# Cancer survival in Lower Silesia: insights from a national oncology network pilot in Poland

## TL;DR

This study examines breast cancer survival in Polish women, showing that early detection significantly improves outcomes, especially for aggressive cancer types.

## Contribution

The study provides population-based insights into breast cancer subtypes and survival in Poland's Lower Silesia region during a national oncology pilot.

## Key findings

- Luminal B subtype is most prevalent, increasing with age to 46% in the 80+ group.
- Luminal A subtype has the highest five-year survival (90.3%), while TNBC has the lowest (68.5%).
- Stage I breast cancer shows ≥92% five-year survival across all subtypes, highlighting the importance of early detection.

## Abstract

This study provides population-based data on biological subtypes of breast cancer (BC) and associated survival outcomes among Polish women diagnosed between 2019 and 2023 in the Lower Silesia region during the national pilot phase of the National Oncology Network (NON).

Data on BC cases were obtained from the DCOPIH databases as the leader of the pilot program in Poland in between 2019 and 2023 also in the Lower Silesia region. The main outcome was overall cancer survival and cases were linked to existing mortality databases. All patient consent and scope of data analysis was provided based on the MoH Regulation. Analyses included stage at diagnosis, biological subtypes, and five-year survival, stratified by age, subtype, and stage.

A total of 4490 women with BC were included. The luminal B subtype was the most prevalent, generally increasing with age and peaking at 46% in the 80+ age group. Across all stages, five-year survival was highest for luminal A (Kaplan Meier estimation of 90.3%. 95% CI: 88.1%–92.5%) and lowest for triple negative breast cancer (TNBC) (Kaplan Meier estimation of 68.5%, 95% CI: 63.4%-74.0%). For stages I disease, five-year survival was 92.8% for all subtypes aggregated (95% CI: 91.1%-94.5%). Survival declined with advancing stage, particularly for TNBC cases, in population with TNBC diagnosed at stage IV no patient surviving above 48 months was observed.

Distinct clinical trajectories of BC subtypes have significant implications for prognosis and healthcare resource allocation. The observation of ≥92% five-year survival for stage I disease across subtypes underscores the critical importance of early detection, particularly in biologically aggressive subtypes such as TNBC breast cancer.