Consideration should be given to extending routine follow-up of lung cancer (LCa) patients to 10 years, concludes a team of researchers led by the University of Cambridge.
In Thorax, the team presents a study which found that the incidence of second primary LCa doubled in England between 2000-2004 and 2010-2014. Furthermore, LCa survivors were found to have an elevated incidence of smoking-related second primary cancer (SPC) that persisted for at least 10 years from first LCa diagnosis.
Around 1.09% of patients alive at six months had SPC during follow-up, some of whom had higher order (ie, third or fourth) primary cancers as well.
Risk for SPC was highest for those aged 30-49 (standardised incidence rate ratios [SIRs] 3.4; 95% CI 2.6-4.4) or 50-59 at diagnosis (SIR 2.7; 95% CI 2.5-3.1), for women (SIR 2.0; 95% CI 1.9-2.1) and the most deprived patients (SIR 1.8; 95% CI 1.7-2.0).
Patients whose first primary lung cancer was adenocarcinoma (SIR 1.9; 95% CI 1.7-2.0) or squamous cell carcinoma (SIR 1.8; 95% CI 1.6-1.9) were at highest risk of SPC, while those with carcinoid tumours were not at increased risk (SIR 0.7; 95% CI 0.5-1.1).
Oesophageal squamous and laryngeal cancers were associated with the greatest excess incidence in LCa survivors, although the most frequent type of subsequent malignancy was non-small-cell lung cancer (NSCLC). Bladder cancer was next, followed by head and neck cancers.
Patients with first primary lung cancer diagnosed in 2010-2014 had double the rate of second primary lung cancers compared with those with first primary diagnosis in 2000-2004.
With the risk of SPC continuing to rise beyond the current 5-year cut-off for routine follow-up, the authors suggest this may need to be extended to 10 years, particularly in those aged 55-79 at first diagnosis.
