Impact of tumor cell burden beyond the elastic layer on prognosis in T2aN0M0 non-small cell lung cancer with visceral pleural invasion.

OBJECTIVES

Visceral pleural invasion (VPI) is a key upstaging T-factor in non-small cell lung cancer (NSCLC). This study aimed to investigate the prognostic significance of VPI patterns.

MATERIAL AND

METHODS

We retrospectively analyzed 107 participants pathologically diagnosed NSCLC (T2aN0M0) with VPI. Five VPI patterns were quantitatively evaluated and analyzed for their survival impact: (1) total tumor cell area beyond the elastic layer (TCA), (2) whole tumor area beyond the elastic layer (WTA), (3) minimum distance from the pleural surface to the tumor cell invading the pleura (min-DST), (4) maximum distance from the pleural surface to the deepest point of the invaginated elastic layer (max-DSI), and (5) density of tumor cells (DTC).

RESULTS

Median values for TCA, WTA, min-DST, max-DSI, and DTC were 353,471 μm2, 2,370,436 μm2, 114 μm, 1,248 μm, and 19.2 %. Five-year recurrence-free survival (RFS) was significantly lower in participants with larger TCA and WTA (log-rank test). In univariable Cox regression analysis, smoking status, Eastern Cooperative Oncology Group performance status (ECOG PS), invasive component size, TCA, and WTA were significant predictors of RFS. In multivariable analysis, ECOG PS [HR = 2.475; 95 % CI, 1.049-5.838], invasive component size [HR = 2.347; 95 % CI, 1.137-4.845], and TCA [HR = 3.574; 95 % CI, 1.318-9.695] remained independent significant prognostic factors for RFS.

CONCLUSION

TCA may serve as a novel prognostic factor in NSCLC with VPI.