Background
As cancer survival rates improve, reports of multiple primary malignancies are increasing. Lung cancer remains a leading cause of cancer incidence and mortality, but data on patients with multiple malignancies are limited. This study compared the demographic and clinical characteristics of lung cancer patients with multiple malignancies to those with a single primary malignancy in Gippsland, Victoria.
Methods
Demographic and clinicopathological data were retrospectively collected from 584 lung cancer patients in the Gippsland lung cancer database at Latrobe Regional Health from 2019 to 2023. Summary statistics described age, sex, smoking status, ECOG status, cancer stage and histology, and survival. For patients with multiple malignancies, the time between each diagnosis was calculated.
Results
Data for 448 patients were analysed; 89 (19.9%) patients had multiple malignancies. The most common additional malignancy was breast cancer (21.3%), followed by non-melanoma skin cancer (19.1%) and colorectal cancer (15.7%). The median time between initial and lung malignancy diagnosis was 6.5 years (range 0-37 years). Lung adenocarcinoma was the most common type of lung cancer in both multiple and single malignancy groups (48.3% and 46.8% respectively). Age, sex and smoking status were similar across groups. A higher percentage of Stage I-II lung cancer was observed in the multiple malignancy (43.8%) compared to lung cancer only (32.9%) group. A higher mortality rate was seen in the single than the multiple malignancy group (52.6% and 48.2%, respectively).
Conclusions
Patients with lung cancer following a prior malignancy had a higher proportion of potentially curable early-stage lung cancer and fewer deaths compared to those with a single lung cancer diagnosis. This suggests that surveillance and healthcare system integration may improve early detection of secondary malignancies and impact survival. Further prospective studies of cancer registries including secondary cancers are warranted.