By Neil Osterweil
FROM SGO 2020
Patients with gynecologic malignancies who consumed only water for 24 hours before and 24 hours after each chemotherapy cycle had fewer dose delays and reductions compared with patients who didn’t fast, results of a small study showed.
She and her colleagues detailed the rationale and results of this studythat had been slated for presentation at the Society of Gynecologic Oncology’s Annual Meeting on Women’s Cancer. The meeting was canceled because of the COVID-19 pandemic. Data have been updated from the abstract.
“We decided to test water-only fasting because there’s not much data about the cell-fitness effects of fasting” on chemotherapy outcomes, she said.
Pre-chemotherapy fasting is based on the concept of differential stress resistance intended to protect normal cells but not cancer cells from the effects of chemotherapy. Fasting decreases levels of insulin-like growth factor 1, which leads healthy cells to enter a protective state by decreasing cell growth and proliferation. Cancer cells, in contrast, cannot enter the protective state, and are therefore more vulnerable than healthy, quiescent cells when exposed to drugs that target the cell cycle, Dr. Riedinger and colleagues noted.
The second study showed that breast and ovarian cancer patients had improved quality of life scores and decreased fatigue when they fasted for 36 hours before and 24 hours after a chemotherapy cycle ().
Dr. Riedinger and colleagues conducted a nonblinded, randomized trial of fasting in women, aged 34-73 years, who had gynecologic malignancies treated with a planned six cycles of chemotherapy. The patients were instructed to maintain a water-only fast for 24 hours before and 24 hours after each cycle. Controls did not fast.
In all, 92% of chemotherapy cycles were completed with fasting as directed.
There were no significant differences in any of the study measures between patients who fasted and those who did not. However, this study was not powered to detect a difference, according to Dr. Riedinger.
Still, there were trends suggesting a benefit to fasting. Fasting patients had a higher mean change in NCCN-FACT FOSI-18 score compared with controls – increases of 5.11 and .22, respectively.
Five patients in the fasting group required changes to their treatment regimen, compared with eight patients in the control group. In addition, there were no hospital admissions in the fasting group and two admissions in the control group.
Patients tolerated the fast well without significant weight loss, and there were no grade 3 or 4 toxicities among patients who fasted.
The investigators are planning a larger study to further evaluate the effect of fasting on quality of life scores and treatment, and to evaluate the effects of fasting on hematologic toxicities. Future studies will focus on the optimal duration of fasting and the use of fasting-mimicking diets to allow for longer fasting periods, Dr. Riedinger said.
The study was internally funded. The authors reported no conflicts of interest.
SOURCE: Riedinger CJ et al. SGO 2020.
This article was published by MDedge.