Eur J Cancer. 2015 Feb 25. pii: S0959-8049(15)00130-6. doi: 10.1016/j.ejca.2015.02.004. [Epub ahead of print]

Distinct effects of anti-inflammatory and anti-thrombotic drugs on cancer characteristics at diagnosis.

Pawitan Y1, Yin L2, Setiawan A3, Auer G4, Smedby KE5, Czene K2.

Author information

• 1Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. Electronic address: yudi.pawitan@ki.se.
• 2Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
• 3Department of Integrative Biology, University of California, Berkeley, United States.
• 4Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden.
• 5Unit of Clinical Epidemiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.

Abstract

BACKGROUND:

A previous study showed that regular use of low-dose aspirin was associated with smaller tumour size and fewer metastases for colorectal and lung cancer. We aim to explain these distinct effects in terms of the anti-inflammatory and anti-thrombotic properties of aspirin.

METHODS:

From the Swedish Cancer Register, we identified patients diagnosed with colorectal and lung cancers between 1st October 2006 and 31st December 2009; each cancer was assessed in terms of tumour size/extent (T), lymph-node (N) and metastatic (M) status. Linkage with the Swedish Prescribed Drug Register was performed to obtain information on the use of low-dose aspirin, anti-inflammatory and anti-thrombotic drugs prior to cancer diagnosis.

RESULTS:

We identified 14,743 individuals with colorectal cancer and 5888 with lung cancer. For low-dose aspirin users we observed a statistically significant association with smaller tumour size and fewer metastases. For both cancers, the use of non-aspirin anti-inflammatory drugs was associated with smaller tumour size in all categories T2-T4 odds ratio (OR=0.76, 95% confidence interval (CI) 0.63-0.92 for T2 versus T1 in colorectal cancer), but not with metastatic status (OR=0.94, 95% CI 0.84-1.06 in colorectal cancer). In contrast, anti-thrombotic drug use was associated with fewer metastases, but not with tumour categories T2 and T3.

CONCLUSIONS:

The results suggest that the use of anti-inflammatories is associated with tumour-growth inhibition at the primary site, while the use of anti-thrombotics is associated with restriction of cancer-cell metastasising capability. These have clinical implications on the potential use of these drugs for chemoprevention or chemotherapy.