Female breast cancer risk in Bryansk Oblast, Russia, following prolonged low dose rate exposure to radiation from the Chernobyl power station accident

Abstract

Background Ionizing radiation is a known cause of female breast cancer, but there have been few studies of the risk after prolonged radiation exposure at low dose rates. Methods This population-based case-control study estimated breast cancer risk after ∼25 years’ exposure to radiation from the Chernobyl accident. Cases (n = 468) were women ≤55 years old when first diagnosed with invasive breast cancer during October 2008 through February 2013, who lived in Bryansk Oblast, Russia at the time of the accident and their diagnoses. Controls, individually matched to cases on birth year, administrative district of residence and urban vs non-urban settlement during the accident, were women without breast cancer who lived in Bryansk Oblast at the time of the accident and on their cases’ diagnosis dates (n = 468). Subjects were interviewed regarding residence, dietary and food source histories to support individualized estimation of their radiation doses to the breast, which ranged from 0.04 − 41 centigray (cGy) (mean 1.3 cGy). Results In multivariable analyses, the odds ratio for breast cancer risk was 3.0 [95% confidence interval (CI): 1.3, 7.0] and 2.7 (95% CI: 1.0, 7.3) in the seventh and eighth dose octiles, respectively, relative to the lowest octile. Analyses of dose effect modification suggested that radiation-related risk may have been higher in women who were younger at the time of the accident and/or at the time of diagnosis. Conclusions This study suggests that prolonged exposure to ionizing radiation at low dose rates can increase risk of breast cancer.

Breast cancer incidence in the regions of Belarus and Ukraine most contaminated by the Chernobyl accident: 1978 to 2016

“…There were contradictory findings on breast cancer incidence trends in Belarus in relation to Chernobyl fallout that could be due to differences in study methods, catchment area and follow‐up period 5,38 . Recently, an analytical study on 468 breast cancers in contaminated Bryansk oblast of Russia utilizing individual dose estimates showed an elevated radiation‐related risk of breast cancer following the exposure at doses up to 41 cGy (mean breast dose of 1.3 cGy) with excess odds ratio (EOR) of 0.57 per 1 cGy (95% CI: −0.0, 15.5) 17 . Given possible recall bias embedded in the case‐control study design, scarce information on study methodology, and the wide nonsignificant confidence interval of the EOR on continuous dose scale, the results of the case‐control study need to be replicated in other groups of women exposed due to Chernobyl fallout, and before that should be taken with caution.…”

“…The breast cancer risk was higher in women younger than 45 years at the time of the accident, but the estimates were based on a small number of cases 5 . Recently, a significant positive association between individually assessed doses to the breast (mean dose of 1.3 centigray, cGy) and risk of breast cancer was reported in a case‐control study in Bryansk oblast for cases diagnosed about 22 to 27 years after the accident 17 …”

“…5 Recently, a significant positive association between individually assessed doses to the breast (mean dose of 1.3 centigray, cGy) and risk of breast cancer was reported in a case-control study in Bryansk oblast for cases diagnosed about 22 to 27 years after the accident. 17 To assess breast cancer incidence rates in female residents of the most contaminated rayons in Belarus and Ukraine after 2001 and to test for association between protracted exposure to low-dose ionizing radiation and breast cancer risk in this population, we conducted an ecological study extending the earlier abovementioned analysis. 5 Advancements of the previous approach included the estimation of the absorbed radiation doses to the female breast instead of the whole body dose and extension of the follow-up for 15 additional years (2002-2016).…”

35 years after the Chernobyl NPP accident: methods of retrospective dosimetry in assessing of the consequences of large-scale uncontrolled radiation exposures, their subsequent development and application in oncoradiology (experience of A. Tsyb MRRC)

“…[3]. Эти программы выполнялись сотрудниками МРНЦ в сотрудничестве с коллегами из областных медицинских и санитарно-эпидемиологических учреждений, а в более отдалённый период после аварии -в сотрудничестве с другими научными и медицинскими центрами России [4], коллегами из Японии [5,6], Европейского Сообщества [7][8][9][10][11] и США [12][13][14][15][16][17][18].…”

“…В процессе и после выполнения программ по ретроспективной оценке доз, по мере накопления медицинских данных, проведена оценка и анализ последствий аварии на Чернобыльской АЭС для загрязнённых радионуклидами территорий Брянской области, выполненных в рамках международных радиационно-эпидемиологических исследований по технологии «случай-контроль» [12][13][14][15][16][17]. Следует отметить, что всесторонние оценки и анализ радиационных рисков для здоровья населения всех загрязнённых радионуклидами территорий РФ, по данным Национального радиационно-эпидемиологического регистра (НРЭР), приведены в монографиях [19][20][21][22].…”