Clinical studies conducted by different research groups investigated the effect of oral intake of glutamine supplements, a non-essential amino acid, on the incidence rate of acute radiation-induced esophagitis/swallowing difficulties and weight loss in Lung Cancer Patients. The results of these studies indicated that increased oral glutamine supplementation reduced the incidence of esophagus inflammation, swallowing problems & related weight loss in lung cancer patients.
Lung cancer is the leading cause of cancer-related deaths in both men and women globally and accounts for more than 18% of the total cancer deaths (GLOBOCAN, 2018). With the latest treatment advances, the number of new lung cancer cases has been reducing in the last few years (American Cancer Society, 2020). Based on the type and stage of the cancer, functioning of the lungs and the overall health of the patient, the treatment for the lung cancer patient is decided from different options including radiotherapy, chemotherapy, immunotherapy, targeted therapy and surgery. However, many of these treatments are associated with several long term and short term side-effects. One of the most common, unpleasant and painful side effects seen in lung cancer patients who received radiation therapy in the chest area is esophagitis.
Esophagitis is the inflammation of the esophagus, a muscular hollow tube which connects the throat with the stomach. Generally, the onset of acute radiation-induced esophagitis (ARIE) happens within 3 months post radiotherapy and can often lead to serious swallowing problems. Hence, extensive research was carried out to explore ways to prevent and manage radiation-induced esophagitis in cancer patients. Many studies published recently highlighted the use of supplements such as glutamine to prevent or delay radiation induced esophagitis. L-Glutamine, generally called Glutamine is a non-essential amino acid which is produced by the body and can also be obtained from a wide variety of foods which include animal sources such as milk, milk products, eggs and meat, and plant sources such as cabbage, beans, spinach, parsley and beet greens. However, glutamine, which constitutes 60% of the aminoacids present in our skeletal muscle, is often significantly depleted in cancer patients leading to weight loss and fatigue.
Oral Glutamine Supplements & Radiation-Induced Swallowing Difficulties
In a recent clinical study conducted by the researchers at Far Eastern Memorial Hospital, Taiwan between September 2014 to September 2015, data from 60 non-small cell lung cancer patients including 42 men and 18 women, with a mean age of 60.3 years, were evaluated. (Chang SC et al, Medicine (Baltimore), 2019) These patients received platinum based regimens and radiotherapy concurrently, with or without oral glutamine supplementation for 1 year. The researchers found that after a mean follow up period of 26.4 months, glutamine supplementation decreased the incidence rate of grade 2/3 acute radiation-induced esophagitis/swallowing difficulties to 6.7 % compared to 53.4% in patients who didn’t receive glutamine supplements. It was also observed that the incidence rate of weight loss had decreased to 20% in glutamine administered patients compared to 73.3% in patients who didn’t receive glutamine. Glutamine supplementation also delayed the onset of acute radiation-induced esophagitis for 5.8 days (Chang SC et al, Medicine (Baltimore), 2019).
In another clinical study conducted by the researchers from Necmettin Erbakan University Meram Medicine School, Turkey, between 2010 and 2014, data from 122 Stage 3 non-small cell lung cancer patients were analyzed (Kanyilmaz Gul et al, Clin Nutr., 2017). These patients received concurrent chemotherapy (with Cisplatin/carboplatin+pactitaxel or Cisplatin+Etoposide, or Cisplatin+Vinorelbine) and radiotherapy, with or without oral glutamine supplementation. A total of 56 patients (46%) were supplemented with oral glutamine. The researchers found that after an average follow up period of 13.14 months, glutamine supplementation decreased the incidence rate of grade 2-3 acute radiation-induced esophagitis/swallowing difficulties to 30% compared to 70% in those who didn’t receive glutamine supplements. They also observed that the incidence rate of weight loss had decreased to 53% in glutamine administered patients compared to 86% in patients who didn’t receive glutamine. The study also showed that glutamine supplementation had no negative impact on tumor control and survival outcomes (Kanyilmaz Gul et al, Clin Nutr., 2017).
In summary, these studies indicate that intake of oral glutamine supplements can reduce the incidence of radiation-induced esophagitis/swallowing difficulties and weight loss in non-small cell lung cancer patients, thereby improving their quality of life. However, since previous in vitro studies suggested that glutamine may support cancer cell growth, oncologists were often reluctant to administer glutamine in cancer patients in order to avoid any complications (Kanyilmaz Gul et al, Asian Pacific Journal of Cancer Prevention, 2015), though the recent clinical studies showed no negative impact on tumor control and survival outcomes with glutamine supplementation. (Kanyilmaz Gul et al, Clin Nutr., 2017) Hence, while the studies summarized in this blog highlight the beneficial effects of glutamine in lung cancer, patients should always discuss with their physician before taking any supplements for their cancer.
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer.Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.