Pancreatic adenocarcinoma mortality risk outweighed by other causes after 9 years

Patients who survived 8.75 years after being diagnosed with pancreatic adenocarcinoma were more likely to die of other causes than of their cancer, according to a research letter published in JAMA Oncology.

However, some patients died of the disease more than 20 years after being diagnosed.

“Most patients who undergo resection of pancreatic ductal adenocarcinoma die within 5 years,” Douglas S. Swords, MD, resident in the department of surgery at The University of Utah, and colleagues wrote. “Five-year survivors remain at risk for pancreatic adenocarcinoma-related death, and recurrences more than 15 years after diagnosis are reported. … Limited prognostic information exists for 5-to-15-year survivors.”

The researchers searched the SEER database to identify 10,988 patients (mean age, 64.8 years; women, 49.5%; white, 74.7%) aged 18 to 89 years diagnosed with pancreatic adenocarcinoma between 1988 and 2009. Researchers included patients with data on disease stage, who had no previous history of cancer and who had at least 1 month of follow-up.

The researchers evaluated OS and cancer-specific survival.

Most patients had tumors located in the pancreatic head (78.2%).

Swords and colleagues classified tumors as T1-T2N0M0, T3-T4N0M0 and T1-T4N1M0 because the available staging codes were inconsistent. Fewer than one-fifth of tumors were stage T1-T2NOMO (14.5%; n = 1,588), whereas 26.9% (n = 2,951) were stage T3-T4N0M0 and 58.7% (n = 6,44) were stage T1-T1N1M0.

Risks for overall and cancer-associated mortality peaked at year 3. Both OS and cancer-specific survival fell below 20% by 5 years.

By 8.75 years following diagnosis, hazards for death of other causes exceeded the pancreatic adenocarcinoma-related risk for death.

Hazards for mortality related to pancreatic adenocarcinoma fell until 13 years, at which point they remained at less than 3% per year.

Five pancreatic adenocarcinoma-related deaths occurred after 5 years. Two occurred after 20 years, with the last occurring at 20.5 years.

Researchers noted estimates for future cancer-specific survival and OS increased with more accrued survival time.

Patients commonly ask their physicians about long-term outcomes after several years of survival, and these findings can contribute to survival prediction, Charles R. Thomas, Jr., MD, professor and chair of radiation medicine at Oregon Health Sciences University and deputy editor of JAMA Oncology, wrote in an editor’s note.

“Consistent with other studies of survivors from treatment for primary gastrointestinal tract tumors, prognosis improves over time,” Thomas Jr. wrote. “There are some open-source datasets of cancer survival prediction calculators that have been developed to facilitate pragmatic discussions between patients and clinicians pertaining to conditional survival for select solid tumors. As these outcome tools are refined to include individualized patient-level ‘-omic’ information, next-generation outcome prediction tools have the potential to be more accurate in estimating outcome for cancer survivors.” – by Andy Polhamus

Disclosures: The authors report no relevant financial disclosures. Thomas Jr. reports no relevant financial disclosures.