Lung cancer screening dramatically increases long-term survival

Screening programme Diagnosing early-stage lung cancer using low-dose CT scans resulted in an overall 20-year survival rate of 80%. (Courtesy: RSNA)

Lung cancer is the leading cause of cancer-related death, with a five-year survival rate of only 10–20% in most countries. Early diagnosis is key to improving survival rates, but only 16% of lung cancers are diagnosed at an early stage. New results from a large multicentre, multinational study show that early detection of lung cancer using low-dose CT screening dramatically improves long-term survival.

“While screening doesn’t prevent cancers from occurring, it is an important tool in identifying lung cancers in their early stage when they can be surgically removed,” explains lead author Claudia Henschke from the Icahn School of Medicine at Mount Sinai, who presented the findings this week at RSNA 2022, the annual meeting of the Radiological Society of North America. “Symptoms occur mainly in late-stage lung cancer. Thus, the best way to find early-stage lung cancer is by enrolling in an annual screening programme.”

The lung cancer screening study began back in 1992 with the creation of the International Early Lung Cancer Action Program (I-ELCAP), which has enrolled over 87,000 participants from over 80 institutions to date.

The researchers have now reported the 20-year follow-up data for participants in the screening programme who were later diagnosed with lung cancer and subsequently treated.

For the 1285 I-ELCAP participants diagnosed with early-stage lung cancer, the 20-year survival rate was 80%. For the 991 patients with solid nodules, the survival rate was 73%, while for those with non-solid cancerous lung nodules or partly solid nodules, it was 100%. For participants with clinical Stage IA lung tumours, the 20-year survival rate was 86%, regardless of consistency, and for those with Stage IA tumours measuring 10 mm or less, it was 92%.

The results show that after 20 years, patients diagnosed with lung cancer at an early stage have significantly better outcomes. The researchers note that their findings confirm previous 10-year estimates of lung cancer survival rates and provide evidence of the high curability of lung cancer diagnosed by screening.

“The key finding is that even after this long a time interval they are not dying of their lung cancer,” says Henschke. “And even if new lung cancers were found over time, as long as they continued with annual screening, they would be OK.”