LUNG CANCER
Non-Small Cell Carcinomas
The two most common types of non-small cell carcinomas are adenocarcinomas and squamous cell carcinomas. Several less common types and subtypes are also occasionally seen. Surgery is the mainstay of treatment for early-stage patients who are medically fit to have an operation. If lymph nodes are involved, the margins of the surgical resection are very close to the tumor or involved by tumor, or extensive tumor is found at surgery, radiation therapy with or without chemotherapy may be recommend postoperatively.
The primary drainage pathways from the lungs are to the lymph nodes in the center of the chest around the breathing tubes (bronchi) and heart. As a result, cancers in the lung will frequently spread to these areas. CT scans and chest x-rays before surgery are often, but not always, successful in identifying this type of spread.
Patients who are found preoperatively to have extensive lymph node involvement or extension of tumor to critical structures in the chest (classified as Stage III) are usually best treated with radiotherapy, possibly in conjunction with chemotherapy. Radiation therapy is usually given once or twice per day, five days a week, for approximately 6 to 8 weeks. Sometimes shorter treatment courses (of 2 to 3 weeks) are used, depending on the situation. Each treatment session lasts only several minutes, although setup times and treatment planning may occasionally cause some sessions to last longer.
General guidelines for treatment of non-small cell lung cancer:
- In general, surgery, plus or minus radiation therapy, is curative in early-stage disease (Stages I and II) in 50% – 90% of cases.
- Radiation therapy plus or minus chemotherapy, without surgery, can cure approximately 20% – 50% of early (Stage I and II) cases.
- More advanced (Stage III) disease is cured in only about 20% of patients using radiotherapy and chemotherapy.
- Cure rates depend on numerous factors, including age and condition of the patient, tumor location and histology, tumor extent (stage), radiation dose administered, and radiation treatment technique.
- Chemotherapy can also improve the survival rates in some instances over radiation therapy alone.
