Familial multiple primary lung cancers: a population-based analysis from Sweden

Area of Science:

• Oncology
• Genetics
• Epidemiology

Background:

• Multiple primary cancers can result from inherited or acquired deficiencies.
• Understanding the genetic predisposition to lung cancer is crucial for risk assessment.

Purpose of the Study:

• To investigate the evidence for a genetic predisposition to lung cancer using a nationwide family dataset.
• To assess the risk of developing a second primary lung cancer in individuals with a family history of lung cancer.

Main Methods:

• Utilized the Swedish Family-Cancer Database, encompassing over 10.2 million individuals and their family members.
• Analyzed cancer cases from the Swedish Cancer Registry up to the year 2000.
• Calculated standardized incidence ratios (SIR) and 95% confidence limits (CI) for first and second primary lung cancers based on family history.

Main Results:

• The incidence of second primary lung cancer was nine times higher in cases with a familial lung cancer history compared to the first primary lung cancer.
• Patients with a family history of lung cancer showed a significantly increased risk for subsequent primary lung cancer: SIR=9.89 for men and SIR=17.86 for women.
• The proportion of multiple primary lung cancer patients with a family history of lung cancer was 4.7% for men and 6.5% for women.

Conclusions:

• The development of a second primary lung cancer may be more strongly influenced by genetic factors than the first primary lung cancer.
• Family history of lung cancer is a significant risk factor for developing subsequent primary lung cancer.