Objective: The present study performed a systematic review and meta-analysis of observational studies on whether calreticulin levels could represent a prognostic factor in carcinoma patients. Calreticulin (CRT) is a multifunctional protein in the endoplasmic reticulum that can play distinct roles in different cancers.
Methods: The search was performed in PubMed, Scopus, the Cochrane Library, Web of Science, Lilacs, Science Direct, Embase, Bireme, and SciELO databases. After a full-text evaluation, only 14 articles remained. The RoBANS tool assessed the risk of bias. The meta-analysis was performed with R software, and the odds ratio (OR) was the effect measure. The random effects model was chosen, and the quality of evidence was evaluated according to GRADE.
Result: The most frequent carcinomas were in the breasts and the colon. CRT expression varied according to carcinoma origin and type, but these diseases had a prevalence of high CRT levels, indicating tumor progression. The high CRT levels were associated with lymph node metastasis (OR = 3.06 [1.71; 5.48]/p = 0.0002/I2 = 0%). All included articles had a blinding bias.
Conclusion: High CRT levels may represent a prognostic factor for metastatic lymph nodes in carcinoma patients.
Keywords: Calreticulin; Carcinoma; Neoplasms; Prognosis; Systematic review.