What Is Large Cell Carcinoma?

Large cell carcinoma is one of the rarer subtypes of non-small cell lung cancer. It is also known as undifferentiated and/or large cell lung cancer due to the appearance of cells under a microscope. Unlike common subtypes such as adenocarcinoma, and squamous cell carcinoma, large cell carcinoma cells are generally atypical and cannot be categorized as another subtype. These types of tumors are estimated to make up between 10 and 15 percent of lung cancers. However, advances in diagnostic testing put some, new estimates as low as 2 percent.

Predominantly, undifferentiated cancerous cells begin in the periphery of the lung, though they can be found anywhere in the organ. Men are more likely to receive an undifferentiated lung cancer diagnosis than women.
This is an image of a chart explaining the percentage of lung cancers that large cell carcinoma cells make up.
Smoking cigarettes (or living with a smoker) is the primary risk factor for developing large cell carcinomas. Typically, the number of cigarettes smoked determines the overall level of risk. Likewise, the length and amount of exposure to other hazardous substances such as asbestos, radiation, radon, and air pollution can lead to the growth of tumors. Too, diet and genetics can factor into who does and does not develop cancer.

Symptoms of Large Cell Carcinoma

For the most part, large cell carcinomas begin in the outer edges of the lungs but spread more quickly than other subtypes to lymph nodes and other areas of the body. Subsequently, the most common symptoms of lung cancer (like a persistent cough and blood in the sputum) may not appear until advanced stages of cancer. Early large cell lung cancer symptoms are often mistaken for everyday pains or signs of age due to their typical subtlety.

Other common large cell carcinoma symptoms include:

  • Fatigue
  • Lethargy
  • Mild shortness of breath
  • Pain in back, shoulder, or chest
  • Pleural effusion
  • Weakness
  • Weight loss

Rarer symptoms include difficulty swallowing or coughing. Additionally, hormone-like chemicals secreted by lung carcinomas can result in breast enlargement in men (referred to as gynecomastia).

Testing and Diagnosis

To diagnose large cell carcinoma, a surgical biopsy and tissue sample cytology (i.e., the analyzation of cells under a microscope) is required. Other tests that may indicate the need for a lung biopsy include blood tests (like a full blood picture, liver function tests, urea and electrolyte tests) and imaging tests (like chest x-rays, CT scans, MRIs, and PET scans). For high-risk patients who don’t attend regular, early screening appointments (using low-dose CT scans), chest x-rays for other pains typically reveal abnormal masses. However, tumors can still go unseen on x-ray results.

If you believe you may be at risk for lung cancer, or are experiencing common symptoms, see your primary health care provider as soon as possible. After conducting an interview on your personal history of risk, the doctor will physically examine the chest and back for abnormalities or a buildup of fluid.

If cancer is suspected, imaging or blood tests may be ordered. Typically, a biopsy is a final step in the diagnostic process because the surgical procedure is invasive and may require patient recovery time or put them at risk of complications.

Prognosis and Staging

The outlook (also known as the prognosis) for large cell carcinoma is generally poor. Currently, the five-year survival rate is approximately 11 percent for men and 14 percent for women (meaning, 11 and 14 percent of men and women have survived five years after diagnosis). Overall, the five-year survival rate for lung cancer is 18 percent. Diagnosed in the early stages, the outlook includes longer survival times and more curative treatment options are available. Your doctor can also recommend some diet and exercise changes at home that may help improve your prognosis.

Large cell carcinoma tumors may spread from the outer edges of the lung to lymph nodes inside the lungs, mediastinum, and thorax. When undifferentiated cancer cells are spread via blood vessels, tumors can eventually develop in the opposite lung, liver, bones, and brain.

Generally, doctors often categorize lung cancer in four stages (stage I, stage II, stage III, and stage IV), based on the spread of tumors outside the original lung and to nearby lymph nodes and organs. The TNM system provides a more detailed description – typically used by oncologists – of large cell carcinoma by assigning further classification about a cancer’s Tumor size (measured in centimeters), Nodes (in reference to the involvement of nearby lymph nodes), and Metastasis (describing the amount of spread to other organs).

Treatment and Clinical Trials

If diagnosed in cancer’s early stages, several treatment options may be available. Which treatment therapies a doctor offers a patient are also dependent on the patient’s health and his or her ability to recover from procedures like surgery and chemotherapy. If diagnosed too late, these treatments may only work as palliative care. The most common large cell carcinoma treatments include:

  • Surgery: For Stage I and Stage II (i.e., smaller tumors without extensive metastases), surgery provides the highest chance of a cure. Common surgical procedures include resection (removal of part of an organ) of cancerous tissue and lobectomy (removal of a lobe).
  • Radiation: If carcinomas cannot be removed with surgery, radiation therapy to the chest may be the best option.
  • Chemotherapy: For patients with advanced-stage large cell carcinoma, chemotherapy can lengthen survival time and allow a better quality of life. When chemotherapy is prescribed, a combination of medications is typically given through alternating treatments. Platinum-based medications have proven most effective in treating carcinomas, so far.
  • Targeted therapy: A new form of cancer treatment, targeted therapies deliver cancer-killing drugs directly to the affected tissue – as opposed to most chemotherapy treatments that bathe areas in chemo medication.
  • Immunotherapy: Another new form of cancer treatment, immunotherapy encourages the body to attack cancer cells by allowing immune cells to recognize which cells to attack. Side-effects and recovery of this form of therapy are often easier to endure compared to other treatments.