Table 2.
Characteristics of studies included in the meta-analysis
| Characteristics | Study | ||||||
|---|---|---|---|---|---|---|---|
| CA209-538 (n = 106) | 2022_Simpson43 (n = 38) | 2021_McCulloch19 (n = 37)a | 2022_Lee18 (n = 165) | 2021_Andrews59 (n = 46) | 2018_Matson37 (n = 39) | 2017_Frankel60 (n = 39) | |
| Country | Australia | Australia | USA |
UK, Netherlands, Spain |
USA | USA | USA |
| Cancer type (%) |
UGB (36%), GYN (34%), NEN (30%) |
MEL (100%) | MEL (100%) | MEL (100%) | MEL (100%) | MEL (100%) | MEL (100%) |
| ICB regimen (%) | CICB (100%) | CICB (100%) | Anti-PD-1 (100%) |
CICB (33%), anti-PD-1 (61%), anti-CTLA-4 (7%) |
CICB (100%) | Anti-PD-1 (100%) |
CICB (62%), anti-PD-1 (36%), anti-CTLA-4 (3%) |
| Response criteria | RECIST 1.1 | Pathological (INMC) | RECIST 1.1 | RECIST 1.1 | RECIST 1.1 | RECIST 1.1 | RECIST 1.1 |
| Response | |||||||
| CR | 3.8% | PathR: 84% | 5.4% | 13% | 11% | 5.1% | 13% |
| PR | 21% | 51% | 26% | 52% | 33% | 36% | |
| SD | 27% | 22% | 17% | 11% | 31% | 13% | |
| PD | 28% | Non-pathR: 16% | 22% | 42% | 26% | 31% | 39% |
| cPD | 20% | 0% | 1.8% | 0% | 0% | 0% | |
| Stool collection kit | OMR-200 | EasySampler | EasySampler |
LO—TF kits, MA—plain tube, NL—plain tube, LD—OMR-200, BL—OMR-200 |
OMR-200 | EasySampler | NR |
| DNA extraction kit | FastDNA soil | FastDNA feces | PowerSoil |
LO—TF MagMAX, MA—TF MagMAX, LD—TF MagMAX, NL—TF MagMAX, BL—PowerFecal |
PowerSoil | PowerFecal | Other |
| Sequencer (bases per read) | NovaSeq (2 × 151) | NovaSeq (2 × 151) | NovaSeq (2 × 151) | NovaSeq (2 × 151) | NextSeq (2 × 151) | NextSeq (2 × 151) | HiSeq (2 × 100) |
| Clean PE reads (millions) | |||||||
| Minimum | 9.10 | 5.05 | 2.72 | 4.38 | 12.8 | 19.3 | 18.1 |
| Median | 20.4 | 22.5 | 30.5 | 20.7 | 40.0 | 35.6 | 45.4 |
| Maximum | 53.8 | 34.5 | 72.2 | 104 | 69.8 | 77.7 | 59.9 |
The clinical and technical characteristics of the studies included in the meta-analysis are summarized. Published studies are denoted by ‘year_author’.
USA, United States of America; UK, United Kingdom; MEL, melanoma; INMC, International Neoadjuvant Melanoma Consortium; LO, London; MA, Manchester; NL, Netherlands; LD, Leeds; BL, Barcelona; TF, Thermo Fisher Scientific; PathR, pathologic response; NR, not reported; PE, paired-end.
aOf the original ‘Pittsburgh early cohort’ (n = 63), n = 37 had their analyzed stool sample collected between day −15 and day 15 of starting ICB and were therefore deemed eligible.