Lung cancer comes in several forms and how a patient is treated depends on what form of lung cancer is diagnosed, and at what stage the cancer is found. There are two major types of lung cancer–non-small cell lung cancer and small cell lung cancer. There is also a non-small cell subtype of lung cancer called bronchoalveolar carcinoma, which is difficult to diagnose. Its treatment can be complex depending on the individual patient.
Non-Small Cell Lung Cancer
There are six types of non-small cell cancers. The cancer is identified based on the way cancer cells look under a microscope. They are:
- Squamous cell carcinoma, which occurs in the thin, flat squamous cells.
- Adenocarcinoma, which occurs in cells that secrete.
- Adenosquamous carcinoma, which occurs in cells that secrete and are flat.
- Large cell carcinoma, which occurs in cells that are abnormally large.
- Undifferentiated carcinoma, which occurs in cells that do not look like normal cells and multiply uncontrollably.
- Bronchoalveolar carcinoma, which can resemble a lung infection
Small Cell Lung Cancers
There are three types of small cell lung cancer. The cancer is identified based on the way cancer cells look under a microscope. They are:
- Small cell carcinoma or oat cell cancer, which occurs in cells that are flat, small and oval, and resemble oat grains.
- Mixed small cell/large cell carcinoma, which occurs in cells that are a mix of small and large cancer cells.
- Combined small cell carcinoma, which is small cell lung cancer combined with squamous and/or secreting cells.
Often, patients feel no symptoms until the disease is well-established and/or has spread to other parts of the body. When symptoms do occur, they can include: frequent bouts of bronchitis (inflammation and swelling of the bronchi) or pneumonia (infection that occurs when fluid collects in the lungs); coughing, especially coughing up blood; wheezing; hoarseness; swelling of the face or arms; fever; and shortness of breath.What are the risk factors for lung cancer?
85 percent of all cases of lung cancer are caused by smoking (cigarettes, pipes or cigars). Cigarette smoke contains more than 4,000 chemicals, many of which are proven cancer triggers. Research suggests that chemicals formed when tobacco is burned, inhaled and absorbed by the lungs trigger a change in the cells, which leads to cancer. Tobacco smoke also contains harmful gases.
Other risk factors include: exposure to radon; exposure to certain chemicals, including asbestos, nickel, mustard gas, and silica; a family history of the disease; secondhand smoke.
Diagnostic tests for lung cancer may include:
Bronchoscopy, involving sliding a lighted tube into the bronchial tubes to look for abnormal areas and to take tissue samples for biopsy
Endobronchial Ultrasound (EBUS), adds an ultrasound probe to the tip of the bronchoscope to further improve diagnostic accuracy
Imaging tests: chest X-ray; CT (or CAT) scan; MRI scan; PET scan, which help your doctor detect cancerous tumors
Mediastinoscopy, in which a lighted tube passes through a small incision to view structures in the center of the chest
Navigational bronchoscopy, which uses “GPS” guidance to evaluate small airways deeper in the lung
Needle aspiration biopsy to remove tissue from a place in the lung that can’t be reached through other means
Surgical lung biopsy, lets the doctor look inside the chest cavity and possibly take tissue samples (biopsies) from the lungs
Treatment depends on the type of cancer, the stage of the disease, the patient’s age and overall health. Approaches include: radiation therapy, which uses high-energy rays to kill cancer cells and shrink tumors; chemotherapy, which uses drugs to kill cancer cells; or open or minimally invasive surgery to remove all or part of the cancerous tissue.What is radiation therapy?
Radiation therapy is the use of high powered x-rays to kill cancer cells. It is sometimes known as radiotherapy. There are many forms of radiation therapy, and your doctor will discuss with you which is the most appropriate type of radiation therapy for your cancer.Types of radiation therapy:
External Beam Radiation Therapy and Conventional External Beam Radiation Therapy
External beam radiation therapy uses a high powered x-ray machine called a linear accelerator to deliver radiation therapy precisely to the cancer. Treatments are usually delivered daily Monday through Friday, and the entire treatment course may last between 5 and 9 weeks. The amount of time the daily treatments will take will depend on the kind of radiation plan your physician has determined is best for you, but treatments usually last between 15 and 30 minutes. At Cancer Centers of New York, we have the most up-to-date technology to deliver cutting edge treatments. Types of external beam radiation therapy that your radiation oncologist they recommend for your treatment may include:
Intensity Modulated Radiation Therapy (IMRT)
Intensity modulated radiation therapy is a form of external beam radiation therapy that uses a constantly varying radiation beam to accurately target the cancer cells, while protecting the normal tissue. Your radiation oncologist will determine whether this form of external beam radiation therapy is appropriate for you.
Image Guided Radiation Therapy (IGRT)
Image Guided Radiation Therapy uses a CT scanner built into the radiation treatment machine to perform a CT scan prior to each radiation treatment in order to ensure pinpoint accuracy of daily radiation treatments.
Stereotactic ablative radiotherapy (SABR)
Stereotactic ablative radiotherapy is used for small lung cancers in patients who may not be candidates for surgery. It uses several small, highly-focused radiation beams to deliver large doses of radiation to the tumor, while sparing nearby normal organs. As opposed to conventional external beam radiation therapy, SABR is given in 3-5 treatments over 1-2 weeks, with each treatment session lasting approximately 1 hour. Because of the need for precise and accurate treatment, specialized CT scans are taken several times before, during and after each treatment to identify the tumor and confirm millimeter precision. At Cancer Centers of New York, we have several clinical studies that are available for patients who are receiving SABR. These include studies for patients with both early stage lung cancer and for metastatic disease. Your physician may also choose to treat you using this technique even if you are not enrolled in a clinical trial, if appropriate.
Internal Radiation Therapy (Brachytherapy)
In certain cases, radioactive material is placed directly into or near the tumor. This is called internal radiation, or brachytherapy. By placing the radioactive material directly into the body, the tumor can be treated effectively, while sparing nearby normal organs from most of the radiation exposure. Typically, there are two types of internal radiation that is used in the treatment of lung cancer:
Wedge resection and brachytherapy
The usual treatment for early stage lung cancer is to remove the entire lobe of the lung (lobectomy) where the cancer is located. However, when patients have poor lung function or other medical conditions, they may not be able to have standard surgery. Patients who cannot have a lobectomy can have a smaller surgery called a wedge resection, where only a portion of the affected lobe of the lung is removed. However, while this surgery may be tolerated by patients with poor lung function and is sometimes successful at removing the cancer, it is not as effective in preventing local tumor recurrence as the standard lobectomy. In patients who cannot undergo the standard lung surgery, a newer treatment technique using radiation implants (“seeds”) sewn into the lung at the time of the smaller wedge resection has been developed and used for patients with early stage lung cancer. This newer treatment gives a better chance of cure than using the more limited surgery alone. At Cancer Centers of New York, we have a unique clinical trial investigating the implantation of radioactive seeds using a robotic-assisted technique.
Sometimes, a tumor is located in one of the breathing tubes such as the trachea or bronchus, and can cause symptoms including cough, shortness of breath, and bleeding. In these cases, your radiation oncologist, together with your pulmonologist, can place one or more thin plastic tubes through your nose and into the area where the tumor is located. A tiny radioactive source can travel through that tube to the area where the tumor is located, giving radiation directly to that area. This type of treatment is usually performed between one and five times and can be very effective in relieving airway obstructions by tumors.
Chemotherapy is a cancer treatment which uses “drugs” to stop the growth of cancer cells either by killing the cells or stopping them from dividing. When chemotherapy is given into a vein (injected) or taken thorough the mouth, the medication enters into the bloodstream, and can reach cancer cells throughout the body (systemic treatment).
Stage IB, II, III: Adjuvant
Non-small cell lung cancer is often difficult to cure with surgery alone, as cancer cells may escape from the lungs and travel to other parts of body but goes undetected by X-rays or CT scans (termed “micro metastatic disease”). Studies have now shown that chemotherapy given after surgery, referred to as adjuvant treatment, can significantly improve survival by theoretically removing micrometastic disease.
Stage III: Concurrent Treatment
Often, lung cancer has spread to local lymph nodes in the chest, but has not moved to other parts of the body. At this stage, termed local-regional lung cancer (stage III), patients can be cured with a combination of chemotherapy with radiation. The type of chemotherapy given in these cases depends on the patient’s clinical condition and the specific type of radiation used.
Stage IV treatment: Palliative treatment
Unfortunately, most patients (55-65%) with lung cancer present with stage IV, inoperable disease. In this all too common scenario, the only options are systemic chemotherapy (chemotherapy given by IV) and oral, targeted agents. The type of chemotherapy, number of cycles and frequency of treatment is based on the patient’s clinical condition and certain features of the tumor. Some commonly used chemotherapy medications are Cisplatin, Carboplatin, Taxotere, Taxol, Gemcitabine, Navelbine and Alimta. Fortunately, we now have a new class of medications for lung cancer that work by blocking the signals that make cancer cells grow and spread (termed “molecular targeted therapy”). This new generation of medications includes anti-angiogenic agents such as bevacizumab (Avastin), which inhibit blood vessel supply and growth of the tumor and oral inhibitors of the epidermal growth factor receptor (EGFR), such as gefitinib (Iressa) and erlotinib (Tarceva). There is much promise in these drugs as they continue to be tested in lung cancer to improve clinical outcomes. In addition to those agents already approved for lung cancer we are investigating new treatment options in our ongoing clinical trials including two vaccine studies and as well as several trials using newer chemotherapy or molecularly targeted agents.
Management of advanced lung cancers can be a technical challenge. 20-30% of patients with lung cancer will present with central airway obstruction. This is a significant cause of morbidity and early mortality, with patients suffering from extreme shortness of breath, hemoptysis (coughing up blood), post-obstructive pneumonia, sepsis and an early death. Further, both a debilitated patient as well as superimposed infection may preclude this group of patients from receiving chemotherapy and radiation therapy. Endobronchial airway stenting usually leads to immediate relief of symptoms with minimal post-operative complications.
Surgical techniques can include such advanced approaches as video-assisted thoracoscopic surgery (VATS), robotic assisted surgery, and minimally invasive brachytherapy (radiation seed implants).
Specialists in thoracic surgery, pulmonary medicine, and medical and radiation oncology work together to develop an individualized treatment plan for each lung cancer patient. The full range of supportive services available are: pain management, integrative medicine, reiki, yoga, acupuncture, social work, nutrition and psychological support.