Correlation of Heavy Metal Content in the Blood of Patients with Ovarian Cancer by Place of Residence

Abstract

Introduction. Malignant ovarian tumours are an urgent problem in oncology today. Ovarian cancer (OC) is in the top ten in terms of prevalence, ranking 7th, and in the top five in terms of mortality, ranking 4th. The asymptomatic course of the disease is explained by the progression of ovarian cancer mainly due to peritoneal dissemination; that is the reason why the disease is diagnosed at late stages. The prognosis of the disease depends on its stage, the degree of differentiation of the tumour, the recurrence-free period, the size of the residual tumour after surgical treatment. Taking into account the above factors, this disease is interesting for scientists in terms of finding new factors for predicting its course and trying to influence them. Purpose: increasing the effectiveness of treatment of patients with ovarian cancer by individualizing supportive therapy taking into account the level of heavy metal salts in the blood.
 Methods. The study is based on the results of observation of 127 patients with ovarian cancer of stages I-IV. The duration of recurrence-free survival was studied and evaluated depending on the place of residence of patients with ovarian cancer. Results. The analysis of the recurrence-free survival of patients by the territorial principle was carried out: higher rates of cumulative survival of patients are recorded in virtually all studied intervals in patients living in Ivano-Frankivsk and Kalush districts (where a higher content of Zn in the blood of patients is recorded). Cox regressions in correlation with Zn variables were constructed for them.
 The Cox regression was calculated in correlation with the variables of Zn in the blood of patients with OC living in the Ivano-Frankivsk and Kalush districts at minimal values of the metal content in the blood. For the Ivano-Frankivsk district, it is predicted that at the 16th month of observation, the recurrence-free survival rate will be 0%. For Kolomyia district, the projected recurrence-free survival rate is even lower, with no patients remaining at the 9th month of follow-up. The predicted recurrence-free survival in correlation with Zn variables in the blood of patients with OC living in Ivano-Frankivsk and Kalush districts at the maximum values of the metal in the blood was determined. For the Ivano-Frankivsk district, it is predicted that 97% of patients will remain under observation at month 36. For Kolomyia district, the predicted recurrence-free survival rate at the 36th month of observation is 99%. Conclusions. A correlation was found between the zinc content in the blood of patients with OC and the place of residence in Ivano-Frankivsk region; according to the analysis of the obtained data set, the strongest correlation of recurrence-free survival of patients is observed with this element.  Increased levels of zinc and copper in the blood of patients resulted in a longer duration of disease-free survival, so patients from Kalush and Ivano-Frankivsk regions have a more favourable prognosis.
 For chromium and copper, the place of residence of patients doesn’t play any role.