Health Sciences Unit, Faculty of Social Sciences, Tampere University, Tampere, Finland.
Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran.
Arch Iran Med. 2021 Mar 1;24(3):167-176. doi: 10.34172/aim.2021.27.
The International Agency for Research on Cancer (IARC) recently classified opium use as a Group 1 carcinogen. However, much remains to be studied on the relation between opium and cancer. We designed the Iranian Opium and Cancer (IROPICAN) study to further investigate the association of opium use and cancers of the head and neck, bladder, lung, and colon and rectum. In this paper, we describe the rationale, design, and some initial results of the IROPICAN Study.
The IROPICAN is a multi-center case-control study conducted in 10 provinces of Iran. The cases were all histologically confirmed and the controls were selected from hospital visitors who were free of cancer, were not family members or friends of the cancer patients, and were visiting the hospital for reasons other than their own ailment. The questionnaires included detailed questions on opium use (including age at initiation, duration, frequency, typical amount, and route), and potential confounders, such as tobacco use (e.g., cigarettes, and water-pipe), and dietary factors. Biological samples, including blood and saliva, were also collected.
The validation and pilot phases showed reasonably good validity, with sensitivities of 70% and 69% for the cases and controls, respectively, in reporting opium use. The results also showed excellent reliability, with intra-class correlation coefficients of 0.96 for ever opium use and 0.88 (95% CI: 0.80, 0.92) for regular opium use. In the main phase, we recruited 3299 cancer cases (99% response rate) and 3477 hospital visitor controls (89% response rate). The proportion of ever-use of opium was 40% among cases and 18% among controls.
The IROPICAN study will serve as a major resource in studies addressing the effect of opium on risk of cancers of the head and neck, bladder, lung, and colon and rectum.
国际癌症研究机构（IARC）最近将鸦片使用归类为 1 类致癌物。然而，关于鸦片与癌症之间的关系仍有许多需要研究。我们设计了伊朗鸦片与癌症（IROPICAN）研究，以进一步调查鸦片使用与头颈部、膀胱、肺、结肠和直肠癌症之间的关联。本文介绍了 IROPICAN 研究的原理、设计和一些初步结果。
IROPICAN 是一项在伊朗 10 个省份进行的多中心病例对照研究。所有病例均经组织学证实，对照组选自医院访客，他们无癌症，不是癌症患者的亲属或朋友，并且因自身疾病以外的原因就诊医院。问卷包括关于鸦片使用（包括起始年龄、持续时间、频率、典型剂量和途径）和潜在混杂因素（如烟草使用（例如香烟和水烟）和饮食因素）的详细问题。还收集了包括血液和唾液在内的生物样本。
验证和试点阶段显示出相当好的有效性，病例和对照组报告鸦片使用的灵敏度分别为 70%和 69%。结果还显示出极好的可靠性，终生鸦片使用的组内相关系数为 0.96，定期鸦片使用的组内相关系数为 0.88（95%CI：0.80，0.92）。在主要阶段，我们招募了 3299 例癌症病例（99%的响应率）和 3477 名医院访客对照（89%的响应率）。病例组中曾经使用过鸦片的比例为 40%，对照组中为 18%。
IROPICAN 研究将成为研究鸦片对头颈部、膀胱、肺和结肠和直肠癌症风险影响的重要资源。
