European Code against Cancer 4th Edition: Medical exposures, including hormone therapy, and cancer

Abstract

The 4th edition of the European Code against Cancer recommends limiting - or avoiding when possible - the use of hormone replacement therapy (HRT) because of the increased risk of cancer, nevertheless acknowledging that prescription of HRT may be indicated under certain medical conditions. Current evidence shows that HRT, generally prescribed as menopausal hormone therapy, is associated with an increased risk of cancers of the breast, endometrium, and ovary, with the risk pattern depending on factors such as the type of therapy (oestrogen-only or combined oestrogen-progestogen), duration of treatment, and initiation according to the time of menopause. Carcinogenicity has also been established for anti-neoplastic agents used in cancer therapy, immunosuppressants, oestrogen-progestogen contraceptives, and tamoxifen. Medical use of ionising radiation, an established carcinogen, can provide major health benefits; however, prudent practices need to be in place, with procedures and techniques providing the needed diagnostic information or therapeutic gain with the lowest possible radiation exposure. For pharmaceutical drugs and medical radiation exposure with convincing evidence on their carcinogenicity, health benefits have to be balanced against the risks; potential increases in long-term cancer risk should be considered in the context of the often substantial and immediate health benefits from diagnosis and/or treatment. Thus, apart from HRT, no general recommendations on reducing cancer risk were given for carcinogenic drugs and medical radiation in the 4th edition of European Code against Cancer. It is crucial that the application of these measures relies on medical expertise and thorough benefit-risk evaluation. This also pertains to cancer-preventive drugs, and self-medication with aspirin or other potential chemopreventive drugs is strongly discouraged because of the possibility of serious, potentially lethal, adverse events.

Prenatal and Postnatal Medical Conditions and the Risk of Brain Tumors in Children and Adolescents: An International Multicenter Case–Control Study

“…Contrary to the overall established carcinogenicity of ionizing radiation (20), a modest lower risk estimate of CABTs was found among children who had an X-ray or scan examination 2 years before the reference date. A similar finding was also observed in the German part of the Interphone study, in which a negative association between exposure to medical diagnostic radiation and risk of adult glioma was found (21).…”

Use of N-nitrosodimethylamine (NDMA) contaminated valsartan products and risk of cancer: Danish nationwide cohort study

“…The study cohort was described according to several characteristics that were also incorporated as covariates in the analyses: use of drugs (prescription fill <120 days before cohort entry) known or suspected to affect cancer risk, including low dose aspirin, non-aspirin non-steroidal anti-inflammatory drugs, 5-α reductase inhibitors, statins, spironolactone, oral steroids, hormone replacement therapy, and selective serotonin reuptake inhibitors 18 ; prior diagnoses (within five years from cohort entry) of diabetes, chronic obstructive pulmonary disease, heart failure, and alcohol related disease; Charlson comorbidity index scores (0, low; 1-2, medium; or ≥3, high; based on diagnoses established within the past five years before cohort entry) 19 20 ; and whether the participant was a prevalent valsartan user at the beginning of the study period or initiated valsartan during the study period.…”

Hydrochlorothiazide use and risk of nonmelanoma skin cancer: A nationwide case-control study from Denmark

“…In addition, the use of immunosuppressants (eg, cyclosporine and azathioprine) induces NMSC, and other drugs have been suggested to either increase (eg, topical and systemic calcineurin inhibitors) or decrease (eg, aspirin and other nonsteroidal antiinflammatory drugs) the risk of NMSC. [2][3][4][5] Recently, we reported a strong association between use of the diuretic hydrochlorothiazide (HCTZ) and squamous cell carcinoma (SCC) of the lip. 6 We found a clear dose-response pattern, with an estimated 7-fold increased risk of SCC lip cancer with cumulative use of 100,000 mg or more of HCTZ.…”