Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Richard Tsang is active.

Publication


Featured researches published by Richard Tsang.


Journal of Clinical Oncology | 2003

Localized Mucosa-Associated Lymphoid Tissue Lymphoma Treated With Radiation Therapy Has Excellent Clinical Outcome

Richard Tsang; Mary K. Gospodarowicz; Melania Pintilie; Woodrow Wells; David C. Hodgson; Alexander Y. Sun; Michael Crump; Bruce Patterson

PURPOSE Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a distinct lymphoma with unique clinicopathologic features. We report the clinical outcome of stage I and II MALT lymphoma treated with involved field radiation therapy (RT). PATIENTS AND METHODS From 1989 to 2000, 103 patients with stage IE and IIE disease were referred. Their median age was 60 years, with a 2:1 female predominance. Presenting sites were stomach (17 patients), orbital adnexa (31 patients), salivary glands (24 patients), thyroid gland (13 patients), and other sites (18 patients). Ninety-three patients received RT--85 received RT alone, and eight received chemotherapy and RT--with a median dose of 30 Gy. The median follow-up time was 5.1 years. RESULTS A complete response (CR) to RT alone was achieved in 84 of 85 patients. Among CR patients, 14 experienced relapse. Relapse sites were mostly contralateral paired-organ or distant MALT locations and, infrequently, lymph nodes. The crude local control rate with RT was 95.3% (81 of 85 patients). No relapses were observed in patients with stomach or thyroid lymphoma, whereas 14 of 63 patients (22%) experienced relapse in the other sites. The overall 5-year survival rate was 98%, and the disease-free survival rate was 77%. Transformed lymphoma was observed in 14% of patients (two of 14) experiencing relapse. CONCLUSION Moderate-dose RT achieved excellent local control in localized MALT lymphomas and had curative potential for three fourths of the patients. Gastric and thyroid MALT lymphomas had better outcome, whereas distant failures were common for other sites. Despite relapse, the disease often maintained an indolent course.


Thyroid | 2009

Second Primary Malignancy Risk After Radioactive Iodine Treatment for Thyroid Cancer: A Systematic Review and Meta-analysis

Anna M. Sawka; Lehana Thabane; Luciana Parlea; Irada Ibrahim-Zada; Richard Tsang; James D. Brierley; Sharon E. Straus; Shereen Ezzat; David P. Goldstein

BACKGROUND The risk of second primary malignancies (SPMs) associated with cancer therapies is an important concern of thyroid cancer survivors and physicians. Our objective was to determine if the risk of SPMs is increased in individuals with thyroid cancer treated with radioactive iodine (RAI), compared to those not treated with RAI. METHODS We performed a systematic review of the literature and meta-analysis. Two independent reviewers screened citations and reviewed full-text papers. If not reported by the primary authors, the relative risk (RR) of SPMs was calculated by dividing the standardized incidence ratio of SPM in individuals with thyroid cancer treated with RAI compared to those not treated with RAI (with associated 95% confidence intervals [CI]). The natural logarithms of RRs of respective SPMs, weighted by the inverse of the variance, were pooled using fixed effects models and the exponential of the results was reported. RESULTS Two multi-center studies (one from Europe and the other from North America) were included in this review. The RR of SPMs in thyroid cancer survivors treated with RAI was significantly increased at 1.19 (95% confidence interval [CI] 1.04, 1.36, p = 0.010), relative to thyroid cancer survivors not treated with RAI (data from 16,502 individuals), using a minimum latency period of 2 to 3 years after thyroid cancer diagnosis. The RR of leukemia was also significantly increased in thyroid cancer survivors treated with RAI, with an RR of 2.5 (95% CI 1.13, 5.53, p = 0.024). We did not observe a significantly increased risk of the following cancers related to prior RAI treatment: bladder, breast, central nervous system, colon and rectum, digestive tract, stomach, pancreas, kidney (and renal pelvis), lung, or melanoma of skin. CONCLUSIONS The risk of SPMs in thyroid cancer survivors treated with RAI is slightly increased compared to thyroid cancer survivors not treated with RAI.


International Journal of Radiation Oncology Biology Physics | 2001

Solitary plasmacytoma treated with radiotherapy: Impact of tumor size on outcome

Richard Tsang; Mary K. Gospodarowicz; Melania Pintilie; A. Bezjak; Woodrow Wells; David C. Hodgson; A. Keith Stewart

PURPOSE Solitary plasmacytoma (SP) is a rare presentation of plasma cell neoplasms. In contrast to multiple myeloma, long-term disease-free survival and cure is possible following local radiotherapy (RT), particularly for soft tissue presentations. In this study, we attempt to identify factors that predict for local failure, progression to multiple myeloma, and disease-free survival (DFS) in patients mainly managed with local RT. METHODS AND MATERIALS We identified 46 patients referred to the Princess Margaret Hospital between 1982 and 1993. The median age was 63 years (range 35-95), with a male:female ratio of 1.9:1. All patients had biopsy-proven SP (osseous: 32, soft tissue: 14). M-protein was abnormal in 19 patients (41%). All patients were treated with local RT (median dose 35 Gy), with 5 patients (11%) also receiving chemotherapy. Maximum tumor size pre-RT ranged from 0 to 18 cm (median 2.5). RESULTS The 8-year overall survival, DFS, and myeloma-free rates were 65%, 44%, and 50%, respectively. The local control rate was 83%. Factors predictive of progression to myeloma (and poorer DFS) included bone presentation and older age. However, these two factors did not influence local control, which was affected by tumor size. All tumors < 5 cm in bulk (34 patients) were controlled by RT. Anatomic location did not predict outcome; however, 3 of the 5 tumors arising in paranasal sinuses did not achieve local control. Lower RT dose (< or =35 Gy) was not associated with a higher risk of local failure. CONCLUSION Solitary plasmacytomas are effectively treated with moderate-dose RT, although osseous tumors have a high rate of recurrence as systemic myeloma. Large tumor bulk locally (> or =5 cm) predicts for local failure. Combined chemotherapy and RT should be investigated in these high-risk patients to increase the local control rate and the cure rate.


Cancer | 2007

Clinical management and outcome of papillary and follicular (differentiated) thyroid cancer presenting with distant metastasis at diagnosis

Elliot Sampson; James D. Brierley; Lisa W. Le; Lorne Rotstein; Richard Tsang

Differentiated thyroid cancer has a good prognosis and only rarely presents with distant metastasis at diagnosis. The clinical outcome of this presentation was assessed with respect to survival and factors that may determine prognosis.


Journal of Clinical Oncology | 2005

Primary CNS Lymphoma of T-Cell Origin: A Descriptive Analysis From the International Primary CNS Lymphoma Collaborative Group

Tamara Shenkier; Jean Yves Blay; Brian Patrick O'Neill; Philip Poortmans; Eckhard Thiel; Kristoph Jahnke; Lauren E. Abrey; Edward A. Neuwelt; Richard Tsang; Tracy T. Batchelor; Nancy Lee Harris; Andrés J.M. Ferreri; Maurilio Ponzoni; Peter O'Brien; James L. Rubenstein; Joseph M. Connors

PURPOSE To describe the demographic and tumor related characteristics and outcomes for patients with primary T-cell CNS lymphoma (TPCNSL). PATIENTS AND METHODS A retrospective series of patients with TPCNSL was compiled from twelve cancer centers in seven countries. RESULTS We identified 45 patients with a median age of 60 years (range, 3 to 84 years). Twenty (44%) had Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1. Twenty-six (58%) had involvement of a cerebral hemisphere and sixteen (36%) had lesions of deeper sites in the brain. Serum lactate dehydrogenase was elevated in 7 (32%) of 22 patients, and CSF protein was elevated in 19 of 24 patients (79%) with available data. The median disease-specific survival (DSS) was 25 months (95% CI, 11 to 38 months). The 2- and 5-year DSS were 51% (95% CI, 35% to 66%) and 17% (95% CI, 6% to 34%), respectively. Univariate and multivariate analyses were conducted for age (</= 60 v > 60 years), PS (0 or 1 v 2, 3, or 4), involvement of deep structures of the CNS (no v yes), and methotrexate (MTX) use in the primary treatment (yes v no). Only PS and MTX use were significantly associated with better outcome with hazard ratios of 0.2 (95% CI, 0.1 to 0.4) and 0.4 (95% CI, 0.2 to 0.8), respectively. CONCLUSION This is the largest series ever assembled of TPCNSL. The presentation and outcome appear similar to that of B cell PCNSL. PS 0 or 1 and administration of MTX are associated with better survival.


International Journal of Radiation Oncology Biology Physics | 2001

Stage I and II MALT lymphoma : results of treatment with radiotherapy

Richard Tsang; Mary K. Gospodarowicz; Melania Pintilie; A. Bezjak; Woodrow Wells; David C. Hodgson; Michael Crump

PURPOSE Mucosa-associated lymphoid tissue (MALT) lymphoma is a distinct disease with specific clinical and pathologic features that may affect diverse organs. We analyzed our recent experience with Stage I/II MALT lymphoma presenting in the stomach and other organs to assess the outcome following involved field radiation therapy (RT). PATIENTS AND METHODS Seventy patients with Stage IE (62) and IIE (8) disease were treated between 1989 and 1998. Patients with transformed MALT were excluded. The median age was 62 years (range, 24--83 years), M:F ratio 1:2.2. Presenting sites included stomach, 15; orbital adnexa, 19; salivary glands, 15; thyroid, 8; lung, 5; upper airways, 3 (nasopharynx, 2; larynx, 1); urinary bladder, 3; breast, 1; and rectum, 1. Staging included site-specific imaging, CT abdomen in 66 patients (94%) and bone marrow biopsy in 54 (77%). Sixty-two patients received radiation therapy: 52 received RT alone, 7 received chemotherapy and RT, and 3 received antibiotics followed by RT. Median RT dose was 30 Gy (range, 17.5--35 Gy). Most frequently used RT prescriptions were 25 Gy (26 patients-18 orbit, 6 stomach, and 2 salivary glands), 30 Gy (23 patients), and 35 Gy (8 patients). Five patients had complete surgical excision of lymphoma and no other treatment (stomach 1, salivary 2, lung 2), whereas 2 patients with gastric lymphoma received antibiotics only. One patient refused treatment and was excluded from the analysis of treatment outcome, leaving 69 patients with a median follow-up of 4.2 years (range, 0.3-11.4 years). RESULTS A complete response was achieved in 66/69 patients, and 3 patients had partial response (2 lung, 1 orbit). The 5-year disease-free survival (DFS) was 76%, and the overall survival was 96%. No relapses were observed in patients with stomach and thyroid lymphoma. The 5-year DFS for these patients was 93%, in contrast to 69% for patients presenting in other sites (p = 0.006). Among the 5 patients treated with surgery only, 2 relapsed locally (lung, and minor salivary gland). Among 62 patients who received RT, 8 relapsed (2 salivary, 3 orbit, 1 nasopharynx, 1 larynx, 1 breast). Three patients relapsed in the nonirradiated contralateral paired organ, 4 in distant sites, and 1 in both local and distant sites. The overall local control rate with radiation was 97% (60/62 patients). CONCLUSION Localized MALT lymphomas have excellent prognosis following moderate-dose RT. Gastric and thyroid MALT lymphomas have better early outcome, as compared to the other sites where distant failure is more common. Relapses were observed in nonirradiated paired organs or distant sites. Further follow-up is required to assess the impact of failure on survival.


International Journal of Radiation Oncology Biology Physics | 2000

Results of radiotherapy for epithelial skin cancer of the pinna : The Princess Margaret Hospital Experience, 1982-1993

Joaquin J. Silva; Richard Tsang; Tony Panzarella; W. Levin; Woodrow Wells

PURPOSE To assess the treatment outcome, late toxicity, and prognostic factors for radiotherapy (RT) of carcinoma of the pinna. METHODS AND MATERIALS The charts of 313 patients treated between 01/82 and 12/93 were retrospectively reviewed. There were 334 lesions treated: 201 basal cell carcinoma (BCC), 122 squamous cell carcinoma (SCC), and 11 basosquamous carcinoma. RT was most commonly given by orthovoltage X-rays (278 lesions) or electrons (39 lesions). The most frequently used dose prescriptions were 35 Gy in 5 fractions (123 treatments with median field size = 4.9 cm(2)), 42. 5-45 Gy in 10 fractions (67 treatments with median field size = 10.5 cm(2)), and 50-65 Gy in 20-30 fractions (42 treatments with median field size = 81 cm(2)).2 cm. RESUL TS: The actuarial 2- and 5-year local control rates were 86.6% and 79.2 %. Multivariate analysis revealed two factors to be statistically signi ficant for increased local failure: tumor size > 2 cm (hazard ratio [HR] = 2.66, 95% confidence interval [CI] = 1.16-6.08), and a low biological effective dose (BED) (for each decrease of 5 BED units, HR = 1.76, 95% CI = 1.07-2.88). The 5-year actuarial rate of significant Grade 4 late toxicity was 7.3%. Factors statistically significant for this endpoint on univariate analysis were tumor size (p = 0.035), T-stage (p = 0.02), field size (p = 0.05), fraction size (p = 0.003), and BED (p = 0.05). CONCLUSIONS RT is an eff ctive treatment option for epithelial skin cancer of the pinna. Large t umor size and low BED were independently statistically significantly ass ociated with increased local failure. Dose-fractionation schedules usin g fraction sizes < 4 Gy may reduce the risk of necrosis and ulceration, particularly for field sizes > 5 cm2.


BMC Cancer | 2006

Prognostic factors in solitary plasmacytoma of the bone: a multicenter Rare Cancer Network study

David Knobel; Abderrahim Zouhair; Richard Tsang; Philip Poortmans; Yazid Belkacemi; Michel Bolla; Fazilet Dinçbas Oner; Christine Landmann; Bernard Castelain; Mahmut Ozsahin

BackgroundSolitary plasmacytoma (SP) of the bone is a rare plasma-cell neoplasm. There are no conclusive data in the literature on the optimal radiation therapy (RT) dose in SP. Therefore, in this large retrospective study, we wanted to assess the outcome, prognostic factors, and the optimal RT dose in patients with SP.MethodsData from 206 patients with bone SP without evidence of multiple myeloma (MM) were collected. Histopathological diagnosis was obtained for all patients. The majority (n = 169) of the patients received RT alone; 32 chemotherapy and RT, and 5 surgery. Median follow-up was 54 months (7–245).ResultsFive-year overall survival, disease-free survival (DFS), and local control was 70%, 46%, and 88%; respectively. Median time to MM development was 21 months (2–135) with a 5-year probability of 51%. In multivariate analyses, favorable factors were younger age and tumor size < 5 cm for survival; younger age for DFS; anatomic localization (vertebra vs. other) for local control. Older age was the only predictor for MM. There was no dose-response relationship for doses 30 Gy or higher, even for larger tumors.ConclusionYounger patients, especially those with vertebral localization have the best outcome when treated with moderate-dose RT. Progression to MM remains the main problem. Further investigation should focus on adjuvant chemotherapy and/or novel therapeutic agents.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2008

Solitary extramedullary plasmacytoma of the head and neck—Long-term outcome analysis of 68 cases

Gideon Bachar; David B. Goldstein; Dale H. Brown; Richard Tsang; Gina Lockwood; Bayardo Perez-Ordonez; Jonathan M. Irish

Head and neck solitary extramedullary plasmacytomas are rare plasma cell neoplasms. Literature review reveals only small numbers of reports. The objective was to review our experience with treating patients with this neoplasm.


Cancer | 2006

Clinical outcome of anaplastic thyroid carcinoma treated with radiotherapy of once‐ and twice‐daily fractionation regimens

Yongjin Wang; Richard Tsang; Sylvia L. Asa; Brendan C. Dickson; Tamara Arenovich; James D. Brierley

The purpose was to assess local control, survival, and toxicity after radiotherapy in patients with anaplastic thyroid carcinoma, and to compare clinical outcomes between once‐daily and twice‐daily fractionation regimens.

Collaboration


Dive into the Richard Tsang's collaboration.

Top Co-Authors

Avatar

James D. Brierley

Princess Margaret Cancer Centre

View shared research outputs
Top Co-Authors

Avatar

Michael Crump

Princess Margaret Cancer Centre

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

John Kuruvilla

Princess Margaret Cancer Centre

View shared research outputs
Top Co-Authors

Avatar

Melania Pintilie

Princess Margaret Cancer Centre

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

David P. Goldstein

Princess Margaret Cancer Centre

View shared research outputs
Top Co-Authors

Avatar

Anna M. Sawka

University Health Network

View shared research outputs
Top Co-Authors

Avatar

Lorne Rotstein

University Health Network

View shared research outputs
Top Co-Authors

Avatar

Vishal Kukreti

Princess Margaret Cancer Centre

View shared research outputs
Researchain Logo
Decentralizing Knowledge