Margin clearance and outcome in resected pancreatic cancer.
OBJECTIVE
Current adjuvant therapies for pancreatic cancer (PC) are inconsistently used and only modestly effective. Because a high proportion of patients who undergo resection for PC likely harbor occult metastatic disease, any adjuvant trials assessing therapies such as radiotherapy directed at locoregional disease are significantly underpowered. Stratification based on the probability (and volume) of residual locoregional disease could play an important role in the design of future clinical trials assessing adjuvant radiotherapy.


METHODS
We assessed the relationships between margin involvement, the proximity to operative resection margins and outcome in a cohort of 365 patients who underwent operative resection for PC.


RESULTS
Microscopic involvement of a resection margin by tumor was associated with a poor prognosis. Stratifying the minimum clearance of resection margins by 0.5-mm increments demonstrated that although median survival was no different to clear margins based on these definitions, it was not until the resection margin was clear by more than 1.5 mm that optimal long-term survival was achieved.


CONCLUSIONS
These data demonstrate that a margin clearance of more than 1.5 mm is important for long-term survival in a subgroup of patients. More aggressive therapeutic approaches that target locoregional disease such as radiotherapy may be beneficial in patients with close surgical margins. Stratification of patients for entry onto future clinical trials based on this criterion may identify those patients who benefit from adjuvant radiotherapy.
Chang
David K
DK
Cancer Research Program, Garvan Institute of Medical Research, New South Wales 2010, Australia.
Johns
Amber L
AL
Merrett
Neil D
ND
Gill
Anthony J
AJ
Colvin
Emily K
EK
Scarlett
Christopher J
CJ
Nguyen
Nam Q
NQ
Leong
Rupert W L
RW
Cosman
Peter H
PH
Kelly
Mark I
MI
Sutherland
Robert L
RL
Henshall
Susan M
SM
Kench
James G
JG
Biankin
Andrew V
AV
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000209:etiology; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D010190:Pancreatic Neoplasms / Q000150:complications* / Q000401:mortality; D011379:Prognosis