A group of international experts, including researchers from AIIMS Delhi, McMaster University (Canada), and the International Agency for Research on Cancer (IARC) in France, have stressed the urgent need to record patients’ smoking status in cancer clinical trials. They warn that continued tobacco use can reduce treatment efficacy, worsen survival outcomes, and confound trial results.
In a commentary published in The Lancet Oncology, the authors — including Dr. Abhishek Shankar from AIIMS Delhi — argued that incorporating tobacco-use assessments and cessation initiatives into cancer research protocols could improve therapeutic outcomes and save lives.
Why Smoking Data Matters in Cancer Research
The authors cited the 2014 US Surgeon General’s report, which first established a causal link between cigarette smoking and adverse cancer-related outcomes, including higher cancer-specific mortality. Since then, multiple studies have shown that patients who continue smoking during treatment — whether undergoing surgery, radiotherapy, or systemic therapies — face significantly worse outcomes.
“Knowledge of smoking status during cancer therapy could potentially influence clinical decisions,” the commentary noted.
For instance, the targeted drug erlotinib requires a double dose (300 mg vs 150 mg daily) in patients who continue smoking to achieve effective therapeutic levels.
Mechanisms and Missed Opportunities
Researchers highlighted several ways tobacco may worsen cancer outcomes:
- Tumour hypoxia reducing treatment effectiveness
- Altered drug metabolism impacting chemotherapy efficacy
- Nicotine-driven signaling pathways that aid tumour growth
- Weakened immune response, including reduced natural killer cells
They warned that failing to capture smoking data risks biasing trial outcomes — especially if smoking prevalence is uneven across study groups.
Calls for Systematic Change
- Meta-analyses show quitting smoking after a cancer diagnosis improves survival, often more than the therapy itself.
- A 2020 FDA–AACR–IASLC workshop and the IASLC’s 2023 position statement both declared smoking status capture as a key standard in oncology trials.
- Some cancer centres in Canada, Australia, and the US have already made cessation support a routine part of patient registration.
Despite evidence, barriers remain. Many clinical trials still lack standardised tobacco-use assessments, and pharma companies may see such data as a threat if smoking diminishes drug efficacy. Limited time, resources, and poor integration of smoking records into electronic health systems also hinder progress.
The Way Forward
The experts urged that:
- Smoking status collection should be mandatory in all cancer trials.
- Cessation support be provided within six months of diagnosis for maximum survival benefit.
- Trials must also start recording e-cigarette use, given its rising global prevalence.
“Capturing smoking status in clinical trials should no longer be considered optional; it must be regarded as an essential element of cancer research,” the authors concluded.
Image Source: File Photo (Representational)
