Presentation on theme: "Helical CT Screening for Lung Cancer at Advanced Radiology Consultants"— Presentation transcript:
1 Helical CT Screening for Lung Cancer at Advanced Radiology Consultants Lung cancer missed on CXR
2 Why screen for lung cancer? Lung cancer is a major health problemIt is the most common cause of cancer death in men and women in the United StatesApproximately 160,400 patients will die as a result of the disease over the course of the next year
3 Why screen for lung cancer? Overall survival for lung cancer is presently very poor- 5 year survival is about 15%Most patients present with advanced disease- regional spread in 29% and distant spread in 52%Advanced stage lung cancer at presentation
4 Why screen for lung cancer? Lung cancer prognosis depends on stage at presentationPatients with Stage IA lesions (less than 3 cm in size and no lymph node or distant metastases) have a 5 year survival of 67% to 80%Therefore, want to identify patients with early stage lung cancer in an attempt to improve long term survival
5 Why screen for lung cancer? CXR screening is not recommended, but physicians will order yearly CXR's on their patients- particularly smokers or ex-smokersA conservative estimate is that about 50% of cancers will go undetected on the patient's initial CXRStudies have demonstrated that helical CT is clearly superior to CXR for the identification of small pulmonary nodules
6 Small Lung Cancer Missed on CXR Where is the cancer? Note small granuloma in left apex.
7 Lung Cancer Missed on CXR- Stage IIA Cancer cannot be definitively seen on CXR even retrospectively
8 BIG Lung Cancer Missed on CXR- T4 lesion Large cancer missed on CXR (luckily not by ARC physician)
9 Helical CT Screening Studies Summary Low dose helical CT is clearly superior to CXR for the detection of early stage lung cancerBetween 60-90% of cancers detected on low dose CT are Stage IA lesionsCXR fails to detect a lesion in about 75% of these patientsEarly detection of Stage I lung cancers will lead to overall improved lung cancer survival (I-ELCAP conclusion)
10 Positive lung screen CT scan Patient had screen in 2002, lost to follow-upPrimary HCP sent patient for repeat screening exam in positive for small lung cancer20022007
11 Helical CT Screening the Controversy Survival ≠ MortalityScreening improves survival, but does screening decrease mortality?
12 JAMA 2007; Bach PB, et al. Computed tomography screening and lung cancer outcomes. 297: 953-961 Screened patients were diagnosed with lung cancer in far greater numbers than would have occurred in the absence of screening and the majority (67%) were stage I or stage IIHowever, there was no decrease in overall mortality based upon “predicted models”
13 Bach PB, et al. Limitations Lacked non-screened comparison groupMortality “estimates” used in the study depend on the validity of prior risk factor analyses- these may not be applicableBecause of the small number of patients in the Bach study, the 95% confidence interval for their data might allow for a lung cancer mortality reduction as large as 30%Therefore- no conclusive data regarding mortality yet published
14 Survival and Mortality Other screening exams have not been shown to have effect on mortalityAlthough in widespread use, prostate cancer screening is not yet validated as providing a clear benefit in terms of reducing mortality from prostate cancer
16 Helical CT Screening Limitations Lung cancers will be missed- up to 50% of cancers will not be detected on the patient’s initial screening examHighlights need for patient follow-upGood news is missed lesions are less than 1 cm and typically ground-glass in character (bronchoalveolar cell carcinoma)
17 Helical CT Screening Limitations Lesions that are missed on initial screening will be detected on follow-up exams and are generally Stage INOTE: CXR detects none of these lesions
18 Missed Cancer on Screening CT 19931995Bronchoalveolar cell cancer
19 Helical CT Screening Study Limitations False positives- non-calcified nodules are detected in a large number of screened patients, but only about 1-2% of these nodules prove to be malignantCT cannot achieve perfect discriminatory performance- cannot 100% reliably conclude a lesion is malignant based upon it’s appearanceSmall nodules require follow-up and this can lead to patient anxiety
20 Helical CT Screening Study Limitations A negative screen does not preclude the subsequent development of lung cancer, even between scans- although a rare occurrenceHighly advanced lung cancer developed over only 10 months
21 Helical CT Screening Limitations Scan involves use of radiationARC uses a low dose techniqueRadiation exposure is approximately 10 times higher than a CXR, but is only one-sixth that of a conventional CTRemember- scan provides about 10 times the information of a standard CXR
22 Screening for lung cancer- The challenge KEY TO SUCCESSFUL SCREENING: Must identify the proper subset of patients that will most benefit from screeningBest candidates are smokers (present or ex) with 20 pack year smoking historiesWe are happy to discuss the scan with you or any patient that expresses an interest in lung cancer screening
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