What Are Primary Lung Tumors?
Primary lung tumors are tumors that originate in the lung tissue and infrequently spread to other sites of the body such as lung lobes, pleura (lining of the chest cavity) bones, and brain. Primary lung tumors are relatively uncommon, making up only about 1% of diagnosed tumors. It is much more common to see lung tumors that have originated from cancer in another region of the body.
Most animals with lung tumors present to their veterinarian for respiratory signs such as couching, difficult breathing, and exercise intolerance. Diagnosis is generally based on chest x-rays, needle aspirate of lung models also.
What Symptoms Can Present as the Disease Progresses?
- Weight loss
- Exercise intolerance
- Persistent early stages
- Hacking and bloody mucus
- Difficulty breathing
- Reclusive behavior
- Unable to rise
- Visible distention of the chest
Crisis – Immediate veterinary assistance needed regardless of disease
- Difficulty breathing
- Prolonged seizures
- Uncontrollable vomiting/diarrhea
- Sudden collapse
- Profuse bleeding – internal or external
- Crying/whining from pain*
*It should be noted that most animals will instinctually hide their pain. Vocalization of any sort that is out of the ordinary for your pet may indicate that their pain and anxiety have become too much for them to bear. If your pet vocalizes due to pain or anxiety, please consult with your tending veterinarian immediately.
Common Signs of Pain
Panting, lameness, difficulty sleeping, pacing, abnormal posture, body tensing, poor grooming habits, tucked tail, dilated pupils, licking sore spot, muscle atrophy, decreased appetite, vocalizing/yowling, reclusive behavior, aggressive behavior, avoiding stairs/jumping, depressed, unable to stand.
How is a Primary Lung Tumor Treated?
For single lung nodules with no sign of spread anywhere else, surgical excision is generally recommended. For very large tumors or tumors that have invaded or spread to other areas, chemotherapy is recommended, in addition to surgical excision of the primary mass.
What is the prognosis for a Primary Lung Tumor?
Pets with small, less aggressive tumors without lymph node involvement have an average survival time of around 16 months with surgery alone. Pets with more aggressive tumors, including lymph node involvement, have an average survival time of 2 months. Because many patients will ultimately develop metastatic disease following surgery, chemotherapy is commonly recommended.
However, it is unknown whether the use of chemotherapy following surgery significantly improves survival over surgery alone. Tumors that are not surgically excisable or that have metastasized to other areas of the body will eventually progress affecting the animal’s ability to breathe.
A personalized treatment plan is important to slow the progression of lung cancer. Talk to your veterinarian regarding the best treatment protocol for your pet.