Introduction Worldwide 1,470,900 women are diagnosed yearly with a gynaecological malignancy; 21 000 in the UK. Some patients treated with pelvic radiotherapy develop chronic changes in their bowel function. Current research on the impact of treatment on the gut and vaginal microbiome in women with a gynaecological malignancy is reviewed.
Method The PRISMA guidelines for systematic reviews were used to ensure transparent and complete reporting. The protocol was registered on the International PROSPERO database. Quantitative studies exploring the gut or vaginal microbiome in this patient cohort were included. Animal studies were excluded. There were no language restrictions.
Results Three prospective cohort studies were identified using sequencing of changes in the gut microbiome reporting on 23 women treated for gynaecological cancer1-3. All studies included patients treated with radiotherapy with a dosage ranging from 43.0 to 54.0 Gy. 8 women (57%) developed grade 2 or 3 diarrhoea1,3. A correlation between changes in the intestinal microbiome and receiving radiotherapy is suggested with a decrease in abundance and diversity of the intestinal bacterial species1-3. Prior to radiotherapy, those with diarrhoea had increased abundance of Bacteroides, Dialister, Veillonella (p<0.01), and decreased abundance of Clostridium, Faecalibacterium, Oscillibacter, Parabacteroides, Prevotella (p<0.05)3.
Conclusion The limited evidence to date implies that larger studies including both the vaginal and gut microbiome in women treated for a gynaecological malignancy are warranted to explore the impact of cancer treatments on the microbiome and its relation to developing long-term GI toxicity. This may lead to new avenues to stratify those at risk and explore personalised treatment options and prevention of gastrointestinal consequences of cancer treatments.
. Manichanh C, Varela E, Martinez C, et al. The gut microbiome predispose to the pathophysiology of acute postradiotherapy diarrhoea. Am J Gastroenterol 2008;103:1754–61.
. Nam Y, Kim H, Seo J et al. Impact of pelvic radiotherapy on gut microbiome of gynaecological cancer patients revealed by massive pyrosequencing. PLoS ONE 2013;8:e82659.
. Wang A, Ling Z, Yang Z et al. Gut Microbial Dysbiosis May Predict Diarrhoea and Fatigue in Patients Undergoing Pelvic Cancer Radiotherapy: A Pilot Study. PLoS ONE 2015;10(5):e0126312.
Disclosure of Interest None Declared
- cancer treatment
- gastrointestinal toxicity
- gut microbiome
- gynacological malignancy