Dr. Thomas Abrams, MD
Next, a retrospective analysis compared adjuvant capecitabine or capecitabine + oxaliplatin (CapeOX) for resected stage II-III colorectal cancer in 606 patients. Fifty-four of these patients were taking a proton pump inhibitor (PPI) as well. The authors found that concomitant use of a PPI with capecitabine monotherapy led to shorter relapse-free survival (adjusted hazard ratio, 2.48; P = .013) compared with those not taking a PPI. Interestingly, the effect on RFS was not observed in patients receiving CapeOX. A proposed mechanism for this finding is that the increased pH in PPI-treated stomachs decreases dissolution of the capecitabine tablet. Certainly, direct observation would be required to prove this, but these data alone may be enough for oncologists to think twice before prescribing capecitabine to patients who must remain on a PPI.
Lastly, a well-done analysis from the Nurses' Health Study found that higher intake of sugar-sweetened beverages and total fructose was associated with increased incidence of and mortality from proximal colon cancer, but interestingly not distal colon or rectal cancers. The hazard ratios for both the incremental incidence of proximal colon cancer for intake of one serving of sugar-sweetened beverage per day and for 25 g/day of fructose were 1.18 (Ptrend = .02), and the hazard ratios for mortality were 1.39 ( Ptrend = .002) and 1.42 ( Ptrend = .003), respectively. I am often asked by my patients what, if any, utility there might be in limiting sugar intake when undergoing cancer treatment. This study provides the basis for an answer that is more than just hand-waving.