Lymphangioleiomyomatosis diagnosis ups risk of lung cancer

Patients with a diagnosis of lymphangioleiomyomatosis (LAM) are at higher risk of developing lung cancer, reveals a recent study.

LAM, a rare neoplastic disease associated with the functional tumour suppressor genes TSC1i and TSC2, can lead to structural destruction in the lungs, thereby potentially increasing the risk of lung cancer.

In this study, the authors examined the relative risk of developing lung cancer among patients diagnosed with LAM between 2001 and 2022 at a single high-volume centre in Japan. Data from the Japanese Cancer Registry were used as the reference population. In addition, next-generation sequencing (NGS) was conducted in patients with available tumour samples.

Overall, 642 patients with LAM were included in the analysis (sporadic LAM: n=557; tuberous sclerosis complex-LAM: n=80; unclassified: n=5). Of these, 13 (2.2 percent) were diagnosed with lung cancer during a median follow-up of 5.13 years.

All lung cancer patients were female and were diagnosed at a median age of 53 years. The majority (61.5 percent) of these individuals were never smokers.

Eight patients developed lung cancer following LAM diagnosis. The estimated incidence of lung cancer was 301.4 cases per 100,000 person-years, while the standardized incidence ratio stood at 13.6 (95 percent confidence interval, 6.2‒21.0; p=0.0008).

Some of these patients (38.5 percent) were found to have actionable genetic alterations (EGFR: n=3; ALK: n=1; ERBB2: n=1). In two patients analysed by NGS, no loss of TSC gene function was noted.

“Further research is warranted to clarify the carcinogenesis of lung cancer in patients with LAM,” the authors said.