Adenosquamous Cell Lung Cancer Stage II

Adenosquamous cell lung cancer stage II is a rare and complex form of lung cancer that contains features of two different cancer types. While it has started to spread beyond the original tumor, it is still considered treatable, with surgery and chemotherapy offering meaningful benefits to many patients.

Table of contents

• What Is Adenosquamous Cell Lung Cancer?
• Other Names for This Disease
• Understanding Stage II Disease
• Diagnosing This Cancer
• Treatment Approaches
• What to Expect

What Is Adenosquamous Cell Lung Cancer?

Adenosquamous carcinoma of the lung is a rare type of non-small cell lung cancer (a cancer that starts in the lungs and grows more slowly than small cell lung cancer). This cancer is unusual because it contains two different types of cancer cells mixed together in the same tumor^[1].

The tumor must have components of both adenocarcinoma (cancer that begins in cells that produce mucus and other substances) and squamous cell carcinoma (cancer that forms in the thin, flat cells lining the inside of the lungs). According to current medical definitions, each type of cell must make up at least 10% of the tumor for it to be classified as adenosquamous carcinoma^[1][4].

This cancer type accounts for only 2% to 4% of all lung cancers, making it quite uncommon^[4]. Like other lung cancers, it most commonly affects people around age 70, occurs more often in men than women, and most patients are current or former smokers^[4].

Stage II Adenosquamous Cell Carcinoma of Lung, Stage II Adenosquamous Cell Carcinoma of the Lung, Stage II Adenosquamous Cell Lung Carcinoma, Stage II Adenosquamous Lung Carcinoma

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• Lungs
• Bronchi (airways leading into the lungs)
• Bronchioles (smaller airways)
• Alveoli (tiny air sacs)
• Lymph nodes

Other Names for This Disease

Medical professionals may use several different terms when referring to this condition. These include Stage II Adenosquamous Cell Carcinoma of Lung, Stage II Adenosquamous Cell Carcinoma of the Lung, Stage II Adenosquamous Cell Lung Carcinoma, and Stage II Adenosquamous Lung Carcinoma^[2].

Understanding Stage II Disease

Stage II lung cancer means the tumor has started to spread but remains relatively contained. The cancer has grown larger than in stage I or has reached nearby lymph nodes, but it has not spread to distant parts of the body^[2].

Stage II is divided into two substages. In Stage IIA, the tumor measures between 4 and 5 centimeters and stays within the lung tissue. In Stage IIB, the tumor is 5 centimeters or smaller but has spread to nearby lymph nodes, or the tumor is larger or has grown into nearby structures^[15].

More specifically, Stage II includes several possible combinations of tumor size and spread. The tumor size may range from 2 centimeters or less to more than 7 centimeters. Some tumors may have spread to lymph nodes within the lung (called N1 lymph nodes), while others have not spread to any lymph nodes. However, all Stage II cancers have not spread to distant organs (M0 means no distant spread)^[2].

Studies suggest that adenosquamous carcinoma tends to be more aggressive than typical adenocarcinoma or squamous cell carcinoma alone. At the time of diagnosis, these tumors often show higher rates of spread to lymph nodes and may grow more rapidly^[4].

Diagnosing This Cancer

Diagnosing adenosquamous carcinoma can be challenging. Because the tumor contains two different types of cells mixed together, small tissue samples may not show both components. Studies indicate that nearly all cases (98% in one study) were either misdiagnosed or undiagnosed before surgery^[4].

A small biopsy taken through a bronchoscope (a thin tube inserted into the airways) or a needle may show only one cell type. Different sampling methods can even produce different results in the same patient. One patient had three different test results: the bronchial samples showed squamous cell carcinoma, special staining showed adenocarcinoma features, and fluid from around the lung showed undifferentiated non-small cell lung cancer^[4].

Because of this complexity, a definitive diagnosis often requires examining a larger tissue sample, such as several core biopsies or the complete tumor removed during surgery. This allows doctors to see the full range of cell types present in the tumor^[4].

Once the tumor is fully examined, doctors may further classify it based on which cell type is more common. If adenocarcinoma makes up 60% or more of the tumor, it’s called adenocarcinoma-predominant. If squamous cell carcinoma makes up 60% or more, it’s called squamous cell carcinoma-predominant. Tumors with a more equal split (40% to 60% of each type) are called structure-balanced adenosquamous carcinoma. Some research suggests that structure-balanced tumors may have a better outlook than the more imbalanced types^[4].

Treatment Approaches

Treatment for Stage II adenosquamous carcinoma typically involves surgery followed by chemotherapy. Because this cancer type is rare, treatment approaches are generally based on guidelines for non-small cell lung cancer as a whole^[1].

Surgery is often the first treatment when the cancer can be completely removed. For early-stage adenosquamous carcinoma, including Stage II disease, studies show that patients who receive both surgery and chemotherapy generally have better outcomes than those who receive only one treatment^[6].

After surgery, doctors typically recommend platinum-based chemotherapy (treatment that uses drugs containing platinum to kill cancer cells). The standard recommendation is at least four cycles of chemotherapy. One common combination uses the drugs taxol and carboplatin, which can target both the adenocarcinoma and squamous cell carcinoma components^[1][11].

In some cases, doctors may perform genetic testing on the tumor to look for specific changes (mutations) that can be treated with targeted drugs. About 30% of adenosquamous carcinomas have EGFR mutations (changes in a gene called epidermal growth factor receptor). When these mutations are present, targeted drugs called EGFR tyrosine kinase inhibitors, such as erlotinib, gefitinib, or dacomitinib, may be effective^[1][10].

Some tumors may also have other genetic changes, such as ALK rearrangements (found in about 5% of cases). When present, these can be treated with drugs like crizotinib, though research on this treatment for adenosquamous carcinoma is limited^[1].

Immunotherapy (treatment that helps the immune system fight cancer) may also be an option. Some adenosquamous carcinomas show PD-L1 expression (a protein that can be targeted by certain immunotherapy drugs). Studies have found PD-L1 in 11% of adenocarcinoma components and 28% of squamous cell components in these tumors^[1].

What to Expect

The outlook for patients with Stage II adenosquamous carcinoma varies depending on several factors. Research indicates that adenosquamous carcinoma tends to be more aggressive than typical adenocarcinoma or squamous cell carcinoma alone^[4].

In studies comparing survival rates after surgery for early-stage lung cancers, patients with adenosquamous carcinoma had five-year survival rates of 65%, compared to 69% for squamous cell carcinoma and 77% for adenocarcinoma^[4].

However, these statistics represent averages, and individual outcomes can vary significantly. Factors that may influence prognosis include the exact size and extent of the tumor, whether cancer has spread to lymph nodes, the patient’s overall health, and how well the cancer responds to treatment^[6].

The good news is that Stage II cancer is still considered potentially curable with appropriate treatment. Many patients treated with surgery followed by chemotherapy achieve long-term survival^[6].