What to do next in a smoker with Squamous Cell Carcinoma (SCC) and a 5 cm right lung tumor involving the main bronchus, with a negative Positron Emission Tomography (PET) scan, in preparation for surgery?

Pulmonary Function Testing (PFT) is Essential Before Lung Cancer Surgery

For a smoker with squamous cell carcinoma and a 5 cm right lung tumor involving the main bronchus with negative PET scan, pulmonary function testing (PFT) is the most appropriate next step while preparing for surgery. 1

Rationale for PFT Before Lung Surgery

Pulmonary function testing is critical in the preoperative evaluation of lung cancer patients for several reasons:

1. Assessment of Operative Risk: PFTs help determine whether the patient can tolerate the planned lung resection by measuring:

   • FEV1 (Forced Expiratory Volume in 1 second)
   • DLCO (Diffusion Capacity)
   • Calculation of predicted postoperative (PPO) values 1

2. Surgical Planning: For a 5 cm tumor involving the main bronchus, extensive resection may be required. PFTs help determine if the patient can tolerate:

   • Lobectomy
   • Pneumonectomy (which may be necessary given the main bronchus involvement) 1

3. Risk Stratification: According to the American College of Chest Physicians guidelines, patients with PPO FEV1 or PPO DLCO <60% are at higher risk and may require additional testing such as cardiopulmonary exercise testing (CPET) 1

Why Other Options Are Not Appropriate at This Stage

• Chemotherapy (Option A): Not indicated as first-line treatment for operable early-stage squamous cell carcinoma. Neoadjuvant chemotherapy could be considered after confirming operability through PFTs 1

• Radiotherapy (Option B): Not the primary approach for potentially resectable disease. Radiotherapy is typically reserved for medically inoperable patients or as adjuvant therapy 1

• Repeat CT in 3 months (Option D): Inappropriate delay in management for a large tumor involving the main bronchus, which requires prompt intervention 1

Preoperative Evaluation Algorithm

1. Perform PFTs including:

   • Spirometry (FEV1)
   • Diffusion capacity (DLCO)
   • Calculate predicted postoperative values based on planned resection 1

2. Risk assessment based on PFT results:

   • If PPO FEV1 and PPO DLCO >60%: Proceed with surgical planning
   • If PPO FEV1 or PPO DLCO <60%: Additional testing required 1

3. For borderline or high-risk patients:

   • Perform cardiopulmonary exercise testing (CPET) with VO₂max measurement
   • VO₂max <10 mL/kg/min or <35% predicted indicates high risk 1

4. Additional considerations:

   • Smoking cessation should be initiated immediately (though surgery should not be delayed) 1
   • Nutritional status assessment (BMI, serum albumin) 1

Important Caveats

• Despite negative PET, thorough mediastinal staging is still essential given the size and location of the tumor 1
• For smokers, the risk of postoperative complications is higher, making PFT evaluation even more crucial 1
• Patients with tumors involving the main bronchus may require pneumonectomy, which carries higher operative mortality (up to 6%) compared to lobectomy (<2%) 2
• If PFTs reveal severely limited function, alternative approaches like sleeve lobectomy or non-surgical options may need to be considered 2

By performing PFTs first, the multidisciplinary team can make an informed decision about the patient's ability to tolerate surgery and determine the appropriate extent of resection, maximizing the chance for optimal outcomes.