Michael Sia

University of Calgary · Department of Oncology

Purpose: To determine whether a system to estimate Absolute Percentage of Biopsied Tissue Positive for Gleason Pattern 4 (eAPP4) is useful as a prognostication tool for patients with intermediate risk prostate cancer (IR-PCa) undergoing low dose rate prostate brachytherapy. Methods: 497 patients with IR-PCa and known grade group 2 or 3 disease t...

To inform clinical practice for women receiving post-mastectomy radiotherapy (PMRT), this study demonstrates the dosimetric impact of removing daily bolus on skin and subcutaneous tissue. Two planning strategies were used: clinical field-based (n = 30) and volume-based planning (n = 10). The clinical field-based plans were created with bolus and re...

Purpose Local prostate radiotherapy (LPRT) for low burden metastatic prostate cancer (mPCa) improves overall survival and is standard of care. The role of LPRT in reducing symptomatic local events (SLE) remains unclear. We aimed to identify SLE risk factors and to evaluate the association between LPRT and SLE in mPCa. Methods and Materials We cond...

Radical treatment of localized prostate cancer in elderly patients may lead to unacceptable treatment-associated toxicities that adversely impact quality of life without improving survival outcomes. This study reports on a cohort of 54 elderly (>70 years) patients that received 4000–5000 cGy of palliative external beam radiotherapy (EBRT) as an alt...

Purpose: It has previously been shown that increased wait times for prostatectomy are associated with poorer outcomes in intermediate-risk prostatic carcinoma (PCa). However, the impact of wait times on PCa outcomes following low-dose-rate brachytherapy (LDR-BT) are unknown. Methods and materials: We retrospectively reviewed 466 intermediate-ris...

111 Background: Local prostate radiotherapy (LPRT) is associated with improved overall survival in patients with low metastatic burden (MB) and is now standard of care. However, the role of LPRT in reducing symptomatic local events (SLE) in metastatic prostate cancer (MPC) remains unclear and requires long-term follow-up. The purpose of this study...

Background: Whole breast irradiation delivered once per day over 3-5 weeks after breast conserving surgery reduces local recurrence with good cosmetic results. Accelerated partial breast irradiation (APBI) delivered over 1 week to the tumour bed was developed to provide a more convenient treatment. In this trial, we investigated if external beam A...

Aims: To evaluate the prevalence, patterns of care and outcome of pathologically node-positive (pN+) prostate cancer (P-Ca) after radical prostatectomy from a provincial population database. Patients and methods: Patients were identified from a provincial cancer registry and a genitourinary cancer outcomes unit (2005-2014). Of a total of 4723 pa...

Introduction: Residency experiences and teaching in oncology among urology residents are variable across Canada. We sought to identify how radiation and medical oncology concepts, as they pertain to genitourinary malignancies, are taught to urology residents. Methods: A total of 190 trainees enrolled in Canadian urology residency training progra...

Purpose To generate an algorithm to calculate radiobiological end-points and composite indices and use them to compare volumetric modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3D-CRT) techniques in patients with locally advanced non-small cell lung cancer (LA-NSCLC). Methods The study included 25 patients of LA-NSCLC t...

Purpose: The aim of this study is to report the long-term outcomes and toxicities from a large cohort of patients with localized prostate cancer treated with low-dose-rate intraoperatively planned brachytherapy. Methods and materials: Prostate-specific antigen levels, urinary symptoms, and erectile function were recorded at baseline, and each fo...

Purpose To develop a model for prostate specific antigen (PSA) values at one year among patients treated with intraoperatively planned ¹²⁵I prostate brachytherapy (IOPB). Material and methods Four hundred and deven patients treated with IOPB for prostate adenocarcinoma were divided into four groups: those with PSA values ≥ 3 ng/ml; < 3 and ≥ 2; <...

423Background: The purpose of this study is to examine the incidence of Second Cancers (SC) in patients with Stage I or II Seminoma treated in British Columbia (BC), and compare rates between patients managed with Radiation Therapy, Chemotherapy, or Active Surveillance. Methods: Consecutive patients with Stage I or II Seminoma (n = 1549, 21167 pers...

Introduction: We aimed to determine the impact of clinical practice guidelines (CPG) on rates of radiation oncologist (RO) referral, androgen-deprivation therapy (ADT), radiation therapy (RT), and radical prostatectomy (RP) in patients with high-risk prostate cancer (HR-PCa). Methods: All men >18 years, diagnosed with PCa in 2005 and 2012 were i...

Introduction: Adjuvant radiotherapy (aRT) can improve biochemical progression-free survival in patients with high-risk features (HRF) after radical prostatectomy (RP). Guidelines from Alberta and the Genitourinary Radiation Oncologists of Canada (GUROC) recommend that patients with HRF be referred to radiation oncologists (RO) based on the finding...

This work was supported by Cancer Research UK (C1094/A11728 to CMLW and NGB for the RAPPER study, C26900/A8740 to GCB, and C8197/A10865 to AMD), the Royal College of Radiologists (C26900/ A8740 to GCB), the National Institute for Health Research (GCB; no grant number), Addenbrooke's Charitable Trust (GCB; no grant number), Institute of Cancer Resea...

Supplementary material.

Purpose: Several small studies have indicated that the ATM rs1801516 SNP is associated with risk of normal tissue toxicity after radiotherapy. However, the findings have not been consistent. In order to test this SNP in a well-powered study, an individual patient data meta-analysis was carried out by the International Radiogenomics Consortium. Ma...

Nearly 50% of cancer patients undergo radiotherapy. Late radiotherapy toxicity affects quality-of-life in long-term cancer survivors and risk of side-effects in a minority limits doses prescribed to the majority of patients. Development of a test predicting risk of toxicity could benefit many cancer patients. We aimed to meta-analyze individual lev...

Purpose: Planning and delivery for permanent breast seed implant (PBSI) are performed with the ipsilateral arm raised; however, changes in implant geometry can be expected because of healing and anatomical motion as the patient resumes her daily activities. The purpose of this study is to quantify the effect of ipsilateral arm position on postplan...

Background and purpose: Rectal bleeding can occur following radiotherapy for prostate cancer and negatively impacts quality of life for cancer survivors. Treatment and clinical factors do not fully predict rectal bleeding, and genetic factors may be important. Materials and methods: A genome-wide association study (GWAS) was performed to identif...

Treatment outcome has been associated with dosimetric implant quality assessed in a postplan. Uncertainties during the implant and in the period before postplan evaluation lead to dosimetric deviations from the original treatment plan. The observed range of postplan results can include patients with dosimetry below recommended levels. Further treat...

To estimate the late morbidity of a novel, hypofractionated external beam radiotherapy schedule of 55 Gy in 16 fractions (4 fractions/week, 3.4 Gy per fraction) for localized prostate cancer. A multi-center phase 2 study enrolled seventy-three patients between September 2004 and June 2006. After insertion of fiducial gold markers, they were treated...

To determine if principal component analysis (PCA) and standard parameters of rectal and bladder wall dose-volume histograms (DVHs) of prostate cancer patients treated with hypofractionated image-guided intensity-modulated radiotherapy (hypo-IMRT) can predict acute and late gastrointestinal (GI) toxicity. One hundred twenty-one patients underwent h...

A study was performed to identify variables that affected cause-specific survival (CSS) and local relapse-free rate (LRFR) in patients with differentiated thyroid cancer (DTC) and extrathyroid extension (ETE) and to examine the role of external beam radiotherapy (XRT). Prognostic factors were similar to those found in studies of all patients with D...

Patients have reported late effects and symptom-related bother following postoperative radiotherapy for prostate cancer. Patients treated with postoperative radiotherapy were surveyed at a median 56 months after radiotherapy using the Prostate Cancer Radiation Therapy instrument. A retrospective review was undertaken to obtain Radiation Therapy Onc...

For patients with recurrent prostate cancer after radical prostatectomy, salvage radiotherapy is the only potentially curative treatment option. However, until recently there has been a paucity of data on the effectiveness of this approach. In light of recently published studies, the Genito-Urinary Radiation Oncologists of Canada (GUROC) met and cr...

The proper management of prostate cancer is dependent on appropriate risk categorization, based on pretreatment prostate-specific antigen (PSA), clinical stage and Gleason score (GS). The use of radiotherapy in low-risk (T1-T2a, PSA < 10 ng/ml and GS <or= 6) and intermediate-risk (T1/T2, PSA < 20 ng/ml and GS <or= 7) disease is well established, wi...

Whole brain radiotherapy (RT) is frequently used to palliate symptoms in patients with brain metastases, but the palliative benefit to patients has not been well documented. We conducted a longitudinal observational prospective study of patients receiving standard RT (20 Gray (Gy)/5 fractions) for symptomatic brain metastases. End-points were obser...

To examine the trafficking, assembly, and turnover of connexin43 (Cx43) in living cells, we used an enhanced red-shifted mutant of green fluorescent protein (GFP) to construct a Cx43-GFP chimera. When cDNA encoding Cx43-GFP was transfected into communication-competent normal rat kidney cells, Cx43-negative Madin-Darby canine kidney (MDCK) cells, or...

Gap junctions have been implicated in growth control, but it remains unclear whether cells that enter a quiescent state continue to express connexins and maintain a high level of gap junction intercellular communication (GJIC). To this end, MAC-T cells, a bovine mammary epithelial cell line, were serum starved for 48 h to induce a quiescent (G0) st...

Epithelial, fibroblast and intermediate cell lines were employed to examine the mechanism(s) essential for heterocellular gap junction intercellular communication in vitro. These cell lines were characterized extensively for cell type based on morphology, intermediate cytoskeletal proteins, cell adhesion molecules and their associated proteins, tig...

Gap junctions are protein transmembrane channels formed between apposing cells whose primary role is in mediating intercellular communication. This study addressed (1) the role of gap junctions in mammary epithelial cells during the transition from proliferation to quiescence, and (2) the mechanism of gap junction formation between different mammar...