It is estimated that more than 90 percent of lung cancers are related to smoking. It can even be observed that states with lower smoking prevalence have a lower incidence of lung cancer, with 50 to 90 cases per 100,000 population.¹ Other data identifies significant social factors like marital status leading to improved survival.² Lung cancer is also treated in a stage-specific, and sometimes tumor-specific, manner. We analyzed data from a lung cancer outcome study at Saint Louis University, compared it to data available through the National Cancer Database, and evaluated the factors that may affect our patients’ survival.

We identified patients from 2000 to 2006 who were diagnosed and treated at Saint Louis University for all stages of non-small cell lung cancer. Factors such as smoking history, marital status, age at diagnosis, first treatment received and gender were noted. The median age at diagnosis was 66 years old (with a range of 22 to 95 years). The majority of patients, 92.5 percent, were prior or present smokers. Approximately 16 percent of patients were never married, 48 percent are married and 17 percent are either separated or divorced. Widowed or unknown marital status represented a minority of patients. Fifty-two percent of patients were male, and 48 percent were female. The stage distribution of all patients diagnosed and treated at Saint Louis University Cancer Center in 2000-2006 is compared to the 1,341 hospitals from the National Cancer Database in Figure 1. Stage I cancer defines tumor isolated within the lung and not invading any nearby structures. Stage II can be more advanced local disease and/or growth to hilar lymph nodes. Stage III describes more advanced local and nodal disease such as multiple lobar nodules, malignant pleural fluid, or disease in the lymph nodes of the center or contralateral chest. Stage IV represents metastasis, or tumor distant from the primary site to another organ. The majority of patients presented at the extremes of either an early stage or a late stage of disease in both local and national data.

Figure 1. Stage Distribution - Saint Louis University Cancer Center

A few notable differences were observed for the first treatment received at Saint Louis University Cancer Center compared to the National Cancer Database institutions when separated by stage (Figure 2). Treatment is tailored to stage, and the options are chosen based upon efficacy in clinical trials. In our group of patients, we noted that surgery was more common at all stages than in the national data. A common local and national treatment is surgery for operable and early stage lung cancer. Likewise, radiation was utilized as the sole treatment more often for early stage lung cancer, but may reflect the inoperable cases. Our local data demonstrates a larger percentage of Stage IV patients opted for no further treatment than the national percentage. Additional unmeasured factors such as comorbidities and tumor burden may have played a significant role in the patient's decision.

Figure 2. Comparison of the Stage and Treatment Regimens

Between Saint Louis University and All State Hospitals

Saint Louis University Cancer Center patients’ overall survival was reviewed via Kaplan Meier analysis for smoking status, marital status, group stage, histology and first treatment received. A dependency upon smoking status was not observed when comparing those who had never smoked and those with prior or current tobacco use, which may be due to the small percentage of non-smoking patients. Marital status was a significant factor for overall survival (data not shown, p=0.0030). Currently married patients had a median survival of approximately 18 months, nearly twice the 9.5 months median survival of non-married patients. The histology of the patient’s tumor was examined and categorized as a pure adenocarcinoma, squamous cell carcinoma or other histology. The pure adenocarcinomas had a higher survival than either the squamous cell carcinoma or other histologies (p=0.0098, data not shown). The most dramatic differences were observed for Stage III patients with 17-month median survival of pure adenocarcinomas, 13-month median survival of squamous cell carcinoma, and 8.5-month median survival of other histologies.

Group stage is a clear factor that determines overall survival (p<0.0001, Figure 3). Stage IV patients have a poorer survival than Stage I or II patients. Saint Louis University Cancer Center patients’ survival was reportedly higher at one year and three years than the reported AJCC survival by stage,³ and within the clinically determined survival data ranges presented by Mountain.⁴ This data is summarized in Table 1.

Significant differences were observed between treatment modalities as well. The combination of early stage and being a surgical candidate yielded the longest median survival of 39 months. Also, if a patient was eligible for a trimodality approach with chemotherapy, radiation and surgery provided a similar long median survival of 31 months. Unfortunately, other combinations with chemoradiotherapy yielded lesser median survivals at 19 and 12 months, respectively. Radiation alone could provide a median survival of 8.6 months and chemotherapy alone provided 8.0 months. If no treatment was provided, survival was only 4 months. A representative survival plot is displayed in Figure 4 with surgery alone, chemoradiation, radiation alone, and no treatment.

It is clear from the national experience and the experience at Saint Louis University that treatments and group stage can affect survival from non small lung cancer. Saint Louis University Cancer Center physicians are taking steps to utilize the factors above in a multidisciplinary approach to treatment and offer the best chance of cure for our patients. Our approach utilizes the efforts of pulmonologists, medical oncologists, surgeons, and radiation oncologists, as well as from oncology nurses, psychiatrists, oncology nutritionists and dietitians. Treatment based upon adequate staging also can help determine ideal candidates for multimodality treatment or obtain tissue for proper histology. We have incorporated new minimally invasive technology to assist disease diagnosis and staging with the endobronchial ultrasound and transbronchial biopsy via the superDimension system. New targeted chemotherapeutic agents available for treatment can selectively bind to tumor cell proteins. These agents have proven to be more effective in certain histologies and are being used to improve patient survival. Our surgeons and radiation oncologists are participating in the STARS trial for early stage operable lung cancer. The STARS study is a worldwide phase III clinical trial investigating and comparing surgery versus CyberKnife stereotactic radiotherapy.

The Grand Vision Information Center provides social support, contacts and information on coping with cancer, smoking cessation and other educational assistance. While the present effects from these therapies, social support and technologies are not fully demonstrated in our 2000-2006 data, I am hopeful that our efforts will be reflected in future analysis and lessons learned.

John Dombrowski, M.D., Ph.D.

Assistant Professor

Department of Radiation Oncology

Saint Louis University School of Medicine

Physician Liaison, Saint Louis University Cancer Center Cancer Committee

1) Jemal etal, CA Cancer J Clin, 2009, 59: 225-249.

2) Saito-Nakaya etal., Psychooncology, 2008 Sep;17(9):869-76

3) Greene etal. AJCC Cancer Staging Manual, Sixth Edition, 2002.

4) Mountain, etal. Chest 1997; 111:1710-17.