Outcomes in surgically managed non-small-cell lung cancer patients with evidence of interstitial pneumonia identified on preoperative radiology or incidentally on postoperative histology.

OBJECTIVES: Although some interstitial pneumonia (IP) cases are not detected on computed tomography (CT) before surgery, they are confirmed by pathological diagnosis after pulmonary resection. In the present study, we aimed to investigate patients who underwent pulmonary resection for non-small-cell lung cancer (NSCLC) and subsequently showed pathological findings of IP but no apparent interstitial changes on CT.

METHODS: We retrospectively analysed 1688 patients with NSCLC who underwent pulmonary resection and presented with a radiological or pathological diagnosis of IP in 64 institutions between January 2000 and December 2009. We compared 135 patients without radiological findings but with pathological findings of IP (Group A) with 1553 patients with radiological findings of IP (Group B).

RESULTS: The percent vital capacity and predicted diffusing capacity for carbon monoxide were higher in Group A than in Group B. Although there was no significant difference in the occurrence of acute exacerbation (AE) between both groups, the mortality after AE in Group A was significantly lower than that in Group B. The overall survival rates of patients in Groups A and B at 5 years were 59.1 and 40.9%, respectively (P = 0.0031).

CONCLUSIONS: The mortality after AE in patients with only pathological findings of IP was significantly lower than in those with radiological findings of IP. Moreover, the patients with only pathological findings of IP had a better prognosis than those with radiological findings of IP. Thus, our findings suggest that patients with pathological findings of IP and without radiological abnormality had early-stage IP.