Women diagnosed with cancer are more likely than men to survive the disease, but they also face a significantly higher risk of severe side effects from treatment, according to a new Australian-led study.
Published in the Journal of the National Cancer Institute, the research was led by Natansh Modi and a team at University of Adelaide. Their analysis reveals consistent differences between male and female cancer patients in both survival outcomes and treatment toxicity.
The study found that female patients had a 21 percent lower risk of death compared with male patients. However, women also experienced a 12 percent higher risk of severe treatment-related toxicities, highlighting a paradox in cancer care: improved survival alongside greater vulnerability to adverse effects.
“These sex-based differences were largely consistent across 12 advanced solid tumor types, as well as treatment modalities including chemotherapy, targeted therapies, and immunotherapy,” the researchers explained. “This suggests the disparities are driven by underlying biological mechanisms rather than drug-specific effects.”
Modi emphasized the broader significance of the findings. “Sex is a fundamental biological factor that influences immune function, drug metabolism, body composition, and tumor biology,” he said. He described the study as providing some of the clearest evidence yet that biological sex is a key predictor of outcomes in cancer care.
The study analyzed data from more than 20,000 patients enrolled in 39 clinical trials that supported U.S. Food and Drug Administration approvals between 2011 and 2021. The analysis included a range of advanced solid tumor types, such as lung, colorectal, melanoma, and breast cancers.
The researchers say the findings have important implications for how cancer drugs are evaluated and prescribed. They argue that clinical research should routinely report and act on sex-specific evidence to ensure both women and men receive treatments tailored to their unique biological responses.
“Recognizing and addressing these differences could improve outcomes and reduce treatment-related complications, particularly for female patients,” the study notes.