Carcinogenesis

Evaluation of carcinogen exposure in people who used 'reduced exposure' tobacco products. Hatsukami, D. K. et al. J. Natl Cancer Inst. 96, 844–852 (2004)

Some tobacco products are being marketed as containing lower levels of carcinogens than conventional products. Stephen Hecht and colleagues found that carcinogen levels were reduced in users of snuff or cigarettes who quit and used medicinal nicotine patches, and in those who switched to 'reduced-exposure' products. However, the reduction was more pronounced when medicinal nicotine was used, showing that this is a safer alternative.

Gene Expression

Large-scale meta-analysis of cancer microarray data identifies common transcriptional profiles of neoplastic transformation and progression. Rhodes, D. R. et al. Proc. Natl Acad. Sci. USA 7 June 2004 (doi:10.1073/pnas.0401994101)

Meta-analysis of microarray data from more than 3,700 samples from a range of cancer types was used to identify a set of genes that are consistently differentially expressed in tumour versus normal cells. A common transcriptional profile was also obtained for undifferentiated versus differentiated tumours, and these profiles were validated using independent data sets.

Angiogenesis

Preexisting lymphatic endothelium but not endothelial progenitor cells are essential for tumour lymphangiogenesis and lymphatic metastasis. He, Y. et al. Cancer Res. 64, 3737–3740 (2004)

In tumour angiogenesis, bone-marrow-derived endothelial progenitors contribute to the formation of blood vessels. By transplanting tumour cells into mice with genetically labelled bone marrow, He et al. showed that this does not apply to tumour lymphangiogenesis. Instead, the pre-existing lymphatic network was found to be required for this process and for metastasis to lymph nodes.

Breast Cancer

Contralateral breast cancer in BRCA1 and BRCA2 mutation carriers. Metcalfe, K. et al. J. Clin. Oncol. 22, 2328–2335 (2004)

Women who carry inherited mutations in either BRCA1 or BRCA2 face a life-long high risk of developing breast cancer. For those women diagnosed with unilateral breast cancer, the risk of developing cancer in the unaffected breast is unclear. Here the authors show that these women have a 40% risk of developing contralateral breast cancer within 10 years, which is reduced if patients opt for oophorectomy or are treated with tamoxifen.