Introduction:
The study of metabolism in children and adolescents with various malignant neoplasms (MN) is due to their high social significance. The reason for the imbalance of chemical elements in patients with MN is the etiopathogenetic mechanisms of carcinogenesis, as well as complications of antitumor therapy.

Methods:
Our research was performed at the Russian Field Medical and Rehabilitation Research Center. All patients aged 12 to 18 years and 18+ were in remission after treatment of MN. Inductively coupled plasma mass spectrometry (ICP-MS) was used to comprehensively assess the elemental status of patients.

Results:
The most informative results of changes in the homeostasis of the essential elements Fe and Cu were found in patients in the ICD-10 C 40.0 group (Malignant neoplasm of the scapula and long bones of the upper limb). There is a change in the content of the studied bioelements in girls (F) and boys (M). There is a tendency to increase the level of both iron and copper in the body of children and adolescents, especially in saliva. The greatest average deviation of excess iron b is observed in boys 18+. A significant accumulation of iron in saliva is typical for boys aged 12-18 and older. For copper, there is no tendency to accumulate in the hair. The average deviation of excess copper in the blood serum is relatively evenly observed in all age and gender groups, most clearly in the group of boys 18+. Significant accumulation of copper in saliva is typical for girls aged 12-18 years.

Conclusions:
The data obtained clearly demonstrate that such measures as timely correction of deficiencies and excesses of individual bioelements at the level of detoxification of the body, nutrition correction and pharmacocorrection should become an important link in full-fledged remission in children and adolescents after MN treatment.