Patients with late-stage non-small cell lung cancer (NSCLC) who have surgery have better survival rates than those who don’t, according to the results of a recent study published in the Annals of Thoracic Surgery. The researchers also reported that despite the improved survival from surgery, fewer patients are receiving the treatment.

The researchers identified more than 34,000 patients with stage IIIA, IIIB, or IV NSCLC in the California Cancer Registry. Of those patients, 25.7% received a combination of chemotherapy and radiation, whereas 11% received surgery, either alone or in combination with chemotherapy or radiation. However, 27% received no treatment at all.

The median overall survival for treatment plans involving surgery was 40.7 months for patients receiving surgery and chemotherapy, 33.3 months for those receiving surgery, chemotherapy, and radiation, 28.8 months for those receiving only surgery, and 18.6 months for surgery and radiation. In contrast, when surgery wasn’t a part of treatment, median overall survival fell to 11.9 months for chemotherapy and radiation, 10.5 months for chemotherapy alone, and 3.7 months for radiation alone.

The researchers noted that additional analysis is needed to explain why 27% of patients received no treatment at all. They hypothesized that some patients may refuse treatment because they believe that the incremental health gains wouldn’t be worth the side effects. Others may have racial or socioeconomic biases or live too far from major cancer centers to make treatment feasible.