Treatment of venous thromboembolism with tinzaparin in oncological patients

Venous thromboembolism (VTE) is a major cause of morbidity and mortality in patients with cancer. For over a decade, the gold standard of treatment and secondary prevention of cancer-associated thrombosis (CAT) has been represented by low-molecular-weight heparins (LMWHs), which are currently recommended as the first-line treatment for CAT. Among the LMWHs that were more extensively tested in patients with CAT, tinzaparin is a LMWH produced by the enzymatic degradation of porcine-derived unfractionated heparin. The efficacy of tinzaparin in this setting is supported by well-grounded evidence. However, there is a need to discuss the positioning of tinzaparin in the continuously evolving treatment scenario of VTE therapy in cancer patients. In this paper, which was developed by a group of clinicians with wide experience in the treatment of VTE in cancer patients, we discuss the current therapeutic options and the role of tinzaparin for the treatment of CAT.

Impact of Metformin Use and Diabetic Status During Adjuvant Fluoropyrimidine-Oxaliplatin Chemotherapy on the Outcome of Patients with Resected Colon Cancer: A TOSCA Study Subanalysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with increased risk of colon cancer (CC), whereas metformin use seems to be protective. However, the impact of metformin use on the risk of death or disease recurrence after radical surgery for CC remains uncertain.

MATERIALS AND METHODS

This is a substudy conducted in patients with high-risk stage II or stage III CC randomized in the TOSCA trial, which compared 3 versus 6 months of fluoropyrimidine-oxaliplatin adjuvant chemotherapy. Objective of the study was to investigate the impact of metformin exposure during adjuvant chemotherapy on overall survival (OS) and relapse-free survival (RFS). We also evaluated the impact of T2DM or metformin dosage on clinical outcomes.

RESULTS

Out of 3,759 patients enrolled in the TOSCA trial, 133 patients with diabetes (9.2%) and 1,319 without diabetes (90.8%) were recruited in this study. After excluding 13 patients with diabetes without information on metformin exposure, 76 patients with T2DM (63.3%) were defined as metformin users and 44 (36.7%) as metformin nonusers. After a median follow-up of 60.4 months, 26 (21.7%) patients relapsed and 16 (13.3%) died. Metformin use was neither associated with OS (adjusted hazard ratio [HR], 1.51; 95% confidence interval [CI], 0.48-4.77; p = .4781) nor with RFS (HR, 1.56; 95% CI, 0.69-3.54; p = .2881). Similarly, we found no association between T2DM or metformin dosage and OS or RFS.

CONCLUSIONS

Metformin use and T2DM did not impact on OS or RFS in patients with resected CC treated with adjuvant fluoropyrimidine-oxaliplatin chemotherapy. Larger studies and longer follow-up are required to clarify the potential efficacy of metformin in improving the prognosis of patients with CC.

IMPLICATIONS FOR PRACTICE

The role of the antidiabetic drug metformin in colon cancer prevention and treatment is highly debated. While low-dose metformin reduced the incidence of colorectal adenomas in two prospective studies, its effect in patients with already established colon cancer remains unclear. In this study, the potential impact of metformin on the survival of resected colon cancer patients who received adjuvant chemotherapy was investigated in the context of the TOSCA study. We did not find any association between metformin use or dosages and patient survival. Prospective studies are required to draw definitive conclusions about metformin impact on colon cancer recurrence and survival.

Disease management considerations: disease management considerations

Colorectal cancer is still a majorhealth and social problem. However, many important advances in treatment have been made in the last 4 to 5 years, and more optimism is now justified both among clinicians and patients. In surgically resectable disease, adjuvant chemotherapy has been clearly demonstrated as able to increase overall survival in patients with colon cancer Dukes' stage C, whereas the role of medical treatment in patients with Dukes' stage B colon cancer is still controversial. At present, the standard regimen is bolus fluorouracil (5-FU) modulated by folinic acid (leucovorin) for 6 months. For rectal cancer, the best adjuvant treatment seems to be represented by radiotherapy (better if administered preoperatively) combined with chemotherapy (usually based on modulated or continuously infused 5-FU). In advanced disease, many new drugs have recently emerged: the most active regimens are those combining an optimal modality of 5-FU administration (i.e. continuous infusion) and one of the most active innovative compounds (irinotecan or oxaliplatin). The role of the oral drugs (e.g. tegafur/uracil, capecitabine) is still under investigation as is the combination of agents excluding 5-FU. It is now recognised that first-line treatment must be offered to all suitable pa- tients, even though asymptomatic, and that a second-line therapy (chiefly with irinotecan) is of value in many patients with cancer that progresses during treatment with 5-FU. From a strategic point of view, the best sequence of drugs/regimens has not yet been defined, while the duration and timing of chemotherapy is still a matter for clinical research. Finally, there is an increasing interest in the role of biological prognostic factors as an aid to a patient-tailored therapy, both in the adjuvant setting and in advanced disease. To achieve further progress in knowledge in this field, we strongly recommended that more and more patients are included in clinical trials.