In many cases, lung cancer signs do not become apparent or prompt an individual to seek medical attention until the tumor reaches an advanced stage. The initial signs, if any, are typically mild and often mistakenly attributed to another, less serious condition, such as the common cold or flu. Also, there are few nerve endings that provide sensation within the lungs, making it difficult to feel changes within that area of the body. For these reasons, some patients wait a few months after symptoms develop before seeing a physician for a diagnosis.
Even so, some people may notice one or more vague warning signs that something is not quite right early on. It is important to pay close attention to these signs. In general, the earlier lung cancer is detected, the more treatment options a patient is likely to have, so it is essential to begin the diagnostic process as soon as possible.
Early-stage lung cancer signs
The initial symptoms of lung cancer usually involve the respiratory system, which includes the nose, mouth, throat, voice box, windpipe and lungs. Some patients experience:
- Persistent coughing
- Shortness of breath (dyspnea)
- A high-pitched whistling sound when inhaling or exhaling (stridor)
- A wet cough that produces mucus, phlegm or blood
- Recurrent bouts of bronchitis or pneumonia
Advanced-stage lung cancer signs
In addition to the respiratory system, advanced-stage lung cancer signs can affect other parts of the body, especially if cancerous cells have entered the bloodstream or lymphatic system and spread (metastasized) to distant tissues or organs, such as the brain, liver or bones. Advanced lung cancer may cause:
- Persistent fever
- Unexplained weight loss
- Loss of appetite
- Weakness and fatigue
- Bone pain
- Swelling in the face, neck or arms
- Jaundice (yellowing of the skin and the whites of the eyes)
- Neurological symptoms, such as memory loss
- Pain in the chest, shoulders or back
The link between smoking and lung cancer
It’s likely not very surprising to learn that smoking is the No. 1 cause of lung cancer. In fact, approximately 85% of all cases are caused by smoking—including secondhand smoke exposure. This is because cigarette smoke contains carcinogens, a substance that can lead to cancer. While the body is able to detoxify and remove many carcinogens, it cannot remove all of them. Leftover carcinogens can then cause cells in the body to mutate, and some of those mutated cells can become cancerous in time. The more someone smokes or inhales smoke from other people, the more possibility there is for carcinogens to remain in the body and lead to cancer.
Lung cancer diagnosis
Early-stage lung cancer can be challenging to diagnose because a lung tumor can grow quite large before it becomes visible in an imaging scan. Usually, a lung tumor cannot be detected in a routine chest X-ray until it reaches 1 centimeter in diameter. In order for a tumor to grow to that size, a minimum of 30 divisions of a single cancer cell must occur, which can take up to several years. For this reason, it is especially important to see a physician and request a lung cancer screening if any warning signs are present.
If lung cancer is suspected, a physician will typically order several imaging tests to begin the diagnostic process. For instance, a series of X-rays, CT (computed tomography) scans or MRI (magnetic resonance imaging) scans can provide the physician with a detailed visual of the patient’s lungs and thoracic cavity. The resulting images can help the physician identify lung abnormalities that may warrant further diagnostic testing. For instance, a sputum cytology, transbronchial needle aspiration or bronchoscopy may be performed to confirm a diagnosis of lung cancer and determine its type.
There are two main types of lung cancer, non-small cell lung cancer and small cell lung cancer.
Non-small cell lung cancer
The more common of the two main types of lung cancer, non-small cell lung cancer affects both smokers and nonsmokers alike. Usually, the cancer progresses slowly. Based on the appearance of the cancerous cells when viewed under a microscope, non-small cell lung cancer can be further classified as:
- Adenocarcinoma – Usually forms in the mucus-producing cells in outer parts of the lungs
- Squamous cell carcinoma – Develops in the squamous cells lining airways (bronchi)
- Large cell carcinoma – Can develop in any part of the lungs
Small cell lung cancer
Small cell lung cancer typically develops in the bronchi, then quickly grows and spreads to other parts of the body, such as the lymph nodes. Primarily caused by exposure to carcinogenic chemicals found in tobacco smoke, small cell lung cancer predominantly affects individuals who are smokers or have a history of smoking.
Because the treatment options for lung cancer can vary based on its type, a physician will consider this information along with other factors when determining the optimal treatment approach.
Differences between small cell & non-small cell lung cancer symptoms
It’s common to wonder if the symptoms of lung cancer are the same across the board. For example, will a patient with small cell lung cancer have symptoms similar to one with non-small cell lung cancer? While fatigue and unexpected weight loss are more common in patients with small cell lung cancer (because it spreads more rapidly), all other symptoms are present in all types of lung cancer. The best way to know if you have non-small cell or small cell lung cancer is to be properly diagnosed.
The role of lung cancer screening
Moffitt Cancer Center has developed a comprehensive lung cancer screening program that's one of the best in the country. It's open to patients who are considered high-risk based on national guidelines and evidence-based practices. Lung cancer screening can help physicians diagnose certain patients even before symptoms develop. The American Cancer Society recommends lung cancer screening for patients who are 55 to 74 years old, in good physical health and in line with all of the following criteria:
- They currently smoke or have quit in the last 15 years.
- They have a smoking history of at least 30 pack-years. (Pack-years is an equation that multiplies the number of years smoked by the number of cigarette packs smoked per day.)
- If they smoke currently, they are receiving counseling to quit.
- They have discussed lung cancer screening with their physician and understand the benefits, harms and limitations.
- They have a facility to go to for experienced lung cancer screening and treatment.
Lung cancer screening and treatment at Moffitt Cancer Center
At Moffitt Cancer Center, we offer comprehensive low-dose CT lung cancer screening and surveillance programs for at-risk individuals. Through extensive research studies and clinical trials, such as the NCI-Sponsored National Lung Screening Trial, scientists have found that lung cancer screening programs such as ours lead to more prompt and precise diagnoses, which have long been correlated with better outcomes and quality of life.
At Moffitt, our patients benefit from our multispecialty team of specialized oncologists, pulmonologists, radiologists, pain management specialists and supportive care specialists. We also offer a tobacco treatment program to help patients and their family members quit smoking as comfortably as possible.
Medically reviewed by Eric Toloza, MD.
To request an appointment to discuss your lung cancer signs with a specialist in the Thoracic Oncology Program at Moffitt Cancer Center, please call 1-888-663-3488 or complete our new patient registration form online. You are a top priority for a cancer center that delivers nationally ranked care in new and transformative ways, and we’ll provide rapid access to a cancer expert within a day.