The goal of this clinical trial is to test meal-timing as a novel and sustainable interventional approach during cancer treatment to improve therapeutic response and metabolic health in an understudied population. This clinical trial will enroll patients with rectal or breast cancer receiving neoadjuvant treatment at the Alaska Native Medical Center (ANMC), which is part of the Alaska Native Tribal Health Consortium (ANTHC). A promising strategy for improving the efficacy of anticancer treatments and reducing associated toxicities involves combining treatment with fasting regimens. In pre-clinical and clinical studies, various forms of fasting have been shown to induce tumor regression and improve long-term survival. According to the differential stress sensitization theory, fasting is thought to sensitize tumor cells to the cytotoxic effects of chemotherapy and radiation, while protecting healthy cells by increasing stress resistance. While healthy cells slow their growth and become more stress resistant in response to fasting, cancer cells cannot survive in nutrient-deficient environments; although the underlying mechanisms are not fully understood. However, extended water-only fasting can be challenging for patients and poses undue health risks. Intermittent fasting, and specifically time-restricted eating (TRE), may offer a viable alternative. TRE involves eating within a shorter window (e.g., 8 hours) and fasting for the remainder of the day but involves no other dietary restrictions. Because of its simplicity, TRE may be more sustainable than other fasting regimens. TRE also improves several cardio-metabolic endpoints, including insulin sensitivity, which may also be beneficial during anticancer treatments.
Participants will be randomized to one of two groups: 1. Time-restricted eating (TRE) (8-hour daily eating period, starting 1-3 hours after waking up), OR 2. A control group defined as a ≥12-hour daily eating period. Participants are assigned to either TRE (8-hour daily eating period, starting 1-3 hours after waking up) or a control group defined as a ≥12-hour daily eating period. Their randomized meal assignment arm begins no later than 1-2 week after they begin cancer treatment and ends at end of treatment (resection if indicated). This is a period of approximately 6 months. During this time, participants will be asked to record the time they started and finished eating every day. Electronic reminders and weekly calls to the participants will be made by study staff who maintain records of patient's meal timing. Researchers will time the TRE schedules relative to sleep time (not time of day), which is a reasonable proxy for circadian time. The control group was designed to mimic typical eating habits in the U.S., as data from NHANES suggest that the median American eats over a 12.5-hour period each day. Aside from these general prescriptions, no set number of snacks, meals, or calories will be prescribed. Instead, researchers will measure how TRE affects self-reported mealtimes, meal frequency, and food intake through a combination of daily adherence surveys, 3-day food records and continuous glucose monitoring (CGM). Participants will receive weekly one-on-one nutrition counseling during the first month and then monthly counseling sessions thereafter. Participants will complete questionnaires at intake and subsequent follow-up assessments. Blood and stool samples will also be collected from participants throughout the study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
100
Participate in time-restricted eating plan
Complete questionnaire
Undergo collection of blood and stool
Receive nutrition counseling
Alaska Native Medical Center (ANMC)
Anchorage, Alaska, United States
RECRUITINGPathological Complete Response (pCR) rate
The pCR will be defined as an absence of residual invasive cancer on hematoxylin and eosin evaluation of the complete resected rectal or breast specimen and all sampled regional lymph nodes. It will be treated as a binary variable.
Time frame: At completion of neoadjuvant treatment (3-6 months)
Treatment-related toxicity
The Patient Reported Outcome-Common Terminology Criteria for Adverse Events (PRO-CTCAE v.5) measurement system will be used to measure treatment-related toxicities. The PRO-CTCAE will be administered on a weekly basis throughout the intervention and will calculate the average over all items for each time point. Surveys will be timed relative to the start of each oncologic treatment segment.
Time frame: From enrollment until completion of neoadjuvant or adjuvant treatment (3-8 months)
Treatment Delivery (RDI and Completion)
Chemotherapy, targeted therapy, immunotherapy and/or radiation data will be abstracted to calculate relative dose intensity (RDI--delivered ÷ planned dose intensity, mg/m²/week) for each drug, expressed continuously and dichotomized at ≥85%. Regimen-level RDI will be calculated as the average across drugs or based on the dose-limiting agent. We will also calculate the proportion of participants completing all planned cycles without unplanned reductions or delays.
Time frame: From enrollment until completion of neoadjuvant or adjuvant treatment (3-8 months)
Clinical Complete Response (cCR)
A cCR will be defined as the clinical absence of residual disease on physical examination, endoscopic examination, and/or repeat MRI imaging following completion of total neoadjuvant treatment.
Time frame: At completion of neoadjuvant treatment (3-6 months)
Tumor volume
Standard of care CT and MRI images will be obtained at the time of diagnosis for staging. A repeat standard of care MRI imaging may be obtained prior to surgery to assess response to neoadjuvant therapy and to guide clinical and surgical management. Researchers will obtain routine clinical restaging scans from participants and use them to estimate changes in tumor volume between the two time points.
Time frame: From baseline to surgery (3-6 months)
Objective response rate (ORR)
The ORR is defined as the percentage of people who have a partial response (defined as a decrease in tumor volume) or a complete response to treatment between enrollment and surgery.
Time frame: At the time of surgery following neoadjuvant treatment completion (3-6 months)
Neoadjuvant rectal (NAR) score
The NAR score is a validated surrogate endpoint for oncologic outcomes used in rectal cancer clinical trials. It takes as input the pathologic nodal status and the clinical and pathologic T-stage.
Time frame: At completion of neoadjuvant treatment for rectal cancer (3-6 months)
Provider-reported adverse events
As secondary measures of toxicity, researchers will collect provider-reported adverse event data. Researchers will analyze the incidence of grade 3-4 toxicities and calculate the aggregated Toxicity Index (TI). The TI accounts for the frequency and cumulative burden of all toxicities during the treatment period.
Time frame: From enrollment until completion of neoadjuvant or adjuvant treatment (3-8 months)
Health-related quality of life (HR-QOL)
We will use the widely-used and validated European Organization for Research and Treatment of Cancer Quality of Life (QOL) core questionnaire C30 (EORTC QLQ-C30), the colorectal-cancer specific questionnaire (EORTC CR29), and the breast cancer specific questionnaire (PR\_BR23). For this study, we focus on highly prevalent rectal and breast cancer treatment-related symptoms, including fatigue, insomnia, pain and bowel-related items (stool frequency, flatulence, and fecal incontinence).
Time frame: From enrollment until completion of neoadjuvant or adjuvant treatment (3-8 months)
Adherence
Adherence will be defined as at least 70% of the daily regimen followed (for example, eating \<8 hours for 6 or more days per week on average during the 6-month treatment period). Participants will be asked to self-report their adherence using a weekly survey, which asks participants to record the time they start and finish eating each day and to document any reasons for non-adherence.
Time frame: From enrollment until completion of study participation (3-8 months)
Progression-free survival (PFS)
Progression-free survival (PFS) is the length of time from randomization to disease progression or death from any cause.
Time frame: 12- and 24 months post completion of neoadjuvant treatment and surgery or adjuvant treatment.
Relapse-free survival (RFS)
Relapse-free survival (RFS) is the length of time after primary cancer treatment ends that a patient survives without any signs or symptoms of that cancer.
Time frame: 12- and 24 months post completion of neoadjuvant treatment and surgery or adjuvant treatment.
Overall survival (OS)
Overall survival (OS) is the time from randomization to death from any cause.
Time frame: 12- and 24 months post completion of neoadjuvant treatment and surgery or adjuvant treatment.
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