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Dive into the research topics where Pamela K. Allen is active.

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Featured researches published by Pamela K. Allen.


Lancet Oncology | 2009

Neurocognition in patients with brain metastases treated with radiosurgery or radiosurgery plus whole-brain irradiation: a randomised controlled trial

Eric L. Chang; J.S. Wefel; Kenneth R. Hess; Pamela K. Allen; Frederick F. Lang; David Kornguth; Rebecca Arbuckle; J. Michael Swint; Almon S. Shiu; Moshe H. Maor; Christina A. Meyers

BACKGROUND It is unclear whether the benefit of adding whole-brain radiation therapy (WBRT) to stereotactic radiosurgery (SRS) for the control of brain-tumours outweighs the potential neurocognitive risks. We proposed that the learning and memory functions of patients who undergo SRS plus WBRT are worse than those of patients who undergo SRS alone. We did a randomised controlled trial to test our prediction. METHODS Patients with one to three newly diagnosed brain metastases were randomly assigned using a standard permutated block algorithm with random block sizes to SRS plus WBRT or SRS alone from Jan 2, 2001, to Sept 14, 2007. Patients were stratified by recursive partitioning analysis class, number of brain metastases, and radioresistant histology. The randomisation sequence was masked until assignation, at which point both clinicians and patients were made aware of the treatment allocation. The primary endpoint was neurocognitive function: objectively measured as a significant deterioration (5-point drop compared with baseline) in Hopkins Verbal Learning Test-Revised (HVLT-R) total recall at 4 months. An independent data monitoring committee monitored the trial using Bayesian statistical methods. Analysis was by intention-to-treat. This trial is registered at www.ClinicalTrials.gov, number NCT00548756. FINDINGS After 58 patients were recruited (n=30 in the SRS alone group, n=28 in the SRS plus WBRT group), the trial was stopped by the data monitoring committee according to early stopping rules on the basis that there was a high probability (96%) that patients randomly assigned to receive SRS plus WBRT were significantly more likely to show a decline in learning and memory function (mean posterior probability of decline 52%) at 4 months than patients assigned to receive SRS alone (mean posterior probability of decline 24%). At 4 months there were four deaths (13%) in the group that received SRS alone, and eight deaths (29%) in the group that received SRS plus WBRT. 73% of patients in the SRS plus WBRT group were free from CNS recurrence at 1 year, compared with 27% of patients who received SRS alone (p=0.0003). In the SRS plus WBRT group, one case of grade 3 toxicity (seizures, motor neuropathy, depressed level of consciousness) was attributed to radiation treatment. In the group that received SRS, one case of grade 3 toxicity (aphasia) was attributed to radiation treatment. Two cases of grade 4 toxicity in the group that received SRS alone were diagnosed as radiation necrosis. INTERPRETATION Patients treated with SRS plus WBRT were at a greater risk of a significant decline in learning and memory function by 4 months compared with the group that received SRS alone. Initial treatment with a combination of SRS and close clinical monitoring is recommended as the preferred treatment strategy to better preserve learning and memory in patients with newly diagnosed brain metastases.


International Journal of Radiation Oncology Biology Physics | 1999

Tumor downstaging and sphincter preservation with preoperative chemoradiation in locally advanced rectal cancer: the M. D. Anderson Cancer Center experience

Nora A. Janjan; Vincent S. Khoo; James L. Abbruzzese; Richard Pazdur; Ronelle A. DuBrow; Karen R. Cleary; Pamela K. Allen; Patrick M. Lynch; Gary Glober; Robert A. Wolff; Tyvin A. Rich; John M. Skibber

PURPOSE To evaluate the rates of tumor downstaging after preoperative chemoradiation for locally advanced rectal cancer. MATERIALS AND METHODS Preoperative chemoradiotherapy (CTX/XRT) that delivered 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-fluorouracil (300 mg/m2/day) was given to 117 patients. The pretreatment stage distribution, as determined by endorectal ultrasound (u), included uT2N0 in 2%, uT3N0 in 47%, uT3N1 in 49%, and uT4N0 in 2% of cases; endorectal ultrasound was not performed in 13% of cases (15 patients). Approximately 6 weeks after completion of CTX/XRT, surgery was performed. RESULTS The pathological tumor stages were Tis-2N0 in 26%, T2N1 in 5%, T3N0 in 21%, T3N1 in 15%, T4N0 in 5%, and T4NI in 1%; a complete response (CR) to preoperative CTX/XRT was pathologically confirmed in 32 (27%) of patients. Tumor downstaging occurred in 72 (62%) cases. Only 3% of cases had pathologic evidence of progressive disease. Pretreatment tumor size (< 5 cm vs. > or = 5 cm) was the only factor predictive of tumor downstaging (p < 0.04). A decrease of > 1 T-stage level was accomplished in 45% of those downstaged. Overall, a sphincter-saving (SP) procedure was possible in 59% of patients and an abdominoperineal resection (APR) was required in 41 % of cases. Factors predictive of SP included downstaging (p < 0.03), age > 40 years (p < 0.007), pretreatment tumor distance, 3 to 6 cm from the anal verge (p < 0.00001), tumor size <6 cm (p < 0.02), mobility (p < 0.004), tumor stage <T4 (p < 0.01), and uN negative (p < 0.008). SP was performed in 23 patients (72%) with a CR and in 48 (67%) of downstaged cases. Among the 69 tumors located < 6 cm from the anal verge, 29 (42%) were resected with a SP. The level of response was important for tumors located < 6 cm from the anal verge because a SP was performed in 9 of the 17 (53%) CRs in this group while only 20 of 52 patients (38%) had a SP when residual disease was present after CTX/XRT. For tumors located > 6 cm from the anal verge, SP was performed in 14 of the 15 (93%) patients with a CR and 32 of 33 (97%) of patients with residual disease (p < 0.00004). CONCLUSIONS Significant tumor downstaging results from preoperative chemoradiation allowing sphincter sparing surgery in over 40% of patients whose tumors were located < 6 cm from the anal verge and who otherwise would have required colostomy.


Journal of Neurosurgery | 2007

Phase I/II study of stereotactic body radiotherapy for spinal metastasis and its pattern of failure

Eric L. Chang; Almon S. Shiu; Ehud Mendel; Leni A. Mathews; Anita Mahajan; Pamela K. Allen; Jeffrey S. Weinberg; Barry W. Brown; Xin Shelly Wang; Shiao Y. Woo; Charles S. Cleeland; Moshe H. Maor; Laurence D. Rhines

OBJECT The authors report data concerning the safety, effectiveness, and patterns of failure obtained in a Phase I/II study of stereotactic body radiotherapy (SBRT) for spinal metastatic tumors. METHODS Sixty-three cancer patients underwent near-simultaneous computed tomography-guided SBRT. Spinal magnetic resonance imaging was conducted at baseline and at each follow-up visit. The National Cancer Institute Common Toxicity Criteria 2.0 assessments were used to evaluate toxicity. RESULTS The median tumor volume of 74 spinal metastatic lesions was 37.4 cm3 (range 1.6-358 cm3). No neuropathy or myelopathy was observed during a median follow-up period of 21.3 months (range 0.9-49.6 months). The actuarial 1-year tumor progression-free incidence was 84% for all tumors. Pattern-of-failure analysis showed two primary mechanisms of failure: 1) recurrence in the bone adjacent to the site of previous treatment, and 2) recurrence in the epidural space adjacent to the spinal cord. Grade 3 or 4 toxicities were limited to acute Grade 3 nausea, vomiting, and diarrhea (one case); Grade 3 dysphagia and trismus (one case); and Grade 3 noncardiac chest pain (one case). There was no subacute or late Grade 3 or 4 toxicity. CONCLUSIONS Analysis of the data obtained in the present study supports the safety and effectiveness of SBRT in cases of spinal metastatic cancer. The authors consider it prudent to routinely treat the pedicles and posterior elements using a wide bone margin posterior to the diseased vertebrae because of the possible direct extension into these structures. For patients without a history of radiotherapy, more liberal spinal cord dose constraints than those used in this study could be applied to help reduce failures in the epidural space.


American Journal of Clinical Oncology | 2001

Improved overall survival among responders to preoperative chemoradiation for locally advanced rectal cancer

Nora A. Janjan; Christopher H. Crane; Barry W. Feig; Karen R. Cleary; Ronelle A. DuBrow; Steven A. Curley; Jean Nicolas Vauthey; Patrick M. Lynch; Lee M. Ellis; Robert A. Wolff; Renato Lenzi; James L. Abbruzzese; Richard Pazdur; Paulo M. Hoff; Pamela K. Allen; Thomas Brown; John M. Skibber

The aim of this study was to determine if the response to preoperative radiation and chemotherapy with continuous infusion 5-fluorouracil (5-FU) was predictive for survival among patients with locally advanced rectal cancer. Preoperative chemoradiation (CTX/XRT) that delivered 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-FU (300 mg/m2/day) was given to 117 patients. The pretreatment stage distribution, as determined by endorectal ultrasound (u), included uT2N0 in 2%, uT3N0 in 47%, uT3N1 in 49%, and uT4N0 in 2% of cases; endorectal ultrasound was not performed in 13% of cases (15 patients). Approximately 6 weeks after completion of CTX/XRT, surgery was performed. Adjuvant chemotherapy, consisting of 400 to 425 mg/m2 of 5-FU plus 20 mg/m2 leucovorin for 5 days, was administered every 28 days for 4 to 6 cycles after surgical resection. Among the 74 patients treated with adjuvant chemotherapy, the preoperative stage of disease was 31 with T3N0 and 43 T3N1. Median follow-up was 46 months (range 2 to 89 months). The pathologic tumor stages were Tis-2N0 in 26%, T2N1 in 5%, T3N0 in 21%, T3N1 in 15%, T4N0 in 5%, and T4N1 in 1%; a complete response (CR) to preoperative CTX/XRT was pathologically confirmed in 32 (27%) of patients. Tumor down-staging occurred in 72 (62%) cases. A sphincter-saving procedure (SP) was possible in 59% of patients. The median DFS and overall survival rates for responders were 46 months and 47 months, respectively; for non-responders these outcome measures were 38 months and 41 months, respectively. Log-rank analysis showed that the distant metastatic-free survival rates improved with any response to CTX/XRT (p < 0.00001), CR to CTX/XRT (p < 0.009) and SP (p < 0.012). Likewise, these parameters also significantly influenced DFS rates (CTX/XRT p < 0.00001; CR p < 0.006; and SP p < 0.008). Control of pelvic disease was influenced by clinical size (p < 0.002) and SP (p < 0.016) on univariate analysis. On multivariate analysis only clinical size (p < 0.002) continued to be a significant factor for local control. Factors on multivariate analysis that resulted in significant improvements in cancer-specific survival included any response to preoperative CTX/XRT (p < 0.017) and administration of adjuvant chemotherapy (p < 0.034). Any response to preoperative CTX/XRT improved distant metastatic-free and disease-free survival rates. Multivariate analysis confirmed that a response to preoperative CTX/XRT predicted for improvements in overall survival among patients with locally advanced rectal cancer. Patients who fail to respond to preoperative 5-FU based chemotherapy given concomitantly with radiation have higher rates of distant metastases with adjuvant 5-FU therapy.


Journal of Clinical Oncology | 2011

Phase II Trial of Erlotinib Plus Concurrent Whole-Brain Radiation Therapy for Patients With Brain Metastases From Non–Small-Cell Lung Cancer

James Welsh; Ritsuko Komaki; Arya Amini; Mark F. Munsell; Wyatt Unger; Pamela K. Allen; Joe Y. Chang; Jeffrey S. Wefel; Susan L. McGovern; Linda Garland; Su S. Chen; Jamie Holt; Zhongxing Liao; Paul D. Brown; Erik P. Sulman; John V. Heymach; Edward S. Kim; Baldassarre Stea

PURPOSE Brain metastasis (BM) is a leading cause of death from non-small-cell lung cancer (NSCLC). Reasoning that activation of the epidermal growth factor receptor (EGFR) contributes to radiation resistance, we undertook a phase II trial of the EGFR inhibitor erlotinib with whole-brain radiation therapy (WBRT) in an attempt to extend survival time for patients with BM from NSCLC. Additional end points were radiologic response and safety. PATIENTS AND METHODS Eligible patients had BM from NSCLC, regardless of EGFR status. Erlotinib was given at 150 mg orally once per day for 1 week, then concurrently with WBRT (2.5 Gy per day 5 days per week, to 35 Gy), followed by maintenance. EGFR mutation status was tested by DNA sequencing at an accredited core facility. RESULTS Forty patients were enrolled and completed erlotinib plus WBRT (median age, 59 years; median diagnosis-specific graded prognostic assessment score, 1.5). The overall response rate was 86% (n = 36). No increase in neurotoxicity was detected, and no patient experienced grade ≥ 4 toxicity, but three patients required dose reduction for grade 3 rash. At a median follow-up of 28.5 months (for living patients), median survival time was 11.8 months (95% CI, 7.4 to 19.1 months). Of 17 patients with known EGFR status, median survival time was 9.3 months for those with wild-type EGFR and 19.1 months for those with EGFR mutations. CONCLUSION Erlotinib was well tolerated in combination with WBRT, with a favorable objective response rate. The higher-than-expected rate of EGFR mutations in these unselected patients raises the possibility that EGFR-mutated tumors are prone to brain dissemination.


Lancet Oncology | 2012

Stereotactic body radiation therapy for management of spinal metastases in patients without spinal cord compression: a phase 1-2 trial

Xin Shelley Wang; Laurence D. Rhines; Almon S. Shiu; James N. Yang; Ugur Selek; Ibrahima Gning; Ping Liu; Pamela K. Allen; Syed Azeem; Paul D. Brown; Hadley J. Sharp; David C. Weksberg; Charles S. Cleeland; Eric L. Chang

BACKGROUND Spinal stereotactic body radiation therapy (SBRT) is increasingly used to manage spinal metastases, yet the techniques effectiveness in controlling the symptom burden of spinal metastases has not been well described. We investigated the clinical benefit of SBRT for managing spinal metastases and reducing cancer-related symptoms. METHODS 149 patients with mechanically stable, non-cord-compressing spinal metastases (166 lesions) were given SBRT in a phase 1-2 study. Patients received a total dose of 27-30 Gy, typically in three fractions. Symptoms were measured before SBRT and at several time points up to 6 months after treatment, by the Brief Pain Inventory (BPI) and the M D Anderson Symptom Inventory (MDASI). The primary endpoint was frequency and duration of complete pain relief. The study is completed and is registered with ClinicalTrials.gov, number NCT00508443. FINDINGS Median follow-up was 15·9 months (IQR 9·5-30·3). The number of patients reporting no pain from bone metastases, as measured by the BPI, increased from 39 of 149 (26%) before SBRT to 55 of 102 (54%) 6 months after SBRT (p<0·0001). BPI-reported pain reduction from baseline to 4 weeks after SBRT was clinically meaningful (mean 3·4 [SD 2·9] on the BPI pain-at-its-worst item at baseline, 2·1 [2·4] at 4 weeks; effect size 0·47, p=0·00076). These improvements were accompanied by significant reduction in opioid use during the first 6 months after SBRT (43 [28·9%] of 149 patients with strong opioid use at baseline vs 20 [20·0%] of 100 at 6 months; p=0·011). Ordinal regression modelling showed that patients reported significant pain reduction according to the MDASI during the first 6 months after SBRT (p=0·00003), and significant reductions in a composite score of the six MDASI symptom interference with daily life items (p=0·0066). Only a few instances of non-neurological grade 3 toxicities occurred: nausea (one event), vomiting (one), diarrhoea (one), fatigue (one), dysphagia (one), neck pain (one), and diaphoresis (one); pain associated with severe tongue oedema and trismus occurred twice; and non-cardiac chest pain was reported three times. No grade 4 toxicities occurred. Progression-free survival after SBRT was 80·5% (95% CI 72·9-86·1) at 1 year and 72·4% (63·1-79·7) at 2 years. INTERPRETATION SBRT is an effective primary or salvage treatment for mechanically stable spinal metastasis. Significant reductions in patient-reported pain and other symptoms were evident 6 months after SBRT, along with satisfactory progression-free survival and no late spinal cord toxicities. FUNDING National Cancer Institute of the US National Institutes of Health.


Radiotherapy and Oncology | 1999

Prognostic implications of response to preoperative infusional chemoradiation in locally advanced rectal cancer.

Nora A. Janjan; James L. Abbruzzese; Richard Pazdur; Vincent S. Khoo; Karen R. Cleary; Ronelle A. DuBrow; Jaffer A. Ajani; Tyvin A. Rich; Mary S. Goswitz; P.A. Evetts; Pamela K. Allen; Patrick M. Lynch; John M. Skibber

BACKGROUND AND PURPOSE To evaluate the influence of response to preoperative infusional chemoradiation on outcome parameters among patients with locally advanced rectal cancer. MATERIALS AND METHODS Preoperative chemoradiotherapy, 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-fluorouracil (300 mg/m2 per day), was given to 117 patients. As determined by pretreatment endorectal ultrasound (EUS), 96% of cases were Stage T3, and 51% had EUS evidence of perirectal adenopathy. Surgery was performed approximately 6 weeks after chemoradiation therapy. Postoperatively adjuvant systemic therapy, consisting of 400-425 mg/m2 of 5-fluorouracil plus 20 mg/m2 leucovorin for 5 days, was administered every 28 days for six cycles. Outcome parameters of local control (LC), freedom from distant metastases (DMC), disease-free survival (DFS) and cancer specific survival (CSS) were evaluated relative to primary tumor characteristics. RESULTS The final post-treatment pathological tumor stages were complete response in 27%, Tis-2 N0 in 26%, T2 N1 in 5%, T3 N0 in 21%, T3 N1 in 15%, T4 N0 in 5% and T4 N1 in 1%. Down-staging occurred in 61% of cases. The pretreatment primary tumor size only influenced rates of local control (P < 0.03) and had no other influence on outcome parameters. Pretreatment evidence of perirectal lymph node involvement had no impact on outcome parameters. Pathologic evidence of nodal involvement did affect DMC (P < 0.002) and DFS (P < 0.003). Pathologic evidence of response did influence freedom from the development of distant metastases (P < 0.004). On pairwise analysis this relationship held only when responders were compared to non-responders. No difference was observed based on the level of downstaging at the primary tumor. Correspondingly, DFS was improved when non-responders were compared to downstaged patients (P < 0.01). Response to preoperative chemoradiation failed to affect rates of LC or CSS. For the group as a whole, adjuvant chemotherapy improved only CSS (P < 0.03). Adjuvant chemotherapy was given to 74 patients, 36 of whom had responded to preoperative chemoradiation. Improvements were only seen in DFS (P < 0.03) when down-staged patients were compared to the non-responders who received adjuvant chemotherapy. In addition, the DFS rates were lower in the non-responder group who received adjuvant chemotherapy even when they were compared to down-staged patients who did not receive adjuvant chemotherapy (P < 0.04). CONCLUSION Consistent with other reports, disease free survival and subsequent development of distant metastases is reduced in the more than 60% of patients who respond to preoperative infusional chemoradiation. Evidence of response appears more significant than the degree of response. At present, no impact is seen on cancer specific survival rates. Consideration should be given for strategies that base selection of subsequent adjuvant chemotherapy on response to preoperative chemoradiation.


International Journal of Radiation Oncology Biology Physics | 2010

Management of Spinal Metastases From Renal Cell Carcinoma Using Stereotactic Body Radiotherapy

Quynh Nhu Nguyen; Almon S. Shiu; Laurence D. Rhines; He Wang; Pamela K. Allen; Xin Shelley Wang; Eric L. Chang

PURPOSE To evaluate the outcomes associated with stereotactic body radiotherapy (SBRT) in the management of spinal metastases from renal cell carcinoma (RCC). METHODS AND MATERIALS SBRT was used in the treatment of patients with spinal metastases from RCC. Patients received either 24 Gy in a single fraction, 27 Gy in three fractions, or 30 Gy delivered in five fractions. Effectiveness of SBRT with respect to tumor control and palliation of pain was assessed using patient-reported outcomes. RESULTS A total of 48 patients with 55 spinal metastases were treated with SBRT with a median follow-up time of 13.1 months (range, 3.3-54.5 months). The actuarial 1-year spine tumor progression free survival was 82.1%. At pretreatment baseline, 23% patients were pain free; at 1 month and 12 months post-SBRT, 44% and 52% patients were pain free, respectively. No Grade 3-4 neurologic toxicity was observed. CONCLUSIONS The data support SBRT as a safe and effective treatment modality that can be used to achieve good tumor control and palliation of pain associated with RCC spinal metastases. Further evaluation with randomized trials comparing SBRT to conventional radiotherapy may be warranted.


International Journal of Radiation Oncology Biology Physics | 1994

Astro research fellowship: Apoptosis as a predictor of tumor response to radiation in Stage IB cervical carcinoma

James A. Wheeler M.D.; L. Clifton Stephens; Carmen Tornos; Patricia J. Eifel; K. Kian Ang; Luka Milas; Pamela K. Allen; Raymond E. Meyn

PURPOSE Levels of apoptosis predict for tumor responsiveness to radiation in various animal systems. To investigate the potential role of apoptosis as a predictor of response in human tumors, a retrospective review was undertaken of patients with adenocarcinoma of the cervix whose primary lesion at presentation measured at least 4 cm and who underwent definitive radiation therapy. A previous report had indicated that roughly half this group of patients should have a long-term relapse free survival. METHODS AND MATERIALS Pretreatment biopsy specimens of 44 patients with Stage IB adenocarcinoma of the cervix, whose primary lesion at presentation measured at least 4 cm in greatest dimension, were scored for apoptosis by two independent investigators without knowledge of the treatment outcome, and the results were averaged. Actuarial methods were used to assess overall survival, disease-free survival, determinate survival, and local control as a function of the baseline level of apoptosis. Patients ranged in age from 21 to 87 years and were treated with definitive radiotherapy between 1964 and 1989. Follow-up for the surviving patients ranged from 1 to 278 months, with a mean of 101 months. RESULTS Patients whose tumors had a baseline level of apoptosis above the median value (2%) had a better overall survival than those with lower levels of apoptosis (p = 0.056). A similar trend for disease-free survival (p = 0.32) and determinate survival (p = 0.27) did not reach statistical significance, perhaps because of the small number of patients. Because only 6 of the 44 patients (13%) had a local tumor failure, it was not possible to establish a correlation between the pretreatment level of apoptosis and the local tumor control by radiation. CONCLUSION The baseline level of apoptosis predicted for survival in patients with Stage IB cervical adenocarcinoma. Further investigation of the measurement of apoptosis as a potential predictive assay is warranted in other human tumor systems.


Cancer | 2011

Phase 2 study of high-dose proton therapy with concurrent chemotherapy for unresectable stage III nonsmall cell lung cancer.

Joe Y. Chang; Ritsuko Komaki; Charles Lu; Hong Y. Wen; Pamela K. Allen; Anne Tsao; M Gillin; Radhe Mohan; James D. Cox

The authors sought to improve the toxicity of conventional concurrent chemoradiation therapy for stage III nonsmall cell lung cancer (NSCLC) by using proton‐beam therapy to escalate the radiation dose to the tumor. They report early results of a phase 2 study of high‐dose proton therapy and concurrent chemotherapy in terms of toxicity, failure patterns, and survival.

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Dive into the Pamela K. Allen's collaboration.

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R. Komaki

University of Texas MD Anderson Cancer Center

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Ritsuko Komaki

University of Texas MD Anderson Cancer Center

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Eric L. Chang

University of Southern California

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Daniel R. Gomez

University of Texas MD Anderson Cancer Center

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X. Wei

University of Texas MD Anderson Cancer Center

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Zhongxing Liao

University of Texas MD Anderson Cancer Center

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James W. Welsh

University of Texas MD Anderson Cancer Center

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Z. Liao

University of Texas MD Anderson Cancer Center

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