Sex Differences in Cancer-Associated Thrombosis.

Men generally exhibit a higher overall incidence of VTE in cancer-associated thrombosis, whereas women may experience earlier, treatment-associated thrombotic events.

• Variability in thrombotic patterns exists according to cancer type, stage, and therapy.
• This pattern was identified through a narrative review of epidemiological, biological, and clinical data across solid and hematologic malignancies.
• The differential timing and triggers of thrombosis between sexes suggest distinct underlying mechanisms rather than simply quantitative differences in risk.

Biological factors linked to coagulation and inflammation differ between sexes and may contribute to sex-differential patterns of cancer-associated thrombosis.

• The mechanistic evidence underlying these biological sex differences remains incomplete.
• These biological factors are distinct from gender-related (social/behavioral) factors, both of which were considered in the review.
• The review covers both solid and hematologic malignancies in examining these biological differences.

Sex-related disparities emerge in treatment-associated complications in cancer-associated thrombosis, including bleeding risk and abnormal uterine bleeding in anticoagulated women of reproductive age.

• Abnormal uterine bleeding is identified as a specific complication relevant to women of reproductive age receiving anticoagulation therapy.
• These treatment-associated complications represent a clinically distinct dimension of sex differences beyond thrombotic risk alone.
• This finding highlights that female-specific adverse events from anticoagulation therapy are an underrecognized area of concern in cancer-associated thrombosis management.

Evidence for sex differences in oncohematology-associated thrombosis is limited and inconsistent compared to solid tumors.

• The review specifically distinguishes between solid malignancies and hematologic malignancies in terms of available sex-differential data.
• The limited and inconsistent evidence in hematologic malignancies contrasts with more established patterns observed in solid tumor-associated thrombosis.
• This gap represents an area identified as requiring further research.

Gender-related inequalities in clinical trial participation constrain the interpretation of available data on sex differences in cancer-associated thrombosis.

• Underrepresentation of women (or sex-unbalanced enrollment) in clinical trials limits the ability to draw sex-stratified conclusions.
• The authors call for sex-stratified reporting in future studies to address this limitation.
• This inequality in trial participation is identified as a systemic barrier to advancing precision medicine in thrombosis and oncology.

Cancer-associated thrombosis arises from complex interactions between tumor biology, host factors, and anticancer therapies, with biological sex and gender-related factors modulating both thrombotic risk and clinical expression of VTE.

• Cancer-associated thrombosis is described as a major cause of morbidity and mortality in oncology.
• Growing evidence indicates that both biological sex and gender-related factors (distinct constructs) modulate CAT.
• The review is narrative in design, synthesizing epidemiological, biological, and clinical data.