Lung cancer originates from the lungs, spongy organs positioned in the chest that take in oxygen and release carbon dioxide upon exhalation.
The classification of lung cancer depends on the extent to which it has spread in the body. Generally, the higher the stage, the more widespread cancer is.
In Stage 4 or advanced lung cancer, the disease proliferates from the lung to other parts of the body. Metastasis happens when cancer cells separate from the primary tumor and flow through the body via the blood or lymph. Lung cancer cells usually move to the brain, bones, liver, and adrenal glands. As the tumor passes through organs, other metastatic tumors start developing in those regions.
Following are the two substages:
Stage 4A cancer occurs in the following cases:
When cancer cells multiply in both lungs
When cancer cells reach into the outer covering of the lung (pleura) or the heart (pericardium).
When cancer cells expand to organs such as the liver or bone.
In this substage, cancer is developed in more than one organ and is challenging to treat.
Following are some symptoms that are most likely to occur as the ailment progresses:
Persistent, worsening cough
Coughing up blood
Dots of blood while spitting out saliva
Pain in the chest is worsened by deep breathing, coughing, or even laughing
Shortness of breath
Exhaustion or weakness
Recurrent infections like bronchitis and pneumonia
Other symptoms occur when cancer starts metastasizing to other parts of the body, which include the following:
If cancer has spread to the brain: Fatigue, headaches or numbness in limbs, dizziness, stability issues, or seizures.
If cancer has spread to the liver: Jaundice, pain in the spinal cord or hips, and swelling of lymph nodes present in the neck.
It is essential to visit a doctor if a patient is experiencing these symptoms, to prevent further growth of lung cancer.
The two primary types of lung cancer include
Non-small cell lung cancer (NSCLC)
Small cell lung cancer (SCLC)
According to the American Cancer Society (ACS), non-small cell lung cancer is one of the most common types of lung cancer, which takes in about 80 to 85 percent of patients. On the other hand, small cell lung cancer is found in 10 to 15 percent of cases. The treatment plan for both of these types is different.
Non-small cell lung cancer (NSCLC) is the major type of lung cancer and ranges from stage 1 to 4. The classification of these stages depends on various factors, including the following:
Size of the tumor of the main lung.
Spread of cancer cells in lymph nodes near the lungs or to other organs in the body.
Stage 4 Non-small cell lung cancer is metastatic, which means it spreads beyond the point it originated. Depending on how far it will metastasize, stage 4 Non-small cell lung cancer is further divided into two substages:
4A and 4B.
Stage 4A NSCLC
In stage 4A, the tumor may differ in size, and it may or may not have metastasized to the lymph nodes. Stage 4A NSCLC can also be present in the following cases:
Cancer has only reached another location, such as the second lung or another organ such as the liver, brain, adrenal gland, or kidney.
It has developed in the outer coverings of the lungs or heart.
Stage 4B NSCLC
In stage 4B, the cancer is prevalent in organs far away from the lung. It is common but generally harder to treat. Stage 4B has a slight chance of survival.
Small cell lung cancer is the second most common stage. SCLC is divided into two stages:
When only one side of the chest is affected by cancer, it is SCLC. In this stage, cancer is advanced only in one lung and the lymph nodes surrounding it. If multiple tumors have grown in both lungs, it is not limited-stage SCLC.
Extensive-stage SCLC is metastatic and is similar to stage 4 non-small cell lung cancer. Lung cancer is considered an extensive-stage SCLC when it has extended in the main lung or into the other lung, remote lymph nodes, or to any other organs of the body.
Lung carcinoid tumor is a rare type of lung cancer caused by neuroendocrine cells, a particular cell found in the lungs. According to the ACS, lung carcinoid tumors account for about 1 to 2 percent of lung cancer cases.
Lung carcinoid tumors are divided into two subtypes:
These tumors grow at a slow pace and make up about 90 percent of lung carcinoid cases. Typical carcinoids do not metastasize to other organs and are not related to smoking either. This tumor is diagnosed at the age of 45 or above.
Atypical carcinoids grow at a much faster rate and have higher chances of developing in other body areas. These carcinoids may be related to smoking and occur less frequently than typical carcinoids. The cells resemble those of a fast-growing tumor. Typical carcinoids are diagnosed in people at the age of 55 or above.
Following are some rare forms of lung cancer:
This forms in cells that produce mucus and is diagnosed in smokers.
Large Cell Neuroendocrine Carcinoma
An aggressive subtype of non-small cell lung cancer.
Salivary Gland-type Lung Carcinoma
This is present in the central airways of the lungs.
Found in younger lung cancer patients.
A kind of cancer that forms in thin tissue called mesothelium, which lines the lungs and abdomen.
Lung cancer becomes more severe and problematic to treat as it progresses. Stage 4 lung cancer has very low survival rates.
The estimation of the life expectancy for a patient suffering from stage 4 lung cancer is done by considering the five-year relative survival rate. A five-year relative survival rate shows the possibility that a person with stage 4 lung cancer would live up to five years after the diagnosis, compared to those who don't have cancer.
According to ACS, patients with metastatic NSCLC have a 7 percent five-year relative survival rate and for metastatic SCLC is 3 percent.
The five-year relative survival rate is based on patients who have had cancer for five years or above and is not dependent on the type of cancer or the treatment the patient is receiving.
Lung cancer is the second most common cancer and the leading cause of death in men and women. The following statistics include both small cell and non-small cell lung cancer. In 2021 the estimated new cases for lung cancer in the United States include 235,760 adults (119,100 men and 116,660 women), and about 131,880 deaths will occur (69,410 in men and 62,470 in women).
Since the mid-1980s, the number of new lung cancer cases in men has decreased annually, while in women, the decline started in the mid-2000s. In black men, the chances of lung cancer increase by 15% compared to white men, while in black women, the chances are 14% less than in white women. Lung cancer typically develops in patients at the age of 65. The average age of diagnosis is 70.
On average, lung cancer makes up about 25% of total cancer deaths. Between 2014 to 2018, the death rates declined by 5% for men with lung cancer, whereas the death rates for women dropped by 4% per year. According to research, the decline in these rates is due to people making lifestyle changes such as quitting smoking and medical advancements in diagnosis and treatment.
Molecular Analysis for Lung Cancer
SCI can now evaluate a set of biomarkers in every lung cancer patient to inhibit cancer-causing pathways using targeted therapies.
Chemosensitivity testing is performed in patients with lung cancer to determine which chemotherapy is effective.
Testing for natural substances is also an essential aspect because:
It helps control chemotherapy resistance
Directly kills lung cancer
Enhances the patient's immunity
Genetic changes are arising due to the unique nature of exposure to carcinogens. SCI can now treat these new cancers with specific therapies that include angiogenesis inhibitors to block new blood vessel growth.
Combination Therapy For Best Results
The treatment plan includes the following:
Personalized Genomic Molecular Profiling
Natural Synergistic Substance
Low-dose Chemotherapy and Natural Synergistic Substance
Low-dose chemotherapy is based on chemosensitivity testing. It has proven to be the best treatment option, resulting in minimal toxicities and more excellent adherence. Low-dose chemotherapy tends to prevent chemotherapy resistance and immune system suppression.
The use of natural substances is synergistic and increases the effectiveness of the treatment.
The prognosis for stage 4 lung cancer has relatively decreased because of Immunotherapy with checkpoint inhibitors. The increased rates of tumor mutational burden and microsatellite instability make these checkpoint inhibitors more effective. During this therapy, the underlying immune system of the patient is critical and is constantly evaluated and optimized.
Autologous tumor vaccines, dendritic cell vaccines, and supportive oligonucleotide therapies (SOT) are combined to provide synergistic effects.