Effect of low molecular weight heparin (Certoparin) versus unfractionated heparin on cancer survival following breast and pelvic cancer surgery: A prospective randomized double-blind trial

Recent studies suggest that low molecular weight heparin (LMW heparin) ther apy in malignancy may improve: cancer survival following surgical resection . We studied prospectively whether cancer mortality during follow-up in wom en with previously untreated breast, and pelvic cancer is reduced in those who randomly received LMW heparin (Certoparin) compared to patients given u nfractionated heparin (UF heparin) for thrombosis prophylaxis during primar y surgery. In a prospective, randomized, double-blind clinical trial, 160 p atients received Certoparin and 164 UF heparin until post-operatively day 7 . Survival estimations are based on the outcome data from a subset of 140 L MW heparin - and 147 UF heparin recipients. Long-term survival in the Certo parin group compared to the UF heparin group was significantly improved aft er 650 days (P=0.0066) but not thereafter where analysis was performed on a ll cancer cell types combined. In the probability estimates survival benefi t within this rime was restricted to patients with pelvic cancer but was no t observed in breast cancer. However, in breast cancer patients who receive d LMW heparin the impact of classical tumor prognostic markers was statisti cally significant after 1,050 days but not after 650 days. Thus, breast can cer patients with unfavorable prognosis seem to benefit in terms of surviva l advantage from LMW heparin within the 650 days after surgery. These resul ts suggest that improvement in cancer survival can be achieved after even a short course of treatment with LMWH (compared to UFH) given for DVT prophy laxis in the post-operative period. An effect of UFH on disease outcome is not excluded. Further definitive trials of LMWH vs. placebo for cancer outc ome (rather then DVT) using doses and schedules that may be more optimal ar e indicated.