Flashcards in Carcinogenesis & Cancer Deck (35):
True or False: Of all cancers, lung cancer causes the most deaths
True (25% of all cancer deaths are lung cancer)
For lung cancer etiology, what is the most common cause? What are some other causes?
Active smoking 85-87%
Air pollution 0-5%
Other (genetic) 0-9%
True or False: Lung cancer risk never falls back to normal no matter how long the smoking cessation
True. Risk improves greatly but never returns to normal risk of never-smokers.
What is the 5 year survival for lung cancer?
What is the 5 year survival for small cell lung cancer?
True or False: lung cancer victims often don't present with symptoms until later stages of cancer
True. Over 2/3 of patients present with non-surgical disease (Stage IIIA or worse), meaning that they can't be treated with surgery.
Approximately ___ % of patients with lung cancer diagnosis die within two years.
When respiratory epithelium is damaged by smoking, what histological change happens?
Squamous metaplasia. Which can be followed by dysplasia and formation of cancer (carcinoma in situ).
In other words, lung cancer can form as a response to the injury that happens in the airways.
True or False: Lung function impairment shows greater risk for lung cancer incidence
True or False: Chronic inflammation of lungs is a common theme for lung cancer development
If you have COPD, you have a ____ fold increased risk for developing lung cancer
Is there familial risk for lung cancer?
1st degree relatives have about 2x risk
1st degree relative with onset at age less than 60 y/o have about 3.5x risk
2nd degree relatives have about 1.3 x risk
3rd degree relatives have about 1.1 x risk
How can sputum help in diagnosing lung cancer?
It's an easy sample to obtain and you can look at dysplastic cells in their sputum (from mild dysplasia through severe dysplasia and carcinoma in situ). The more abnormal cells in someone's sputum, the greater incidence of lung cancer.
We can also do genetic testing on sputum to find identify gene methylation that causes cancer.
What are the risk factors for lung cancer?
- history of smoking
- previous history of tobacco related cancer
- age, gender
- asbestos/radon exposure
- family history
- airflow obstruction (COPD)
- sputum cytologic atypia
*in highest risk populations, yearly incidence of lung cancer approaches 2%
What are the 2 main categories for lung cancer? Which is more prevalent?
Non-small cell lung cancer (87% of all lung cancers) and small cell lung cancer (13%)
What are the 3 types of non-small cell lung cancer? Which is the most common?
Adenocarcinoma (40% of all lung cancers)
Squamous cell carcinoma (35% of all lung cancers)
Large cell (12% of all lung cancers)
What markers can you stain for when looking for small cell lung carcinoma?
NCAM (neuroendocrine marker)
TTF-1 can be used to stain lung cancer cells in general
How does TNM staging work?
T = size and location
N = number of nodes involved (higher #s also mean higher up)
M = metastasis
What are two growth factors that we keep an eye out for when evaluating lung cancer treatment?
Epidermal growth factor (ERB1 or EGFR) is present in 50-80% of NSCLC (less than 5% of SCLC). Mutations in exons 18-21 in 10% (important for non-smokers or younger patients as their cancer is likely to be more genetic). There are drugs available to treat this growth factor problem but they are expensive (e.g. erlotinib/Tarceva)
10% NSCLC and less than 5% of SCLC. Drug available is trastuzumab (Herceptin)
What does EGFR do? Is it increased or decreased in cancer?
Proliferation, invasion, inhibition of apoptosis, metastasis, angiogenesis. EGFR is over expressed in cancer.
True or False: There can be dramatic and rapid response to EGFR inhibitor therapy
True, depending on mutation. We have specific drugs for specific gene mutations and the medications can really help patients dramatically if treatment fits.
What is immunotherapy for cancer?
Using the immune system to fight the cancer.
E.g. Tumor cells down-regulate T-cell effector functions by binding PD-L1 to PD-1 receptors. For immunotherapy, antibody-mediated blockage of the binding of PD-L1 protein to PD-1 receptors restores T-cell effector functions.
What's the difference between nodules and masses?
Nodules are less than or equal to 3 cm
What are solitary pulmonary nodules?
Lesions that are less than or equal to 3 cm in diameter
Round or oval with smooth contour
Surrounded by aerated lung
No satellite lesions
No associated atelectasis, pneumonitis, or regional adenopathy.
What are the goals for evaluating solitary pulmonary nodules?
To expedite the resection of potentially curable lung cancer.
To minimize resection of benign nodules
What is the risk of solitary pulmonary nodule evaluation?
5-10% morbidity and mortality of nodule evaluation.
We have to take the right patients to evaluation. We can do this by assessing risk factors such as nodule size, age, prior cancer history, tobacco use, smoking, COPD, asbestos exposure, nodule characteristics.
True or False: nodule size is associated with likelihood of malignancy
What are the ACCP evidence-based guidelines for solitary pulmonary nodules?
1. All previous CXRs should be reviewed
2. Stable for greater than 2 years does not need evaluation
3. Benign, central calcification does not need further evaluation (granuloma)
4. Spiral chest CT with contrast
5. If nodule is greater than 8mm, estimate a pretest probability of cancer
6. SPN in marginal candidates, PET, if negative and repeat CT in 3 months (glucose taken up by nodules)
7. If growth on serial imaging, proceed to non-surgical biopsy and/or surgical resection
8. All resections must include a lymph node dissection
9. Lobectomy is preferred over wedge or segmentectomy.
True or False: The bigger the solitary pulmonary nodule size, the greater the risk for malignancy and the more frequent you need to follow up with imaging and evaluation
What if you see ground glass/hazy appearance solitary nodules?
You want to follow them for longer because they may be slower growing cancers. (up to 36 months)
What are the goals of lung cancer screening?
Diagnosis at an early age, reduction of lung cancer mortality.
What imaging techniques are used for lung cancer screening and which is the best?
CT is the best but you have to consider balancing the amount of radiation given and the quality of imaging.
What did the NLST trial show?
CT screening prevented 20% more mortality than CXR screening.
6.7% all cause mortality reduction
320 persons screened with LDCT to prevent one death
The difference between the two groups was nearly completely accounted by higher incidence of stage IA.
This means that CT found cancers earlier so they could be treated earlier.
What is lead time bias?
If two patients have lung cancer and both die at the same age, the patient who was diagnosed earlier has a longer "survival time" because survival time is from age of diagnosis until death. This bias makes it seem like the earlier you are diagnosed the longer you have to live, but you have to consider lead time bias.