CANCER OF THE LUNG
 Nicholas S. Muff, MD, FACR
Cancer Committee Chairman
Director of Radiation Oncology
North Puget Cancer Center
Incidence and survival:
According to the American Cancer Society Lung cancer is the most common cause of cancer mortality world-wide for both men and women causing approximately 1.2 million deaths per year. In the United States in 2007 there were an estimated 215,000 new cases of lung cancer and 152,000 deaths. In contrast, colorectal, breast, and prostate cancers combined will be responsible for only 124,000 deaths. Both the absolute and relative frequency of lung cancer have risen dramatically. As an example, the age-adjusted death rates of lung cancer were similar to that of pancreatic cancer prior to 1930 for men and prior to 1950 for women. Around 1953, lung cancer became the most common cause of cancer deaths in men and in 1985 it became the leading cause of cancer deaths in woman. Although lung cancer deaths have begun to decline in men, the death rate in women continues to rise and almost one-half of all lung cancer deaths now occur in women.
In 2007, 44 patients were diagnosed with lung cancer at United General Hospital, See Table No. 1. This represents 18% of our analytic caseload for that year.
Table No. 1
Source: United General Hospital Cancer Registry
Risk factors:
A number of environmental and lifestyle factors have been associated with the subsequent development of lung cancer, of which cigarette smoking is the most important. Cigarette smoking is estimated to account for 90% of all lung cancers. The risk of developing lung cancer gradually was thought to fall for patients who quit smoking. Recent data indicates that the risk does not fall but remains stabilized at the risk level corresponding to the time at which the patient quit smoking.
Other factors associated with the development of lung cancer are radiation therapy which increases the risk of second primary lung cancer in patients who have been treated for other malignancies. This appears to be associated more with those patients who also smoke.
Environmental toxins:
Pulmonary fibrosis, HIV infection, and genetic and dietary factors have also been implicated.
Signs and symptoms:
There are a wide range of symptoms due to intrathoracic effects of lung cancer, the most common of which are cough, hemoptysis, bleeding, chest pain, and shortness of breath. Cough is present in about 50-75% of lung cancer patients at presentation. The new onset of a cough in a smoker or former smoker should raise the suspicion that lung cancer is present. Coughing up blood or hemoptysis is reported by 25-50% of patients diagnosed with lung cancer, although bronchitis is the most common cause of this symptom. Chest pain is present in approximately 20% of patients presenting with lung cancer. It tends to be variable in character and more common in younger than older patients. The pain is typically present on the same side of the chest as the primary tumor. Dyspnea or shortness of breath is a common symptom in patients with lung cancer at the time of diagnosis occurring in approximately 25% of cases. Shortness of breath may be due to compression on the airway, a blockage of air flow in the lung, or spread of tumor in the lymphatics of the lung.
Early detection:
The diagnosis of lung cancer is primarily based upon evaluation of individuals with symptoms. Screening for lung cancer is not widely used since no screening test (chest x-rays, sputum cytology, or CT) has been shown to reduce the death rate from lung cancer.
Diagnosis and staging:
Diagnosis requires obtaining tissue from the tumor for pathologic review. Staging requires both x-ray and pathology data. Following physical exam the use of radiographic imaging is critical to establishing the diagnosis of lung cancer for staging purposes. Chest x-ray, CT scan, and PET scan are all used for this purpose.
Lung cancer staging using the TNM classification system is divided into four stages. Stage I is primary cancer of the lung without lymph node involvement. Stage II is primary cancer of the lung with involvement of adjacent lymph node at the root of the lung. Stage III is primary cancer of the lung involving lymph nodes in the center or mediastinal portion of the chest. Stage IV presents presence of metastasis or spread outside the chest.
Management:
Management for patients with nonsmall cell lung cancer, stage I consist of complete resection, either by open thoracotomy or video-assisted thoracotomy with no further adjuvant treatment needed. For patients with stage II disease spread to adjacent lymph nodes, primary treatment is surgical resection followed by adjuvant chemotherapy. For patients with stage III disease involving lymph nodes in the central chest, treatment is more controversial. For those patients with stage IIIA disease, consideration is for combined radiation therapy/chemotherapy followed by surgery. For those patients with stage IIIB, primary radiation and chemotherapy are recommended. Finally, for patients with stage IV metastatic disease, chemotherapy, palliative radiation, and best supportive care are options for the patient.
Additional considerations:
Patients with lung cancer in advanced stage requiring chemotherapy and radiation therapy will require close nutritional support and supportive care to help them deal with generalized symptoms such as fatigue.
Statistical Evaluation and Outcomes Analysis:
1. Stage at Diagnosis (Table No. 2)
Though numbers are too small to draw conclusions, 8% of patients were Stage I at diagnosis, 2% Stage II, 41% Stage III and 43% stage IV. NCDB stage at diagnosis is also listed.
2. Gender, Non-Small Cell Lung Cancer Diagnosed in 2005 (Table No. 3)
59% of Non-Small Cell lung cancer cases diagnosed at United General Hospital during 2005 were male, 41% female. For the national database 56% were male and 44% female.
3. Type of Treatment for Non-Small Cell Cancer Diagnosed in 2005 (Table No. 4)
38% of our patients are listed as receiving radiation only as opposed to 14% for NCDB. This caused us to review all of those cases and we found that 27% of these cases were actually treated with radiation only. Further analysis of the data revealed that this is due mainly to a number of patients being too sick to tolerate other treatment. Although our numbers are too small to draw firm conclusions, treatment differences could be attributed to a higher number of patients presenting with advanced stage III and IV disease and our skewed age distribution. Results from this review of treatment are now reflected in our Cancer Registry and will be reflected with the NCDB when this data is resubmitted.
4. Age at Diagnosis for Non-Small Cell Lung Cancer Diagnosed in 2005 (Table No. 5)
The age at diagnosis for Non-Small Cell lung cancer cases diagnosed at United General Hospital during 2005 compares favorably with information from the national database. The higher percentage of patients in the 80-89 year old category ( 22% UGH vs. 16% national) is partly due to a skewed age distribution in this region which is a popular area for retirement.
5. Survival Data for Non-Small Cell Lung Cancer Patients Diagnosed and Treated 1998-2000 (Table No. 6 and Diagram 1, Diagram 2)
Survival data at one year at United General is 42.3% vs. 46.2% NCDB, two years 25.8% vs. 29.4%, three years 18.7% vs. 22.3%, four years 12.9% vs. 18.3% and five years 11.5% vs. 15.5%. The difference is partly explained by the higher number of patients presenting at United General Hospital with advanced Stage III and IV disease.
Table No. 2
Source: NCDB, CoC, ACoS, Benchmark Reports, v9.0
Table No. 3
Source: NCDB, CoC, ACoS, Benchmark Reports, v9.0
Table No. 4
Source: NCDB, CoC, ACoS, Benchmark Reports, v9.0
Table No. 5
Source: NCDB, CoC, ACoS, Benchmark Reports, v9.0
Table No. 6
Source: United General Hospital Cancer Registry
Diagram No. 1
 Source: United General Hospital Cancer Registry
Diagram No. 2
Summary:
1. Lung cancer is the most common cause of cancer death world-wide with approximately 215,000 cancer deaths in the US in 2007.
2. There is not yet a good screening test to detect early lung cancer so that patient complaints and appropriate x-ray evaluation are part of the initial process of diagnosing and staging lung cancer.
3. A multi-disciplinary approach is necessary to treat patients with lung cancer.
4. Since a great majority of lung cancers are related to cigarette smoking promoting smoking cessation in the community will help decrease the incidence of this deadly cancer.
5. Although the overall outlook for patients with lung cancer is dismal, approximately one-half to two-thirds of patients with stage I lung cancer survive 5 years. Survival rate for stage II vary from 28-57%, for stage III 19-39%, and for stage IV 0-5%.
6. Statistical data from United General Hospital compares favorably with national data with the exception noted above. Efforts to diagnose patients in a earlier stage are still hamper by the lack of an effective screening tool or program for lung cancer that makes a difference in survival.
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