A Phase II Study of External Irradiation and Weekly Paclitaxel for Non-Metastatic, Unresectable Pancreatic Cancer: A Preliminary Report of RTOG Protocol 98-12

Ryan Smith, MD
University of Pennsylvania Cancer Center
Last Modified: November 5, 2001

Presenter: T. Rich
Affiliation: University of Virginia
Type of Session: Scientific

Background

Unresectable/locally advanced pancreatic cancer remains a difficult disease to treat, with median survival of less than 1 year

This is a new approach to the management of pancreatic cancer, using paclitaxel (Taxol) and radiation therapy to improve palliation and extend life.

Materials and Methods

122 patients with adenocarcinoma of the pancreas were entered into the study at multiple institutions. A total of 110 were eligible for analysis

All were unresectable based on CT/MRI, though patients with residual disease were also eligible.

Paclitaxel (50 mg/m2) was delivered weekly x 6 cycles

Radiation was delivered concurrently. Initial fields included the primary tumor plus regional nodes to 45 Gy, followed by a conedown to the primary tumor to a total tumor dose of 50.4 Gy

KPS >80 in 81% of patients

80% had T3 or T4 disease, 66% had N0 disease, while 22% had N1 disease

Median followup was 280 days

Results

85% of patients received all cycles of paclitaxel and 89% received >48 Gy. An additional 3% received >53 Gy

37% of patients experienced acute grade 3 toxicity (though 43% of these were asymptomatic neutropenia). 4% experienced grade 4 toxicity, and 1 patient died of infection during treatment.

Local-Regional response was assessed via CT 6 weeks after radiation. 26% had PR, 7% had CR, and 59% had no response

Median survival was 11.9 months with 1 year survival of 43%

Author's Conclusions

This regimen of concurrent paclitaxel with radiation is well tolerated, with a fairly low incidence of severe toxicity.

Median survival of 1 year is better than historical results with concurrent 5-FU chemoradiation

The newly opened RTOG PA-0020 builds onto this: paclitaxel, gemcitabine, FTI, and XRT to 50.4 Gy

Clinical/Scientific Implications
Unresectable or locally advanced pancreatic carcinoma has an extremely poor prognosis of approximately 9 months with traditional treatment using concurrent 5-FU and radiation therapy. This represents a new approach to the treatment of this disease using paclitaxel in place of 5-FU. It was well tolerated with 37% having grade 3 toxicity (and 43% of these being asymptomatic neutropenia). With this taken into account, approximately 20% had clinically evident grade 3 toxicity with this regimen. Median survival was approximately 1 year in a somewhat selected group of partients. Whether this represents an increase in efficacy over standard treatments is unknown, though the results presented here are not substantially better. Further investigations are warranted.

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