WOMEN MORE LIKELY TO SURVIVE CANCER BUT FACE A HIGHER RISK OF SEVERE SIDE EFFECTS

Women were found to have a 12% higher risk of experiencing severe toxicities linked to cancer treatment

Women diagnosed with cancer are more likely to survive than men, but face a significantly higher risk of serious treatment side effects, according to a major international study led by Adelaide University researchers.

The landmark research highlights important biological differences between male and female cancer patients, raising fresh questions about how treatments are tested, prescribed and personalised.

A survival advantage with a hidden cost

Published in the Journal of the National Cancer Institute (JNCI), the study found female patients had a 21% lower risk of death compared with male patients.

However, women were also found to have a 12% higher risk of experiencing severe toxicities linked to cancer treatment.

Researchers say the pattern was consistent across multiple therapies and tumour types, suggesting the differences are rooted in biology rather than specific drugs.

“These sex-based differences were largely consistent across 12 advanced solid tumour types as well as treatment modalities including chemotherapy, targeted therapies and immunotherapy, suggesting they stem from underlying biological mechanisms, not just drug-specific effects.”

Looking beyond treatment type

Unlike many previous studies that examined how particular treatments affect men and women differently, this research explored whether biological sex itself predicts survival and toxicity regardless of therapy.

Lead author Dr Natansh Modi said the findings provide strong evidence that sex should be considered a core factor in cancer care.

“Sex is a fundamental biological factor that influences immune function, drug metabolism, body composition and tumour biology,” Dr Modi said.

“Yet despite longstanding recommendations from regulatory and funding bodies to report outcomes by sex, it is still treated as an afterthought in many trials and is rarely factored into baseline risk or used to personalise treatment decisions.

“Our study addresses this by looking at whether sex itself predicts survival and toxicity across a wide range of cancers and therapies.

“The results were clear: women had a 21% lower risk of death compared to men, but they also faced a 12% higher risk of severe side effects.

Women demonstrated a survival advantage, but at the cost of increased severe toxicity.”

data from thousands of patients

The research analysed outcomes from more than 20,000 cancer patients across 39 clinical trials that supported US Food and Drug Administration approvals between 2011 and 2021.

It included 12 advanced solid tumour types, such as lung, colorectal, melanoma and breast cancers.

Experts say the findings could influence how new drugs are evaluated and highlight the importance of reporting sex-specific outcomes in clinical research.

A call for more personalised cancer care

Researchers are now urging the medical community to recognise biological sex as a key prognostic factor in oncology, both in clinical trials and routine treatment planning.

“This is about improving outcomes for every cancer patient,” Dr Modi said.

“If women are living longer but experiencing more severe side effects, we need to acknowledge that and respond to it. At the same time, we need to better understand why male patients appear to have poorer survival.”

The team says further investigation is needed to understand the biological mechanisms behind these differences, including the roles of immune regulation, hormonal influences, drug exposure and body composition.

The findings add to growing calls for more personalised approaches to cancer treatment, ensuring both survival outcomes and quality of life are considered in future care strategies.