Modern Radiation Further Improves Survival in Non-Small Cell Lung Cancer: An Analysis of 288,670 Patients

Abstract

Background: Radiation therapy plays an increasingly important role in the treatment of patients with non-small-cell lung cancer (NSCLC). The purpose of the present study is to assess the survival outcomes of radiotherapy treatment compared to other treatment modalities and to determine the potential role of advanced technologies in radiotherapy on improving survival. Methods: We used cancer incidence and survival data from the Surveillance, Epidemiology, and End Results database linked to U.S. Census data to compare survival outcomes of 288,670 patients with stage I-IV NSCLC treated between 1999 and 2008. The primary endpoint was overall survival. Results: Among the 288,670 patients diagnosed with stage I-IV NSCLC, 92,374 (32%) patients received radiotherapy-almost double the number receiving surgery (51,961, 18%). Compared to other treatment groups and across all stages of NSCLC, patients treated with radiotherapy showed greater median and overall survival than patients without radiation treatment (p < 0.0001). Radiotherapy had effectively improved overall survival regardless of age, gender, and histological categorization. Radiotherapy treatment received during the recent time period 2004 - 2008 is correlated with enhanced survival compared to the earlier time period 1999 - 2003. Conclusion: Radiation therapy was correlated with increased overall survival for all patients with primary NSCLC across stages. Combined surgery and radiotherapy treatment also correlates with improved survival, signaling the value of bimodal or multimodal treatments. Population-based increases in overall survival were seen in the recent time period, suggesting the potential role of advanced radiotherapeutic technologies in enhancing survival outcomes for lung cancer patients.

Keywords: non-small cell lung cancer (NSCLC); overall survival; radiotherapy; treatments.

Figure 1

A. Among all primary NSCLC patients (n=288,670), 18% of patients received surgery, 4% combined surgery and radiotherapy, 32% radiotherapy, and 45% neither surgery nor radiotherapy. Overall, the proportion of NSCLC patients receiving radiation (32%) is almost double that receiving surgery (18%). B-E. Survival plots for NSCLC patients (n=288,670) between treatment types show that, across all stages, NSCLC treated with radiotherapy is associated with greater OS than NSCLC treated without surgery or radiation. While surgical treatment is correlated with the greatest OS across all stages of NSCLC, the survival distribution of combined surgery and radiation treatment begins to match that of surgery for patients with stage II/III NSCLC.

Figure 2

In the 224,655 patients who did not undergo surgery, radiotherapy is correlated with greater OS across all stages.

Figure 3

Survival between the time period of 1999-2003 and 2004-2008. A-D: Among all primary NSCLC patients (n=288,670), overall survival improved significantly for patients with stage I, stage, III, and stage IV NSCLC between the time periods 1999-2003 and 2004-2008 (P<0.0001). E-H: Among the 93,633 patients receiving radiotherapy, treatment given during the recent time period (2004-2008) is correlated with enhanced OS compared to the earlier time period (1999-2003).

Figure 4

In the 10,838 patients receiving surgery, survival improved in the recent years (2004-2008) compared to the earlier years (1999-2003) only in stage III and stage IV NSCLC. Overall survival did not increase significantly for stage I and stage II NSCLC.

Figure 5

Among the 131,022 patients who did not receive surgery or radiotherapy, survival improved between the time periods 1999-2003 and 2004-2008 across every stage.