metastases (30 Gy in 10 fractions) appears to also be associated with an improvement in MMSE and a lack of decline of MMSE below 23 in long-term survivors.

Adult↗

Carriage of HFE mutations and outcome of surgical resection for hepatocellular carcinoma in cirrhotic patients.

BACKGROUND: Aggressive hepatocellular carcinoma (HCC) complicates frequently hereditary hemochromatosis, a disease for which a strong candidate gene, named HFE, has recently been identified. Patients with HCC who are heterozygotes for mutations in the HFE gene might have distinct features and a distinct disease course. METHODS: The presence of the 2 mutations associated with hereditary hemochromatosis (C282Y and H63D) was sought by restriction fragment length polymorphism in 61 cirrhotic patients (46 males and 15 females) who underwent resection for HCC at a single institution. RESULTS: There were 4 heterozygotes for the C282Y mutation and 6 homozygotes + 20 heterozygotes for the H63D mutation, with no compound heterozygotes. Carriage of >/= 1 HFE mutated allele was significantly more frequent in HCC patients than in 149 control subjects (44% vs. 29%, P = 0.005). Among C282Y heterozygotes, 3 of 4 were female, compared with 12 of 57 wild-type carriers (P = 0.015); no gender distribution existed among patients carrying H63D alleles (6 of 26 vs. 9 of 35, P = 0.813). Survival was longer for patients with wild-type HFE than for those with mutated HFE (67% vs. 22% at 3 years; hazard ratio = 0.42, 95% confidence interval = 0.21-0.80) (P < 0.01). The negative effect on survival that resulted from possessing >/= 1 HFE mutated allele was maintained even after adjustment for gender, age, presence of tumor capsule, presence of comorbid factors, Okuda stage, Edmonson grading, and number of lesions (P = 0.01). CONCLUSIONS: Testing for HFE mutations may help identify HCC patients with dismal prognoses for whom surgical resection may not represent the best treatment option.

Adult↗

Validation of the RTOG recursive partitioning analysis (RPA) classification for brain metastases.

PURPOSE: The Radiation Therapy Oncology Group (RTOG) previously developed three prognostic classes for brain metastases using recursive partitioning analysis (RPA) of a large database. These classes were based on Karnofsky performance status (KPS), primary tumor status, presence of extracranial system metastases, and age. An analysis of RTOG 91-04, a randomized study comparing two dose-fractionation schemes with a comparison to the established RTOG database, was considered important to validate the RPA classes. METHODS AND MATERIALS: A total of 445 patients were randomized on RTOG 91-04, a Phase III study of accelerated hyperfractionation versus accelerated fractionation. No difference was observed between the two treatment arms with respect to survival. Four hundred thirty-two patients were included in this analysis. The majority of the patients were under age 65, had KPS 70-80, primary tumor controlled, and brain-only metastases. The initial RPA had three classes, but only patients in RPA Classes I and II were eligible for RTOG 91-04. RESULTS: For RPA Class I, the median survival time was 6. 2 months and 7.1 months for 91-04 and the database, respectively. The 1-year survival was 29% for 91-04 versus 32% for the database. There was no significant difference in the two survival distributions (p = 0.72). For RPA Class II, the median survival time was 3.8 months for 91-04 versus 4.2 months for the database. The 1-year survival was 12% and 16% for 91-04 and the database, respectively (p = 0.22). CONCLUSION: This analysis indicates that the RPA classes are valid and reliable for historical comparisons. Both the RTOG and other clinical trial organizers should currently utilize this RPA classification as a stratification factor for clinical trials.

Age Factors↗

Strong correlation between imaging response and survival among patients with primary central nervous system lymphoma: a secondary analysis of RTOG studies 83-15 and 88-06.

PURPOSE: Primary central nervous system lymphoma (PCNSL) is the brain tumor with the most rapidly increasing incidence, yet little is known about its radiographic response to cranial irradiation. If traditionally used doses of radiotherapy ( approximately 60 Gy) are associated with low rates of complete response and poor survival, then an argument can be made to consider dose escalation of radiotherapy. Alternatively, if poor survival rates are associated with high rates of complete response, there would be no reason to subject patients to higher radiation doses with increased risks of treatment-related morbidity. The purpose of this analysis is to provide a detailed review of response following cranial irradiation. Based on these findings, recommendations are offered for future protocol design. METHODS AND MATERIALS: Patients were treated on either RTOG 83-15 (whole brain irradiation to 40 Gy followed by a 20 Gy boost to the tumor plus 2-cm margin) or RTOG 88-06 (induction cyclophosphamide, doxorubicin, vincristine, dexamethasone [CHOD] followed by whole brain irradiation to 41.4 Gy and an 18 Gy tumor boost). Imaging surveillance (CT, MR) was required following surgery, prior to the initiation of RT and following completion of RT. Complete response referred to the absence of enhancement on follow-up scans in comparison to the pretherapy study. A tumor size reduction of at least 50% in the product of the largest cross-sectional diameter and its largest perpendicular diameter was scored as a partial response. RESULTS: Seventy-nine patients had scans available for central review. Complete response was achieved in 83% and 85% of patients treated on RTOG 83-15 and 88-06, respectively. The rates of partial response (14%, 11%) and radiographic progression (3%, 4%) also were comparable between the studies. For survival analyses, data were aggregated from the two studies. The 4-year survival rates were 24% for complete responders versus 11% for other patients (p = 0.0006). In multivariate analysis, only complete radiographic response (p < 0.0007), and high Karnofsky performance status (KPS >/= 70) (p < 0.005) were independently associated with increased rates of 4-year survival. CONCLUSION: A high rate of complete radiographic response was observed following moderate doses of cranial irradiation (alone or in combination with CHOD chemotherapy). Although complete responders had a statistically significant survival advantage at 4 years when compared with partial responders and nonresponders, the majority of patients who achieved complete response were dead of disease by 4 years following treatment. Based on this analysis of the RTOG database, there is no rationale for radiation dose escalation as a therapeutic strategy to combat PCNSL. Consequently, the radiotherapy component of the current RTOG Phase II trial (RTOG 93-10) now includes relatively low total doses of hyperfractionated irradiation for patients without residual disease (36 Gy/1.2 Gy, twice a day) as well as a more aggressive chemotherapy regimen.

Adult↗

Single dose radiosurgical treatment of recurrent previously irradiated primary brain tumors and brain metastases: final report of RTOG protocol 90-05.

PURPOSE: To determine the maximum tolerated dose of single fraction radiosurgery in patients with recurrent previously irradiated primary brain tumors and brain metastases. METHODS AND MATERIALS: Adults with cerebral or cerebellar solitary non-brainstem tumors </= 40 mm in maximum diameter were eligible. Initial radiosurgical doses were 18 Gy for tumors </= 20 mm, 15 Gy for those 21-30 mm, and 12 Gy for those 31-40 mm in maximum diameter. Dose was prescribed to the 50-90% isodose line. Doses were escalated in 3 Gy increments providing the incidence of irreversible grade 3 (severe) or any grade 4 (life threatening) or grade 5 (fatal) Radiation Therapy Oncology Group (RTOG) central nervous system (CNS) toxicity (unacceptable CNS toxicity) was < 20% within 3 months of radiosurgery. Chronic CNS toxicity was also assessed. RESULTS: Between 1990-1994, 156 analyzable patients were entered, 36% of whom had recurrent primary brain tumors (median prior dose 60 Gy) and 64% recurrent brain metastases (median prior dose 30 Gy). The maximum tolerated doses were 24 Gy, 18 Gy, and 15 Gy for tumors </= 20 mm, 21-30 mm, and 31-40 mm in maximum diameter, respectively. However, for tumors < 20 mm, investigators' reluctance to escalate to 27 Gy, rather than excessive toxicity, determined the maximum tolerated dose. In a multivariate analysis, maximum tumor diameter was one variable associated with a significantly increased risk of grade 3, 4, or 5 neurotoxicity. Tumors 21-40 mm were 7.3 to 16 times more likely to develop grade 3-5 neurotoxicity compared to tumors < 20 mm. Other variables significantly associated with grade 3-5 neurotoxicity were tumor dose and Karnofsky Performance Status. The actuarial incidence of radionecrosis was 5%, 8%, 9%, and 11% at 6, 12, 18, and 24 months following radiosurgery, respectively. Forty-eight percent of patients developed tumor progression within the radiosurgical target volume. A multivariate analysis revealed two variables that were significantly associated with an increased risk of local progression, i.e. progression in the radiosurgical target volume. Patients with primary brain tumors (versus brain metastases) had a 2.85 greater risk of local progression. Those treated on a linear accelerator (versus the Gamma Knife) had a 2.84 greater risk of local progression. Of note, 61 % of Gamma Knife treated patients had recurrent primary brain tumors compared to 30% of patients treated with a linear accelerator. CONCLUSIONS: The maximum tolerated doses of single fraction radiosurgery were defined for this population of patients as 24 Gy, 18 Gy, and 15 Gy for tumors </= 20 mm, 21-30 mm, and 31-40 mm in maximum diameter. Unacceptable CNS toxicity was more likely in patients with larger tumors, whereas local tumor control was most dependent on the type of recurrent tumor and the treatment unit.

Adult↗