An association between preoperative anemia and decreased survival in early-stage non-small-cell lung cancer patients treated with surgery alone.

PURPOSE: Surgical resection is the mainstay of therapy for patients presenting with Stage I and II non-small-cell lung cancer (NSCLC). Despite optimal staging and surgery, these patients are still at significant risk for failure. The purpose of this study is to report a retrospective analysis of the outcome of patients treated with surgery alone, as well as to analyze prognostic factors associated with survival.

MATERIALS AND METHODS: From May 2000 to November 2002, there was a total of 125 patients who were treated with surgery for NSCLC at University of Maryland Medical Center. Of these, 82 Stage I and II patients who received surgery alone as the definitive therapy were identified. The median age of the entire cohort was 68 years (range, 43-88 years). There were 48 males and 34 females. Sixty-three patients (76.8%) underwent lobectomies whereas 19 patients (23.2%) underwent nonlobectomy (wedge resection or segmentectomy) procedures. Patients who received neoadjuvant or adjuvant radiation therapy or chemotherapy were excluded from the study. Factors included in univariate and multivariate analyses were age, sex, tumor histology, pathologic stage, p53 status, preoperative hemoglobin (Hgb), and type of surgery performed. Endpoints of the study were relapse-free survival (RFS) and overall survival (OS).

RESULTS: Median follow-up was 20.8 months (range, 0.4-43.2 months). For the entire cohort, the 2-year RFS was 66.0% and 2-year OS was 76.3%. Median survival for the entire cohort has not been achieved. In univariate analysis, the only factor that achieved statistical significance was preoperative Hgb level. Patients who had preoperative Hgb <12 mg/dL experienced significantly worse RFS (mean RFS: 26.6 months vs. 34.9 months, p = 0.043) and OS (median OS: 27 months vs. 42.5 months, p = 0.011). For Stage I patients (n = 72), the 2-year RFS and OS were 66.4% and 77.1%, respectively. In the subgroup of stage IA patients (n = 37), there was a trend toward decreased overall survival in the anemic patients (2-year OS of 65.6% vs. 90.9%, p = 0.07). For Stage II patients (n = 10), the 2-year RFS and OS were 60.0% and 66.7%. In the Cox multivariate regression analysis, the only factor that achieved statistical significance was preoperative Hgb, with patients with Hgb <12 mg/dL having decreased RFS (RR 4.1, p = 0.020) and OS (RR 2.9, p = 0.026). There was a trend toward worse RFS (p = 0.056) and OS (p = 0.068) in p53-negative patients (n = 39). Stage, histologic type, type of surgery performed, age, and sex did not affect outcome.

CONCLUSIONS: In our cohort of mostly Stage I NSCLC patients treated with surgery only, preoperative Hgb <12 mg/dL predicted for worse outcome. This effect was observed even in the traditionally low-risk subgroup of completely resected stage IA patients. Much has been written in the literature about anemia causing possible worsening of tumor hypoxia within solid tumors, thereby increasing radio-resistance. This has been a popular argument to explain poorer outcomes of anemic patients with solid tumors who undergo radiotherapy. However, our data suggest that anemia may be a sign of a more aggressive tumor that is at an increased risk of failure independent of the treatment modality.