Discussion
In this meta-analysis, F. nucleatum test showed better discrimination ability for detecting 5-FU resistance in CRC patients as compared with B. fragilis and E. coli . To the best of our knowledge, ours is the first meta-analysis to assess the diagnostic value of F. nucleatum , B. fragilis and E. coli test for discriminating CRC patients with 5-FU-based regimen. The pooled DOR was 4.92 (95% CI:2.23-7.33), indicating the test’s relatively high discrimination ability. The pooled sensitivity and specificity were 64.9% and 69.6%, respectively, suggesting the test’s superior ability for ruling out CRC patients which are not suitable for 5-FU-based regimen. However, the PLR and NLR of the test was 2.57 (95% CI:1.47-3.21) and 0.52 (95% CI:0.43-0.63), respectively, which shows that CRC patients with 5-FU resistance have approximately 2.57 times higher possibility of testing positive F. nucleatum compared with subjects without 5-FU resistance, as well as 52% chance of an CRC individual having 5-FU resistance if the test of F. nucleatum is negative. The performance of the fecal F. nucleatum test in the pooled PLR and NLR did not achieve the requirements of clinical practice, and remains to be modified for clinical confirmation and exclusion purposes. Nonetheless, the pooled results suggest that the fecal F. nucleatum test has better discrimination ability thanB. fragilis and E. coli in clinical practice of suitable 5-FU-based therapy for CRC patients.
We identified the weaknesses of this study. First, the number of patients and studies included were relatively small, which may affect the overall quality of evidence. Second, these studies lacked a unified criterion for F. nucleatum , B. fragilis and E. colipositive expression. Thus, larger-scale, multicenter and higher-quality studies are required to confirm our findings in the future, allowing a better comparison of analytical results of F. nucleatum on clinical outcomes.
In conclusion, the fecal F. nucleatum test shows better discrimination ability for detecting whether 5-FU-based regimen is suitable for a colorectal cancer patient in our meta-analysis. We certainly recognize that our suggested method is incomplete, mainly from the limited sample size, but it is indicated that the fecal F. nucleatum test represents at least a starting point toward non-invasive and accurate procedures in the detection of 5-FU resistance for CRC treatment.