Study reveals, incorporating metastasis-directed radiation therapy enhances progression-free survival in patients with metastatic pancreatic cancer

In a recent study published in the journal of clinical oncology, Researchers from The University of Texas MD Anderson Cancer Center demonstrated that adding metastasis-directed radiation therapy to standard-of-care chemotherapy improves progression-free survival (PFS) in patients with oligometastatic pancreatic cancer. At a median follow-up of 17.3 months, PFS was 10.3 months in patients who received metastasis-directed therapy (MDT) plus chemotherapy compared to only 2.5 months in those who received standard chemotherapy treatment. Additionally, increased immune responses from MDT were connected to longer survival times.

Metastatic pancreatic cancer spreads rapidly to vital organs, posing significant challenges for disease management. Diagnosis often occurs at an advanced stage, reducing treatment efficacy and decreasing survival rates. The disease's complexity and resistance to many therapies also contributes to its poor prognosis. Chemotherapy, the main treatment option, generally offers a seven-month average survival time before disease progression.

MDT targets metastases with high-dose ablative radiation therapy, aiming to eliminate all cancer cells at all sites identified on a scan. This approach is primarily being evaluated for patients with oligometastatic disease for whom imaging shows five or fewer metastases. Oligometastatic disease is often described as an intermediate stage of cancer, between a localised tumour and widespread cancer.

The median time to new lesion recurrence was 14 months in the MDT arm versus five months in the control arm. The 12-month freedom from new lesion recurrence rate was 54% in the MDT arm and 38% in the control arm. Crossover from the control arm to MDT was allowed. MDT, which primarily consisted of high-dose ablative radiation therapy, was very well tolerated, with no grade three or greater adverse events related to MDT observed.

The study's exploratory endpoints aimed to investigate the effects of MDT on the body's immune system, following earlier research demonstrating its potential to boost immune response. The researchers found that systemic immune activation events were associated with MDT and correlated with improved PFS.

The results suggested that metastasis-directed therapy is effective and safe for patients with oligometastatic pancreatic cancer. Nevertheless, larger trials are necessary to confirm the survival advantage observed with metastasis-directed local treatment and to investigate systemic immune activation as a potential mechanism for therapeutic benefits.

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