Karen Reckamp MD @KarenReckampMD Of City of Hope Discusses Who Should We Test: Theres No Screening Study That Has Been Shown To Help Improve Finding The Cancer Early In Non Smokers.
Eligibility for lung cancer screening is based largely on pack-years of smoking, missing many cases. To propose additional groups for screening, this observational study evaluated whether germline mutations associated with cancer risk accelerate onset of lung adenocarcinoma (LA) in ever- and never-smokers.
Patients with LA and family history of cancer were recruited from our oncology clinic and the Clinical Cancer Genomics Community Research Network. With consent, blood samples were screened by large multi-gene panel for 4 categories of germline mutation [lung cancer-associated genes (TP53, EGFR); BRCA2; other genes in Fanconi anemia (FA) pathway; other DNA repair genes]. Accelerated failure-time models of age at LA diagnosis, adjusted for sex, ethnicity, and packs per day, were constructed for never-smokers and ever-smokers. Statistical significance, at p<0.05 limited the False Discovery Rate to 5% across 8 hypotheses.
In never-smokers with LA (n=104), mutated BRCA2,TP53 or EGFR were associated with younger age at diagnosis, while mutation in other FA or DNA repair gene was not. In ever-smokers with LA (n=65), mutated BRCA2 and other FA gene were associated with younger age at diagnosis, while other mutation categories were not (Table).
Regardless of smoking history, BRCA2 mutation carriers experience accelerated onset of LA, as do never-smokers carrying TP53 or EGFR mutation and ever-smokers with mutation in FA gene other than BRCA2. With the exception of TP53 carriers (who merit whole body MRI), lung cancer screening with low-dose computed tomography, starting earlier in adulthood than usual, may be warranted for individuals with germline mutations in these genes. Age at Diagnosis of Lung Adenocarcinoma, by Germline Mutation and Smoking History, Adjusted for Sex, Ethnicity, and Packs per Day.