The role of glutamine supplementation in thoracic and upper aerodigestive malignancies.

In cancer patients, marked glutamine (gln) depletion develops over time. Host tissues (epithelial cells and lymphocytes) that depend upon adequate stores of gln for optimal functioning can be negatively influenced. In addition, radiation and/or chemotherapy cause normal tissues damage that might be enhanced by this depletion effect. The present review evaluates in vivo clinical data about the potential beneficial role of gln administration in the prevention of host tissue toxicity, in a patient group with thoracic and upper aerodigestive malignancies (T&UAM) during cancer treatment. Publications were identified in a systematic review of MEDLINE Database from the last 2 decades (1994-2014) using key search terms and through manual searches. Overall, 13 clinical studies (9 oral/4 parenteral) evaluated the safety and tolerance of gln supply, showing a beneficial effect in the grade, duration of mucositis and esophagitis, decreased gut permeability, and weight loss. Only 1 Phase 1 clinical trial had negative results because the chemo-radiotherapy combined treatment was not feasible. The use of oral gln may especially have an important role in the prevention of acute radiation toxicities, the weight loss and the need for analgesics in patients with T&UAM, especially if the treatment plan includes combined modality therapy with chemo-radiation.