#IDIBELLfellows: Nuria Nadal & Lucia Fernández

Association between physical activity and mortality among breast cancer survivors
Nuria Nadal Zaragoza
Unit of nutrition and cancer
Purpose: It is known that a greater physical activity (PA) reduces the risk of breast cancer (BC). Nevertheless, there is still limited evidence about what role PA may play in the prognosis of the disease. The aim of this study was to assess the association of pre- and postdiagnosis PA with overall and BC-specific mortality among BC survivors.

Methods: A total of 13,399 BC survivors from the European Prospective Investigation into Cancer and Nutrition (EPIC) study were included. During the follow-up period (average 8.6 years) 2,380 women died, of whom 1,480 from BC. The main exposure was an overall measure of PA derived from a PA index (PA at work and leisure-time activities). We further analysed recreational PA (walking, cycling and sport activities). A subset of 2,023 survivors completed a second questionnaire within a 6-month to 4-year postdiagnosis period. Multivariable Cox and Fine-Gray models were employed to evaluate the association of PA with overall and BC-specific mortality respectively, adjusted for relevant confounders.

Results: BC survivors who were physically active before diagnosis had a 14% lower risk of all-cause mortality (HR 0.86, 95% CI: 0.78-0.95), and 12% lower risk of BC-specific mortality (HR 0.88, 95% CI: 0.77-1.00). PA postdiagnosis was associated with a lower risk of overall and BC-specific mortality of 43% (HR 0.57, 95% CI: 0.44-0.75) and 52% (HR 0.48, 95% CI: 0.34-0.68), respectively. A significant lower risk of mortality was also observed among those who practiced recreational PA after diagnosis. Those women who became active postdiagnosis had lower risk of overall mortality (HR 0.48, 95% CI 0.27-0.83) and BC-specific mortality (HR 0.35, 95% CI 0.16-0.74).

Conclusion: Being physically active (pre- and postdiagnosis) reduces the risk of mortality among BC survivors. Additionally, changes towards higher levels of PA seem to have also positive impact on survival.

Post-pandemic shifts in the bacterial aetiology of acute otitis media in Spanish children

Lucia Fernández Delgado
Epidemiology of bacterial infections. Research on pathogenesis and molecular basis of antimicrobial resistance group.
This talk presents an epidemiological and genomic analysis of Streptococcus pneumoniae strains causing acute otitis media (AOM) in children from a prospective study conducted in 12 primary care centres in Barcelona between 2022 and 2024. The project explores recent shifts in the aetiology of this infection in the context of universal PCV13 vaccination and the post-pandemic period. Results confirm a decline in S. pneumoniae as a causative agent and the predominance of non-typeable Haemophilus influenzae. Nevertheless, vaccine failures were identified, particularly involving serotype 3. Surprisingly, a marked increase in AOM caused by Streptococcus pyogenes was observed, coinciding with the expansion of the M1UK lineage. In-depth isolate analysis revealed high genomic homogeneity among H. influenzae and S. pyogenes isolates, as well as high antibiotic susceptibility. In contrast, S. pneumoniae strains exhibited greater genomic heterogeneity, even within isolates from the same patient