Cracking the code for pancreatic cancer screening

Pancreatic cancer presents an imposing foe. Mortality is high, owing to the fact that many cases are diagnosed late stage, yet routine screening of those at average risk is not practical. The key will be targeting screening to those at high risk, and one of this week’s top stories featured the short-term results of a small screening program that did just that.

Pancreatic adenocarcinoma has bucked the trends of some of the other prominent cancers in recent years. While death rates for lung, breast and colorectal cancers have declined, the death rate from pancreatic adenocarcinoma has increased since 2003. Five-year relative survival is less than 10 percent for all stages combined.

Earlier detection could help, and endoscopic ultrasound or MRI could play a role here. However, since only 3 percent of new cancer cases in the U.S. each year are pancreatic cancer, and current noninvasive tests have limitations, a widespread routine screening program is not recommended.

In 2012, the International Cancer of the Pancreas Screening Consortium summit attempted to come to some consensus on what should be done. The 49 experts on the panel generally agreed that a successful screening program should detect and treat T1N0M0 margin-negative prostate cancer and high-grade dysplastic precursor lesions. Candidates for screening could include those with at least two affected first-degree relatives, patients with Peutz–Jeghers syndrome, and carriers of p16, BRCA2 and hereditary non-polyposis colorectal cancer mutation carriers with at least one affected first-degree relative.

A recent study published online in JAMA Surgery showed the potential of an MRI-based screening program that adhered to some of these ideas. Conducted by Marco Del Chiaro, MD, PhD, of the Karolinska Institute in Stockholm, and colleagues, the study had a population of just 40 patients with follow up of 12.9 months, but early results were promising.

Patients in the study were largely referred based on a family history of the disease, and several had BRCA2, BRCA1 or p16 gene mutations. MRI-based screening found pancreatic lesions in 16 patients (40 percent). Fourteen had intraductal papillary mucinous neoplasia and two had pancreatic ductal adenocarcinoma. The presence of these precursor lesions resulted in surgery for five patients.

Much more work needs to be done, however. As explained in an associated commentary by Mark S. Talamonti, MD, of the NorthShore University HealthSystem in Evanston, Ill., pancreatic cancer is diagnosed in only 10 percent of patients with syndromic risk factors or family history, while most are considered sporadic cancers with no known risk factors.

“There is a clear and unequivocal need for affordable screening strategies based on reliable biomarkers and efficient imaging modalities,” wrote Talamonti. Hopefully that need is met soon.

-Evan Godt
Editor – Health Imaging