Lung Cancer Program
Lung cancer is the most common cause of cancer mortality worldwide for both men and women, causing approximately 1.2 million deaths per year. The United States in 2009, will have nearly 220,000 new cases of lung cancer and 160,000 deaths related to lung cancer.The term lung cancer refers to cancers that originate in the respiratory airways or lung tissue. Approximately 95 percent of all lung cancers are classified as either small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC). This distinction is essential for staging, treatment, and prognosis. Other cell types comprise about 5 percent of malignancies arising in the lung.
RISK FACTORS — A number of environmental and life-style factors have been associated with the subsequent development of lung cancer, of which cigarette smoking is the most important. The most important risk factors associated with the development of lung cancer are listed below :
1. Smoking — The primary risk factor for the development of lung cancer is cigarette smoking, which is estimated to account for approximately 90 percent of all lung cancers
2. Radiation therapy — Radiation therapy (RT) can increase the risk of a second primary lung cancer in patients who have been treated for other malignancies.
3. Environmental toxins —These include exposure to second-hand smoke, asbestos, radon, metals (arsenic, chromium, and nickel), ionizing radiation, and polycyclic aromatic hydrocarbons
4. Pulmonary fibrosis —This increased risk appears to be independent of smoking.
5. HIV infection — The incidence of lung cancer among individuals infected with HIV appears to be increased compared to that seen in uninfected controls.
6. Genetic factors — Genetic factors can affect both the risk for and prognosis from lung cancer. There is a clearly established familial risk.
7. Dietary factors — Evidence has suggested that various dietary factors (antioxidants, cruciferous vegetables, phytoestrogens) may reduce the risk of lung cancer, but the role of these factors is not well established.
SCREENING — 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 radiography, sputum cytology, or CT) has been shown to reduce mortality from lung cancer.
PATHOLOGY — The World Health Organization classification for primary lung cancer recognizes four major histologic cell types :
- Adenocarcinoma (including bronchioloalveolar carcinoma) — 38 percent
- Squamous cell carcinoma — 20 percent
- Large cell carcinoma — 5 percent
- Small cell carcinoma 13 percent
- Other non-small cell carcinomas, which cannot be further classified (18 percent)
- Other (6 percent)
CLINICAL SYMPTOMS— Symptoms may result from local effects of the tumor, from regional or distant spread, or from distant effects not related to metastases. Some common symptoms include:
- Cough — Cough is present in 50 to 75 percent of lung cancer patients
- Hemoptysis — Blood with coughing is reported by 25 to 50 percent of patients who are diagnosed with lung cancer, although bronchitis is the most common cause of this symptom
- Chest pain — Chest pain is present in approximately 20 percent of patients presenting with lung cancer
- Dyspnea — Shortness of breath is a common symptom in patients with lung cancer at the time of diagnosis, occurring in approximately 25 percent of cases
- Hoarseness - In patients with lung cancer, this is due to malignancy involving the nerves around the lungs
DIAGNOSIS AND STAGING
All patients with suspected Lung Cancer should undergo some basic tests, some of these are mentioned below:- Liver function test – To rule out liver abnormalities
- Calcium testing – To rule out bone
- Complete blood testing – To rule out blood loss or kidney problems, etc
- Tumor markers - obtained from serum or tumor tissue have prognostic significance in some situations
- Contrast-enhanced computed tomography (CT) that extends through the lungs, liver, and adrenal glands. CT is essential for ‘staging’ lung cancer (putting the cancer into a certain group which helps figure out the best treatment plan and diagnosis).
- Positron emission tomography (PET) – To have a closer look at the body and rule out any other sites of disease
- CT of the brain or magnetic resonance imaging (MRI) of the brain – To evaluate the status of the Brain previous to treatment
- Radionuclide bone scintigraphy. – To evaluate the bones
- TISSUE SAMPLING — Lung Cancer cannot be diagnosed or accurately staged via noninvasive methods alone. Tissue sampling is required usually with a surgical or Intervantional Radiology Guided BIOPSY
| Primary tumor (T) | |
| T1 -Tumor 3 cm diameter, surrounded by lung or visceral pleura, without invasion more proximal than lobar bronchus | |
| T1a - Tumor 2 cm in diameter | |
| T1b - Tumor >2 cm but 3 cm in diameter | |
| T2 -Tumor >3 cm but 7 cm, or tumor with any of the following features: | |
| Involves main bronchus, 2 cm distal to carina | |
| Invades visceral pleura | |
| Associated with atelectasis or obstructive pneumonitis that extends to the hilar region but does not involve the entire lung | |
| T2a - Tumor >3 cm but 5 cm | |
| T2b - Tumor >5 cm but 7 cm | |
| T3 - Tumor >7 cm or any of the following: | |
| Directly invades any of the following: chest wall, diaphragm, phrenic nerve, mediastinal pleura, parietal pericardium, main bronchus <2 cm from carina (without involvement of carina) | |
| Atelectasis or obstructive pneumonitis of the entire lung | |
| Separate tumor nodules in the same lobe | |
| T4 - Tumor of any size that invades the mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina, or with separate tumor nodules in a different ipsilateral lobe | |
| Regional lymph nodes (N) | |
| N0 -No regional lymph node metastases | |
| N1 -Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension | |
| N2 -Metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s) | |
| N3 -Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph node(s). | |
| Distant metastasis (M) | |
| M0 - No distant metastasis | |
| M1 - Distant metastasis | |
| M1a - Separate tumor nodule(s) in a contralateral lobe; tumor with pleural nodules or malignant pleural or pericardial effusion | |
| M1b - Distant metastasis | |
| Stage groupings | |||
| Stage I A | T1a-T1b | N0 | M0 |
| Stage IB | T2a | N0 | M0 |
| Stage II A | T1a,T1b,T2a | N1 | M0 |
| T2b | N0 | M0 | |
| Stage II B | T2b | N1 | M0 |
| T3 | N0 | M0 | |
| Stage III A | T1a,T1b,T2a,T2b | N2 | M0 |
| T3 | N1,N2 | M0 | |
| T4 | N0,N1 | M0 | |
| Stage III B | T4 | N2 | M0 |
| Any T | N3 | M0 | |
| Stage IV | Any T | Any N | M1a or M1b |
Treatment — Surgical resection offers the best opportunity for long-term survival and cure in patients with resectable Lung Cancer. The appropriateness of surgical resection of candidates includes preoperative staging and an assessment of performance status with concurrent comorbidities and pulmonary function to allow prediction of postoperative function.
- Patients with stage I or II NSCLC should be treated with complete surgical resection whenever possible. Postoperative chemotherapy has been shown to improve survival in patients with pathologic stage II disease and may have a role for patients with stage IB NSCLC
- For patients with pathologically proven stage III disease prior to definitive therapy, a combined modality approach using concurrent chemotherapy is generally preferred. The role of surgery following chemoradiotherapy is an area of active investigation.
- Patients with stage IV disease are generally treated with systemic therapy or a symptom-based palliative approach. In appropriately selected patients, chemotherapy and/or molecularly targeted therapy may prolong survival without sacrificing quality of life. Radiation therapy and surgery may also be useful for symptom palliation in some patients.