Abstract
OBJECTIVE: Gastrointestinal cancer is one of the most common causes of death worldwide. As there are no clinical symptoms at the beginning of the disease, the diagnosis can be delayed and the stage increased. Timely diagnosis is therefore crucial. Since one of the factors involved in cell division is phosphate, and considering the benefits of using saliva, this study investigated the phosphate concentration in saliva and serum in patients with gastric and colorectal cancer as well as in healthy patients. METHODS: 26 patients with gastric and colorectal cancer confirmed by pathologic criteria were admitted to the oncology department of Imam Reza Hospital, and 30 healthy individuals participated in this study. Saliva and serum samples were collected in the morning. Phosphate concentration was determined using a photometric method. RESULTS: The average phosphate content in serum as well as in stimulated and unstimulated saliva was significantly lower in the patient group. In addition, the results showed that the patients reported more dry mouth than the control group despite increased salivary flow. CONCLUSION: It appears that patients with malignant diseases of the gastrointestinal tract, such as colorectal cancer and gastric cancer, have lower serum and salivary phosphate levels than healthy individuals.