Diameter of Solid Tumor Component Alone Should be Used to Establish T Stage in Lung Adenocarcinoma

• Published in: Annals of surgical oncology 2015-12, Vol.22 (Suppl 3), p.1318-1323
• Main Authors: Burt, Bryan M., Leung, Ann N., Yanagawa, Masahiro, Chen, William, Groth, Shawn S., Hoang, Chuong D., Nair, Viswam S., Shrager, Joseph B.
• Format: Article
• Language: English
• Subjects: Aged; Cohort Studies; Female; Follow-Up Studies; Humans; Lung Neoplasms - pathology; Lung Neoplasms - surgery; Male; Medicine; Medicine & Public Health; Middle Aged; Neoplasm Staging; Oncology; Pneumonectomy; Prognosis; Surgery; Surgical Oncology; Survival Rate; Thoracic Oncology; Tumor Burden
• ISSN: 1068-9265; 1534-4681
• DOI: 10.1245/s10434-015-4780-0

Purpose The computed tomographic (CT) appearance of so-called ground glass components within lung adenocarcinomas correlate with noninvasive tumor histology, and solid radiographic components correlate with invasive histology. We hypothesized that T stage might be more accurately applied by considering the solid component nodule diameter rather than total nodule diameter. Methods We identified 74 patients with a solitary lung adenocarcinoma who underwent resection without receiving neoadjuvant therapy. Maximum total diameter and solid diameter of the nodules were measured on CT scans performed within 3 months of surgery. Cox proportional hazard modeling and Kaplan–Meier analyses were performed to determine whether total nodule diameter or solid component diameter was more predictive of overall survival. Results Thirty-three patients (45 %) had a solid nodule and 41 patients (55 %) had a part-solid nodule. Most patients were white (59 %) and female (69 %), and 42 % had never smoked. Seventy-four percent underwent lobectomy and 23 % sublobar resection. Sixty-six percent had pathologic stage I disease, 22 % stage II, and 12 % stage IIIA. Mean ± SD total and solid nodule diameters were 32.1 ± 17.5 and 24.8 ± 18.0 mm, respectively ( p  = 0.01). Among patients with part-solid nodules, multivariate modeling incorporating significant univariate predictors of survival (age, gender, procedure, N descriptor) revealed that maximum solid diameter was associated with overall survival (hazard ratio 1.4, p  = 0.01), while maximum total diameter was not. Conclusions In a largely non-Asian cohort undergoing resection for adenocarcinoma, radiographic diameter of the solid component of a part-solid lesion on CT predicts overall survival better than total lesion diameter. These data provide further evidence to support altering the T descriptor for lung adenocarcinoma for part-solid nodules.