A sentinel case series of cancer patients with occupational exposures to electromagnetic non-ionizing radiation and other agents

A sentinel case series of cancer patients with occupational exposures to electromagnetic non-ionizing radiation and other agents

Yael Stein, Or Levy-Nativ, Elihu D. Richter Unit of Occupational and Environmental Medicine, Hebrew University-Hadassah School of Medicine, Jerusalem, Israel
Eur. J. Oncol. - Vol. 16 - N. 1 - March 2011

Summary

Background. There are reports that intense prolonged occupational exposure to non-ionizing radiation may increase risks for cancer. We previ- ously have reported a sentinel cluster, of 7 workers with high exposures and short latent periods, and individual patients with brain cancer high occupational exposures and short latent periods. We present a sentinel case series (n=47, 40M, 7F) of cancer patients, referred to our medical unit with occupational exposures to non-ionizing radiation of all types. Objectives. Our aims were to report the findings on tumour types, age of first diagnosis, and latency, to describe their exposures and to examine the hypothesis that latencies for all tumour types (solid tissue, hematolymphatic, testicular) were coherently related to high occupational exposures starting at young ages.

Methods. We divided the patients into groups by latency. We categorized each patient's exposures in regard to types of radiation, far or near field exposure and direct body contact. For some we had data on frequencies, for others we provided assessments. We also present the patient data categorized by age of diagnosis. We used a case-case type comparison to examine latencies for tumour types [solid, hematolymphatic (HL), testicular].

Results. 15 patients developed cancer with latent periods of less than 5 years and 12 patients with latent periods between 5 and 10 years. The remaining 20 patients had longer latent periods between first occupational exposure to EMF and diagnosis of cancer. 6 patients (12.7%) had multiple tumours. 12 patients (25.5%) reported cancer cases in co-workers. In the <5 years latency group there were 8 hematolymphatic cancers, 3 testicular cancers and 6 solid tumours [head & neck (including brain) and GI tract]. In all latency groups there were patients who were exposed to intense levels of electromagnetic fields (EMF), to several types of EMF, or to EMF in combination with ionizing radiation (IR) or other exposures, and patients who had direct body contact with the equipment, were in direct focus of high radiation, or worked in small, electronically dense environments. Case classification by age showed shorter latencies with younger ages, but this association is complicated by the fact that shorter latencies co-vary with younger ages especially for testicular tumours. But patients with testicular and hematolymphatic tumours had shorter latencies than those with solid tumours.

Conclusion. Many of the patients were young and had extremely short latent periods, especially for HL and testicular cancers. The fact that latent periods for testes were very short, HL longer and solid still longer suggests a coherent and biologically plausible pattern of latency in relation to the onset of exposure to EMF and other agents. The findings strengthen the hypothesis that these exposures may possibly be the major cause of many of these tumours. The findings state the case for (1) better modelling of exposure sources and penetration into the body and (2) preventive and protective measures based on control of exposure at source, barriers, and personal protection.