Thoracic Cancers

Question 1

What is the epidemiology of lung cancer?

Answer 1

• Lung cancer is the number one cancer killer in the US. Its incidence is over 225,000 new cases per year
• Long term survival is poor mainly due to the prevalence of nodal and metastatic disease at the time of presentation
• Efforts to decrease the impact of lung cancer focus on early detection with growing efforts at screening and prevention with public health efforts to encourage smoking cessation and education among youth to discourage starting the habit

Question 2

Describe the staging of lung cancer?

Answer 2

• Lung cancer is staged by the standard TNM system
• Staging may be either clinical (based on imaging) or pathologic (based on resection)
• Tumor stage depends on size and location
• Nodal stage depends on the anatomic relationship of nodes to the tumor location
• Presence or absence of metastatic disease needs to be assessed in every patient

Question 3

What is stage-based treatment for lung cancer?

Answer 3

• The three potential treatment modalities for lung cancer are surgery, chemotherapy and radiation
• Disease within the lung only is best treated by surgery with radiation as a secondary option
• Nodal disease within the pleura is best treated by surgery followed by chemotherapy
• Ipsilateral nodal disease in the mediastinum is best treated by definitive chemoradiation although patients with a low tumor burden can be considered for neoadjuvant therapy followed by surgical resection
• Contralateral nodal disease is best treated by definitive chemoradiation
• Distant metastatic disease is best treated with chemotherapy alone
• Radiation can be considered to sites causing local symptoms such as pain

Question 4

How does tumor biology play a role in surgical decision making for lung cancer?

Answer 4

• Tumor biology provides a theoretical basis for the clinical finding that the optimal amount of lung to remove is an anatomic lobe
• Removal of a smaller amount of lung leads to a three times higher rate of local recurrence

Question 5

How does individual anatomy play a role in surgical decision making for lung cancer?

Answer 5

• Sometimes the tumor in a location that precludes simple lobectomy and may require more complex resections such as:
  
  • bilobectomy
  • sleeve resection
  • pneumonectomy

Question 6

How does patient physiology play a role in surgical decision making for lung cancer?

Answer 6

• Patients must be evaluated to determine if they can tolerate the indicated resection
• Pulmonary function tests
  
  • Predicted postoperative FEV1 and DLCO less than 40% of reference values are associated with a dramatic increase in pulmonary complications
  • Predicted postoperative values are calculated by estimating the amount of lung to be removed and subtracting that from the baseline lung function
• Cardiac evaluation
  
  • Removal of a significant portion of the lung decreases the available pulmonary capillary bed
  • This leads to some degree of pulmonary hypertension and right heart strain
  • The normal heart can compensate for these changes but preexisting ischemia or valvular disease can lead to postoperative right heart failure

Question 7

What is the management of the medically inoperable patient?

Answer 7

• If a patient is determined to have inadequate pulmonary or cardiac reserve to undergo the optimal procedure, there are two options for management
  
  • The patient can undergo a lesser resection (wedge or segment) understanding that there is likely a higher rate of local recurrence
  • The other option is radiation, specifically SBRT to the target lesion