Author of

• 12544

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  P3.08 - Poster Session 3 - Radiotherapy (ID 199)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Radiation Oncology + Radiotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 12557

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    P3.08-013 - High local control rates with post-operative radiation therapy in incompletely resected non-small cell lung cancer (NSCLC) patients (ID 1659)

    09:30 - 09:30  |  Author(s): D.Y. Gelblum
    • Abstract

    Background
    Post-operative radiation therapy (PORT) is frequently given to patients with NSCLC who have microscopically positive margins (R1 resection) or gross residual disease (R2 resection) based on oncologic first principles. However, the data to support this practice is scarce. Here we report our institutional experience comparing patients who received PORT in the setting of R0, R1 or R2 resections.

    Methods
    Between 1999 and 2012, 203 patients with NSCLC were treated with PORT in 25-39 fractions to 45-70 Gy. All surgery and PORT were performed at our institution. Twenty-one patients had a sublobar resection, 158 had a lobectomy, and 24 underwent a pneumonectomy. PORT was given to R0 patients with pathologic N2 disease, R1 or R2 resections. Patients with negative margins were compared to patients with residual disease (R1 and R2 resections). Patients with tumor recurrence within the PORT field were recorded as local failures. Local failure-free survival (LFFS), disease-free survival (DFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Univariate analysis was performed using the log-rank test.

    Results
    Fifty-five of 203 patients had residual disease after resection; 45 had R1 and 10 had R2 resections. The predominant histology was adenocarcinoma (80%). Stage at diagnosis was stage I-II in 17 patients, stage III in 186 patients. One-hundred and twenty-six (62%) patients received neoadjuvant and 39 (19%) adjuvant chemotherapy. Median age was 60 years and median KPS before PORT was 80. Median interval from surgery or adjuvant chemotherapy to PORT initiation was 1.6 months (range of 0-3.7 months). With a median follow up of 21 months, local failure occurred in 33/148 (22%) without and 14/55 (25%) patients with residual disease. Two- and 5-year actuarial LFFS rate were 79%/66% for R0 and 75%/58% for R1/R2 resections. Two- and 5-year actuarial DFS rate were 44%/30% for R0 and 48/26% for R1/R2 resections. Two-year and 5-year overall survival (OS) for all patients were 62.4% and 33.1%. LFFS, DFS and OS were not significantly different when comparing R0 to R1/R2 resections. Radiation dose, KPS, T-stage, N-stage, lymphovascular invasion, histology and chemotherapy were all not found to be significantly associated with any endpoint. OS was significantly worse for patients with R2 resection compared to R0/R1 resection (2-year OS 20% vs 64%; p= 0.002) and patients with age >65 (p=0.03). Multivariate analysis will be presented.

    Conclusion
    PORT results in equivalent local control rates after R1 and R2 resections when compared to R0 resections. This suggests that PORT has a significant role in local control of residual disease. However, OS was significantly worse for patients with gross residual disease postoperatively.