Mark Clemons

Dr. Mark Clemons

orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

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

Representative Publications

View All Publications
25 September 2013 in Breast Cancer Research
Verified
Journal Article
Open access
PDF file
RDRebecca A Dent
Rebecca A Dent
GLGeoffrey J Lindeman
Geoffrey J Lindeman
MCMark Clemons
Mark Clemons
HWhans wildiers
hans wildiers
ACArlene Chan
Arlene Chan
JCJames Carmichael
James Carmichael
Introduction: This Phase I study evaluated the safety, tolerability and efficacy of olaparib, a potent oral poly(ADP-ribose) polymerase (PARP) inhibitor, in combination with paclitaxel in patients with metastatic triple-negative breast cancer (mTNBC). Methods: Eligible patients who had received ≤1 prior cytotoxic regimen for mTNBC were treated with olaparib 200 mg bid continuously plus weekly paclitaxel 90 mg/m2 for three weeks per four-week cycle. Dose modifications in a large proportion of patients due to neutropenia resulted in enrollment of a second cohort of patients who, if they experienced grade ≥2 neutropenia in cycle 1, received granulocyte-colony stimulating factor, which was continued prophylactically in subsequent cycles. All patients had measurable disease; tumor responses were evaluated according to RECIST (version 1.0). Results: Nineteen patients (cohort 1, n = 9; cohort 2, n = 10) received treatment; 15 had received prior taxane chemotherapy. The most frequent adverse events were diarrhea (n = 12, 63%), nausea (n = 11, 58%) and neutropenia (n = 11, 58%). Seven neutropenia events were reported in cohort 1 (four grade ≥3) and four in cohort 2 (two grade ≥3, including one event of febrile neutropenia). The median (range) dose intensity of paclitaxel was 57% (26 to 100%) in cohort 1 and 73% (29 to 100%) in cohort 2. Seven patients (37%) had a confirmed partial response; one patient remains on olaparib monotherapy without progression. Conclusions: The combination of olaparib and weekly paclitaxel was complicated by a significant clinical interaction, with higher-than-expected rates of neutropenia despite secondary prophylaxis. Given the encouraging response rate, alternative scheduling and dosing strategies should be considered (funded by AstraZeneca; ClinicalTrials.gov, NCT00707707).

10 December 2019 in Systematic Reviews
Verified
Journal Article
Open access
PDF file
MPMisty Pratt
Misty Pratt
ASAdrienne Stevens
Adrienne Stevens
MTMicere Thuku
Micere Thuku
CBClaire Butler
Claire Butler
BSBecky Skidmore
Becky Skidmore
BHBrian Hutton
Brian Hutton
Background: There has been increased interest in the role of cannabis for treating medical conditions. The availability of different cannabis-based products can make the side effects of exposure unpredictable. We sought to conduct a scoping review of systematic reviews assessing benefits and harms of cannabis-based medicines for any condition.Methods: A protocol was followed throughout the conduct of this scoping review. A protocol-guided scoping review conduct. Searches of bibliographic databases (e.g., MEDLINE®, Embase, PsycINFO, the Cochrane Library) and gray literature were performed. Two people selected and charted data from systematic reviews. Categorizations emerged during data synthesis. The reporting of results from systematic reviews was performed at a high level appropriate for a scoping review.Results: After screening 1975 citations, 72 systematic reviews were included. The reviews covered many conditions, the most common being pain management. Several reviews focused on management of pain as a symptom of conditions such as multiple sclerosis (MS), injury, and cancer. After pain, the most common symptoms treated were spasticity in MS, movement disturbances, nausea/vomiting, and mental health symptoms. An assessment of review findings lends to the understanding that, although in a small number of reviews results showed a benefit for reducing pain, the analysis approach and reporting in other reviews was sub-optimal, making it difficult to know how consistent findings are when considering pain in general. Adverse effects were reported in most reviews comparing cannabis with placebo (49/59, 83%) and in 20/24 (83%) of the reviews comparing cannabis to active drugs. Minor adverse effects (e.g., drowsiness, dizziness) were common and reported in over half of the reviews. Serious harms were not as common, but were reported in 21/59 (36%) reviews that reported on adverse effects. Overall, safety data was generally reported study-by-study, with few reviews synthesizing data. Only one review was rated as high quality, while the remaining were rated of moderate (n= 36) or low/critically low (n= 35) quality.Conclusions: Results from the included reviews were mixed, with most reporting an inability to draw conclusions due to inconsistent findings and a lack of rigorous evidence. Mild harms were frequently reported, and it is possible the harms of cannabis-based medicines may outweigh benefits.Systematic review registration: The protocol for this scoping review was posted in the Open Access (https://ruor.uottawa.ca/handle/10393/37247).

1 March 2022 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
AEAndrea Eisen
Andrea Eisen
MSMark R. Somerfield
Mark R. Somerfield
MAMelissa K. Accordino
Melissa K. Accordino
PBPhillip S. Blanchette
Phillip S. Blanchette
MCMark Clemons
Mark Clemons
CPCatherine H. Van Poznak
Catherine H. Van Poznak
PURPOSE: To update recommendations of the American Society of Clinical Oncology (ASCO)-Ontario Health (Cancer Care Ontario [CCO]) adjuvant bone-modifying agents in breast cancer guideline. METHODS: An Expert Panel conducted a systematic review to identify new, potentially practice-changing data. RESULTS: Four articles met eligibility criteria and form the evidentiary basis for revision of the previous recommendations. RECOMMENDATIONS: Adjuvant bisphosphonate therapy should be discussed with all postmenopausal patients (natural or therapy-induced) with primary breast cancer, irrespective of hormone receptor status and human epidermal growth factor receptor 2 status, who are candidates to receive adjuvant systemic therapy. Adjuvant bisphosphonates, if used, are not substitutes for standard anticancer modalities. The benefit of adjuvant bisphosphonate therapy will vary depending on the underlying risk of recurrence and is associated with a modest improvement in overall survival. The NHS PREDICT tool provides estimates of the benefit of adjuvant bisphosphonate therapy and may aid in decision making. Factors influencing the decision to recommend adjuvant bisphosphonate use should include patients' risk of recurrence, risk of side effects, financial toxicity, drug availability, patient preferences, comorbidities, and life expectancy. When an adjuvant bisphosphonate is used to prevent breast cancer recurrence, the therapeutic options recommended by the Panel include oral clodronate, oral ibandronate, and intravenous zoledronic acid. The Panel supports starting bisphosphonate therapy early, consistent with the points outlined in the parent CCO-ASCO guideline; this is a consensus recommendation. The Panel does not recommend adjuvant denosumab to prevent breast cancer recurrence, because studies did not show a consistent reduction of breast cancer recurrence in any subset of those with early-stage breast cancer. Additional information can be found at www.asco.org/breast-cancer-guideline .

1 December 2013 in Journal of Bone Oncology
Verified
Journal Article
Open access
IKI. Kuchuk
I. Kuchuk
BHBrian Hutton
Brian Hutton
PMP. Moretto
P. Moretto
TNT. Ng
T. Ng
CAC.L. Addison
C.L. Addison
MCMark Clemons
Mark Clemons
There is a paucity of literature about the benefits of bone-targeted agents for breast cancer patients with bone metastases treated in the non-trial setting. We explored the incidence, consequences, and treatment of bone metastases at a single cancer centre. Electronic records of metastatic breast cancer patients were reviewed and pertinent information was extracted. Of 264 metastatic breast cancer patients, 195 (73%) developed bone metastases. Of these patients, 176 were eligible for analysis. Median age at bone metastases diagnosis was 56.9 years (IQR 48-67) and initial presentation of bone metastases included asymptomatic radiological findings (58%), bone pain (40%), or a SRE (12.5%). Most patients (88%) received a bone-targeted agent, starting a median of 1.5 months (IQR 0.8-3.30) after bone metastasis diagnosis. 62% of patients had ≥1 SRE. The median time from bone metastasis diagnosis to first SRE was 1.8 months (IQR 0.20-8.43 months). Median number of SREs per patient was 1.5 (IQR 0-3). Overall, 26.8% of all SREs were clinically asymptomatic. Within the entire cohort, 51% required opioids and 20% were hospitalized due to either an SRE or bone pain. Despite extensive use of bone-targeted agents, the incidence of SREs remains high. Nearly half of SREs occur prior to starting a bone-targeted agent. Use of opioids and hospitalizations secondary to bone metastases remain common. More effective treatment options are clearly needed.

16 October 2013 in Breast Cancer Research and Treatment
Verified
Journal Article
Closed access
PDF file
IKI. Kuchuk
I. Kuchuk
NBN. Bouganim
N. Bouganim
KBK. Beusterien
K. Beusterien
JGJ. Grinspan
J. Grinspan
LVL. Vandermeer
L. Vandermeer
MCMark Clemons
Mark Clemons

28 January 2014 in The Oncologist
Verified
Journal Article
Closed access
PDF file
KBKathleen Beusterien
Kathleen Beusterien
JGJessica Grinspan
Jessica Grinspan
IKIryna Kuchuk
Iryna Kuchuk
SMSasha Mazzarello
Sasha Mazzarello
SDSusan Dent
Susan Dent
MCMark Clemons
Mark Clemons
Objective.: Our objective was to evaluate preferences associated with grade I/II and grade III/IV chemotherapy side effects among breast cancer patients receiving chemotherapy. We also assessed trade-offs that patients are willing to make between treatment side effects and the route and schedule of treatment administration. Methods.: In this cross-sectional study, patients receiving chemotherapy for breast cancer completed a one-time Web survey. Conjoint analysis was used to elicit preferences for 17 grade I/II and III/IV side effects associated with available chemotherapies and regimens. In the analysis, the risk of each side effect was increased by 5%, holding all others constant, and the respective impact on patient preferences was identified. Results.: A total of 102 women participated (mean age 54 ± 11). Among the grade I/II side effects, a 5% reduction in the risk of sensory neuropathy, nausea, and motor neuropathy had the highest impact on preferences. Among grade III/IV side effects, motor neuropathy, nausea/vomiting, and myalgia made the most difference. An oral twice-daily regimen was most preferred; however, patients were willing to receive an intravenous regimen relative to oral to avoid an increased risk of 5% in the majority of side effects. Avoiding an increased chance of grade III/IV motor neuropathy was associated with willingness to tolerate one of the least preferred administration schedules. Conclusion.: This study identified relative preferences among both mild/moderate to severe side effects from the patient perspective. Patients appear to be willing to make trade-offs between side effects and different regimens. These findings may help to inform medical decision-making processes.