Traditionally invasive lobular breast carcinoma (LBC) has been considered a good prognosis histology. However, it has a unique molecular pathogenesis and different genomic profile. Our objective was to establish whether there is a difference in disease-free survival (DFS) between LBC and ductal carcinoma.
We evaluated a cohort of 5185 breast cancer patients with lobular and ductal carcinoma (DC) treated the at National Cancer Institute Mexico between 2006 and 2016. We compared presentation variables using the chi squared test. A Cox proportional hazards regression model was constructed to evaluate disease-free survival.
With a median of 60 months follow-up, patients with LBC were older (p < 0.001), more frequently patients with Ki67 <18% (40.2% vs 28.6% p < 0.001), had lower nuclear grade (p < 0.001), and predominantly hormone receptor positive disease (77.9% vs 56.9% p < 0.001). Nevertheless, LBC patients had a higher recurrence rate (25.2% vs 21.1% p = 0.011). For both LBC and DC patients, factors that negatively influence 5-years DFS in the univariate analysis were stage III (71.9% vs 78.9% p < 0.001), Ki67>18% (83.3% vs 93.1% p = 0.016), low nuclear grade (82.1% vs 95.9% p < 0.001), triple negative (46.7% vs 71.8% p = 0.002), and Her2 positive (72.4% vs 84.5% p = 0.023). In the multivariate analysis patients with stage III, (OR 10.8, 95%CI 5.9–19.9), high nuclear grade (OR 1.5, 95%CI 1.0-2.4), Ki67 >18 (OR 1.5, 95%CI 1.1–1.9), triple negative phenotype (OR 2.7, 95% CI 1.1-6.6) and lobular carcinoma (OR 1.8, 95%CI 1.1-2.7) are independent negative factors for DFS.
The presence of lobular invasive carcinoma is an independent negative factor for DFS. Despite the high rate of good prognosis elements in pathological reports, lobular carcinoma seems to be another disease and we need to evaluate deeply new and old treatment strategies to provide better disease control. Particulary in clinical stage III, Latin America has a challenge to be aware of it.
Clinical trial identification
Legal entity responsible for the study
Instituto Nacional de Cancerología, Mexico.
Has not received any funding.
All authors have declared no conflicts of interest.