The following is a summary of the “Tryptophan and Kynurenine Pathway Metabolites and Psychoneurological Symptoms Among Breast Cancer Survivors,” published in the February 2023 issue of Pain management by Li, et al.

Breast cancer survivors were studied to see if there was a connection between the metabolites in the tryptophan-kynurenine pathway and psychological and nervous system symptoms. Examining a group of people from different points in time. People were scouted for the study at the University of Illinois Hospital & Health Sciences System’s oncology clinic. Subjects/Participants: 79 people had breast cancer and had gone through substantial therapy. 

Among breast cancer survivors undergoing intensive cancer therapy, they collected metabolites from fasting blood and evaluated their effects on the PROMIS-29 score for psychoneurological symptoms (tryptophan, kynurenine, kynurenic acid, and quinolinic acid). Using latent profile analysis, subgroups were determined depending on the presence or absence of the 5 psychoneurological symptoms. In addition, Mann-Whitney Targeted metabolites were compared between groups using U tests and multivariable logistic regression. 

Most people (81%) had mild symptoms, while 19% had severe ones. Patients in the high-symptom subgroup were more likely to have a higher body mass index (P =.024) and to take antidepressants at the time of the study (P =.008) than those in the low-symptom subgroup. After controlling for body mass index and antidepressant use, those with lower tryptophan levels (P =.019) and a higher kynurenine/tryptophan ratio (P =.028) were more likely to fall into the high symptom category. One possible cause of psychoneurological symptoms is a disruption in the tryptophan-kynurenine pathway and the availability of tryptophan.