According to data from the National Lung Screening Trial, the incidence of second primary lung cancer varied from 4% in the total cohort of lung cancer patients to 8% in those receiving surgery for stage IA disease.
The work was presented today at the IASLC World Conference on Lung Cancer 2022 in Vienna. Second primary lung cancer incidence, timing, and survival are poorly known, particularly in people with lung tumours diagnosed by lung cancer screening. Ms Alexandra Potter of Massachusetts General Hospital in Boston and colleagues used data from the National Lung Screening Trial to investigate second primary lung tumours.
Primary Lung Cancer
Second primary lung cancer is a new primary lung cancer that arises after the first primary lung cancer has been treated or when two lung tumours with distinct histologies are discovered at the time of diagnosis.
Patients diagnosed with first-line lung cancer in the NLST were divided into two groups based on whether they were diagnosed with second-line lung cancer less than six months after the first (synchronous) or more than six months after the first (asynchronous) (metachronous).
Ms. Potter and her colleagues then analysed the histology of second and first primary lung tumours. The researchers also computed the incidence rate of metachronous primary lung cancer per 100 person-years, as well as the five-year survival rates for individuals with synchronous and metachronous secondary primary lung malignancies.
Of the 2,053 individuals who satisfied the study’s inclusion criteria, 85 (4.14%) had second primary lung cancer, with 48 (56%) being synchronous and 37 (44%) being metachronous. The incidence of second primary lung cancer varied according to treatment method and stage, reaching as high as 8% in individuals receiving surgery for stage IA illness.
The median period from cancer diagnosis to diagnostic date for metachronous primary lung cancer was 32.0 months (IQR: 17.5- 50.5). The incidence of metachronous primary lung cancer rose with increasing time from the diagnostic date of the first lung cancer in patients with early-stage first primary lung cancer.
The histology of second primary lung tumours revealed that 46% were adenocarcinoma, 25% were squamous cell lung cancer, 8% were lepidic adenocarcinoma, and 6% were small-cell lung cancer. Approximately 44% (n=37) of patients were diagnosed with a second primary lung carcinoma of the same histologic subtype as the first.
Patients with synchronous and metachronous lung malignancies had a five-year survival rate of 45.6 percent (95 percent CI: 29.9-60.1) and 80.3 percent (95 percent CI: 63.0-90.1), respectively, from the date of first primary lung cancer diagnosis.
“We discovered that the incidence of second primary lung cancer in the NLST was around 1-2 percent per year over the total lung cancer patient cohort.”
The risk of second primary lung cancer rose with time following the initial primary lung cancer diagnosis among individuals who received surgery for stage IA illness.”
Ms Potter provided information. “Even five years after the date of the initial primary lung cancer diagnosis, the incidence.