Häufigkeit fortgeschrittener Mammakarzinome mit Fernmetastasen bei Frauen und deren Prognose – Ergebnisse aus dem saarländischen Krebsregister

Advanced breast cancer with involvement of distant organs is classified as breast cancer with synchronous or metachronous metastasis. The presence of distant metastases has a significantly negative influence on the prognosis of patients.

This work analyzes the frequency of breast cancer with synchronous and metachronous metastasis and the prognosis of these patients using population-wide cancer registry data.

For this work, data collected by the Saarland Cancer Registry were used. The analysis included women with invasive breast cancer in whom (synchronous) distant metastases had already been detected at the time of diagnosis in the period 2017–2021 or in whom (metachronous) distant metastases appeared for the first time in the course of a previously diagnosed breast cancer in the same period. The number and distribution of patients are presented in tabular form with regard to the type and number of distant metastases that occurred as well as other tumor characteristics for the two groups. Patient survival was calculated using Kaplan–Meier estimators.

Between 2017 and 2021, 470 women residing in the federal state of Saarland were diagnosed with breast cancer with synchronous metastases (19 per 100,000 person years). In 525 women, metachronous metastasis occurred for the first time after being diagnosed with breast cancer between 1990 and 2021 (21 per 100,000 person years). Approximately 50% of the women had distant metastases being limited to one distant site, whereas three or more distant sites were involved in 20 and 26% of patients with synchronous and metachronous metastases. Women with synchronous metastases had an overall 5‑year survival of 26%, and those with metachronous metastases had a survival of 23%.

In the observation period from 2017–2021, about 40 out of 100,000 women per year had synchronously and metachronously metastasized breast cancer. The three most common metastasis locations are bones, liver, and lungs. The criteria that influenced the prognosis of the patients were age, time at which distant metastases were detected, the number and type of distant metastases detected at the time of initial diagnosis and, in the case of tumors with synchronous distant metastases, other tumor characteristics, such as hormone receptor status and status of human epidermal growth factor receptor 2. Comprehensive clinical cancer registries can provide current, detailed, and unselected data on tumor diseases in the general population. In the upcoming years, the amount of usable data for detailed and specific analyses of the frequency and care of cancer and the prognosis of patients will increase significantly.