Her2, weight, and disease progression

This study basically says that if you are Her2+, and you relapse, you do better if you are normal weight versus overweight.  To me it suggests that for non-relapsed Her2+ patients, it might be good to keep our weight under control too.  I'm not sure if this is good news or bad news.  Bad because now I will feel guilty for every cookie I ingest.  Good, because weight control is possibly another tool in our arsenal against this disease.

From ASCO 2010 meeting held in Washington last week.

The prognostic and predictive impact of BMI on clinical outcome of HER2-positive breast cancer. Print this page
 Sub-category:New Systemic Agents – New drugs and targets (includes anti-angiogenics) - HER2 directed  Category:Systemic Therapy  Meeting:2010 Breast Cancer Symposium  Session Type and Session Title:General Poster Session C  Abstract No:289  Author(s):V. Parolin, E. Fiorio, A. Mercanti, M. Riolfi, E. Surmacz, A. Molino; Department of Medical Oncology, Ospedale Civile Maggiore, Azienda Ospedaliera Integrata Universitaria, Verona, Italy; Medical Oncology, Policlinico G. Rossi, Azienda Ospedaliera Integrata Universitaria, Verona, Italy; Sbarro Institute for Cancer Research, Temple University, Philadelphia, PA Abstract: Background: Obesity and HER2 overexpression are associated with poor prognosis in breast cancer (BC). Recent studies suggest the existence of functional crosstalk between the Leptin Receptor and HER2: stimulation with Leptin can rapidly transactivate HER2 in BC cells. Resistance to trastuzumab, a mAb antiHER2, is an increasing problem related to activation of alternative cell signaling. The aim of the study was to evaluate the impact of overweight and obesity on outcome of patients with HER2 positive BC treated with trastuzumab. Methods: We analyzed retrospectively 155 patients with HER2 positive BC treated with trastuzumab for early stage or metastatic disease from 2003 to 2008. Overweight and obese patients were classified by Body Mass Index (BMI) according to WHO classification. Overall survival (OS) and time to progression (TTP) curves were calculated by the Kaplan-Meier method and comparisons were made using the log-rank test. Results: 103 patients were treated with adjuvant trastuzumab (median age 53.3 years). 12.5% of the population relapsed: 31% and 23% were overweight and obese, respectively. In relapsed patients OS and TTP decreased with increasing BMI: we found the median OS for normal weight, overweight and obese patients was 40, 36.5 and 31 months, respectively (p=ns); median TTP was 11, 8 and 5 months, respectively (p=0.0351). 52 patients received trastuzumab for metastatic disease in association to chemotherapy (median age 50 years); 20 (38%) patients were defined as postmenopausal and 32 (62%) as premenopausal. 33% and 15% were overweight and obese, respectively. Median OS was 65 months and TTP 10.5 months. We observed that OS and TTP decreased with increasing BMI: median OS for normal weight, overweight and obese patients was 67, 54 and 39 months, respectively (p=0.0010); median TTP was 12, 7.5 and 7 months, respectively (p=0.0442). The negative impact of increasing BMI was confirmed in the subgroup analysis by hormone receptor and menopausal status. Conclusions: Our results suggest that obesity is not only a risk factor and indicator of poor prognosis for BC, but also a negative predictive parameter in presence of HER2 overexpression, impairing therapeutical response to trastuzumab and promoting resistance.