Messaggi chiave
- Utilizzando un data mart istituzionale di dati del mondo reale, è stato condotto uno studio volto ad accertare il tasso di tumori in fase avanzata e la sopravvivenza globale (OS) in pazienti con carcinoma mammario in funzione dell’intervallo intercorso tra le due mammografie di screening immediatamente precedenti la diagnosi di malattia, ovvero annuale (≤15 mesi), biennale (>15 e ≤27 mesi) o intermittente (>27 mesi).
- In totale, sono state individuate 8145 pazienti idonee all’analisi. La percentuale di tumori in fase avanzata è aumentata significativamente all’aumentare dell’intervallo di screening (rispettivamente, 9, 14 e 19% nei gruppi annuale, biennale e intermittente [p <0,001]), trend che si è mantenuto a prescindere da età, etnia e stato menopausale. I gruppi biennale e intermittente hanno mostrato esiti di sopravvivenza significativamente peggiori rispetto al gruppo sottoposto a screening annuale, con hazard ratio di OS di 1,42 (IC 95%, 1,11-1,82) e 2,69 (IC 95%, 2,11-3,43), rispettivamente (1,39 [IC 95%, 1,08-1,78] e 2,01 [IC 95%, 1,58-2,55] dopo aggiustamento per il possibile lead time).
- Come affermato dal curatore della rivista, le linee guida per lo screening devono bilanciare i benefici dell’intensificazione dei controlli con i rischi potenziali e i costi associati ai falsi positivi. Lo studio osservazionale presentato integra i risultati di precedenti studi di modellizzazione e supporta l’adozione di un intervallo di screening annuale per la maggior parte delle donne.
Abstract
Purpose
- Controversy continues regarding the effect of screening mammography on breast cancer outcomes.
- We evaluated late-stage cancer rate and overall survival (OS) for different screening intervals using a real-world institutional research data mart.
Methods
- Patients having both a cancer registry record of new breast cancer diagnosis and prediagnosis screening history between 2004 and 2019 were identified from our institutional research breast data mart.
- Time interval between the two screening mammograms immediately preceding diagnosis and the time to cancer diagnosis were determined.
- Screening interval was deemed annual if ≤15 months, biennial if >15 and ≤27 months, intermittent if >27 months, and baseline if only one prediagnosis screen was known.
- The primary end point was late-stage cancer (TNM stage IIB or worse), and the secondary end point was OS.
- The association of screening interval and late-stage cancer was analyzed using multivariable logistic regression adjusting for prediagnosis characteristics.
- Proportional hazards regression was used for survival analysis.
- Potential lead time was analyzed using survival from a uniform fixed time point.
Results
- In total, 8,145 patients with breast cancer had prediagnosis screening mammography in the timeframe.
- The percentage of late-stage cancers diagnosed increased significantly with screening interval with 9%, 14%, and 19% late stages for annual, biennial, and intermittent groups (p <0.001), respectively.
- The trend persisted regardless of age, race, and menopausal status.
- Biennial and intermittent groups had substantially worse OS than the annual screened group, with relative hazards of 1.42 (95% CI, 1.11 to 1.82) and 2.69 (95% CI, 2.11 to 3.43), respectively, and 1.39 (95% CI, 1.08 to 1.78) and 2.01 (95% CI, 1.58 to 2.55) after adjustment for potential lead time.
Conclusion
- Annual mammographic screening was associated with lower risk of late-stage cancer and better OS across clinical and demographic subgroups.
- Our study suggests benefit of annual screening for women 40 years and older.