Abstract |
Purpose: This postgraduate thesis attempted to investigate the longitudinal changes in the incidence of breast cancer among younger and older adult women in Crete. In addition, it investigated various risk factors such as obesity and place of residence, as well as other clinical determinants.
Methodology: In this thesis, a data mining study (pooled study) was carried out from the database maintained by the Cancer Registration Center of Crete (CRC). From this base, data were used for the new cases of cancer by type, for the period 1992 to 2022 in Crete. 4,985 women were included in the study. The analysis was done using statistical and spatial analysis software (IBM SPSS, STATA, ArcGIS). First, age-specific incidence rates (ASpIR/100,000/year) and age-weighted incidence rates (ASIR/100,000/year) were calculated. Finally, the annual percentage change of incidence indices (APC%) was calculated. All tests were performed at a statistical significance level of α=0.05.
Results: An increase in annual percentage change of standardized incidence rates (APC 1.2, 95%CI 1.1 -1.3) of breast cancer cases was found. In particular, a large increase in the annual percentage change was found in the younger ages 20-34 (APC 1.9, 95%CI 1.7-2.2) and 35-49 (APC 1.8, 95%CI 1.5-2.1) while in ages over 50 a decrease is observed. Regarding the place of residence, in Chania we have the largest annual percentage change (APC 0.9, 95%CI 0.7-1.2) as well as in Heraklion 0.4 (095%CI .1-0.8). In Rethymno a large increase of 0.5 (95%CI 0.4-0.6) is observed, while in Lasithi the smallest is observed of 0.2 (95%CI 0.0-0.4). Focusing on incidence by age, ages under 45 show a rapid increase in incidence rates, with ages 30-34 having an ASpIR=31.2/100,000 and the 35-39 age group having an even higher ASpIR= 65, 8/100,000. The largest increase occurs in the 40-44 age group with ASpIR=124.6/100000. As for those over the age of 45, they have an even higher incidence that increases proportionally with age. However, when the age-weighted incidence indices and change by age were studied, significant increasing trends were observed in recent years, among younger adults. After 2011, an increasing course is observed in the ages 20-34 and 35-49, while we have a decreasing steady course in the ages 50-74 and a decreasing course in the ages over 75. In relation to the risk factors for younger adults, those who had a high mass index body during the period 1992-2001 had an increased risk RR=2.3 (95%CI =2.1-2.4), in the period 2002-2011 we had an increase RR=2.1 (95%CI =2.5-2.9) and in the period 2012-2021 we had significant increase in risk RR=3.7 (95%CI =3.6-3.8). Corresponding trends were shown by obesity based on BSA. Other risk factors were smoking, alcohol consumption and self-employment.
Conclusions: The observed increasing trends in younger adults raise new research questions and certainly open the dialogue for lowering the age of mandatory screening.
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