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Month: July 2019

Lung Cancer Screening

Lung Cancer Screening

Lung Cancer Screening saves lives and MRI appears to be a new, non-invasive and radiation-free alternative to screening instead of CT.

Lung cancer is by far the leading cause of cancer death among both men and women.

Each year, more people die of lung cancer than of colon, breast, and prostate cancers combined. The five year survival rate for lung cancer is only 17%.

Overall, the chance that a man will develop lung cancer in his lifetime is about 1 in 15; for a woman, the risk is about 1 in 17. These numbers include both smokers and non-smokers. For smokers the risk is much higher, while for non-smokers the risk is lower. A common view of lung cancer is that it is self-inflicted by smoking – and that the problem will eventually disappear when everyone gives up the habit. But aside from the fact that none of this helps former or current smokers who currently have the disease, there are two major flaws with this thinking.

Firstly, lung cancer cases aren’t declining across the board. Globally, while the number of men diagnosed with lung cancer has dropped over the last two decades, among women it’s risen by 27%.

Secondly, the proportion of lung cancer patients who never have smoked is going up.

One US study reported that 17% of people diagnosed with the most common form of lung cancer in 2011-2013 had never smoked, compared to 8.9% of people diagnosed in 1990-1995. In the UK, researchers reported that the proportion of non-smokers undergoing surgery for lung cancer jumped from 13% to 28% from 2008 to 2014. And in Taiwan, the proportion of never-smoker patients increased from 31% in 1999-2002 to 48% in 2008-2011.

This, too, seems to affect women differently: one study has found that one in five women who develop lung cancer have never smoked, compared to one in 10 men.

Lung cancer screening represents an exciting opportunity to fundamentally change approach to our patients and save lives from lung cancer.

USA and Canada currently already have Lung Cancer Screening programs for adults aged 55 to 80 with a history of smoking. There is no such screening program in Australia.

The results from the European (NELSON) and American (NLST) Lung Cancer Screening studies recently presented at the International Association for the Study of Lung Cancer provided compelling evidence supporting the need for lung cancer screening. NELSON results were even more profound than those seen in the NLST, demonstrating a 26% reduction in mortality for men and 39–61% for women with screening.

Current Lung Cancer Screening is with low-dose CT annually. This approach has a number of potential problems including exposure to radiation with CT. As a result MRI screening has been explored as a potential screening test (MRI has no radiation).

Recent research presented by Dr Bradley Allen at Radiological Society of North America in 2018 answers this question:

  • The researchers found that screening with CT or MRI resulted in a nearly equivalent outcome for patients in terms of life expectancy — though MRI had an improved diagnostic accuracy and lower false-positive rate than CT.
  • “The real benefit of MRI in the study is the nearly fivefold reduction of false-positive screens relative to CT,” Allen said.

Similar findings were published in European Radiology in February 2019 by Michael Meier-Schroers et al in evaluating MRI for Lung Cancer Screening:

  • MRI performed comparably to low-dose CT in a lung cancer-screening programme’

Lung Cancer Screening saves lives and MRI appears to be a new, non-invasive and radiation-free alternative to screening instead of CT.

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Cardiac Risk Assessment with Calcium Score and CT Angiography

Cardiac Risk Assessment with Calcium Score and CT Angiography

This interesting study by Gary Gray et al was published in the British Medical Journal in January 2019. It looked at providing Cardiac Screening Guidelines for Asymptomatic Individuals and Air Crew in particular.

Coronary events remain a major cause of sudden incapacitation, including death, in both the general population and among aviation personnel, and are an ongoing threat to flight safety and operations. The presentation is often unheralded, especially in younger adults, and is often due to rupture of a previously non-obstructive and asymptomatic coronary atheromatous plaque. The challenge for medical practitioners is to identify individuals at increased risk for such events.

This paper presented the NATO Cardiology Working Group (HFM 251) consensus approach for screening and investigation of aircrew for asymptomatic coronary disease.

Their recommendation was to screen all aircrew from the age of forty and initially calculate the Coronary Artery Disease Risk using a risk calculator such as Framingham Risk Score. This scoring system provides an estimate of an individual cardiac risk based on factors such as age, cholesterol, smoking and blood pressure.

All individual Aircrew identified as being at increased cardiovascular risk based on initial screening should then undergo enhanced screening. Enhanced screening includes additional testing with Coronary Artery Calcium Scoring alone, or combined with CT Coronary Artery Angiography.

Calcium Score (extent of calcified plaque in coronary arteries) quantifies cardiac risk as it reflects overall coronary plaque burden. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens, narrows your arteries and causes heart attacks. The higher the Calcium Score, the more likely an individual is to have separate, non-calcified plaque that is vulnerable to rupture and cause a sudden heart attack.

Therefore, for aircrew identified at higher risk based on traditional risk factor estimation, Calcium Score provides a better estimation of future risk and is the preferred modality for enhanced screening alone or combined with a CT Coronary Artery Angiography. For space flight participants travelling to the International Space Station (and International Space Station (ISS) crew members), Coronary Artery Calcium Score is a required primary screening test.

Not all plaque however is calcified, and plaque rupture events may occur in individuals with only non-calcified plaque and low Calcium score.

CT Coronary Angiography provides additional information about the number, extent and location of narrowing in the coronary arteries. It additionally has the advantage of being able to both image and characterise plaque (into calcified or non-calcified). This allows identification of plaque disease that may be present in significant quantities even with very low/no coronary calcium and thus identify individuals with low coronary calcium scores who are nevertheless at increased risk for coronary events.

We believe that the science behind these guidelines for screening of asymptomatic pilots and air crew is applicable to any health-conscious person who wants to assess and improve his/her cardiac risk.

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Breast Cancer Screening with MRI

Breast Cancer Screening with MRI

Breast Cancer is the most common cancer diagnosed in Australian women.

Early detection and appropriate treatment can significantly improve breast cancer survival.

Mammography (Breast X-ray) is currently the standard screening tool for the early detection of breast cancer. The government’s national screening program invites women aged 50-74 to undergo mammograms every two years. Women aged 40-49 and those aged over 74 can also undergo mammograms, however they are not sent invitation letters.

In recent year some experts have voiced their concerns regarding the sensitivity and accuracy of Breast Cancer Screening with mammography (Breast X-ray) alone.

This latest study was published in one of the major medical journals – Lancet Oncology in June 2019 by S Saadatmand et al and looked at 1355 women allocated to either MRI group or Mammography group for Screening.

This multicenter, randomized trial compared the benefit of MRI versus mammography for breast cancer screening among patients with a familial risk of breast cancer.

MRI screening detected more breast cancers and detected breast cancer at an earlier stage than mammography.

MRI screening appears to detect breast cancer at an earlier stage compared with mammography, and this could potentially improve outcomes.

However, MRI may be associated with more false positives, particularly in women with a high breast density

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Pancreatic Cancer Screening with MRI

Pancreatic Cancer Screening with MRI

Pancreatic cancer is the fifth most common cause of cancer death overall.

In 2015, 3307 new cases of pancreatic cancer were diagnosed in Australia. The risk of being diagnosed with pancreatic cancer by age 85 is 1 in 54 for Australian men, and 1 in 70 for Australian women.

Pancreatic cancer presents with late symptoms and as a result, the five year survival rate for pancreatic cancer is 8%.

The goal of a cancer screening program is to detect cancer at an early stage when cure rates are higher.

The recent article by Canto et al in Gastroenterology Journal in 2018 demonstrates that a comprehensive pancreatic cancer screening program for high-risk individuals (based on genetic factors or family history) is effective in identifying precancerous lesions and early-stage cancers.

In this multicenter prospective cohort of patients, cancers detected were nearly all resectable, and the 5-year survival rate was an encouraging 85% in that group.

In summary, these results are encouraging and suggest that outcomes may be greatly improved with high risk individuals enrolled in a comprehensive pancreatic cancer screening program.

The difficulties are that for most individuals we do not actually know what their risks are (and whether they should be classed as high risk) as they have not had genetic testing for CDKN2A, BRCA1/2 or PALB2 gene mutations associated with pancreatic cancer.

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