Mahdi Sheikh

Dr. Mahdi Sheikh

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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14 November 2017 in American Journal of Epidemiology
Verified
Journal Article
Closed access
PDF file
HPHossein Poustchi
Hossein Poustchi
SESareh Eghtesad
Sareh Eghtesad
FKFarin Kamangar
Farin Kamangar
AEArash Etemadi
Arash Etemadi
AKAbbas-Ali Keshtkar
Abbas-Ali Keshtkar
RMReza Malekzadeh
Reza Malekzadeh
Noncommunicable diseases (NCDs) account for 76% of deaths in Iran, and this number is on the rise, in parallel with global rates. Many risk factors associated with NCDs are preventable; however, it is first necessary to conduct observational studies to identify relevant risk factors and the most appropriate approach to controlling them. Iran is a multiethnic country; therefore, in 2014 the Ministry of Health and Medical Education launched a nationwide cohort study—Prospective Epidemiological Research Studies in Iran (PERSIAN)—in order to identify the most prevalent NCDs among Iran’s ethnic groups and to investigate effective methods of prevention. The PERSIAN study consists of 4 population-based cohorts; the adult component (the PERSIAN Cohort Study), described in this article, is a prospective cohort study including 180,000 persons aged 35–70 years from 18 distinct areas of Iran. Upon joining the cohort, participants respond to interviewer-administered questionnaires. Blood, urine, hair, and nail samples are collected and stored. To ensure consistency, centrally purchased equipment is sent to all sites, and the same team trains all personnel. Routine visits and quality assurance/control measures are taken to ensure protocol adherence. Participants are followed for 15 years postenrollment. The PERSIAN study is currently in the enrollment phase; cohort profiles will soon emerge.

26 January 2023 in Cancers
Verified
Journal Article
Open access
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MSMahdi Sheikh
Mahdi Sheikh
GRGholamreza Roshandel
Gholamreza Roshandel
VMValerie McCormack
Valerie McCormack
RMReza Malekzadeh
Reza Malekzadeh
Esophageal cancer (EC) is the ninth most common cancer and the sixth leading cause of cancer deaths worldwide. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two main histological subtypes with distinct epidemiological and clinical features. While the global incidence of ESCC is declining, the incidence of EAC is increasing in many countries. Decades of epidemiologic research have identified distinct environmental exposures for ESCC and EAC subtypes. Recent advances in understanding the genomic aspects of EC have advanced our understanding of EC causes and led to using specific genomic alterations in EC tumors as biomarkers for early diagnosis, treatment, and prognosis of this cancer. Nevertheless, the prognosis of EC is still poor, with a five-year survival rate of less than 20%. Currently, there are significant challenges for early detection and secondary prevention for both ESCC and EAC subtypes, but Cytosponge™ is shifting this position for EAC. Primary prevention remains the preferred strategy for reducing the global burden of EC. In this review, we will summarize recent advances, current status, and future prospects of the studies related to epidemiology, time trends, environmental risk factors, prevention, early diagnosis, and treatment for both EC subtypes.

1 April 2019 in Gastroenterology
Verified
Journal Article
Closed access
MSMahdi Sheikh
Mahdi Sheikh
HPHossein Poustchi
Hossein Poustchi
APAkram Pourshams
Akram Pourshams
AEArash Etemadi
Arash Etemadi
FIFarhad Islami
Farhad Islami
RMReza Malekzadeh
Reza Malekzadeh

1 September 2021 in Annals of Internal Medicine
Verified
Journal Article
Closed access
MSMahdi Sheikh
Mahdi Sheikh
AMAnush Mukeriya
Anush Mukeriya
OSOxana Shangina
Oxana Shangina
PBPaul Brennan
Paul Brennan
DZDavid Zaridze
David Zaridze
Up to half of patients diagnosed with non–small cell lung cancer are active smokers at diagnosis. This study examined the relationship between smoking cessation after diagnosis and all-cause mortal... Visual Postdiagnosis Smoking Cessation and Lung Cancer Survival. Up to half of patients diagnosed with non–small cell lung cancer are active smokers at diagnosis. This study examined the r... Background: Lung cancer is the leading cause of cancer death worldwide, and about one half of patients with lung cancer are active smokers at diagnosis. Objective: To determine whether quitting smo...

1 May 2020 in The Lancet Global Health
Verified
Journal Article
Open access
MSMahdi Sheikh
Mahdi Sheikh
RSRamin Shakeri
Ramin Shakeri
HPHossein Poustchi
Hossein Poustchi
APAkram Pourshams
Akram Pourshams
AEArash Etemadi
Arash Etemadi
RMReza Malekzadeh
Reza Malekzadeh
Evidence is emerging for a role of opiates in various cancers. In this study, we aimed to investigate the association between regular opium use and cancer incidence. This study was done in a population-based cohort of 50 045 individuals aged 40-75 years from northeast Iran. Data on participant demographics, diet, lifestyle, opium use, and different exposures were collected upon enrolment using validated questionnaires. We used proportional hazards regression models to estimate hazard ratios (HRs) and corresponding 95% CIs for the association between opium use and different cancer types. During a median 10 years of follow-up, 1833 participants were diagnosed with cancer. Use of opium was associated with an increased risk of developing all cancers combined (HR 1·40, 95% CI 1·24-1·58), gastrointestinal cancers (1·31, 1·11-1·55), and respiratory cancers (2·28, 1·58-3·30) in a dose-dependent manner (ptrend<0·001). For site-specific cancers, use of opium was associated with an increased risk of developing oesophageal (1·38, 1·06-1·80), gastric (1·36, 1·03-1·79), lung (2·21, 1·44-3·39), bladder (2·86, 1·47-5·55), and laryngeal (2·53, 1·21-5·29) cancers in a dose-dependent manner (ptrend<0·05). Only high-dose opium use was associated with pancreatic cancer (2·66, 1·23-5·74). Ingestion of opium (but not smoking opium) was associated with brain (2·15, 1·00-4·63) and liver (2·46, 1·23-4·95) cancers in a dose-dependent manner (prend<0·01). We observed consistent associations among ever and never tobacco users, men and women, and individuals with lower and higher socioeconomic status. Opium users have a significantly higher risk of developing cancers in different organs of the respiratory, digestive, and urinary systems and the CNS. The results of this analysis show that regular use of opiates might increase the risk of a range of cancer types. World Cancer Research Fund International, Cancer Research UK, Tehran University of Medical Sciences, US National Cancer Institute, International Agency for Research on Cancer.

20 March 2019 in International Journal of Cancer
Verified
Journal Article
Closed access
PDF file
FIFarhad Islami
Farhad Islami
HPHossein Poustchi
Hossein Poustchi
APAkram Pourshams
Akram Pourshams
MKMasoud Khoshnia
Masoud Khoshnia
AGAbdolsamad Gharavi
Abdolsamad Gharavi
RMReza Malekzadeh
Reza Malekzadeh