Body mass index (BMI) is a main indicator of obesity and its association with breast cancer is well established. However, little is known in the metastatic setting, especially in HER2-positive patients. We assessed the influence of BMI on clinical outcomes of patients treated with pertuzumab and/or trastuzumab emtansine (T-DM1) for HER2+ metastatic breast cancer (mBC). BMI was addressed as a categorical variable, being classified on the basis of the following ranges, that is, 18.5–24.9, 25–29.9, and 30.0–34.9, namely, normal weight, overweight, and Class I obesity. The outcomes chosen were progression-free survival to first-line chemotherapy (PFS1) and overall survival (OS). Overall (N = 709), no impact of BMI was observed on PFS1 (p =.15), while BMI ≥ 30 was associated with worse OS (p =.003). In subjects who progressed to first line (N = 575), analyzing data across PFS1 quartiles and strata of disease burden, BMI predicted lower PFS1 in patients within the I PFS1 quartile and with the lowest disease burden (p =.001). Univariate analysis showed a detrimental effect of BMI ≥ 30 on OS for women within the I PFS1 quartile (p =.03). Results were confirmed in multivariate analysis. According to PFS1 quartiles a higher percentage of patients with high BMI and low disease burden progressed within 6 months of therapy. The effect of BMI on prognosis was also confirmed in multivariate analysis of OS for overall population. In our cohort, a BMI ≥ 30 correlated with worse OS in patients with HER2+ mBC who received pertuzumab and/or T-DM1 but had no impact on PFS to first line. BMI predicted worse I PFS1 quartile.
Impact of BMI on HER2+ metastatic breast cancer patients treated with pertuzumab and/or trastuzumab emtansine. Real-world evidence / Eriseld, K.; Laura, P.; Giacomo, B.; Domenico, S.; Silvia, C.; Claudio, B.; Ramy, K.; Giuseppe, S.; Paolo, M.; Andrea, B.; Daniele, M.; Teresa, G.; Clara, N.; Antonino, G.; Nicola, T.; Silverio, T.; Giuseppe, T.; Daniele, S.; Aandrea, M.; Lucia, M.; Aangela, V.; Emanuela, M.; Alain, G.; Valentina, M.; Enrico, C.; Loretta, D.; Alessandra, C.; Marina, C.; Luca, M.; Agnese, F.; Angelo Fedele, S.; Domenico, C.; Luisa, C.; Emilio, B.; Nicla, L. V.; Carlo, G.; Pia, D. S.; Rossana, M.; Enzo, V.; Ida, P.; Francesco, G.; Vito, L.; Elisa, L.; Corrado, F.; Mario, R.; Vincenzo, A.; Giuseppina, R.; Antonio, R.; Maria Rosaria, V.; Berardi, Rossana; Pistelli, Mirco; Katia, C.; Claudio, Z.; Ornella, G.; Editta, B.; Lorenzo, L.; Icro, M.; Pietro, D. M.; Daniele, G.; Ruggero, D. M.; Emanuela, R.; Gennaro, C.; Alice, V.; Isabella, S.; Marco, M.; Maddalena, B.; Antonio, G.; Patrizia, V.. - In: JOURNAL OF CELLULAR PHYSIOLOGY. - ISSN 0021-9541. - (2020). [10.1002/jcp.29445]