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Featured researches published by Brian O’Sullivan.


Annals of Surgical Oncology | 2001

Malignant Gastrointestinal Stromal Tumors of the Small Intestine: A Review of 50 Cases From a Prospective Database

Jacqueline A. Crosby; Charles Catton; Aileen M. Davis; Jean Couture; Brian O’Sullivan; Rita Kandel; Carol J. Swallow

Background: Malignant gastrointestinal stromal tumors (M-GIST) are rare mesenchymal tumors originating in the wall of the gastrointestinal (GI) tract. Previous studies have included limited numbers of patients, and most included malignant and benign cases from throughout the GI tract. We reviewed the experience of a single tertiary cancer care center with M-GIST of the small intestine only.Methods: A prospective database identified all patients seen from 1989 to 1998. Clinical and pathological data, treatment, and outcome were analyzed. Overall median follow-up time was 24 months (range, 1-176 months).Results: Fifty patients (31 male, 19 female) were identified. Mean age at diagnosis was 55 years. Disease was localized in 11 patients, locally advanced (invasion into adjacent organs/peritoneum) in 24 patients, perforated in 4 patients, multiple primary lesions in 2 patients, and distant metastases in 9 patients. All patients underwent resection, which was complete in 70%. Locoregional recurrence (LR) developed in 43% (median, 25 months), and distant metastases in 59% (median, 21 months) of patients at risk. At last follow-up, 14 patients were alive (6 disease-free), 2 had died disease-free, and 34 died with recurrent disease. Overall survival (OS) was similar for localized and locally advanced disease; OS also was similar for patients with multiple primaries and distant metastases at diagnosis. Patients were grouped into three stages: (I) patients with localized and locally advanced disease; (II) patients with perforated; and (III) patients with multiple primaries and distant metastases. Actuarial OS at 5 years was 41% (n = 50)—42% for those with complete resection and 8% for incomplete resection. Univariable analysis showed that earlier stage at diagnosis (P = .001) and completeness of resection (P = .004) predicted for longer OS.Conclusions: Most patients with M-GIST of the small intestine relapse following resection, but survival may be prolonged. In univariable analysis, stage at presentation and complete resection were significant prognostic variables for OS; grade was not significant. Localized and locally advanced M-GIST of the small intestine have a mean OS > 5 years. Complete resection should be the goal of initial surgical treatment.


Journal of Clinical Oncology | 2002

Function and Health Status Outcomes in a Randomized Trial Comparing Preoperative and Postoperative Radiotherapy in Extremity Soft Tissue Sarcoma

Aileen M. Davis; Brian O’Sullivan; R. Turcotte; Charles Catton; Jay S. Wunder; P. Chabot; A. Hammond; Veronique Benk; M. Isler; C. Freeman; K. Goddard; Andrea Bezjak; Rita A. Kandel; A. Sadura; A. Day; K. James; D. Tu; J. Pater; Benny Zee

PURPOSE Morbidity associated with wound complications may translate into disability and quality-of-life disadvantages for patients treated with radiotherapy (RT) for soft tissue sarcoma (STS) of the extremities. Functional outcome and health status of extremity STS patients randomized in a phase III trial comparing preoperative versus postoperative RT is described. PATIENTS AND METHODS One hundred ninety patients with extremity STS were randomized after stratification by tumor size dichotomized at 10 cm. Function and quality of life were measured by the Musculoskeletal Tumor Society Rating Scale (MSTS), the Toronto Extremity Salvage Score (TESS), and the Short Form-36 (SF-36) at randomization, 6 weeks, and 3, 6, 12, and 24 months after surgery. RESULTS One hundred eighty-five patients had function data. Patients treated with postoperative RT had better function with higher MSTS (25.8 v 21.3, P <.01), TESS (69.8 v 60.6, P =.01), and SF-36 bodily pain (67.7 v 58.5, P =.03) scores at 6 weeks after surgery. There were no differences at later time points. Scores on the physical function, role-physical, and general health subscales of the SF-36 were significantly lower than Canadian normative data at all time points. After treatment arm was controlled for, MSTS change scores were predicted by a lower-extremity tumor, a large resection specimen, and motor nerve sacrifice; TESS change scores were predicted by lower-extremity tumor and prior incomplete excision. When wound complication was included in the model, patients with complications had lower MSTS and TESS scores in the first 2 years after treatment. CONCLUSION The timing of RT has minimal impact on the function of STS patients in the first year after surgery. Tumor characteristics and wound complications have a detrimental effect on patient function.


Annals of Surgical Oncology | 2002

Initial results of a trial of preoperative external-beam radiation therapy and postoperative brachytherapy for retroperitoneal sarcoma

Julia J. Jones; Charles Catton; Brian O’Sullivan; Jean Couture; Ryan L. Heisler; Rita A. Kandel; Carol J. Swallow

BackgroundSurgical resection alone does not cure the majority of patients with retroperitoneal sarcoma (RPS). We evaluated the effects of preoperative external-beam radiotherapy (XRT) and postoperative brachytherapy (BT) combined with complete surgical resection.MethodsFifty-five patients with primary or locally recurrent RPS judged to be resectable were entered onto a trial of combined therapy and observed prospectively. Forty-six patients underwent complete gross resection with curative intent. Of these, 41 patients completed preoperative XRT and 23 patients received BT. Outcome measures were treatment toxicity, overall survival, and disease-free survival (DFS).ResultsPreoperative XRT was very well tolerated and was associated with Radiation Therapy Oncology Group acute toxicity scores of ≤2 in all patients. Acute postoperative and BT-related toxicity resulted in modified RTOG scores of ≥3 in 39.1% (18 of 46) of patients. Late toxicity was associated with death in 4.3% (2 of 46) and with life-threatening illness in 2.2% (1 of 46) of patients, all of whom had been treated with BT to the upper abdomen. The 2-year overall survival and DFS for resected RPS were 88% and 80%, respectively. Significantly better 2-year DFS was achieved in patients with primary RPS and in those with low-grade tumors (93% and 95%, respectively).ConclusionsThe initial results of combined therapy are promising. Although preoperative XRT was very well tolerated, BT to the upper abdomen was associated with substantial toxicity. Our current protocol includes selective application of BT to the lower abdomen only.


International Journal of Radiation Oncology Biology Physics | 1998

T1/T2 GLOTTIC CANCER MANAGED BY EXTERNAL BEAM RADIOTHERAPY: THE INFLUENCE OF PRETREATMENT HEMOGLOBIN ON LOCAL CONTROL

Padraig Warde; Brian O’Sullivan; Robert G. Bristow; Tony Panzarella; Thomas J. Keane; Patrick J. Gullane; Ian P Witterick; David Payne; Fei-Fei Liu; M. McLean; John Waldron; Bernard Cummings

Abstract Purpose: Pretreatment hemoglobin (Hb) level has been reported to be an important prognostic factor for local control and survival in various malignancies. However, in many settings, the adverse effect of a low Hb may be related to more advanced disease. The purpose of this analysis was to assess the influence of pretreatment Hb on local control in a large series of patients with a localized cancer (T1/T2 glottic cancer, AJCC 1992) treated in a standard fashion. Materials and Methods: Between January 1981 and December 1989, 735 patients (median age 63; 657 males, 78 females) with T1/T2 glottic cancer were treated with radiation therapy (RT). The standard RT prescription was 50 Gy in 20 fractions over 4 weeks (97% of patients). Factors studied for prognostic importance for local failure included pretreatment Hb, age, sex, T category, anterior commissure involvement, subglottic extension, and tumor bulk (presence of visible tumor vs. subclinical disease). Results: With a median follow-up of 6.8 years (range 0.2–14.3), 131 patients have locally relapsed for an actuarial 5-year relapse-free rate of 81.7%. The 5-year actuarial survival was 75.8%. The mean pretreatment hemoglobin level was 14.8 g/dl and was similar in all prognostic categories. On multivariate analysis, using the Cox proportional hazards model, pretreatment Hb predicted for local failure after RT. The hazard ratio (HR) for relapse was calculated for various Hb levels. For example, the HR for a Hb of 12 g/dl vs. a Hb of 15 g/dl was 1.8 (95% confidence interval 1.2–2.5). Previously established factors, including gender, T category, subglottic extension, as well as tumor bulk, were also prognostically important for local control. Conclusions: This analysis, in a large number of similarly treated patients, indicates that pretreatment Hb is an independent prognostic factor for local control in patients with T1/T2 carcinoma of the glottis treated with RT. The underlying biology of this observation needs to be explored, and using this information, it may be possible to develop strategies to improve treatment outcome.


International Journal of Radiation Oncology Biology Physics | 2000

AN ANALYSIS OF 78 BREAST SARCOMA PATIENTS WITHOUT DISTANT METASTASES AT PRESENTATION

Tom McGowan; Bernard Cummings; Brian O’Sullivan; Charles Catton; Naomi Miller; Tony Panzarella

PURPOSE A retrospective review of a single cancer center experience was undertaken to identify clinical or treatment prognostic factors for these unusual tumors, to allow for a recommendation regarding management. METHODS AND MATERIALS The charts of 76 women and 2 men with breast sarcoma and without distant metastases at presentation registered from 1958 to 1990 were reviewed. Pathology was centrally reviewed in 54 cases. Histology, tumor size, grade, nodal status, age, menopausal status, history of benign breast disease, extent of surgery, resection margins, and radiation dose were each examined as potential prognostic factors by univariate analysis. To allow an analysis of radiation dose, total dose was normalized to a daily fraction size of 2 Gy. RESULTS The median age at diagnosis was 50.5 years (13-82 years). The pathologic diagnosis was found to be malignant cystosarcoma phyllodes in 32 patients, with the remainder being stromal sarcoma (14), angiosarcoma (8), fibrosarcoma (7), carcinosarcoma (5), liposarcoma (4), other (8). Eighteen patients had grade I or II tumors, 43 had grade III or IV, and 18 were not evaluable. The 5- and 10-year actuarial rates for all 78 patients were 57% and 48% for cause-specific survival (CSS), and 47% and 42% for the relapse-free rates (RFR), respectively. The local relapse-free rate (LRFR) was 75% at both 5 and 10 years. The 5-year CSS for grade I or II tumors was 84% versus 55% for grade III or IV tumors (p = 0.01). Conservative surgery versus mastectomy did not lead to statistically significant different outcomes for CSS, RFR, or LRFR. The comparison of positive versus negative margins showed a 5-year LRFR of 33% versus 80% (p = 0.009). Pairwise comparisons of the 5-year CSS of 91% for > 48 Gy versus either 50% for < or = 48 Gy or 50% for no radiation showed p-values of 0.03 and 0.06, respectively. CONCLUSION The authors propose that if negative surgical margins can be achieved, breast sarcoma should be managed by conservative surgery with postoperative irradiation to a microscopic tumoricidal dose (50 Gy) to the whole beast, and at least 60 Gy to the tumor bed. The decision to treat should be preceded by a preoperative multidisciplinary assessment. It is also recommended that an axillary lymph node dissection is not indicated, with the possible exception of patients with carcinosarcoma.


International Journal of Radiation Oncology Biology Physics | 2012

Atypical clinical behavior of p16-confirmed HPV-related oropharyngeal squamous cell carcinoma treated with radical radiotherapy.

Shao Hui Huang; Bayardo Perez-Ordonez; Fei-Fei Liu; John Waldron; Jolie Ringash; Jonathan C. Irish; Bernard Cummings; Lillian L. Siu; John Kim; Ilan Weinreb; Andrew Hope; Patrick J. Gullane; Dale H. Brown; Willa Shi; Brian O’Sullivan

PURPOSE To report atypical clinical behavior observed in human papillomavirus (HPV)-related oropharyngeal carcinoma (OPC) treated with radiotherapy. METHODS AND MATERIALS A retrospective cohort study was conducted for all newly diagnosed OPC cases treated with radiotherapy on July 1, 2003 to April 30, 2009. HPV positivity was determined by p16 immunostaining in tumors. The incidence of additional malignancies and the pattern of distant metastases (DMs) were compared between the HPV-positive (HPV+) and HPV-negative (HPV-) cohorts. RESULTS HPV status was evaluated in 318 of 613 consecutive OPC cases (52%), showing 236 HPV+ and 82 HPV- patients. Compared with HPV-, HPV+ cases were less likely to have additional malignancies (prior: 11% vs. 20%, p = 0.038; synchronous: 1% vs. 9%, p = 0.001; metachronous: 6% vs. 16%, p = 0.003). Whereas the majority (10 of 12) of HPV- additional head-and-neck (HN) mucosal malignancies were in the oral cavity, there was none (0 of 7) in the HPV+ cohort (p < 0.001). HPV+ synchronous HN second primaries (SPs) were in the supraglottis, post-cricoid, and nasopharynx; metachronous HN SPs were in the glottis, supraglottis, and ethmoid plus glottis/post-cricoid region. All SPs that could be tested were HPV+. There was no difference in DM rate (10% vs. 15%, p = 0.272), but HPV+ DMs were more likely to involve multiple organs (46% vs. 0%, p = 0.005) and unusual sites. CONCLUSIONS This study reports atypical clinical behavior seen in HPV+ OPC, including multicentric lesions in HN mucosa and DM to multiple organs and unusual sites. The frequency of these events is low, but they may have clinical implications. The routine assessment of HPV status for all OPC is warranted.


European Journal of Cancer | 2010

Nasopharyngeal carcinoma: The next challenges

Albiruni R. A. Razak; Lillian L. Siu; Fei-Fei Liu; Emma Ito; Brian O’Sullivan; Kelvin K. Chan

Nasopharyngeal carcinoma (NPC) differs from other head and neck cancers in its aetiology, epidemiology and potential therapeutic options. Despite cure for the majority of the patients, challenges still exist in the prevention of disease relapse, treatment of patients with refractory or metastatic NPC and the management of long-term toxicities. This article discusses the specific challenges in pushing the boundaries of NPC treatments further, with an emphasis on prognostic/predictive markers, molecularly targeted therapies, immunotherapies and the areas of interest with regard to long-term toxicities arising from therapeutic interventions.


Seminars in Radiation Oncology | 2003

Late radiation-related fibrosis: pathogenesis, manifestations, and current management

Brian O’Sullivan; Wilfred Levin

Radiation-induced fibrosis (RIF) represents one of the most common long-term adverse effects of curative radiotherapy. Current cancer treatment approaches, involving more intensive radiotherapy regimens, used in combination with systemic agents, will likely be associated with a higher incidence and greater degree of damage to normal tissues, especially RIF. Traditionally, the development of fibrosis after radiation therapy has been considered static and irreversible. Contemporary understanding recognizes RIF as a continuum of responses mediated by molecular pathways that may be amenable to interventions. Preliminary evidence suggests that pharmacological or other interventions may be possible to reverse the manifestation of the injury and restore function to tissues. A variety of strategies have been tested for the management of RIF, although formal trials of these therapies that permit treatment comparisons are unavailable at this time. It is critical that we formally evaluate new management approaches for RIF with larger patient accrual. To this end, it is also important to develop a means of registering its occurrence for outcome analysis and to refer these patients to colleagues familiar with optimal management and enrollment in clinical trials.


Radiotherapy and Oncology | 2012

Outcomes of HPV-related oropharyngeal cancer patients treated by radiotherapy alone using altered fractionation.

Brian O’Sullivan; Shao Hui Huang; Bayardo Perez-Ordonez; Christine Massey; Lillian L. Siu; Ilan Weinreb; Andrew Hope; John Kim; A. Bayley; Bernard Cummings; Jolie Ringash; Laura A. Dawson; B.C. John Cho; Eric X. Chen; Jonathan M. Irish; Ralph W. Gilbert; Angela Hui; Fei-Fei Liu; Helen Zhao; John Waldron; Wei Xu

PURPOSE To report outcome of HPV-related [HPV(+)] oropharyngeal cancer (OPC) managed predominantly by altered-fractionation radiotherapy-alone (RT-alone). METHODS OPCs treated with RT-alone (n = 207) or chemoradiotherapy (CRT) (n = 151) from 2001 to 2008 were included. Overall survival (OS), local (LC), regional (RC) and distant (DC) control were compared for HPV(+) vs. HPV-unrelated [HPV(-)], by RT-alone vs. CRT, and by smoking pack-years (≤ 10 vs. >10). Multivariate analysis identified predictors. RESULTS HPV(+) (n = 277) had better OS (81% vs. 44%), LC (93% vs. 76%), RC (94% vs. 79%) (all p < 0.01) but similar DC (89% vs. 86%, p = 0.87) vs. HPV(-) (n = 81). HPV(+) stage IV CRT (n = 125) had better OS (89% vs. 70%, p < 0.01), but similar LC (93% vs. 90%, p = 0.41), RC (94% vs. 90%, p = 0.31) and DC (90% vs. 83%, p = 0.22) vs. RT-alone (n = 96). Both HPV(+) RT-alone (n = 37) and CRT (n = 67) stage IV minimal smokers had favorable OS (86% vs. 88%, p = 0.45), LC (95% vs. 92%, p = 0.52), RC (97% vs. 93%, p = 0.22), and DC (92% vs. 86%, p = 0.37). RT-alone and heavy-smoking were independent predictors for lower OS but not CSS in multivariate analysis. CONCLUSIONS Overall, HPV(+) RT-alone stage IV demonstrated lower survival but comparable disease control vs. CRT, but no difference was apparent among minimal smokers.


International Journal of Radiation Oncology Biology Physics | 2001

A Phase III placebo-controlled trial of oral pilocarpine in patients undergoing radiotherapy for head-and-neck cancer.

Padraig Warde; Brian O’Sullivan; Julie Aslanidis; Barbaranne Kroll; Gina Lockwood; John Waldron; David Payne; A. Bayley; Jolie Ringash; John Kim; Fei-Fei Liu; Walter G. Maxymiw; Shelley Sprague; Bernard Cummings

PURPOSE To test the hypothesis that the use of oral pilocarpine during and after radiotherapy (RT) for head-and-neck cancer would reduce the symptoms of post-RT xerostomia. METHODS AND MATERIALS One hundred thirty patients were randomized in a double-blind method to receive either pilocarpine (5-mg tablets) or placebo three times daily starting on Day 1 of RT and continuing for 1 month after treatment. The eligibility criteria included a planned dose of >50 Gy as radical or postoperative RT for head-and-neck cancer, with at least 50% of both parotid glands included in the treatment fields. The primary outcome measure was the severity of xerostomia as assessed by a patient-completed linear analog scale 3 months after RT. Secondary outcome measures included quality of life during therapy (as assessed by the McMaster University Head-and-Neck Questionnaire) and severity of mucositis during RT (as assessed using Radiation Therapy Oncology Group scales). RESULTS No difference was observed between the pilocarpine-treated patients and the placebo group in the severity of xerostomia score as assessed by linear analog scale at baseline and 1, 3, and 6 months after treatment (repeated measures analysis, p = 0.92). No difference was apparent in the severity of mucositis during RT; 56.3% of patients receiving pilocarpine had Grade III/IV mucositis compared with 50.8% treated with placebo. No difference in quality of life was noted between the treatment groups during or after RT. The questionnaire score at 3 months after RT was 5.0 (SD 1.0). in the pilocarpine group and 4.9 (SD 0.9) in the placebo group. CONCLUSION We were unable to detect a beneficial effect of pilocarpine on RT-induced xerostomia when administered during RT for head-and-neck cancer.

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John Waldron

Princess Margaret Cancer Centre

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Jolie Ringash

Princess Margaret Cancer Centre

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Shao Hui Huang

Princess Margaret Cancer Centre

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A. Bayley

Princess Margaret Cancer Centre

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Bernard Cummings

Princess Margaret Cancer Centre

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John Kim

Princess Margaret Cancer Centre

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Andrew Hope

Princess Margaret Cancer Centre

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