Mitochondrial DNA is a small, well characterized chromosome which is transmitted across the generations in the maternal lineage, independently of nuclear DNA. mtDNA acts in effect as a robust, species specific biological clock and tracer which can be used to follow the evolution and spread by geographic migration of populations from their origins. Mutations in mtDNA cause specific maternally hereditable diseases, and can be used for forensic purposes. They are not specifically implicated in neoplasia, but they may provide clues as to the nature and origins of cancer susceptibility in various populations.

Microarray technology transforms the study of functional genetics. The entire genomic activity of cells and tissues can be analysed and compared on single slides, or gene chips. In cancer research, this will allow the better understanding of the regulation of activity of cells and tumours in various states. It will also allow the classification of individual tumours by their gene expression patterns, which may also describe and predict therapeutic resistance and sensitivity patterns. This short article provides a short introduction to the technology and its applications.

Surgery for cancer imparts a high risk of morbidity and premature mortality. Inappropriate decisions and inadequate information can have a profound effect on the outcome of interventions. A formal process of appraisal of options, aided by modern information technology, may help rationalize and improve management stratagems and reduce risk. Rigorous and obsessional attention to risks in clinical and surgical procedures and processes, including the selection and training of surgeons, process and human reliability analysis, and ubiquitous error reduction strategies will also help minimize risk. These approaches will have a significant bearing on familiar surgical practice and will need to be extended across the multidisciplinary spectrum of cancer care.

The bromodeoxyuridine derived labelling indices (LI) of invasive breast carcinomas were studied in histochemical sections. The mean histochemical total tumour labelling index was 5.8% ± 3.1% SD (range 0.9–15.8%). There was no significant difference between the mean histochemical LI values when stratified for tumour size and node status, but a trend was seen to increasing proliferation with higher tumour grades.