Treatment for Lung Cancer

Treatment for Lung Cancer

Treatment for lung cancer depends upon a variety of factors. The most important factors are the histopathologic (diseased tissue) type of lung cancer and the stage of the cancer. 
Once the stage of the lung cancer has been determined, the oncology team and the patient work together to develop a treatment plan. It is important for lung cancer patients to discuss the value of different forms of therapy with their oncologist. Other factors that affect lung cancer treatment include the patient's general health, medical conditions that can affect treatment (such as chemotherapy), and tumor characteristics.
Characteristics of the lung tumor are used to help separate patients into two groups: patients who are at low risk for cancer recurrence and patients who are at high risk for cancer recurrence. Specific prognostic—disease-forecasting—factors are used to place patients in either of these groups. In particular, the histopathologic groupings of small cell lung carcinoma (SCLC) versus non-small cell lung carcinoma (NSCLC) may be used to better predict a patient's prognosis and expected response to therapy.
Surgical resection (cutting away) of the tumor generally is indicated for cancer that has not spread beyond the lung. Surgery for lung cancer may be conducted using a variety of techniques. Thoracotomy, which is performed throught the chest wall, and median sternotomy, which is performed by cutting through the breastbone, are standard methods used for lung cancer surgery.
Alternative approaches include anterior limited thoractomy (ALT), which is performed on the frontal chest using a small incision; anterioraxillary thoracotomy (AAT), which is performed on the frontal chest near the underarm; and posterolateral thoracotomy (PLT), which is performed on the back/side region of the trunk.
ALT, in particular, is less invasive than standard thoractomy—that is, this procedure involves less disturbance of the body than large incisions or other intrusive measures. ALT may result in less blood loss during and after surgery, less postoperative drainage, and less postoperative pain than standard thoracotomy.
Recently, surgeons have developed other less invasive procedures for the removal of cancerous lung tissue. For example, video-assisted thoracoscopy (VAT), also known as video-assisted thoracic surgery (VATS), involves using a video camera to help visualize and operate on the lung within the chest cavity. The surgical incisions made during VAT are much smaller than those required for thoracotomy or sternotomy.
However, some physicians caution that VAT does not allow complete lung examination to identify and remove metastases that are not detected by preoperative chest x-ray. VAT is perhaps most appropriate for Stage 1 and Stage 2 cancers that require lobectomy (surgical removal of a lung lobule) with lymphadenectomy (removal of one or more lymph nodes) and for peripheral (outer edge) lung tumors that can be removed by wedge resection. In such cases, follow-up is required to establish a long-term prognosis.
Computed tomography (CT) scans also have been added to VAT technology to improve lung cancer surgery. Experts have found that percutaneous (through the skin) CT-guided localization wires can help to identify tumorous lung nodules. In this way, wires are used to assist VAT in cases that require sublobectomy resection (partial removal of a lung lobe).
Unfortunately, surgical procedures can cause a condition called lymphocytopenia—low number of lymphocytes (white blood cells) in the blood—which is linked to shorter survival times among patients with advanced lung cancer. Lymphocytopenia may be related to a deficiency in interleukin-2 (IL-2), a hormone that controls the activity of T lymphocytes (thymus-dependent lymphocytes). Preoperative treatment with recombinant human interleukin-2 (rhIL-2) may help to prevent the decrease in lymphocytes that occurs after surgery for operable lung cancer.
If the tumor is aggressive and/or widespread, chemotherapy, radiotherapy (radiation therapy), and other therapies may be used in addition to or instead of surgery to treat lung cancer.
Photodynamic therapy (PDT) often is used to treat inoperable lung cancer. Photodynamic therapy involves the injection of a light-activated drug (e.g., photofrin/polyhaematoporphyrin, lumin). Then, during bronchoscopy (examination of the airways using a flexible scope), the lung tumor is illuminated by a laser fiber that transmits light of a specific wavelength. At that time, the laser light is used to destroy the sensitized tumor tissue. Skin photosensitivity (light sensitivity) is a side effect of PDT.
The curative potential of PDT is the most exciting aspect of this therapy in lung cancer patients whose tumors are occult (hidden, unseen) on chest x-ray. The tissue-sparing effects of PDT may be particularly important for patients who have limited lung function.
Electrosurgery is surgery performed using a needle, bulb, or disk electrode. Nd-YAG laser therapy (neodymium-yttrium/argon laser that concentrates high-energy electromagnetic radiation to destroy tissue), cryotherapy (destruction of tissue using extreme cold), and brachytherapy (treatment with ionizing radiation) are additional tumor debulking, or size-reducing, techniques that may be performed during bronchoscopy. These methods are especially useful for obstructive, inner cavity (intraluminal) lung tumors.
Radiotherapy, also known as radiation therapy, is a treatment method that uses high-energy, ionizing radiation (e.g., gamma rays) to kill cancer cells. Ionizing radiation is produced by a number of radioactive substances, such as cobalt (60Co), radium (228Ra), iodine (131I), radon (221Rn), cesium (137Cs), phosphorus (32P), gold (198Au), iridium (192Ir), and yttrium (90Y). Radiotherapy may be applied to shrink a tumor that is later removed by surgery, to relieve symptoms, or to destroy malignant cells in a tumor that cannot be removed surgically.
Because cancer cells usually multiply faster than most normal body tissues, they are especially affected by radiation, which prevents cell division and the formation of DNA (deoxyribonucleic acid; human genetic material). Other bodily tissues that divide rapidly, such as hair and skin, are also particularly vulnerable to radiotherapy.
Side effects of radiotherapy include hair loss and skin disorders, such as erythema (skin redness due to blood vessel congestion), itching (puritis), desquamation (sloughing-off of outer skin layers), pain, shrinking (atrophy), increased pigmentation, and swelling (edema).
Radiation also can cause the following:

• Anorexia (loss of appetite)
• Changes in taste perception
• Damage to the fetus (in women who are pregnant)
• Increased heart rate (tachycardia)
• Increased risk for infection
• Malaise
• Nausea
• Vomiting

Radiosurgery, also called stereotactic radiosurgery or radiation surgery, is a type of external radiation therapy that may be used to treat inoperable lung cancer. In this treatment, a single large dose of radiation is administered precisely to the tumor, causing little damage to healthy tissue. In spite of its name, stereotactic radiosurgery is not a surgical procedure. The CyberKnife® System is a type of radiosurgery that may be used in patients who have lung cancer.

Forecasting the Course of Disease: Lung Cancer Prognosis

Overall, fewer than 10% of people with primary lung cancer are alive 5 years after diagnosis. But 5-year survival rates may be as high as 35–40% among patients who undergo surgical resection for cancer that has not spread beyond the lung. General estimates of stage-specific median survival times—the point at which 50% of patients are still living—are as follows:

Stage 1a	—more than 60 months (> 5 years)
Stage 1b	—about 36 months (3 years)
Stage 2a	—about 24 months (2 years)
Stage 2b	—about 20 months (< 2 years)
Stage 3a	—about 15 months (< 1.5 years)
Stage 3b	—about 12 months (1 year)
Stage 4	—about 8 months (< 1 year)

Recent findings indicate that 5-year survival rates approach 85% among patients who are younger than 30 years of age and have surgically removable lung cancers (Mizushima et al., Cancer 85:1730-33, April 1999). Researchers believe that genetic mutations may be responsible for differences in survival rates between older and younger people with lung cancer.
Nearly half of limited-stage SCLC patients who have been treated aggressively are alive after 2 to 3 years. By contrast, untreated patients with localized disease show median survivals of approximately 3 to 4 months. Extensive-stage SCLC patients who undergo comfort care have expected median survivals of 4 to 6 weeks. (Note: these findings are based on a group of patients and may not be true for any one patient).