Demetris Papamichael

Dr. Demetris Papamichael


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

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11 July 2014 in Annals of Oncology
Verified
Journal Article
Closed access
PDF file
DPDemetris Papamichael
Demetris Papamichael
RAR. A. Audisio
R. A. Audisio
BGB. Glimelius
B. Glimelius
AGA. de Gramont
A. de Gramont
RGR. Glynne-Jones
R. Glynne-Jones
MAM. Aapro
M. Aapro
Colorectal cancer (CRC) is one of the most commonly diagnosed cancers in Europe and worldwide, with the peak incidence in patients >70 years of age. However, as the treatment algorithms for the treatment of patients with CRC become ever more complex, it is clear that a significant percentage of older CRC patients (>70 years) are being less than optimally treated. This document provides a summary of an International Society of Geriatric Oncology (SIOG) task force meeting convened in Paris in 2013 to update the existing expert recommendations for the treatment of older (geriatric) CRC patients published in 2009 and includes overviews of the recent data on epidemiology, geriatric assessment as it relates to surgery and oncology, and the ability of older CRC patients to tolerate surgery, adjuvant chemotherapy, treatment of their metastatic disease including palliative chemotherapy with and without the use of the biologics, and finally the use of adjuvant and palliative radiotherapy in the treatment of older rectal cancer patients. An overview of each area was presented by one of the task force experts and comments invited from other task force members.

15 October 2008 in Annals of Oncology
Verified
Journal Article
Open access
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DPDemetris Papamichael
Demetris Papamichael
RAR. Audisio
R. Audisio
JHJ.-C. Horiot
J.-C. Horiot
BGB. Glimelius
B. Glimelius
JSJ. Sastre
J. Sastre
MAM. Aapro
M. Aapro
Colorectal cancer (CRC) is one of the commonest malignancies of Western countries, with approximately half the incidence occurring in patients >70 years of age. Elderly CRC patients, however, are understaged, undertreated and underrepresented in clinical trials. The International Society of Geriatric Oncology created a task force with a view to assessing the potential for developing guidelines for the treatment of elderly (geriatric) CRC patients. A review of the evidence presented by the task force members confirmed the paucity of clinical trial data in elderly people and the lack of evidence-based guidelines. However, recommendations have been proposed on the basis of the available data and on the emerging evidence that treatment outcomes for fit, elderly CRC patients can be similar to those of younger patients. It is hoped that these will pave the way for formal treatment guidelines based upon solid scientific evidence in the future.

2 February 2013 in BMC Cancer
Verified
Journal Article
Open access
PDF file
George PentheroudakisGeorge Pentheroudakis
George Pentheroudakis
VKVassiliki Kotoula
Vassiliki Kotoula
WRWendy De Roock
Wendy De Roock
GKGeorge Kouvatseas
George Kouvatseas
PPPavlos Papakostas
Pavlos Papakostas
George FountzilasGeorge Fountzilas
George Fountzilas
More than half of patients with KRAS-wild type advanced colorectal cancer (CRC) fail anti-EGFR monoclonal antibodies. We studied EGFR-axis messenger RNA (mRNA) expression and RAS, RAF, PIK3CA mutations in order to identify additional biomarkers of cetuximab efficacy.

13 August 2008 in BMC Cancer
Verified
Journal Article
Open access
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EREvangelia Razis
Evangelia Razis
EBEvangelos Briasoulis
Evangelos Briasoulis
EVEleni Vrettou
Eleni Vrettou
DSDimosthenis V Skarlos
Dimosthenis V Skarlos
DPDemetris Papamichael
Demetris Papamichael
George FountzilasGeorge Fountzilas
George Fountzilas
The epidermal growth factor receptor (EGFR) is over-expressed in 70–75% of colorectal adenocarcinomas (CRC). The anti-EGFR monoclonal antibody cetuximab has been approved for the treatment of metastatic CRC, however tumor response to cetuximab has not been found to be associated with EGFR over-expression by immunohistochemistry (IHC). The aim of this study was to explore EGFR and the downstream effector phosphatase and tensin homologue deleted on chromosome 10 (PTEN) as potential predictors of response to cetuximab. CRC patients treated with cetuximab by the Hellenic Cooperative Oncology group, whose formalin-fixed paraffin-embedded tumor tissue was available, were included. Tissue was tested for EGFR and PTEN by IHC and fluorescence in situ hybridization (FISH). Eighty-eight patients were identified and 72 were included based on the availability of tissue blocks with adequate material for analysis on them. All patients, except one, received cetuximab in combination with chemotherapy. Median follow-up was 53 months from diagnosis and 17 months from cetuximab initiation. At the time of the analysis 53% of the patients had died. Best response was complete response in one and partial response in 23 patients. In 16 patients disease stabilized. Lack of PTEN gene amplification was associated with more responses to cetuximab and longer time to progression (p = 0.042). PTEN could be one of the molecular determinants of cetuximab response. Due to the heterogeneity of the population and the retrospective nature of the study, our results are hypothesis generating and should be approached with caution. Further prospective studies are needed to validate this finding.

14 February 2014 in Therapeutic Advances in Medical Oncology
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Journal Article
Open access
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ZKZ. Kordatou
Z. Kordatou
PKP. Kountourakis
P. Kountourakis
DPDemetris Papamichael
Demetris Papamichael
In a continuously aging population, the burden of colorectal cancer (CRC) is rising among older patients. Despite the fact that almost half of the cases occur in patients over 75 years, this age group is subjected to disparities regarding diagnostic and therapeutic options. So far, exclusion of older patients from randomized clinical trials has resulted in a lack of evidence-based guidelines. Nevertheless, newer data from studies specifically targeting older patients and subgroup analyses indicate that proper treatment planning and specific medical and geriatric assessment can achieve a safe and beneficial treatment result in older patients, often with similar outcomes to their younger counterparts. Resection of the primary tumour, if feasible, should be the primary goal of surgery aiming for cure, although it should be avoided under emergency conditions. Chronological age per se should not be an exclusion criterion for adjuvant or palliative chemotherapy, or targeted therapies. Careful patient selection, dose adjustments, close monitoring and early intervention in the event of side effects are essential. The benefits of treatment must be balanced with potential effects of treatment and patients’ wishes.

1 July 2024 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
CGClaire Gallois
Claire Gallois
QSQian Shi
Qian Shi
LPLevi D. Pederson
Levi D. Pederson
TAThierry André
Thierry André
TITimothy J. Iveson
Timothy J. Iveson
DPDemetris Papamichael
Demetris Papamichael
PURPOSE: A number of studies suggest that older patients may have reduced or no benefit from the addition of oxaliplatin to fluoropyrimidines as adjuvant chemotherapy for stage III colon cancer (CC). MATERIALS AND METHODS: We studied the prognostic impact of age, as well as treatment adherence/toxicity patterns according to age, in patients with stage III CC who received 3 or 6 months of infusional fluorouracil, leucovorin, and oxaliplatin/capecitabine and oxaliplatin (CAPOX) on the basis of data collected from trials from the ACCENT and IDEA databases. Associations between age and time to recurrence (TTR), disease-free survival (DFS), overall survival (OS), survival after recurrence (SAR), and cancer-specific survival (CSS) were assessed by a Cox model or a competing risk model, stratified by studies and adjusted for sex, performance status, T and N stage, and year of enrollment. RESULTS: A total of 17,909 patients were included; 24% of patients were age older than 70 years (n = 4,340). Patients age ≥70 years had higher rates of early treatment discontinuation. Rates of grade ≥3 adverse events were similar between those older and younger than 70 years, except for diarrhea and neutropenia that were more frequent in older patients treated with CAPOX (14.2% v 11.2%; P = .01 and 12.1% v 9.6%; P = .04, respectively). In multivariable analysis, TTR was not significantly different between patients <70 years and those ≥70 years, but DFS, OS, SAR, and CSS were significantly shorter in those patients ≥70 years. CONCLUSION: In patients ≥70 years with stage III CC fit enough to be enrolled in clinical trials, oxaliplatin-based adjuvant chemotherapy was well tolerated and led to similar TTR compared with younger patients, suggesting similar efficacy. TTR may be a more appropriate end point for efficacy in this patient population.