"Lung cancer, of which non-small cell lung cancer (NSCLC) accounts for 85% of the cases, retains its position as one of the most commonly diagnosed cancer forms and the leading cause of cancer-related mortality (Jemal et al. 2011). Approximately 30% of NSCLC patients present with early-stage disease, but relapse occurs in nearly half of these patients despite curatively intended surgical resection.
One possible explanation could be that some patients diagnosed with localised NSCLC may have a more extensive disease, with a systemic dissemination of tumour cells that is not detectable using the standard clinical methods. Such cells can be detected in the blood (circulating tumour cells, CTCs) or in the bone marrow (disseminated tumour cells, DTCs) (Pantel et al, 2008).
The ability to detect early dissemination could potentially identify subgroups of early-stage patients with a high risk of disease relapse that could benefit from adjuvant therapy. A number of studies on various cancer types have reported an association between the presence of DTCs at the time of tumour resection and patient outcome (Pantel et al, 2008).
Several methods exist to identify tumour cells in the bone marrow of cancer patients. Immunocytochemistry (ICC), using antibodies against epithelial markers, has traditionally been the most common approach, followed by RT–PCR for the detection of tumour- and epithelial-cell-specific mRNA transcripts (Coello et al, 2004).
In this prospective study, we have investigated the presence of DTCs in the bone marrow collected from 296 patients with stages I–IIIA NSCLC undergoing curatively intended surgery, using both IMS and ICC. In addition, 81 bone marrow samples from healthy volunteers were investigated using IMS. We have compared the results from the two methods, investigated the associations with clinicopathological parameters and examined the prognostic impact of the presence of DTCs." - according to Mælandsmo et al. as written in "Clinical significance of disseminated tumour cells in non-small cell lung cancer" (PubMed 23942067). This paper has been pre-published in the British Journal of Cancer's advanced online publication 13th of August 2013.