Mesothelioma vs Lung Cancer: 7 Key Differences in Diagnosis, Causes, and Treatment

Mesothelioma and lung cancer are two biologically distinct diseases that are frequently confused — by patients, families, and sometimes even clinicians. Mesothelioma develops in the mesothelial lining surrounding the lungs, while lung cancer grows inside the lung tissue itself. This distinction matters enormously: it determines treatment approach, prognosis, and access to compensation programs. Studies in the Journal of Thoracic Oncology indicate that 10-25% of mesothelioma cases are initially misdiagnosed, often as lung cancer.

What are the key facts comparing mesothelioma and lung cancer?

• Cell Origin: Mesothelioma grows in mesothelial lining cells; lung cancer grows in lung parenchyma (tissue)
• Annual U.S. Cases: ~3,000 mesothelioma vs. ~238,000 lung cancer diagnoses per year
• Asbestos Connection: Mesothelioma is caused almost exclusively by asbestos; asbestos causes ~4,500 lung cancer cases annually
• Misdiagnosis Rate: 10-25% of mesothelioma cases are initially misdiagnosed
• Median Survival (Mesothelioma): 12-21 months with treatment
• 5-Year Survival (Mesothelioma): Approximately 12%
• 5-Year Survival (Lung Cancer NSCLC): Approximately 28%
• Diagnostic Test: Immunohistochemistry (IHC) panel distinguishes the two diseases
• Trust Fund Access: Both asbestos-caused diseases qualify for trust fund compensation
• Treatment Difference: Different surgical approaches, chemotherapy regimens, and clinical trials

Where does each disease originate in the body?

The most fundamental difference between mesothelioma and lung cancer is where each disease begins at the cellular level. Mesothelioma develops in the mesothelium — a thin membrane of specialized cells that lines the chest cavity (pleura), abdominal cavity (peritoneum), and the sac around the heart (pericardium). Approximately 80% of mesothelioma cases are pleural, developing in the lining around the lungs rather than in the lungs themselves.

Lung cancer, by contrast, originates inside the lung tissue — in the cells lining the airways (bronchi), smaller air passages (bronchioles), or tiny air sacs (alveoli). The two main types are non-small cell lung cancer (NSCLC), which accounts for about 85% of cases, and small cell lung cancer (SCLC), which accounts for about 15%.

"First and foremost, we make sure the family understands exactly what the diagnosis means. The difference between mesothelioma and lung cancer isn't just academic — it determines every treatment decision, every clinical trial option, and every legal right available to them. A correct diagnosis is the foundation everything else builds on."

— David Foster, Executive Director of Client Services, Danziger & De Llano

What causes mesothelioma compared to lung cancer?

Mesothelioma has one dominant cause: asbestos exposure. The National Cancer Institute estimates that 70-80% of mesothelioma cases have a documented history of asbestos exposure, and most remaining cases likely involve unrecognized or forgotten exposure. Non-asbestos causes are rare and include erionite fiber exposure and certain radiation treatments.

Lung cancer has multiple known causes. Cigarette smoking is responsible for approximately 80-90% of all lung cancer deaths. Other causes include radon gas exposure (the second leading cause), air pollution, occupational carcinogens, and genetic factors. However, asbestos exposure is also a significant cause — the EPA estimates approximately 4,500 asbestos-related lung cancer cases are diagnosed annually in the United States, distinct from the roughly 3,000 mesothelioma cases.

Does smoking affect mesothelioma and lung cancer differently?

Smoking does not increase the risk of mesothelioma — this is a common misconception. However, smoking dramatically increases the risk of asbestos-related lung cancer. A person exposed to asbestos who also smokes has a 50 to 90 times greater lung cancer risk compared to someone who neither smokes nor has asbestos exposure. This synergistic effect makes the distinction critically important for asbestos-exposed workers who smoke.

Risk Factor	Mesothelioma	Lung Cancer
Asbestos exposure	Primary cause (70-80%+)	Significant cause (~4,500/year)
Smoking	No increased risk	Primary cause (80-90%)
Asbestos + smoking combined	No synergistic effect	50-90x increased risk
Radon gas	Not a factor	2nd leading cause
Latency period	20-50 years	10-30 years (asbestos-related)

How do the symptoms of mesothelioma and lung cancer differ?

Symptom overlap is one of the primary reasons mesothelioma is misdiagnosed as lung cancer. Both diseases can cause shortness of breath, chest pain, fatigue, and weight loss. However, the pattern and character of symptoms differ in ways that help distinguish the two.

Symptoms more common in mesothelioma

• Chest wall pain: Localized, persistent pain in the chest wall from pleural thickening
• Pleural effusion: Fluid buildup between the lung and chest wall, often the first detectable sign
• Shortness of breath: Progressive, caused by fluid accumulation and pleural restriction
• Abdominal swelling: In peritoneal mesothelioma, fluid and tumor growth cause abdominal distension

Symptoms more common in lung cancer

• Persistent cough: Chronic cough that worsens over time, often the earliest symptom
• Coughing blood (hemoptysis): More common in lung cancer because the tumor is inside the airways
• Visible lung mass: Lung cancer typically appears as a distinct mass on imaging
• Hoarseness: Tumor pressing on the recurrent laryngeal nerve

Recognizing mesothelioma-specific symptoms early is critical for timely diagnosis. Any person with a history of asbestos exposure who develops chest pain, unexplained shortness of breath, or pleural effusion should specifically mention their exposure history to their physician and request evaluation for mesothelioma.

"I always tell families to make sure the doctor knows about any asbestos exposure in the patient's history. That single piece of information changes the entire diagnostic workup. Without it, mesothelioma can easily be mistaken for more common conditions, and that delay costs precious time."

— David Foster, Executive Director of Client Services, Danziger & De Llano

How does diagnosis differ between mesothelioma and lung cancer?

Definitive diagnosis of both diseases requires tissue biopsy and pathological examination. However, distinguishing mesothelioma from lung cancer — particularly lung adenocarcinoma — requires specialized immunohistochemistry (IHC) testing. Standard pathology without IHC may not differentiate the two conditions, contributing to the 10-25% misdiagnosis rate.

Key diagnostic markers

Marker	Mesothelioma	Lung Adenocarcinoma
Calretinin	Positive (present)	Negative (absent)
WT-1	Positive	Negative
D2-40 (Podoplanin)	Positive	Negative
TTF-1	Negative	Positive
Napsin A	Negative	Positive
CEA	Usually negative	Usually positive

The IHC panel provides a molecular fingerprint that clearly identifies whether cancer cells are mesothelial (mesothelioma) or epithelial (lung cancer). Understanding your diagnosis requires confirming that proper IHC testing was performed. If the initial biopsy report does not include these markers, patients should request additional testing or seek a second opinion at a specialized mesothelioma treatment center.

How do treatment approaches differ?

Treatment for mesothelioma and lung cancer follows different surgical, chemotherapy, and immunotherapy pathways. Using the wrong approach — which can happen with misdiagnosis — reduces treatment effectiveness and worsens outcomes.

Mesothelioma treatment

• Surgery: Pleurectomy/decortication (P/D) removes the pleural lining, or extrapleural pneumonectomy (EPP) removes the lung plus lining. These are specialized procedures performed at select centers.
• Chemotherapy: Standard first-line is pemetrexed plus cisplatin or carboplatin. This combination was specifically developed and approved for mesothelioma.
• Immunotherapy: Nivolumab plus ipilimumab (Opdivo + Yervoy) is now approved as first-line treatment for unresectable mesothelioma.
• Clinical trials: Mesothelioma-specific trials test novel approaches including targeted therapies and combination immunotherapy.

Lung cancer treatment

• Surgery: Lobectomy (removal of a lung lobe), wedge resection, or pneumonectomy. Different surgical approach than mesothelioma surgery.
• Chemotherapy: Platinum-based doublets (different regimens than mesothelioma). Targeted therapies for specific mutations (EGFR, ALK, ROS1).
• Immunotherapy: Pembrolizumab (Keytruda) and other checkpoint inhibitors, often combined with chemotherapy.
• Targeted therapy: Mutation-specific drugs (erlotinib, osimertinib, crizotinib) — not applicable to mesothelioma.

"Treatment centers that specialize in mesothelioma have surgeons who perform these procedures regularly. That surgical volume matters — studies consistently show better outcomes at high-volume centers. We help connect every patient with the right specialists for their specific diagnosis."

— David Foster, Executive Director of Client Services, Danziger & De Llano

How does prognosis compare between the two diseases?

Both mesothelioma and lung cancer are serious diagnoses, but survival statistics differ. According to the NCI SEER database, mesothelioma has an overall five-year survival rate of approximately 12%. Lung cancer survival varies widely by type and stage — non-small cell lung cancer has a five-year survival rate of about 28%, while small cell lung cancer is approximately 7%.

Factors that improve prognosis for both diseases include earlier stage at diagnosis, younger age, better overall health, access to specialized treatment, and eligibility for multimodal therapy. For mesothelioma specifically, treatment at a specialized center with experienced surgeons correlates with significantly better outcomes. The survival statistics continue to improve as new treatments including immunotherapy become standard of care.

What are the legal and compensation differences?

Both mesothelioma and asbestos-related lung cancer qualify for legal compensation, but the pathways and documentation requirements differ.

Mesothelioma legal options

Mesothelioma is caused almost exclusively by asbestos, making causation relatively straightforward to establish in legal proceedings. Patients can access over $30 billion in asbestos trust funds, file personal injury lawsuits, and pursue VA benefits (for veterans). Mesothelioma diagnosis alone establishes the asbestos-disease link.

Asbestos-related lung cancer legal options

Lung cancer caused by asbestos also qualifies for trust fund compensation and legal claims, but proving the asbestos connection requires additional documentation since lung cancer has multiple possible causes. Medical evidence establishing the asbestos link (exposure history, presence of asbestosis, pleural plaques, or pathological markers) is needed. An experienced mesothelioma attorney can help establish the asbestos connection for lung cancer cases.

"My father died of asbestos lung cancer in 1999. I know firsthand how important the correct diagnosis is — not just for treatment, but for ensuring families have access to every compensation program they're entitled to. Whether it's mesothelioma or asbestos-related lung cancer, there are legal options available."

— David Foster, Executive Director of Client Services, Danziger & De Llano

Frequently asked questions

Is mesothelioma the same as lung cancer?

No. Mesothelioma and lung cancer are two distinct diseases. Mesothelioma originates in the mesothelial lining surrounding the lungs, abdomen, or heart. Lung cancer originates inside the lung tissue itself. They differ in cell type, causes, treatment approaches, and prognosis. Both can be caused by asbestos exposure, and mesothelioma is sometimes initially misdiagnosed as lung cancer.

Can asbestos cause both mesothelioma and lung cancer?

Yes. Asbestos exposure can cause both diseases through different mechanisms. Mesothelioma develops when inhaled asbestos fibers become embedded in the mesothelial lining. Asbestos-related lung cancer develops when fibers penetrate deep into lung tissue. Approximately 4,500 cases of asbestos-related lung cancer are diagnosed annually compared to about 3,000 mesothelioma cases.

How is mesothelioma diagnosed differently from lung cancer?

Both require tissue biopsy, but immunohistochemistry (IHC) testing distinguishes them. Mesothelioma is identified by markers like calretinin, WT-1, and D2-40. Lung cancer is identified by TTF-1 and Napsin A. On CT scans, mesothelioma appears as pleural thickening while lung cancer appears as a lung mass. The medical terminology on pathology reports can be complex — patients should ask their oncologist to explain results clearly.

Why does it matter whether the diagnosis is mesothelioma or lung cancer?

Correct diagnosis determines treatment, prognosis, and legal options. Mesothelioma and lung cancer require different surgical techniques, different chemotherapy regimens, and qualify for different compensation programs. Misdiagnosis can lead to less effective treatment and missed financial resources.

What is the survival rate for mesothelioma compared to lung cancer?

Mesothelioma has a five-year survival rate of approximately 12% and median survival of 12-21 months. Non-small cell lung cancer has a five-year survival rate of about 28%. Small cell lung cancer has a five-year survival rate of approximately 7%. Prognosis for both diseases improves with early detection and specialized treatment.

Can mesothelioma be misdiagnosed as lung cancer?

Yes. Studies suggest 10-25% of mesothelioma cases are initially misdiagnosed. This typically occurs when initial biopsies are too small for proper IHC testing, or when pathologists without mesothelioma expertise interpret the samples. Seeking a second opinion from a mesothelioma specialist is strongly recommended.

Do mesothelioma and lung cancer have different symptoms?

While symptoms overlap, mesothelioma more commonly presents with chest wall pain and pleural effusion. Lung cancer more commonly presents with persistent cough and hemoptysis (coughing blood). Both cause shortness of breath, weight loss, and fatigue. The symptom overlap is one reason misdiagnosis occurs.

What should patients with an asbestos-related cancer diagnosis do?

Whether the diagnosis is mesothelioma or asbestos-related lung cancer, patients and families should take three immediate steps: confirm the diagnosis with proper immunohistochemistry testing (especially if mesothelioma is suspected), seek treatment at a specialized mesothelioma treatment center, and consult an experienced mesothelioma attorney to evaluate all compensation options.

Our team at Danziger & De Llano has helped thousands of families navigate both mesothelioma and asbestos-related lung cancer diagnoses. We provide free case evaluations and work on a contingency fee basis — there is no cost unless we recover compensation.

Related resources

• Asbestos Trust Funds: $30+ Billion Compensation Guide
• Veterans Mesothelioma Benefits and VA Disability
• Find Mesothelioma Lawyers by State
• Free Mesothelioma Case Assessment

Last updated: February 5, 2026