Neoadjuvant treatment followed by surgery is currently the standard of care for resectable locally advanced esophageal cancer patients. Pathological response of the primary tumor to previous chemotherapy and/or radiotherapy and post-treatment pathological stage have been shown to be the best predictor of overall survival in both squamous cell cancer and adenocarcinoma of the esophagus. The best prognosis is associated with pathological complete response (pCR) which was found in 29% of patients participating in the CROSS trial. At this time, there is no good way to predict response reliably short of performing esophageal resection. Thus, new strategies to either predict, and potentially even modulate tumor response are of great interest.
The influence of microbiota on cancer and cancer therapies has recently gained attention and several studies have started to elucidate an important link between the human microbiome, the immune system and their impact on cancer development, progression and response to treatment. All human body surfaces host a complex system of microorganisms and its composition is influenced by a variety of host factors. Some of these factors can be altered, for example, through life style modifications or nutritional changes. It has been shown that these microorganisms have a profound effect on disease, through local, but also through long-distance effects on a systemic level. A relationship between the microbiome and carcinogenesis has been suggested for several cancer types, but little is known about the role of the microbiome in esophageal cancer. Evidence suggests that the gut microbiome is an essential player in immunosurveillance influencing carcinogenesis and cancer progression.
Recent research suggests that all tissues can get in contact with microbiota via the lymphatic system and an attempt has been made in a few cancer types to describe a cancer specific microbiome and even correlate certain microbiome signatures with advanced disease states. No studies have addressed the microbiome in esophageal cancer samples and patients.
We aim to identify specific characteristics of the stool and tissue specific microbiome associated with the development and progress of esophageal cancer as well with the response to treatment. Analyzing the microbiome of our cancer patients over time, we will evaluate the use of the microbial community composition as a biomarker of treatment response.
