- • There was a positive relationship between the O&D use and the increased risk of PC.
- • PC was higher among participants starting the use of O&D at a younger age than those who started at an older age.
- • A significant dose-response relation was detected between the use of O&D; the relation was stronger in heavy users.
Pancreatic cancer (PC) is ranked as the seventh leading cause of cancer deaths worldwide. The current study was conducted to explore the correlation between the use of opium and its derivatives (opium) and PC in Iran.
In this case-control study which was conducted in Kerman province, south east part of Iran; 176 patients with PC, and 352 healthy individuals as the control group were matched in terms of age, sex, and place of residence. A structured questionnaire including questions of opium usage, alcohol usage, cigarette smoking, and diet was used to collect the data. The relation between the use of opium and PC was adjusted for tobacco smoking, education, daily intake of fruit, vegetables, red meat, and hydrogenated fats and analyzed using the conditional logistic regression.
There was a positive relationship between the opium use and the increased risk of PC (Adjusted Odds Ratio (AOR) = 4.33, 95 % CI: 2.09–8.95), which was even stronger than its association with cigarette smoking (AOR = 1.67, 95 % CI: 0.86–3.24), although their difference was not statistically significant. A significant dose-response relation was detected between the use of opium; as the relation was stronger in heavy users (AOR low users = 4.93, 95 % CI: 1.79–13.54 and AOR heavy users = 5.10, 95 % CI: 2.10−12.35). Moreover, PC was higher among participants starting the use of opium at a younger age than those who started opium at an older age (AOR = 8.03, 95 % CI: 3.19–20.23).
This study demonstrated that opium use is associated with a high and strong risk of PC as an independent risk factor. Further studies should be done to reduce the use of opium in Iran and other world countries.
One of the most lethal cancers worldwide is pancreatic cancer. PC is the seventh leading cause of death of cancers in both genders and according to the GLOBOCAN, the pancreatic cancer accounted for 4% of deaths [ ]. In 2018, PC was fourteenth common cancer in Iran; and cause of 3.8 % of cancer deaths [ ].
Research has shown that pancreatic cancer has several modifiable risk factors including high body mass index (BMI) and diabetes [ ]. However, cigarette smoking is the strongest known environmental risk factor for PC [ ], but the relationship between smoking and different cancers in Iran has often been much less strong than what is seen in Western countries [ ]. Accordingly, several meta-analyses have shown the risk of PC due to cigarette smoking, to be depended on the duration and frequency of smoking, the odds ratios (OR) range from 1.5 to 2.0 [ ]. The results of pooled analysis of case-control studies support a moderate increased risk of pancreatic cancer with heavy daily alcohol consumption ; however, there was no evidence for a role of light or moderate alcohol drinking in pancreatic carcinogenesis, but the increased risk was seen only for heavy drinking [ ].
Recently the long-term effects of opium consumption, especially its carcinogenic effects have been assessed [ ]. Previous studies have addressed the effects of opium use on the incidence of cancers like esophagus [ ], stomach [ , ], larynx [ ], lung [ , ] colorectal [ , ], bladder [ ], head and neck [ , ] Brain, and liver [ ] cancers. However, there are few studies on the effect of opium use on the incidence of PC [ , ].
Opium is a substance commonly used for recreational and medical purposes in some people in different regions throughout the world. Besides, Based on the national survey which was done among Iranian workers, opium was the most popular substance used 2.7 %, but the simultaneous biochemical assessment conforms this predominance with 14.4 % positive results [ ].
In Kerman, one of the southern cities of Iran, due to geographical conditions, the rate of opium usage is high, and in several studies, it is estimated to be between 11 and 15 % [ ]. This substance is mostly used orally or smoked [ ]. In a recent study in Kerman, on hospitalized patients and their healthy companions, the rate of self-reported opium use was 36.5 % in patients and 19.3 % in healthy companions [ ].
Recent studies in north of Iran, known as region with high opioid use, have found a relationship between pancreatic cancer and opium use [ , ].
According a study of International Agency for Research on Cancer on the carcinogenicity of opium, the positive association has been established between larynx, lung, and bladder; however, the evidence was limited for other cancers such as pancreatic cancer [ ].
Hence, this case-control study aimed to assess the relation between opium usage and the risk of PC in Iran. According to the limitation of the current evidence in this issue, this study could be a valuable study to show this gap. It also explores the impact of cigarette smoking and alcohol use on the risk of PC.