Phase II induction therapy with docetaxel and carboplatin in NSCLC IIIA/IIIB: FDG-PET response predicts overall and disease free survival

Abstract

7184 Background: Pathologic response after induction therapy (ITx) assessed from surgical specimens as been shown to have a major impact on outcome and to identify potential candidates for cure in locally advanced NSCLC. The non-invasive prediction of pathologic tumor response would represent a major advance in the management allowing risk adapted post-induction therapy. FDG-PET holds the promise to be a non-invasive tool to predict tumor response in NSCLC. Thus, the aim of the study was to correlate metabolic response be FDG-PET with outcome and histologic response in NSCLC IIIA/IIIB after ITx with D/C/Epo. Methods: 60 patients (pts) with pathologically staged or in some cases PET-staged NSCLC IIIA/B were enrolled in the study from 08–99 to 12–02. 56 pts. (median age 62y, 11 IIIA, 49 IIIB, received treatment with D 100 mg/m2 d1 and C AUC 7.5 d2 q21 days for 4 cycles, Epo at 10,000 IU s.c. 3x/week. 24 to 28 days after d 1 of the 4th cycle of ITx, PET scan was repeated and pts were evaluated for surgery. All pts received adjuvant radiotherapy. For each tumor, MTI was calculated (mean tumor diameterxSUV), metabolic response was given as MTI-ratio (MTI-R), i.e. MTI post/MTI pre ITx. Morphometric responses were evaluated independently by two pathologists. Results: 37/60 pts (62%) achieved ORR by CT. 47 pts received a repeat PET. 18 pts were in metabolic (m) CR (MTI-R 15%). The R0 resection rate was 48% (29/60 evaluable pts.). Regression grades III (no vital tumor cells) or IIB (< 10% vital tumor cells and induced apoptosis) have been histologically proven in 14 of 18 patients with metabolic CR. Median OS for all patients is estimated at 22,7 mo, DFS at 19,2 mo with a median follow-up period of 21 and 16 mo, respectively. R0 resection was predictive of superior survival (R0: median survival not reached, R1/2: median survival 14.5 mo, p=0.0054). In the 47 pts receiving repeat PET, 4 year OS is estimated at 68% and 14% (p=0.002) and PFI at 64%% and 9% (p=0.00047) for mCR and m-non-CR pts, respectively. Conclusions: Morphometric tumor response after ITx correlates strongly with metabolic remission by FDG-PET. Metabolic response is a strong non-invasive predictor of PFS and OS in NSCLC III. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Aventis, Janssen-Cilag Aventis, Janssen Cilag Aventis