Purpose of Review This review summarizes a selection of epidemiologic research assessing the associations between carbohydrate intake and cancer incidence and survival. Evidence for plausible biological mechanisms is also considered. Recent Findings The mechanistic paradigm explaining the relationship between carbohydrates and cancer risk has been contested by numerous observational studies. Summary Carbohydrates have conventionally been ascribed a deleterious role in the field of cancer research due to previous preclinical findings. A breadth of studies suggests that complex carbohydrate intake is inversely associated with risk of a number of cancer types. Data from studies assessing simple carbohydrates and cancer risk are mixed. Furthermore, recommendations for subsequent studies are framed.

While there is an association between Western diets and the incidence of colorectal cancer (CRC), this dietary association has remained unexplored in Palestine. The aim of this study was to examine how fiber and fruit and vegetable (FV) intakes are associated with CRC risk among Palestinian adults. We recruited 528 Palestinians between 2014 and 2016. We identified 118 patients who received CRC treatment at Augusta Victoria Hospital, East Jerusalem. We additionally identified 410 controls who consisted of community-based Palestinians without cancer. All participants completed a survey on demographics and a validated dietary intake food screener. Multivariable logistic regression models tested associations between fiber and FV intakes (categorized into quartiles) with CRC risk. After adjusting for significant covariates (age, sex, education, physical activity, smoking status, BMI, IBD, and family history of CRC), as fibers increased across increasing quartiles, the CRC risk significantly decreased (OR = 0.36, 95% CI: 0.15–0.86, p-trend = 0.02). After adjusting for age and sex, as FV intake increased, the CRC risk significantly decreased (OR = 0.34, 95% CI: 0.15–0.75, p-trend = 0.009). Consumption of fiber-rich foods was inversely associated with CRC risk. Understanding this relationship among Palestinians is essential in order to develop targeted, culturally relevant strategies that may potentially alleviate the burden of CRC.

Background The associations between specific types of fat and head and neck squamous cell carcinoma (HNSCC) recurrence and mortality rates have not yet been examined. Objectives The purpose of this study was to determine how intakes of various fat subtypes before cancer treatment are associated with recurrence and mortality in adults diagnosed with HNSCC. Methods This was a secondary analysis longitudinal cohort study of data collected from 476 newly-diagnosed HNSCC. They completed baseline Food Frequency Questionnaires and epidemiologic health surveys. Recurrence and mortality events were collected annually. Fat intakes examined included long-chain fatty acids (LCFAs), unsaturated FAs, polyunsaturated FAs (PUFAs), omega-3 (ω3) PUFAs, omega-6 (ω6) PUFAs, monounsaturated FAs, animal fats, vegetable fats, saturated FAs, and trans fats. Associations between fat intake (categorized into tertiles) and time-to-event were tested using Multivariable Cox Proportional Hazards models, adjusting for age, sex, smoking status, HPV status, tumor site, cancer stage, and total caloric intake. Intake of fats was compared to the lowest tertile. Results During the study period, there were 115 recurrent and 211 death events. High LCFAs intake was associated with a reduced all-cause mortality risk (HR: 0.55; 95% CI: 0.34–0.91, P-trend: 0.02). High unsaturated FAs intake was associated with a reduced all-cause mortality risk (HR: 0.62, 95% CI: 0.40–0.97, P-trend: 0.04) and HNSCC-specific mortality risk (HR: 0.51, 95% CI: 0.29–0.90, P-trend: 0.02). High intakes of ω3 PUFAs (HR: 0.56; 95% CI: 0.35–0.91, P-trend: 0.02) and ω6 PUFAs (HR: 0.57; 95% CI: 0.34–0.94, P-trend: 0.02) were significantly associated with a reduced all-cause mortality risk. There were no significant associations between other fat types and recurrence or mortality risk. Conclusions In this prospective survival cohort of 476 newly-diagnosed HNSCC patients, our data suggest that HNSCC prognosis may vary depending on the fat types consumed before cancer treatment. Clinical intervention trials should test these associations.

6056 Background: Dietary interventions have promise for improving cancer outcomes, but remain an understudied area of cancer care. The relationship between head and neck squamous cell carcinoma (HNSCC) mortality and dietary fat intake has not yet been examined. The objective of this study was to determine how pre- and post-treatment intake of various types of fat are associated with disease-specific and all-cause mortality in adults diagnosed with HNSCC. Methods: Our sample included 472 newly diagnosed HNSCC patients recruited into the University of Michigan Head and Neck Specialized Program of Research Excellence (HN-SPORE) between 2008 and 2012. Participants completed pre-treatment and post-treatment Food Frequency Questionnaires (FFQs) and health surveys. Multivariable Cox Proportional Hazards models were used to test the associations between both the type and quantity of fat intake (categorized into tertiles: low, medium and high intake) and time to mortality, after adjusting for relevant covariates. Fat types included animal, vegetable, medium-chain-fatty-acids (MCFA), long-chain-fatty-acids (LCFA), unsaturated, saturated, and trans. Results: During the study period, there were 144 total deaths and 97 cancer-specific deaths. In considering pre-treatment dietary intake, compared to low intake levels of LCFA, high intake was associated with a reduced risk of all-cause mortality (HR: 0.57; 95% CI: 0.34–0.94). High intakes of unsaturated-fats were associated with a reduced risk of HNSCC-specific mortality compared to low intake (HR 0.52; 95% CI: 0.29–0.93). Considering post-treatment dietary variables, medium (HR: 0.21; 95% CI: 0.08–0.49) and high (HR: 0.41; 95% CI: 0.21–0.78) total fat intakes were associated with reduced risk of all-cause mortality compared to low intake. Medium (HR: 0.25; 95% CI: 0.08–0.67) and high (HR: 0.26; 95% CI: 0.09–0.67) total fat intakes were associated with reduced risk of HNSCC-specific mortality compared to low intake. Conclusions: Our data suggest that HNSCC prognosis may vary depending on both the type and quantity of fats consumed, specifically total fat and long chain fatty acids. Clinical intervention trials are needed to further examine this hypothesis.