Mortality rate in the Russian Federation in 2018 exceeded the birth rate again. At the same time, a stable and high frequency of early reproductive losses was noted. Every fifth wanted pregnancy terminates spontaneously before the due date. Living in the subarctic zone is associated with several unfavorable climatic factors. Implementation of the reproductive function in these conditions is influenced by region-specific factors, which have multiple effects on the mechanisms of recurrent pregnancy loss. The literature search was performed using PubMed, Medline, Cyberleninka, Scopus and HAC databases. Assessing the degree of adaptation of women of reproductive age living in the subarctic zone of the Russian Federation helps to assess their psychosomatic status and heart rate variability. Taking into account the adaptation parameters, certain patterns were revealed for women of reproductive age, as well as for each trimester of a normal and pathologically ongoing pregnancy. Particular attention in the assessment of adaptive resources of the body deserve leukocyte indices, by changing the parameters of which it is possible to make a forecast of the ongoing pregnancy. The results of this review are of interest to the clinicians working in the subarctic zone of Russia from the standpoint of personalized approach to prevention and prediction of recurrent pregnancy loss.

Relevance. PIK3CA belongs to the top three most frequently mutated genes in breast cancer (BC), especially in estrogen receptor (ER) positive, HER2 negative BC subtype. With an approval of selective PI3K-alpha inhibitor, alpelisib, this alteration has become actionable in ER+HER2- tumors. The frequency and spectrum of PIK3CA alterations in various cohorts is affected by a number of factors, including the distribution of BC expression subtypes, histological types, patient age, and even ethnicity. Aim. Aim of the current study was to characterize the frequency and spectrum of PIK3CA alterations in Russian BC patients. Materials and methods. The analysis of PIK3CA exon 7, 9 and 20 mutations was performed in a cohort of Russian ER+HER2- BC patients by a combination of high-resolution melting analysis, allele-specific PCR, and digital droplet PCR. Results. PIK3CA lesions were identified in 62/206 (30%) patients. Noteworthy, 59/62 (95%) of the identified variants were represented by the three most common p.E542K, p.E545K, and p.H1047R substitutions. The analysis of clinical and morphological characteristics revealed the trends towards association of PIK3CA mutations with older age and more frequent metastatic lung involvement. Conclusion. The obtained data on the frequency and spectrum of PIK3CA somatic aberrations can be helpful when organizing molecular genetic testing of breast cancer patients and using PI3K inhibitors in Russian population.