Investigating the relationship between secreted protein acidic and rich in cysteine expression level and therapeutic efficacy of nab-paclitaxel: a meta-analysis.

Background: Secreted protein acidic and rich in cysteine (SPARC) is always considered as a marker of poor prognosis. However, it helps to transport nab-paclitaxel and may lead better therapeutic ending. This meta-analysis was aimed to assess the relationship between SPARC expression level and clinical efficacy of nab-paclitaxel.

Methods: The PubMed and Embase databases were searched from inception to April 2020, and search terms included nanoparticle albumin-bound paclitaxel, nab-paclitaxel, nab-PTX, Abraxane, ABI-007, secreted protein acidic and rich in cysteine, SPARC, osteonectin, and BM-40. In addition, funnel plots were used to indicate the existence of publication bias.

Results: After further screening the full text, 5 studies that involved 336 patients were finally included in the study, of which, 3 studies concentrated on non-small cell lung cancer (NSCLC) and the other 2 on breast cancer and pancreatic cancer. SPARC status in tumor cells and stromal cells was taken into account. The HR for progression-free survival (PFS) between SPARC high and low groups was 1.25 (95% CI: 0.72-2.14, stromal cell) and 1.51 (95% CI: 0.93-2.46, tumor cell). The HR for OS between SPARC high and low groups was 1.07 (95% CI: 0.57-2.03, stromal cell) and 1.34 (95% CI: 0.74-2.43, tumor cell). It was revealed that SPARC expression level in tumor cells or stromal cells was not significantly correlated with the patient's survival outcomes. No significant publication bias was found in each analysis.

Conclusions: SPARC expression level detected by immunohistochemistry (IHC) cannot predict the efficacy of nab-paclitaxel, while further large-scale clinical trials are required to confirm our findings.