MUTATIONS OF GENES BRCA1 AND BRCA2 IN WOMEN WITH OVARIAN CANCER EXPOSED TO FACTORS OF CHORNOBYL NUCLEAR ACCIDENT

OBJECTIVE

to determine a frequency of germline mutations 185delAG, 5382insC in BRCA1 gene and 6174delT in BRCA2 gene in Ukrainian patients with OC including women who were exposed to the factors of Chornobyl nuclear accident.

MATERIAL AND METHODS

In the study we enrolled 306 OC patients of different age who were tested for the presence of the major BRCA1 and BRCA2 gene mutations using allele specific multiplex polymerase chain reaction.

RESULTS

The mutation frequency in patients exposed to IR with OC (main group) was 5.3 % (2 from 38). Among unexposed patients (control group) 11,2 % (30 from 268) of cases with mutation were identified. However, the dif- ference between the groups was not significant (p = 0.39). It was shown that the BRCA1/2 mutations frequency in the patient of both groups was 10,4 % (32 from 306). The mutation BRCA1 5382insC was positive in 87.5 % (28 from 32) of cases, nevertheless nobody was identified with the allelic variant BRCA2 6174delT among both groups. There was a tendency toward an earlier age of the OC manifestation in the patients exposed to IR due to Chornobyl nuclear accident compared to BRCA-positive women of the control group (р = 0.06). When comparing BRCA-positive and BRCA-negative patients with OC of the main group, there was a statistical significance regarding the earlier age of the disease manifestation in the patients with mutations (р = 0.04). However, such difference was not observed in the control group (р = 0.22).

CONCLUSIONS

The frequency of the mutations in exposed to IR and unexposed patients with OC does not differ and depends on a spectrum of studied BRCA1/2 gene mutations, level of DNA amplification and sample number. The allel- ic variant BRCA1 5382insC is dominant and accounts for 87.5 % of the total number of the found mutations. Due to the radiation factor the OC in the BRCA1-positive individuals is realized at the earlier age than in patients negative for these mutations. The incidence of OC after the Chornobyl accident was observed 27-38 years later in a cohort of women who were from 4 to 40 years old at the moment of the nuclear explosion.

EVALUATION OF BURDENSOME SYMPTOMS IN PATIENTS WITH RADIATION6ASSOCIATED AND SPONTANEOUS MYELOPROILIFERATIVE NEOPLASMS WITH THE USE OF OPTIMIZED SELF-ASSESSMENT MPN-SAF TSS

OBJECTIVE

To investigate the intensity of burdensome symptoms using self-assessment MPN-SAF TSS in patientswith radiation-associated and spontaneous myeloproiliferative neoplasms (MPNs).

MATERIALS AND METHODS

The study included 89 patients with radiation-associated and spontaneous MPNs, the bur-densome symptoms of MPN were determined using MPN-SAF TSS.

RESULTS

The average score for complaints in patients with radiation-associated MPNs was significantly higher thanin patients with spontaneous MPNs - 43.46 and 25.04 points, respectively (p = 0.003). MPN patients classified bysubtypes also showed differences regarding intensity of burdensome MPN symptoms, demonstrating significantlyhigher average score of complaints among primary myelofibrosis patients (35.60), compared to polycythemia vera(29.60) and essential thrombocythemia (18.05) patients, (p = 0.005). Our study did not reveal any influence of theJAK2 V617F mutation on MPN burdensome symptoms intensity in MPN patients.

CONCLUSIONS

We demonstrated a higher intensity of the MPN burdensome symptoms determined by the optimizedself-assessment MPN-SAF TSS in patients with radiation-associated, and in primary myelofibrosis patients, indicat-ing increased severity of patient's general conditions at the stage of diagnosis verification. It is advisable to usethe optimized MPN-SAF TSS at the moment of molecular genetic testing during the diagnosis of MPN for selectionor modifying treatment strategies in order to achieve better quality of life for patients.

Doses of Ukrainian female clean-up workers with diagnosed breast cancer

The Chernobyl reactor accident in 1986 has caused significant exposure to ionizing radiation of the Ukrainian population, in particular clean-up workers and evacuees from the exclusion zones. A study aiming at the discovery of radiation markers of the breast cancer was conducted from 2008 to 2015 within a collaborative project by HZM, LMU, and NRCRM. In this study, post-Chernobyl breast cancer cases both in radiation-exposed female patients diagnosed at age less than 60 from 1992 to 2014 and in non-exposed controls matched for residency, tumor type, age at diagnosis, TNM classification as well as tumor grading were investigated for molecular changes with special emphasis to copy number alterations and miRNA profiles. Cancer registry and clinical archive data were used to identify 435 breast cancer patients among female clean-up workers and 14 among evacuees from highly contaminated territories as candidates for the study. Of these, 129 breast cancer patients fit study inclusion criteria and were traced for individual reconstruction of the target organ (breast) doses. The doses were estimated for 71 exposed cases (clean-up workers and evacuees from which biomaterial was available for molecular studies and who agreed to participate in a dosimetric interview) by the use of the well-established RADRUE method, which was adjusted specifically for the assessment of breast doses. The results of 58 female clean-up workers showed a large inter-individual variability of doses in a range of about five orders of magnitude: from 0.03 to 929 mGy, with median of 5.8 mGy. The study provides the first quantitative estimate of exposures received by female clean-up workers, which represent a limited but very important group of population affected by the Chernobyl accident. The doses of 13 women evacuated after the accident who did not take part in the clean-up activities (from 4 to 45 mGy with median of 19 mGy) are in line with the previous estimates for the evacuees from Pripyat and the 30-km zone.

Reserch of the gene polymorphism TOX3 / LOC643714 and the risk of breast cancer development in persons exposed to ionizing radiation after Chornobyl disaster

OBJECTIVE

The objective of this work was to identify and compare the polymorphism of the rs3803662 polymorphism of the TOX3/LOC643714 gene in breast cancer patients who have undergone ionizing radiation due to the Chornobyl accident and in patients without ionizing radiation (IR) in the history.

MATERIALS AND METHODS

The determination of the rs3803662 polymorphism of the TOX3/LOC643714 gene was per formed by polymerase chain reaction (PCR) in 83 patients with breast cancer: 42 subjects who were exposed to ion izing radiation due to the Chornobyl accident, 41 people without ionizing radiation in history and 17 controls in Ukraine without cancer pathology. In order to compare the obtained data on spontaneous and radiation associated breast cancer and to calculate the differences in the frequencies of alleles and the risk of oncopathology, data from literature on control groups of the populations of the Russian Federation, Sweden, and the United Kingdom were used.

RESULTS

Comparing with the literature data and the group of exposed subjects, the homozygous carriers of the minor alleles of the TOX3/LOC643714 ТТ gene revealed an increased risk of developing breast cancer: OR = 2.89, p = 0.02 (CI 95% 1.17 7,16). In subjects without the influence of IR in history, the carrier of homozygous minor axis of the gene TOX3/LOC643714 ТТ is also associated with the risk of breast cancer: OR = 3.83, p = 0.0002 (CI 95% 0.82-14.14). In the homozygous carriers of the minor alleles of the TOX3 / LOC643714 gene exposed to IR, there was no increase in the risk of developing breast cancer (OR = 0.65, p = 0.46, CI 95% 0.21-2.04) compared with the con trol group of Ukrainian population.

CONCLUSIONS

The carrier of homozygous minor alleles of the TOX3/LOC643714 gene is not a risk factor for the devel opment of breast cancer under conditions of exposure to ionizing radiation in the study group of the Ukrainian population.

Prognosis of probability of BRCA1 and BRCA2 mutations carriage in women with compromised family history of breast and/or ovarian cancer

Burdened family history of breast and/or ovarian cancer may indicate the mutations carriage in the BRCA1 and BRCA2 genes.

OBJECTIVE

Estimation and compare of the Manchester Scoring system, Penn II and Myriad algorithm in an ability to distinguish the cases with BRCA1/2 mutation those and no mutant alleles at the individual level among the Ukrainian women with early onset of a breast cancer and/or compromised family history with breast cancer and/or ovarian cancer.

MATERIAL AND METHODS

Results of genealogy, molecular genetic and morphological study from 44 females with breast cancer, with early development of the disease or family history of a breast cancer and/or ovarian cancer were the material of research. Determination of carriers BRCA1 and BRCA2 mutations among women was performed by Manchester Scoring system and Penn II and Myriad algorithm.

RESULTS AND CONCLUSIONS

Manchester Scoring system has better capacity to distinguish patients with and without mutant alleles at the individual level. The area under the curve of Manchester Scoring system is 0.84, Penn II - 0.66, Myriad - 0.68.