Influence of pre-operative oral carbohydrate loading vs. standard fasting procedure on tumor proliferation and clinical outcome in breast cancer patients — a randomized trial

Abstract

Background The influence of carbohydrates in breast cancer is conflicting. Objective To determine whether preoperative per-oral carbohydrate load influences proliferation in breast tumors. Design Randomized controlled trial. Setting University hospital with primary and secondary care functions in South-West Norway. Patients A population-based cohort of 61 patients with operable breast cancer. Intervention Per-oral carbohydrate load (preOp™) 18 and 2-4 hours before surgery (n=26) or standard pre-operative fasting procedure with free consume of tap water (n=35). Measurements Primary outcome was post-operative tumor proliferation measured as mitotic activity index (MAI). Secondary outcomes were changes in serum insulin, insulin-c-peptide, glucose, IGF-1 and IGFBP3. Other secondary outcomes were patients´ well-being and clinical outcome (median follow-up 88, range 33-97 months). Results In the estrogen receptor (ER) positive subgroup (n=50), high proliferation (MAI≥ 10) occurred more often in the carbohydrate group (CH) than in the fasting group (p=0.038). Progesterone receptor (PR) was more frequently negative in the CH-group (p=0.014). CH-patients had a significant between group rise in insulin (+ 24.31 mIE/L, 95% CI, 15.34 mIE/L to 33.27 mIE/L), insulin c-peptide (+ 1.39 nM, 95% CI, 1.03 nM to 1.77 nM), but reduced IGFBP3 levels (– 0.26 nM; 95% CI, ­– 0.46 nM to – 0.051 nM). CH-Intervention ER-positive patients had poorer relapse free survival (73%) than the fasting group (100%) (p=0.012; HR= 9.3 (95%CI, 1.1 to 77.7)). In the ER-positive patients, only tumor size (p=0.021; HR=6.07, 95%CI=1.31 to 28.03) and CH-or-fasting grouping (p=0.040; HR=9.30, 95% CI=1.11 to 77.82) had independent prognostic value. The adverse clinical outcome of carbohydrate loading occurred only in T2 patients with Relapse Free Survival of 100% in the fasting group vs. 33% in the CH-group (p=0.015; HR= inf). The CH-group reported less pain on day 5 and 6 compared to the control group (p<0.001) but showed otherwise no factors related to well-being. Limitation Only applicable to ER-positive breast cancer patients with T2-tumors. Conclusions Preoperative carbohydrate load increases proliferation and PR-negativity in ER-positive patients and worsens clinical outcome in ER-positive T2-patients. Keywords: breast cancer, carbohydrate load, proliferation, insulin, insulin c-peptide, IGF-1, IGFBP3, tumor size, relapse free survival, breast cancer specific survival