Abstract 437P
Background
Pulmonary nodules present diagnostic challenges, particularly without tissue confirmation, requiring MDTs to rely on clinic-radiological evaluations. Malignancy risk models (Herder/Brock) are vital for guiding MDT decisions. The British Thoracic Society (BTS) guidelines classify nodules with >70% malignancy probability as high risk, recommending treatment based on fitness. This study investigates survival outcomes of nodules lacking tissue diagnoses, exploring the prognostic utility of Herder/Brock scores, volume doubling time (VDT), and nodule characteristics across various risk thresholds.
Methods
A retrospective review of 43 of 277 patients diagnosed clinico-radiologically as lung cancer at a local Lung MDT (Jan 2019–Mar 2020). Inclusion: tumour size ≤3 cm, no radiological evidence of nodal or distant metastases. Data included demographics, nodule characteristics, WHO PS, Herder/Brock scores, and VDT (where available). Kaplan-Meier and Cox regression were used for survival analysis, and treatment details, including SABR,were evaluated.
Results
Among 43 patients, 60.5% were male, mean age 77.1 years (57–95); 93% smokers, 51.2% had PS >2, 55.8% spiculated nodules, and 23.1% received SABR. VDT or Herder/Brock scores documentation: 20.9% (n=9); Brock >50%: 25.6% (n=11); Herder >50%: 46.5% (n=20); Brock ≥70%: 4.7% (n=2); Herder ≥70%: 37.2% (n=16). Cox regression showed no significant survival associations for Brock >50% (HR 1.162, p=0.824), Herder >50% (unstable, p=0.984), or spiculated nodules (HR 0.752, p=0.661). The model was significant (p=0.006); radical treatment improved survival (HR 0.193, p=0.033). VDT ≤400 days (n=8) had shorter survival than >400 days (n=3), p=0.316. Brock ≥70% had no significant survival impact (HR 1.268, p=0.764). Herder ≥70% trended toward worse survival (HR 4.815, p=0.053).
Conclusions
Brock and Herder Scores >50% or ≥70% showed no significant survival prediction, though Herder ≥70% indicated a trend toward worse outcomes. Radical treatment improved survival, highlighting the importance of refining risk thresholds and enhancing MDT strategies for managing high-risk nodules in patients unfit for tissue diagnosis or declining invasive tests.
Legal entity responsible for the study
Glenfield Hospital, University Hospitals of Leicester.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.