Arsenic Exposure and the Risk of Cancer

Abstract

It is known that exposure to environmental chemicals increases the risk of cancerous and non-cancerous pathologies. Geomedical and anthropic evidence indicates that there is a close relationship between increased morbidities from cardiovascular diseases and cancer among the population in the Antofagasta Region and the etiology of exposure to arsenic. The most commonly used drugs with chemotherapy are platinum-based. The present work characterizes short-term urinary evacuation, that is, the pooled urine excreted 24 hours after the first cycle of treatments of cancer patients with cisplatin or carboplatin. The inorganic biochemical status and behavior of excreted As, Se and Pt administered to and evacuated by patients could be involved in the post-treatment quality of life of the patients and the evolution and final outcome of the disease. There were 90 patients in the group, 32 with lung cancer and 58 with different cancers termed “other types of cancer”, as well as 10 patients untreated with platinum-based drugs. Platinum and selenium were determined by ICP-OES and As by HGAAS. The detection limits were 7.7, 5.4 and 0.2 (ng/mL), respectively. The decreasing tendency of the administered Pt followed the order: carboplatin (other types of cancer) >cisplatin (lung cancer) >cisplatin (other types of cancer); the short-term urinary excretion of Pt was low. The decreasing tendency of the quantities of excreted Se was: carboplatin (other types of cancer) >cisplatin (other types of cancer) ≈ cisplatin (lung cancer); and the tendency of decreasing quantities of excreted As was cisplatin (other types of cancer) >carboplatin (other types of cancer) >cisplatin (lung cancer).The quantities of excreted Pt did not present significant differences among the cases of patients with lung cancer or with other cancers treated with cisplatin, despite significant variations in the quantities of Pt administered by the drug. The tendency in quantities of excreted Pt was similar to that of selenium and arsenic, but the evacuation of selenium was greater than that of arsenic, including in the group of patients with “other types of cancer” treated with drugs without Pt. The results of the study could arise from the subtle participation of antagonist mechanisms among Se, As and Pt that are involved in apoptotic and autophagic events in homeostasis, which could indicate the presence of cancer in patients from areas with chronic exposure to arsenic, as is the case of the Antofagasta Region in Chile.