Cadmium exposure and risk of pancreatic cancer: a meta-analysis of prospective cohort studies and case–control studies among individuals without occupational exposure history

Abstract

Pancreatic cancer is one of the most deadly types of cancer for both genders. Classified as a human carcinogen, cadmium has been related to diverse cancers. However, the association between cadmium exposure and the risk of pancreatic cancer is still unclear. We quantitatively reviewed the observational studies on the association of cadmium exposure with pancreatic cancer risk among individuals without occupational exposure history published through July 2014 in PubMed by using a fixed–effects model. Four prospective cohort studies (112,934 participants with 335 events) and two case-control studies (177 cases and 539 controls) were identified. The summarized relative risk (RR) with a 95% confidence interval (CI) was 2.05 (95% CI=1.58 – 2.66), comparing the highest to the lowest category of cadmium exposure. This positive association persisted in men (RR=1.78; 95% CI=1.04 – 3.05), but not in women (RR=1.02; 95% CI=0.63 – 1.65). Further research is needed to provide more solid evidence on the association of cadmium exposure with pancreatic cancer risk and to elucidate the underlying biological mechanism of the potential gender difference.

Concentrations of trace elements and KRAS mutations in pancreatic ductal adenocarcinoma

“…Cadmium and lead were particularly high in KRAS wild‐type cases, lower in KRAS mutated cases, and much lower in controls. This pattern is in line with studies that identified cadmium and lead as important risk factors for developing PDAC (Amaral et al ; Chen et al ; Kriegel et al ; Luckett et al ). For cadmium, both KRAS mutational situations exhibited similar aORs in case–control comparisons.…”

“…Lifestyle risk factors include tobacco smoking, heavy alcohol intake, and obesity (Hart et al ). Among environmental factors, PDAC has been linked with exposure to aromatic amines and to several trace elements such as arsenic, cadmium, and lead (Amaral et al ; Antwi et al ; Chen et al ; Hart et al ; Luckett et al ; Porta et al ).…”

“…In contrast, higher levels of selenium and nickel were protective (Amaral et al ). Several studies have identified cadmium exposure as a risk factor for PDAC (Amaral et al ; Chen et al ; Luckett et al ; Kriegel et al ). Higher selenium levels were also protective against PDAC and were associated with longer survival (Lener et al ).…”

Pancreatic Cancer: Current Status and Challenges

“…Of these, exposure to hydrocarbons is the most extensively studied occupational risk factor for PanCA and is associated with a 2–8 fold enhanced risk [16, 38]. Although the heavy metal relationship to PanCA was previously contested, recent reports have demonstrated that individuals with high exposure to cadmium, arsenic, and lead have a significantly higher risk for developing PanCA [16, 39]. Interestingly, cadmium exposure has been reported to be positively associated with PanCA in men, but not in women [39].…”

“…Although the heavy metal relationship to PanCA was previously contested, recent reports have demonstrated that individuals with high exposure to cadmium, arsenic, and lead have a significantly higher risk for developing PanCA [16, 39]. Interestingly, cadmium exposure has been reported to be positively associated with PanCA in men, but not in women [39]. These data warrant more thorough investigations including gender differences and underlying molecular mechanism to determine the role of cadmium in pancreatic cancer.…”