circulating tumor cells as risk factor --in patients with early bc (stage 1-3)

[Lani]

Cancer cells in blood can identify risk of recurrence in breast cancer [News-Medical.Net]
Cancer cells circulating in the blood, or circulating tumour cells (CTCs), are known to be associated with a bad prognosis in women with metastatic breast cancer. Now, for the first time, a group of scientists have shown that they can also detect CTCs before and after chemotherapy treatment and hence may be able to identify those patients likely to have a recurrence of their cancer after such treatment in future.
Dr. Julia Rack, from the University of Munich, Munich, Germany, told a press conference at the European Cancer Conference (ECCO 14) today (Monday September 24) that the results could help improve the design of trials of chemotherapy in breast cancer, as well as reducing costs to health services.
The team, led by Dr. Brigitte Rack, also from Munich, set out to look at the role of CTCs in blood at the first diagnosis of breast cancer and during adjuvant chemotherapy and endocrine treatment. They analysed blood samples from 1,767 node-positive and high-risk node-negative breast cancer patients before the start of their treatment, and compared the results to those obtained from 852 of the same patients after completion of chemotherapy.
"We found that 10% of patients whose blood was sampled before the start of treatment had more than one CTC, and 5% of these patients had more than two CTCs in approximately 20 ml of blood," said Dr. Rack. The presence of CTCs did not correlate with other prognostic factors such as tumour size, grading, hormonal or Her-2 status, but the scientists did see a significant correlation with the presence of lymph node metastases.
Of 24 healthy individuals used as controls, none showed more than one CTC, said the scientists. Among the 852 patients whose blood was analysed post-treatment, 11% were CTC positive before the start of treatment, while 7% had more than one CTC after completion of chemotherapy.
Of those patients who were initially CTC positive, 10% remained so and 90% had a negative CTC test after chemotherapy. Of those initially CTC negative, 93% remained negative, whereas 7% had a positive CTC result.
The advantage of screening for CTCs is that, unlike other predictive factors, including genetic signatures, it can be carried out after the completion of primary therapy, and, if needed, on other occasions during the duration of disease. Other predictive methods can only be used on diagnosis, and only once, say the scientists.

ABSTRACT: Circulating tumor cells (CTCs) in peripheral blood of primary breast cancer patients - Results from the translational research program of the German SUCCESS-Trial [European Cancer Organization]
Background: In metastatic breast cancer, the presence of CTCs has been shown to be associated with bad prognosis and their persistence predicted lack of treatment efficacy. Only limited data, however, has been published in the adjuvant setting. We evaluated the role of CTCs in peripheral blood at primary diagnosis and during adjuvant chemotherapy, endocrine and bisphosphonate treatment within the SUCCESS-trial (n = 3658 pts.)
Methods: We analyzed methods of 23 ml of peripheral blood from 1767 N+ and high risk N- primary breast cancer patients before systemic treatment. 852 of these patients have undergone follow-up blood sampling after completion of chemotherapy. The presence of CTCs was assessed with the CellSearch System (Veridex, Warren, USA). Briefly, after immunomagnetic enrichment with an anti-Epcam-antibody, cells were labeled with anticytokeratin (8, 18, 19) and anti-CD45 antibodies to distinguish epithelial cells and leukocytes.
Results: 10% of pts with a blood sampling before systemic treatment (n = 170) showed >1CTC before the start of systemic treatment (mean 13, range 2-827). While we found 2 CTCs in 5% of patients, 3% had 3-5 CTCs and 1% 6-10 and >10 CTCs each. The presence of CTCs did not correlate with tumor size (p = 0.07), grading (p = 0.30), hormonal status (p = 0.54) or Her2-Status of the primary tumor (p = 0.26). However, we observed a significant correlation with the presence of lymph node metastases (p = 0.015). None of 24 healthy individuals showed more than 1 CTC. Among those 852 patients with follow-up blood sampling after the completion of cytostatic treatment, 11% were CTC positive before starting systemic treatment (mean 7, range 2-166), while 7% of patients presented with >1CTC after completion of chemotherapy (mean 6, range 2-84). Of those, initially CTC positive, 10% remained positive (n = 9) and 90% had a negative CTC test after chemotherapy (n = 82). Of those initially CTC negative, 93% remained negative (n = 711), whereas 7% returned with a positive CTC test (n = 50) (p = 0.24).
Conclusions: The SUCCESS-trial is the first trial to perform the detection of CTCs in a large number of primary breast cancer patients with this highly standardized and easily applicable approach. If the observed persistence of CTCs after completion of adjuvant chemotherapy is prognostically relevant, will have be further evaluated with longer follow-up.