STANFORD, CA — Lung cancer survivors have a high risk of developing second primary lung cancer (SPLC); the risk is three to four times higher than the risk of someone in the general population developing initial primary lung cancer (IPLC).
“Moreover, over 80% of the detected SPLC cases are known to be comprised of asymptomatic individuals, with SPLC patients showing significantly worse survival compared to those who remain with single primary lung cancer,” according to a study in the journal Cancer. “Recent therapeutic advances and screening technologies have improved survival among patients with lung cancer, who are now at high risk of developing second primary lung cancer (SPLC).”1
Stanford University researchers with colleagues including those from the VA Palo Alto, CA, Healthcare System noted that, recently, an SPLC risk-prediction model –SPLC-RAT — was developed and validated using data from population-based epidemiological cohorts and clinical trials. They pointed out, however, that real-world validation has been lacking.
To remedy that, the study team evaluated the predictive performance of SPLC-RAT in a hospital-based cohort of lung cancer survivors. Data from 8,448 ever-smoking patients diagnosed with initial primary lung cancer (IPLC) in 1997-2006 at Mayo Clinic was evaluated, with each patient followed for SPLC through 2018. In addition to the predictive performance of SPLC-RAT, the researchers also explored the potential of improving SPLC detection through risk model-based surveillance using SPLC-RAT vs. existing clinical surveillance guidelines.
Of 8,448 IPLC patients, 483 (5.7%) developed SPLC over 26,470 person-years. Study results indicated that “the application of SPLC-RAT showed high discrimination area under the receiver operating characteristics curve: 0.81). When the cohort was stratified by a 10-year risk threshold of ≥5.6% (i.e., 80th percentile from the SPLC-RAT development cohort), the observed SPLC incidence was significantly elevated in the high-risk versus low-risk subgroup (13.1% vs. 1.1%, p < 1 × 10-6 ).”
The authors advised that the risk-based surveillance through SPLC-RAT (≥5.6% threshold) outperformed the National Comprehensive Cancer Network guidelines with higher sensitivity (86.4% vs. 79.4%) and specificity (38.9% vs. 30.4%) and required 20% fewer computed tomography follow-ups needed to detect one SPLC (162 vs. 202).
“In a large, hospital-based cohort, the authors validated the predictive performance of SPLC-RAT in identifying high-risk survivors of SPLC and showed its potential to improve SPLC detection through risk-based surveillance,” the researchers concluded.
The article discussed how existing post-treatment surveillance guidelines based on the expert panels’ consensus opinion, including the National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO), “recommend computed tomography (CT) every 2–6 months for the first 2–5 years then annual CT thereafter based on stage and treatment history for IPLC patients. However, recent studies showed that several other factors, such as smoking history, are associated with ongoing and increased risk of SPLC. Despite their importance, these risk factors are not reflected in the existing guidelines, thereby raising questions on the efficiency of the current surveillance guidelines for identifying high-risk patients for SPLC to be screened or followed up.”
- Choi E, Luo SJ, Ding VY, Wu JT, et. Al. Risk model-based management for second primary lung cancer among lung cancer survivors through a validated risk prediction model. Cancer. 2024 Mar 1;130(5):770-780. doi: 10.1002/cncr.35069. Epub 2023 Oct 25. PMID: 37877788; PMCID: PMC10922086.