A history of allergy was identified as a potential risk factor with marginal significance (OR 1.85, 95% CI 0.97–3.54, p = 0.06), while H2RA premedication, ovarian cancer, and female sex were not significantly associated with HSR risk.
A pooled analysis of the remaining studies yielded an overall OR of 1.85 (95% CI 0.97–3.54, Z = 1.85, p = 0.064), indicating a marginally non-significant increase in risk for patients with a history of allergy.
Our key findings include: (1) a marginally significant association between history of allergy and increased HSR risk; (2) substantial heterogeneity in the effects of factors such as obesity and postmenopausal state; (3) no significant association for factors including sex, cancer type, and H2RA premedication; and (4) a potential role of genetic polymorphisms, though limited by the small number of studies.