(HealthDay News) — The new International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS) lung adenocarcinoma classification can be used to predict recurrence after limited resection, according to a study published online Aug. 7 in the Journal of the National Cancer Institute.
Jun-ichi Nitadori, M.D., Ph.D., from the Memorial Sloan-Kettering Cancer Center in New York City, and colleagues analyzed the prognostic significance of the IASLC/ATS/ERS classification using data from 734 consecutive patients who underwent lung resection (LR; 258 patients) or lobectomy (LO; 476 patients) for small lung adenocarcinoma between 1995 and 2009.
The researchers found that, in the LR group, but not the LO group, micropapillary (MIP) component of 5 percent or greater versus less than 5 percent correlated with a significantly increased risk of recurrence (LR: five-year cumulative incidence of recurrence, 34.2 versus 12.4 percent; P < 0.001). For patients in the LR group with tumors with an MIP component of 5 percent of greater, 63.4 percent of recurrences were locoregional.
When the surgical margin was less than 1 cm, but not when it was 1 cm or greater, an MIP component of 5 percent or greater correlated with a significantly increased risk of local recurrence (five-year cumulative incidence of recurrence, 32.0 percent for MIP ≥5 percent versus 7.6 percent for MIP <5 percent; P = 0.007).
“Application of the IASLC/ATS/ERS classification identifies the presence of an MIP component of 5 percent or greater as independently associated with the risk of recurrence in patients treated with LR,” the authors write.