Tumor‑stroma ratio as a clinical prognostic factor in colorectal carcinoma: A meta‑analysis of 7,934 patients

The tumor-stroma ratio (TSR) has been regarded as an important factor associated with tumor metastasis, based on the 'seed and soil' theory, which may have guiding significance for the selection of chemotherapy regimens. Therefore, a high TSR may be a new risk factor for tumor recurrence in patients with stage II colorectal cancer (CRC). The present study aimed to evaluate the prognostic value of TSR in CRC, especially for the computer-calculated TSR. A comprehensive literature retrieval was performed using the PubMed, Web of Science, Embase and Cochrane Library databases to identify relevant studies published up to December 13, 2023. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to estimate the prognostic value of the TSR in CRC. A total of 21 studies published between 2007 and 2023 were included in the present meta-analysis. The combined analysis demonstrated that a high TSR was significantly associated with worse overall survival (OS; HR=1.84; 95% CI, 1.44-2.34; P<0.001), disease-free survival (DFS; HR=1.85; 95% CI, 1.27-2.68; P<0.001), cancer-specific survival (CSS; H=1.97; 95% CI, 1.46-2.65; P<0.001) and recurrence free survival (RFS; HR=1.55; 95% CI, 1.25-1.92; P<0.001) in patients with CRC. Moreover, an elevated computer-calculated TSR was also associated with poor OS (HR=1.89; 95% CI, 1.48-2.40; P<0.001) and DFS (HR=1.85; 95% CI, 1.27-2.68; P<0.001). However, a high TSR was not associated with poor OS in patients with stage I CRC (HR=1.01; 95% CI, 0.48-2.14; P=0.97). In conclusion, the results of the present meta-analysis indicate that a high TSR is associated with poor OS, DFS, CSS and RFS in patients with CRC, especially for those with stage II-III. In addition, TSR calculated by computer using whole-slide images may also be an effective prognostic marker for OS and DFS in patients with CRC.