CHEMOTHERAPY-INDUCED LACTOSE-INTOLERANCE IN ADULTS

Background. Anorexia and weight loss contribute to the morbidity and m ortality from cancer. This study was designed to test the hypothesis t hat chemotherapy produces lactose intolerance which could have an adve rse effect on the nutritional status of patients receiving cytotoxic d rugs. Methods. Twenty-seven patients were evaluated for the developmen t of lactose intolerance during chemotherapy. Lactose breath hydrogen testing (LBHT) was used to assess lactose malabsorption objectively. T his test is based on the principle that in patients with lactase defic iency, lactose is not hydrolyzed in the small intestine and ultimately is degraded by colonic bacteria. This results in the production of hy drogen gas, which is excreted by the lungs and can be quantified with a breath hydrogen analyzer. Results. Of the 27 patients studied, 8 (30 %) had an abnormal postchemotherapy LBHT results, and for the populati on as a whole, postchemotherapy LBHT values were significantly greater than prechemotherapy values (P = 0.04). However, only three patients (11%) showed clinical symptoms of lactose intolerance during the postc hemotherapy LBHT. Five patients had asymptomatic elevations in breath hydrogen excretion on prechemotherapy testing. One of these patients h ad a further increase in hydrogen excretion on Day 8 after chemotherap y, which was accompanied by symptoms of lactose intolerance. Twenty-tw o patients had normal prechemotherapy LBHT results. Two of these patie nts had abnormal postchemotherapy LBHT results, which were associated with symptoms of lactose intolerance. Conclusion. Although chemotherap y may interfere with lactose metabolism, the development of symptomati c lactose intolerance is uncommon. Dietary restriction of milk product s in patients receiving chemotherapy therefore is not warranted unless clinical symptoms of lactose intolerance are observed.