Correlation of pretreatment surgical staging and PET SUV(max) with outcomes in NSCLC Giancarlo Moscol, MD PGY-5 Hematology-Oncology UTSW
BACKGROUND AJCC staging 1 gives valuable prognostic information, but does not recognize all variables in relation to outcome, especially for patients with stage IIIA NSCLC. 1. AJCC Staging manual 2009.
Financial Disclosures I do not currently have any relevant financial relations to disclose 3
Off-Label Use Disclosures I do not intend to discuss off-label uses of products during this activity. 4
AJCC 6TH 7TH ED
BACKGROUND Current staging edition (7th, 2009) 1 does not consider the number of mediastinal LN, the number of involved nodal stations or PET scan findings as prognostic factors. Most clinical studies 2,3 report poorer survival with greater number of involved LN or maximal tumor SUV >5.30 2. Okereke et al. SUV predicts survival in NSCLC. Annals of thoracic surgery 2009, 88#): 911-916. 3. Lee J et al. Thorac Cardiovasc Surg 2008; 135(3):615-9.
OBJECTIVES We hypothesized that clinical outcomes can be predicted by the following prognostic factors: Number of involved LN; Number of involved nodal stations; PET SUV(max) of primary tumor PET SUV(max) of mediastinum
METHODS Retrospective chart review of all patients diagnosed with NSCLC stages I-IIIA between 1999-2010 at Albert Einstein Medical Center, Philadelphia, PA. Expedited IRB approval was obtained previous to data gathering. Data collected included: age at diagnosis, type of surgery, AJCC stage, number of LN sampled, number of LN stations sampled, PET-SUV(max) of primary tumor, PET-SUV(max) of mediastinal LN. Censored outcomes were tumor recurrence and death.
METHODS Descriptive statistics were used to summarize demographics. Prognostic factors were analyzed and corrected for age, size of tumor, size of LN, use of chemotherapy, use of radiotherapy and histology using a multivariate Cox s proportional hazard model. Survival was estimated by the Kaplan-Meier method.
RESULTS Complete staging information was available for 369 patients: NSCLC (Stages I-IIIA) 369 pts Surgical staging 207 pts Clinical staging 130 pts Lost to follow up 32 pts Mediastinoscopy 62 pts VATS/thoracotomy 135 pts
RESULTS The median number of LN sampled was 9 (range 1-35) and the median number of stations biopsied was 3 (range 1-9). PET-CT was performed in 89 out of 207 patients, with 59 PET scans showing tumor SUV(max)>5. 65/207 patients received chemotherapy. Median follow up was 29 months (range 1-116). By the time of analysis, 73 recurrences and 90 deaths were censored.
RESULTS Table 1. Analysis of recurrence risk factors HR CI p Age 1.00 0.97-1.04 0.794 Size of tumor 0.96 0.84-1.09 0.525 Size of LN 1.02 0.99-1.05 0.254 <4 involved LN 1.71 0.53-5.53 0.368 >4 involved LN 4.66 1.19-18.18 0.027 Chemotherapy 0.66 0.35-1.25 0.202 Radiotherapy 1.20 0.64-2.25 0.566
RESULTS Table 2. Analysis of mortality risk factors HR CI p Age 1.01 0.96-1.05 0.730 Size of tumor 1.03 0.87-1.22 0.711 Size of LN 1.16 0.78-1.72 0.476 Tumor SUV <5 0.99 0.95-1.03 0.642 Tumor SUV >5 7.12 1.47-34.39 0.015 Node SUV <5 1.03 0.93-1.13 0.602 Node SUV >5 1.87 0.41-8.51 0.417
RESULTS Cox analysis showed greater recurrence risk for patients with 4 or more involved LN (p=0.027). Significant mortality risk was associated with a primary tumor SUV(max) >5 (p=0.015) after correcting for all other variables. All the other variables (age, size of primary tumor, size of LN, use of chemotherapy and radiotherapy) did not correlate with worsening clinical outcomes in our cohort.
CONCLUSIONS The number of LNs involved and the SUV of the primary tumor were significant predictive factors of the outcomes: Having 4 or more LNs positive for disease correlated with higher risk of recurrence (HR=4.66, p=0.027). A primary tumor SUV >5 by PET-CT correlated with higher mortality risk (HR=7.12, p=0.015) These results are limited due to the retrospective nature of the study, the small number of patients actually undergoing PET/CTs and the short term follow up.
REFERENCES 1. AJCC Staging Manual 2009. 2. Okereke I., Gangadharan S., Kent M. et al. SUV predicts survival in NSCLC. Annals of thoracic surgery 2009;88: 911-6. 3. Lee B., Redwine J. Foster C. et al. Mediastinoscopy might not be necessary in patients with NSCLC with mediastinal LN SUV<5.3. J Thorac Cardiovasc Surg 2008;135(3):615-9.