# Long-Term Outcomes and EUSOMA Quality Indicators in a Large Single-Center Surgical Breast Cancer Cohort from North Africa

## TL;DR

This study tracks breast cancer outcomes in Morocco over 10 years, showing high survival rates comparable to high-income countries.

## Contribution

It provides one of the largest and longest single-center evaluations of breast cancer care in North Africa.

## Key findings

- Five-year overall survival was 96%, declining to 91% at 10 years.
- High adherence to EUSOMA quality indicators was observed, including timely surgery and radiotherapy.
- Local recurrence occurred in 6.2% of patients, with bone being the most common site of distant metastasis.

## Abstract

Breast cancer is the most frequent cancer among women in North Africa, yet long-term survival data from the region remain scarce. This study followed 1826 Moroccan women who underwent surgery for breast cancer and provides one of the largest and longest evaluations of outcomes in the area. After 10 years of follow-up, survival rates were high and comparable to those reported in many high-income countries. Most patients were treated according to international standards, with excellent adherence to recommended timelines, surgical quality, radiotherapy, and endocrine therapy. The limited use of HER2-targeted therapies in earlier years reflects historical availability rather than current practice. Overall, these findings show that well-organized breast cancer care can achieve strong long-term outcomes even in resource-limited settings. They also highlight the importance of continuing to improve access to modern treatments to ensure that all patients benefit equally from advances in breast cancer therapy.

Background: Long-term real-world data on breast cancer outcomes in North Africa remain limited, despite rising incidence and increasing access to multimodal treatment. This study reports survival outcomes, recurrence patterns, and quality-of-care performance in the largest single-center breast cancer cohort in the region. Methods: A retrospective analysis was conducted on a prospectively maintained registry of 1826 women who underwent curative-intent breast cancer surgery between 2002 and 2016. Overall survival (OS) and disease-free survival (DFS) were estimated using Kaplan–Meier methods. Prognostic factors were examined through univariate and multivariate Cox regression analysis. Adherence to selected EUSOMA quality indicators was assessed across two time periods. Results: At a median follow-up of 10 years, five-year OS and DFS were 96% and 90%, respectively, declining to 91% and 84% at 10 years. Local recurrence occurred in 6.2% of patients and distant metastasis in 11%, with bone being the most frequent metastatic site. TNM stage, tumor size, SBR grade, and tumor localization were independent predictors of OS, while younger age and TNM stage independently predicted DFS. Hormone receptor status and TNM stage were associated with local recurrence; age and tumor site predicted distant metastasis. Quality-of-care evaluation showed high adherence to EUSOMA indicators, including timeliness of surgery, proportion of single-operation resections, and use of postoperative radiotherapy after breast-conserving surgery. Limited administration of HER2-targeted therapy during the earlier years of the cohort reflected historical availability constraints rather than current practice. Conclusions: This study provides robust long-term evidence from North Africa, demonstrating that high survival rates can be achieved when standardized surgical pathways, multidisciplinary coordination, and adherence to quality indicators are maintained. The findings underline the importance of sustained investment in diagnostic access and treatment organization and highlight the expected benefits of the expanded availability of HER2-targeted therapies in the region. These results offer a valuable benchmark for strengthening breast cancer care in comparable LMIC settings.