Two EORTC questionnaires cover the common side effects in NSCLC labels, and miss 62 rarer ones

Sixty-two symptomatic adverse events fall outside both questionnaires

The mapping took every symptomatic adverse event classified in a label as very common, meaning 10% or more, or common, meaning 1% to 10%, and asked whether the QLQ-C30 or the QLQ-LC29 contains an item a patient could use to report it. Sixty-two did not have one. That is the headline number, and on its own it makes the two instruments look considerably less complete than they are.

What changes the picture is how often each of those 62 appears. The authors report that 58.1% of them were listed for a single treatment among the 38 analysed, and they describe most of the missing events as rare.

Oedema and pyrexia are the only gaps common to most labels

Two of the missing adverse events are frequent enough to matter across the field. Oedema appeared in 65.8% of the labels examined and pyrexia in 57.9%, and neither has an item in the core questionnaire or the lung module. No other missing event was reported in more than half of the documents.

The authors report that both are well covered in the EORTC Item Library, and their recommendation is to add items from that library rather than to replace either instrument. They give no figure for how much of the 62-event gap such an addition would close.

What the two instruments already capture

On the events that appear most often in the labels, the questionnaires performed as designed. The authors report that the QLQ-C30 and QLQ-LC29 effectively capture common and very common symptomatic adverse events such as diarrhoea, nausea and vomiting, pain and skin problems, a group they describe as reported in over 75% of the Summaries of Product Characteristics examined.

The gap the study identifies therefore sits at the edges of the adverse event profile rather than at its centre. The finding is not that these instruments miss what patients experience most often, but that a fixed pair of questionnaires, measured against 38 product labels, leaves 62 less frequent events without an item.

The case the authors make for reporting from both directions

The study was prompted by the discrepancies that arise between clinician-assessed and patient-reported symptomatic adverse events in trials, including in non-small cell lung cancer, and the conclusion returns to that starting point.

“This study highlights the need for a dual approach to AE reporting in clinical trials that combines clinician assessments with patient-reported outcomes.”van der Weijst et al., Lung Cancer (2026)

The authors’ recommendation is additive rather than corrective. They report that the QLQ-C30 and QLQ-LC29 capture the common symptomatic adverse events patients report, and they propose adding an item list from the EORTC Item Library to capture the missing ones. Optimising the integration of the two sources is named as the subject for further work.

What a label-based comparison cannot settle

The comparison was made against what the Summaries of Product Characteristics record, not against what patients in those trials actually experienced. The mapping measures instrument coverage against regulatory documentation, and the study reports no patient-level data of its own.

Nor does it estimate the size of the disagreement it sets out from. The frequencies given are frequencies across labels, meaning the percentage of the 38 treatments whose documentation lists a given event, and not the percentage of patients affected. Whether adding items from the Item Library closes any part of the clinician-patient gap in practice is a question the design cannot answer.