Background. The World Health Organization (WHO) has confirmed the outbreak of covid infection and defined it as a global pandemic. Recently, complications have been increasingly reported in patients who have had COVID-19. At the same time, clinical symptoms of the long-term course of this disease overlap, differing from acute manifestations of the infection, and may persist in recovered patients for several weeks, months or years, adding a number of other problems. Therefore, the importance of a thorough study of the post-COVID-19 syndrome as a modern phenomenon has increased. And this syndrome requires proper research to improve the efficiency of its prevention and treatment. 
 Purpose. To evaluate the current state of the problem of post-COVID-19 syndrome, in particular in cancer patients.
 Materials and methods. A literature review was performed based on the array of digital publications found in the world databases PubMed, Scopus and Web of Science Core Collection for 2020–2023. The sources were systematized in separate groups, i.e., issues related to post-Covid, in particular, the mechanisms and pathogenesis of its development; treatment features, including cancer patients; long-term consequences in recovered patients, etc.
 Results and discussion. The terminology on the subject of the study has been analyzed: post-COVID, post-COVID syndrome, PASC, long-COVID, acute COVID, chronic COVID, etc. The views regarding the pathogenesis of post-COVID syndrome and its main symptoms were systematized. It is determined that in the field of oncology, research is conducted in certain fields and the risk of progression and occurrence of cancer in the post-COVID period is evaluated; the efficiency of the process of cancer care organization in the post-COVID period and the level of complications and mortality of cancer patients who have suffered from COVID-19. The pandemic has also led to multiple changes in the field of radiological diagnosis of the consequences of cancer patients with COVID. Evaluating the impact of the pandemic on the outcomes and adaptation of radiotherapy and chemotherapy, it was determined that delays in the provision of timely care and changes in treatment regimens will affect long-term survival of cancer patients.
 Conclusion. Assessing the current state of the problem of post-COVID syndrome, most researchers believe that cancer progression during delay in cancer care will negatively affect the long-term survival of cancer patients, and coincidence of cancer-related symptoms and symptoms of long-term COVID is another major challenge for oncologists in the future.
Read full abstract