Michael Vickers

Dr. Michael Vickers

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 May 2021 in World Journal of Gastroenterology
Verified
Journal Article
Open access
MRMichael N Rosen
Michael N Rosen
RGRachel A Goodwin
Rachel A Goodwin
Michael VickersMichael Vickers
Michael Vickers
BRCA mutated pancreatic cancer: A change is coming

5 July 2019 in BMC Cancer
Verified
Journal Article
Open access
PDF file
SDShaan Dudani
Shaan Dudani
HMHoria Marginean
Horia Marginean
PTPatricia Tang
Patricia Tang
JMJose G. Monzon
Jose G. Monzon
SRSoundouss Raissouni
Soundouss Raissouni
Michael VickersMichael Vickers
Michael Vickers
A standard therapy for locally advanced rectal cancer (LARC) includes fluoropyrimidine (FP)-based neoadjuvant chemoradiation (nCRT). Previous studies have inconsistently demonstrated that baseline neutrophil- and platelet-to-lymphocyte ratios (NLR and PLR) are predictive of response to nCRT or prognostic of outcomes in LARC. We reviewed patients with LARC undergoing nCRT followed by surgery from 2005 to 2013 across 8 Canadian cancer centres. Outcome measures of interest were pathological complete response (pCR), disease-free survival (DFS) and overall survival (OS). Logistic regression and Cox proportional hazard models were used to assess for associations between baseline hematologic variables and outcomes. Of 1527 identified patients, 1237 (81%) were included in the DFS/OS analysis. Median age was 62 (range 23–88), 69% were male, and 80% had performance status (PS) 0–1. Twenty-six percent had elevated NLR (≥ 4), and 66% had elevated PLR (≥ 150). Ninety-seven percent of patients received FP-based nCRT, with 96% receiving ≥44 Gy. 81% completed neoadjuvant chemotherapy and 95% completed neoadjuvant radiotherapy, with a pCR rate of 18%. After a median follow-up time of 71 months, 8% developed local recurrence, 22% developed distant recurrence and 24% died. 5-year DFS and OS were 69% (95% CI 66–72%) and 79% (95% CI 77–82%), respectively. In multivariate analyses, elevated baseline NLR and PLR were neither prognostic for DFS and OS nor predictive of pCR. NLR and PLR were not found to be independently prognostic for DFS or OS and did not predict for pCR in patients with LARC undergoing nCRT followed by surgery.

1 June 2015 in Canadian Journal Of Surgery
Verified
Journal Article
Closed access
AIAmal Imbulgoda
Amal Imbulgoda
AMAnthony MacLean
Anthony MacLean
JHJohn Heine
John Heine
SDSebastien Drolet
Sebastien Drolet
Michael VickersMichael Vickers
Michael Vickers
Self-expanding metal stents (SEMS) are increasingly used in the treatment of malignant large bowel obstruction in the setting of inoperable colorectal cancer. Perforation is a well-known complication associated with these devices. The addition of the vascular endothelial growth factor inhibitor bevacizumab is suspected to increase the rate, but the extent of the increase is not known. We retrospectively reviewed the records of patients receiving SEMS in tertiary hospitals in Calgary, Alta., between October 2001 and January 2012. We reviewed the records of 87 patients with inoperable colorectal cancer who received SEMS during our study period. Nine perforations occurred in total: 4 of 30 (13%) patients who received no chemotherapy, 3 of 47 (6%) who received chemotherapy but no bevacizumab, and 2 of 10 (20%) who received chemotherapy and bevacizumab. These two patients received bevacizumab with FOLFIRI after SEMS placement, and they had peritoneal disease. Our case series and other studies suggest that bevacizumab may increase the risk of colonic perforation in the setting of SEMS. Caution should be used when combining these therapies.

30 July 2015 in Annals of Oncology
Verified
Journal Article
Closed access
PDF file
DJDi (Maria) Jiang
Di (Maria) Jiang
SRS. Raissouni
S. Raissouni
JMJ. Mercer
J. Mercer
AKA. Kumar
A. Kumar
RGR. Goodwin
R. Goodwin
Michael VickersMichael Vickers
Michael Vickers
Studies of clinical outcomes of elderly patients treated with neoadjuvant chemoradiation (nCRT) for locally advanced rectal cancer (LARC) are limited. Our aim was to assess the impact of age on clinical outcomes in a large multi-institutional database. Data for patients diagnosed with LARC who received nCRT and curative-intent surgery between 2005 and 2012 were collected from five major Canadian cancer centers. Age was analyzed as a continuous and dichotomous variable (<70 versus ≥70 years) and correlated with disease-free survival (DFS), cancer-specific survival (CSS) and overall survival (OS). Cox regression models were used to adjust for important prognostic factors. Of 1172 patients included, 295 (25%) were ≥70 years, and they were less likely to receive adjuvant chemotherapy (ACT; 60% versus 79%, P < 0.0001), oxaliplatin-based ACT (12% versus 31%, P < 0.0001), less likely to complete nCT (76% versus 86%, P < 0.001), and more likely to be anemic at initiation of nCRT (42% versus 30%, P = 0.0004). In multivariate analyses, age ≥70 years was associated with similar DFS [hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.68–1.26, P = 0.63], similar CSS (HR 0.81, 95% CI 0.46–1.41, P = 0.45), and similar OS (HR 1.28, 95% CI 0.88–1.86, P = 0.20), compared with the younger age group. As a continuous variable, increasing age was not predictive of DFS (HR 1.00, 95% CI 0.99–1.02, P = 0.49) or CSS (HR 1.002, 95% CI 0.98–1.02, P = 0.88); however, it correlated with an inferior OS (HR 1.02, 95% CI 1.00–1.03, P = 0.04). Elderly patients (≥70 years) who receive nCRT followed by surgery appear to have similar outcomes compared with younger patients. Decisions regarding eligibility for nCRT and surgery should not be based on age alone.

1 September 2016 in Clinical Colorectal Cancer
Verified
Journal Article
Closed access
DJDi (Maria) Jiang
Di (Maria) Jiang
KDKristopher Dennis
Kristopher Dennis
ASAndrew Steinmetz
Andrew Steinmetz
MCMark Clemons
Mark Clemons
TATimothy R. Asmis
Timothy R. Asmis
Michael VickersMichael Vickers
Michael Vickers

14 February 2019 in BMC Cancer
Verified
Journal Article
Open access
PDF file
OKOmar Farooq Khan
Omar Farooq Khan
ECEllen Cusano
Ellen Cusano
SRSoundouss Raissouni
Soundouss Raissouni
MPMica Pabia
Mica Pabia
JHJohanna Haeseker
Johanna Haeseker
PTPatricia Tang
Patricia Tang
Cognitive impairment is commonly reported in patients receiving chemotherapy, but the acuity of onset is not known. This study utilized the psychomotor vigilance test (PVT) and trail-making test B (TMT-B) to assess cognitive impairment immediately post-chemotherapy. Patients aged 18–80 years receiving first-line intravenous chemotherapy for any stage of breast or colorectal cancer were eligible. Patient symptoms, peripheral neuropathy and Stanford Sleepiness Scale were assessed. A five-minute PVT and TMT-B were completed on a tablet computer pre-chemotherapy and immediately post-chemotherapy. Using a mixed linear regression model, changes in reciprocal transformed PVT reaction time (mean 1/RT) were assessed. A priori, an increase in median PVT reaction times by > 20 ms (approximating PVT changes with blood alcohol concentrations of 0.04–0.05 g%) was considered clinically relevant. One hundred forty-two cancer patients (73 breast, 69 colorectal, median age 55.5 years) were tested. Post-chemotherapy, mean 1/RT values were significantly slowed compared to pre-chemotherapy baseline (p = 0.01). This corresponded to a median PVT reaction time slowed by an average of 12.4 ms. Changes in PVT reaction times were not correlated with age, sex, cancer type, treatment setting, or use of supportive medications. Median post-chemotherapy PVT reaction time slowed by an average of 22.5 ms in breast cancer patients and by 1.6 ms in colorectal cancer patients. Post-chemotherapy median PVT times slowed by > 20 ms in 57 patients (40.1%). Exploratory analyses found no statistically significant association between the primary outcome and self-reported anxiety, fatigue or depression. TMT-B completion speed improved significantly post-chemotherapy (p = 0.03), likely due to test-retest phenomenon. PVT reaction time slowed significantly immediately post-chemotherapy compared to a pre-chemotherapy baseline, and levels of impairment similar to effects of alcohol consumption in other studies was seen in 40% of patients. Further studies assessing functional impact of cognitive impairment on patients immediately after chemotherapy are warranted.