Paper - Review

DOI: 10.1158/1078-0432.CCR-20-3445

Abstract

Purpose

The gut microbiome
→ is involved
← in 1⃣ antitumor immunotherapy 2⃣ chemotherapy responses

Evidence-based research
← on the role of gut microbiome
← in predicting response → to neoadjuvant chemotherapy (nCRT)
← in patients with locally advanced rectal cancer (LARC)
→ is scarce ❓

❗: longitudinal study
→ aimed → to evaluate the feasibility of the gut microbiome
← in predicting nCRT response

Experimental Design

collected
→ 1⃣ 167 fecal samples ← from 84 patients with LARC ← before & after nCRT
→ 2⃣ 31 specimens ← from healthy individuals
→ for 16S rRNA sequencing

Patients
→ were divided → into 1⃣ responders 2⃣ non-responders
← according to pathologic response → to nCRT

Constructed → a random forest classifier
→ for nCRT response prediction ← of a training cohort of (baseline samples) ← from 37 patients
Validated → the classifier
← in another cohort of 47 patients

Results

Observed → significant microbiome alterations
→ 1⃣ a decrease ↓ ← in LARC-related pathogens
→ 2⃣ an increase ↑ ← in 1⃣ Lactobacillus 2⃣ Streptococcus
← during nCRT

❗: A prominent microbiota difference
← between 1⃣ responders 2⃣ non-responders
→ was noticed ← in the baseline samples

1⃣ Roseburia 2⃣ Dorea 3⃣ Anaerostipes
→ were over-represented ← in responders
1⃣ Coriobacteriaceae 2⃣ Fusobacterium
→ were over-represented ← in non-responders

10 biomarkers → were selected
→ for the response-prediction classifier
← e.g. 1⃣ Dorea 2⃣ Anaerostipes 3⃣ Streptococcus
← yielded an AUC of 93.57%

Conclusions

The gut microbiome
→ offers novel potential biomarkers → for predicting nCRT responses
∴ Important manifestations ← in the clinical management of these patients

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