Clinical and metabolic characteristics of patients with cancer

Oncological diseases, especially cancer, are characterized by intoxication and violation of all links of metabolism. The degree of severity of disorders depends on the localization, prevalence, features of the tumor process. Most catabolism processes occur in patients with cancer of the digestive system and with the development of complications of tumor growth (tumor disintegration, bleeding, obstruction at any level of the gastrointestinal tract, adherence of purulent-septic complications).

[1], [2], [3], [4], [5], [6]

Metabolic disease

Main article: Metabolic disorders

In cancer patients as a result of the systemic action of the tumor on the body, all types of metabolism (protein, carbohydrate, lipid, energy, vitamin and mineral) are violated.

Hypermetabolism of glucose is a specific and permanent manifestation of a disorder of carbohydrate metabolism in cancer patients. There is an acceleration of gluconeogenesis processes aimed at maintaining the glucose level in the blood plasma, which leads to the depletion of protein and fat depots.

Increased catabolism of body proteins is also characteristic for cancer patients and is accompanied by increased release of nitrogen in the urine and negative nitrogen balance. Assessment of nitrogen balance is considered one of the most reliable criteria for protein metabolism, allowing timely diagnosis of the catabolic stage of the pathological process, to select the optimal diet and evaluate the dynamics. With catabolism, structural proteins break down in muscles, vital organs and regulatory systems (enzymes, hormones, mediators), as a result of which their functions and neurohumoral regulation of metabolism are violated.

During growth, the tumor also uses fatty acids. In patients with preserved natural nutrition, the required level of essential fatty acids in blood plasma is maintained by mobilizing them from endogenous fat stores. The most profound violations of lipid metabolism are revealed in patients with GI tract cancer, they are characterized by hyperlipidemia, an increase in free plasma content due to interchangeable fatty acids and progressive loss of fat mass in the body, which leads to an intensive disintegration of structural lipids of the blood plasma and cell membranes. Detect the insufficiency of essential fatty acids, the severity of these disorders is associated more with alimentary deficiency.

The peculiarity of the metabolism of cancer patients is the violation of vitamin metabolism in the form of deficiency as water-soluble vitamins of group C, B, and fat-soluble (A, E). With a deficit of antioxidant vitamins, a decrease in the power of the antioxidant cell protection system is associated. Changes in oxidation-reduction processes in cells are characterized by the transition of tissue respiration to the anaerobic pathway and the formation of "oxygen debt". In the blood of patients, the content of lactic and pyruvic acids is increased.

Metabolic disorders are one of the starting moments of activation of the hemostasis system, especially its platelet link, and the inhibition of the immune system. Changes in hemostasis in cancer patients take place in the form of chronic compensated ICE of blood, without clinical manifestations. With the help of laboratory studies, hyperfibrinogenemia, increased aggregation properties of platelets (degree of aggregation, platelet factor IV), an increase in the content of soluble complexes of fibrin monomers, circulating degradation products of fibrinogen are revealed. Signs of DIC syndrome are most often noted in lung cancer, kidney, uterus, pancreas and prostate gland.

Disturbance of the immune system

The overwhelming number of oncological patients develop secondary immunodeficiency of varying severity with a decrease in all links of anti-infective immunity. Violations of the immune system affect almost all of its links. The absolute number of T cells is reduced, the number of T suppressors is increased, their activity is significantly increased, the number of T-helpers and their functional activity is reduced, the proliferation of stem cells is inhibited, the stem cell differentiation processes in T and B lymphocytes are slowed. There is a decrease in the indicators of natural and acquired humoral immunity, phagocytic activity of neutrophils.

The presence of a malignant tumor in patients in itself is an independent risk factor for infection, infectious complications in cancer patients occur 3 times more often and are more severe than in patients with other pathologies.

[7], [8], [9], [10], [11], [12], [13], [14]

Anemia and cancer

Anemia is a frequent complication of malignant tumors or their treatment. According to the European anemia cancer survey, at the time of the initial diagnosis of a malignant neoplasm anemia is noted in 35% of patients. Among the causes are common (deficiency of iron and vitamins, renal failure, etc.) and specific for oncological patients:

• bleeding from the tumor,
• tumor damage to the bone marrow,
• anemia of tumor disease and toxicity of antitumor treatment.

[15], [16], [17], [18], [19], [20]

Features of preoperative examination

Preoperative examination and therapy are aimed at detecting abnormalities in vital organs for intensive therapy, which maximizes the function of the organs. The majority of operated patients (60-80%) have a diverse concomitant pathology of cardiovascular, respiratory and endocrine systems (hypertension, chronic nonspecific lung diseases, diabetes, kidney pathology) Up to 50% of patients undergoing surgery are elderly (over 60), among them about 10% - senile age (more than 70 years).

Oncological patients have limited respiratory reserves, and respiratory failure of varying severity is observed in almost all patients with lung cancer, tumors of the trachea, mediastinum and gastrointestinal tract. Even with normal function of external respiration in lung cancer, cardiac department of the stomach, esophagus, postoperative pulmonary complications develop in 50% of cases. Reduction of the Vital and respiratory reserves below 60% with a high probability of predetermining the severe course of the early postoperative period and prolonged ventilation. About a third of patients have respiratory failure of I-II degree, as a rule, it is obstructive at the level of small and medium bronchi and restrictive disorders. In patients with severe obstruction, special attention should be paid to forced heart failure (FVC), forced expiratory volume in the first second (FEV1) and peak flow (PF). The FEV1 / FVC ratio helps to differentiate restrictive and obstructive diseases, it is within normal limits for restrictive diseases, as both indicators are reduced, and in obstructive pathology it is usually reduced due to a decrease in FEV1. The postoperative mortality of patients with MVV is increased depending on the age, the scope of the operative intervention and is increased 5-6 times compared with the mortality of patients without the pathology of the respiratory system.

When assessing the state of the respiratory system of the patient before the operation, a thorough investigation is necessary.

[21], [22], [23], [24], [25], [26]

Auscultation of the lungs

Bronchoscopy with sputum culture when the tumor is localized in the lung, esophagus, cardiac compartment of the stomach allows to assess the condition of the mucous membrane, the degree of colonization of the tracheobronchial tree and the nature of the microbial flora, which can become the causative agent of infection in the postoperative period.

In 50-70% of patients, serious cardiovascular diseases are revealed, which reduce the functional reserves of the circulatory system and increase the risk of complications:

• IHD,
• myocardial infarction in anamnesis,
• disturbance of rhythm and conductivity,
• hypertonic disease

[27], [28], [29], [30], [31]

Scope of examination of patients

• ECG in 12 leads.
• Bicycle ergometry.
• Echocardiography (patients older than 60 years).
• A general blood test with the definition of a leukocyte formula (moderately expressed leukocytosis and a stab-shift in the absence of clinical manifestations of any infection do not serve as indications for prescribing antibiotics before surgery).
• Crops of sputum and urine (if spleen or Candida albicans are found in the sputum or urine, antifungal medication should be prescribed within 3-4 days).
• Screening assessment of kidney function (urea and serum creatinine, urine analysis according to Nechiporenko). If infection is detected, it is necessary to appoint uroseptics.
• In renal failure, renotscintigraphy should be performed and the creatinine clearance determined.
• Immunological studies help to identify secondary immunodeficiency of varying severity with a decrease in all links of anti-infective immunity.
• Intra- and postoperative monitoring of central hemodynamics with severe valve defects and a decrease in PV is below 50%.