453P - Body mass index did not correlate with short term overall survival in breast cancers

Background

Obesity is a risk factor for the development of new cases of breast cancer and also affects survival in women who have already been diagnosed with breast cancer, but in Asian women, these findings is not evident. We aimed to investigate the correlation between the body mass index (BMI) and overall survival of patients with a breast cancer.

Methods

We conducted a retrospective observational study from a single institute from January 2014 to December 2018. Among all 412 patients diagnosed and treated with breast cancer, we categorized them as three groups (low weight: BMI < 18kg/m², normal: BMI < 25kg/m², obesity: BMI ≥25kg/m²) and investigated overall survival according to menopausal status and adjuvant endocrine therapy. We used a kaplan-meier analysis with log-rank test.

Results

Total 412 patients were enrolled. Mean duration of follow up was 33.3 months. Obesity, normal BMI and low BMI was 120(29.1%), 202(49.0%), and 40 (9.7%) patients, respectively. BMI was correlated with age, patients with obesity was 16% (28/174) of women with less than 50 years, but 38.6% (92/238) of women with more than 50 years. Overall survival was not significantly different among groups (Obesity group: 95%, Normal group: 95.5%, low BMI: 97.5%, p = 0.77, χ²=1.1). Women without adjuvant hormone therapy show lower overall survival, but it is not significant (Obesity group: 87.7%, Normal group: 94.4%, low BMI: 90%, p = 0.89, χ²=0.62). In women with more than 50 years, low BMI was better than normal to obese women (p = 0.89, χ²=0.6).

Conclusions

Obesity is not major risk factor of overall survival in Korea, but in hormone receptor negative breast cancers, it correlated with early onset death or recurrence. Not only further studies need to lighten the relationship between obesity and long-term survival, but also intervention to reduce BMI needs to know its effects on breast cancer survival in Korea.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The author.

Funding

Has not received any funding.

Disclosure

The author has declared no conflicts of interest.