Better Ways to See Second Cancers

Lung cancer recurrences efficiently detected with minimal dose CT scans

(RxWiki News) Lung cancer doesn’t go away easily. Even after surgical removal, this cancer can return. It's really important that these returning cancers be detected -  and the earlier the better.

Low-dose CT scans are almost five times better at picking up recurrent lung cancers than standard x-rays.  

These minimal dose CT scans also detected the cancers at much earlier stages than X-rays. These younger tumors could then be treated, which extended the lives of lung cancer survivors.

Just one hitch – the low-dose CT scans had high false-positives – meaning that something that looks suspicious turns out to be nothing.

"Visit your doctor if you have a cough that doesn’t go away."

Lead study investigator, Waël C. Hanna, MDCM, MBA, of the Department of Thoracic Surgery at the University of Toronto, said, “Up to a few years ago, we were using chest x-rays to monitor patients after surgery for lung cancer, but this follow-up was ineffective, and many patients still died of recurrent lung cancer.”

He went on to say that CT (computed tomography) scans are effective but there has been a great deal of concern about the amount of radiation these scans deliver. So standard CT scans haven’t been used to follow people who’ve been treated for lung cancer.

Fred R. Hirsch, MD, PhD, professor of medicine and pathology at the University of Colorado Cancer Center, told dailyRx News that lung cancer recurrence is a “significant clinical problem,” striking about 25 percent of patients.

“Thus, finding methods to detect the recurrences as early as possible is clinically very important. The method of minimal dose CT- scan seems to be very promising for that purpose,” Dr. Hirsch said.

A total of  271 patients who had been surgically treated for mostly early stage lung cancer were followed. Repeated imaging was performed at 3, 6, 12, 18, 24, 36, 48 and 60 months using both standard chest x-rays and minimal dose computed tomography (MnDCT).

MnDCT discovered 94 percent of recurrent cancers compared to 21 percent with standard x-rays.

The majority of these cancers were discovered within two years of surgery before symptoms had appeared. And 75.5 percent of these patients were able to have additional treatment – surgery or radiation. Palliative (comfort vs. curative) therapy was recommended for the remainder of patients.

Individuals who received treatment lived significantly longer than those given palliative care – 69 months vs. 15 months.

There was one serious drawback with MnDCT: a high rate of false-positives.

Dr. Hirsch said, “The high frequency of false-positive results is not trivial, as such findings give fear and psychological issues for the many patients and also morbidity [complications] related to eventual diagnostic procedures.  Thus, either further improvements in technology or supplemental measures (i.e., biomarkers) to reduce the false-positive rate have to be focus for further research.

“Despite the latter fact, the study results with minimal dose CT is very encouraging, and it will be interesting to see in the future whether this technology compared to standard follow-up programs and technologies will reduce the lung cancer mortality,” Dr. Hirsch said.

This study was presented at the 93rd American Association of Thoracic Surgery (AATS) Annual Meeting. All research is considered preliminary before it’s published in a peer-reviewed journal.

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Review Date: 
May 4, 2013