Recent studies suggest that
low molecular weight heparin (LMW
heparin)
therapy in
malignancy may improve
cancer survival following surgical resection. We studied prospectively whether
cancer mortality during follow-up in women with previously untreated breast, and
pelvic cancer is reduced in those who randomly received LMW
heparin (
Certoparin) compared to patients given
unfractionated heparin (UF
heparin) for
thrombosis prophylaxis during primary surgery. In a prospective, randomized, double-blind clinical trial, 160 patients received
Certoparin and 164 UF
heparin until post-operatively day 7. Survival estimations are based on the outcome data from a subset of 140 LMW
heparin - and 147 UF
heparin recipients. Long-term survival in the
Certoparin group compared to the UF
heparin group was significantly improved after 650 days (P=0. 0066) but not thereafter when analysis was performed on all
cancer cell types combined. In the probability estimates survival benefit within this time was restricted to patients with
pelvic cancer but was not observed in
breast cancer. However, in
breast cancer patients who received LMW
heparin the impact of classical
tumor prognostic markers was statistically significant after 1,050 days but not after 650 days. Thus,
breast cancer patients with unfavorable prognosis seem to benefit in terms of survival advantage from LMW
heparin within the 650 days after surgery. These results suggest that improvement in
cancer survival can be achieved after even a short course of treatment with
LMWH (compared to UFH) given for DVT prophylaxis in the post-operative period. An effect of UFH on disease outcome is not excluded. Further definitive trials of
LMWH vs. placebo for
cancer outcome (rather then DVT) using doses and schedules that may be more optimal are indicated.