12/5 Cancer of Thorax - Pistun

Question 1

three major categories of cancer of thorax

Answer 1

1. primary malignancies
2. metastatic disease to lung
3. mediastinal tumors: “4 T’s”

• thymoma
• teratoma
• thyroid cancer
• “terrible” lymphoma

Question 2

metastatic spread

2 categories and types within

Answer 2

lymphangitic spread

• breast
• stomach
• pancrease
• ovary
• prostate
• lung

hematogenous spread

• colon
• thyroid
• kidney
• testes
• sarcomas

Question 3

primary malignancies

basics

classification

Answer 3

lung cancers may originate in epithelial or mesodermal elements

• may exhibit benign or malignant behavior
  
  • some lung tumors are benign, but this is rare

1. non-small cell (80%)

• adenocarcinoma (50)
• squamous cell (30)
• large cell (10)

2. small cell (15%)
3. others (5%)

• carcinoid (neuroendocrine) - incl in small cell
• sarcomas - NOT incl in small cell bc it comes from mesodermal elements
• others

Question 4

smoking and lung cancer

Answer 4

85-90% of people with lung cancer smoke

30% of smokers get lung cancer

Question 5

environmental factors assoc with lung cancer

sex and racial diffs

Answer 5

• passive smoking
• radon
• asbestos
• arsenic
• beryllium
• silica
• PAH (polycyclic aromatic hydrocarbons - coal ovens chemical exposure)

sex: women have 1.5x risk of males

race: higher indicence and mortality in African American males than white males

Question 6

genetic factors assoc with lung cancer

Answer 6

requires large number of genetic lesions

• activation of dominant oncogene (ras, myc, Her-2/neu)
• inactivation of tumor suppressor gene or recessive oncogenes (p53, 2p, Rb)

first deg relatives have 2-6x incr risk

non-smokers with fam hx have 2-4x incr risk

Question 7

squamous cell carcinoma

Answer 7

• centrally located
  
  • common complications: atelectasis and postobstr pneumonia
• keratin production
• cavitation common
• assoc with Pancoast’s syndrome (apex of lung - often see Horner’s Syndrome), hypercalcemia

high correlation with smoking

Question 8

adenocarcinoma

Answer 8

• peripheral parenchymal or subpleural mass
• metastatic spread via vascular and lymphatic channels
  
  • common to see metastatic disease at dx

histo: glandular

most common form of primary lung cancer

most common in women and non-smokers

Question 9

adenocarcinoma in situ or with lepidic growth

Answer 9

formerly “bronchoalveolar cell adenocarcinoma”

• subtype of adenocarcinoma
• well differentiated columnar cells lining alveolar spaces
• can be multifocal
• massive bronchorrea (lots of bronchial mucus)
• CXR: appears to be infiltrate or mass

Question 10

large cell carcinoma

Answer 10

• poorly differentiated adenocarcinoma or squamous cell carcinoma
• malignant cells with abundant cytoplasm
• peripherally located, cavitation present
• early metastatic spread occurs
• gynecomastia-assoc paraneoplastic syndrome

Question 11

small cell carcinoma

Answer 11

aka neuroendocrine tumor

• larger than lymphocytes with scant cytoplasm
• DON’T cavitate
• distant disease at dx (presume that they already have metastasis)
• multiple paraneoplastic syndromes
  
  • SIADH
  • Cushing’s Syndrome
  • Eaton-Lambert Syndrome
• CXR: hilar mass

Question 12

clinical presentation of thoracic cancer

Answer 12

can be asymptomatic, can see general sx

• cough
• weight loss
• dyspnea (if lots of active lung parenchyma affected)
• hemoptysis (if blood vessels eroded)
• hoarsness (if recurrent laryngeal nerve affected)

local effects

• vocal cord paralysis
• diaphragm paralysis
• SVC syndrome
• Pancoast’s Syndrome (apex of lung)
• pleural effusion (bad sign - stage IV)

metastatic effects

• lymph nodes (89)
• liver (44)
• brain (44)
• adrenals (33)
• bone (29)
• kidneys (23)

paraneoplastic syndromes

• Horner’s Syndrome
• hypertrophic osteoarthropathy
• clubbing
• erythema multiforme
• hyper/hypoglycemia
• peripheral neuropathy
• dementia
• hypercoagulable state

anorexia, weight loss, weakness, paraneoplastic syndromes can occur indep of metastatic disease

Question 13

prevention/detection recommendations

Answer 13

never start or immediately quit smoking

annual low dose CT screening of current/former smokers

• 30+ pack year hx
• age 55-74
• quit within last 15 years

Question 14

dx techniques

Answer 14

fiber optic bronchoscopy (w/ ultrasound)

percutaneous needle biopsy

• more sensitive than FOB for small, periph nodules
• high risk of pneumothorax and considerable false negs

sputum cytology

• useful for central lesions
• squamous carcinoma

Question 15

how to stage non-small-cell carcinomas

how to stage small cell carcinomas

Answer 15

non-small-cell

1. is tumor resectable?
   * stages I-IIIa potentially surgically resectable
2. is patient operable?

T = tumor, N = nodes, M = distant metastasis

small cell

• rapid dissemination
• ltd vs extensive disease
  
  • majority of pts have extensive disease

Question 16

treatment:

non-small cell carcinoma

Answer 16

surgery : stages IA, IB, IIA, IIB

adjuvant chemo : stage IB and II

survery and neoadjuvant chemo +/- rx : stage IIIA

palliative options

• radiation
• brachytherapy
• laser therapy
• thoracentesis with pleurodesis

Question 17

treatment:

small cell carcinoma

Answer 17

chemotherapy

adjuvant radiation for ltd disease

prophylactic whole brain irradiation

surgery: ltd role