Bone marrow and sentinel lymph node biopsy in patients with breast cancer: from staging to ultrastaging?

Bone marrow (BM) biopsy has been suggested as an independent prognostic tool to improve staging in patients with breast cancer. Two hundred and ten consecutive patients operated for breast cancer from June 2000 to June 2005 who signed an informed consent were enrolled in this protocol. Patients underwent SLN biopsy, and lymph nodes were analysed with serial sections and stained with hematossilin-eosin and immunohistochemistry. At the end of the procedure a BM aspirate from the iliac crest was obtained and 5-10 cc of blood collected. A CEA specific nested reverse transcriptase (RT) polymerase chain reaction (PCR) assay was used to examine BM samples. Results were blinded to both patients and clinicians. The median age of the patients was 56 years (range 34-80), and the median tumor diameter 1,5 cm (range 0.2-4.5). BM aspirates were unsuccessful in ten patients, and RT-PCR was not technically feasible in seventeen women, leaving 183 patients available for analysis of results and follow up. SLN biopsy allowed diagnoses of occult metastases (micrometastases and isolated tumor cells) in 16% of patients (29/183). 25% of T1N0 patients (23/92), 35% of T2N0 patients (6/17), and 44% of N1-2 patients (32/72) were BM+ (p = 0.03). At a median follow up of 35 months 5/122 in the BM- group and 6/61 in the BM+ group have relapsed (p = 0.2), while 1/122 and 4/61 have died of disease (p = 0.04) In conclusion, ultrastaging of breast cancer patients may identify a substantial subgroup of patients N-/BM- who may not require adjuvant chemotherapy, as well as a subgroup N-/BM+ with a decreased survival who may need more aggressive therapies. Further follow-up is needed to confirm this hypothesis, and several studies are under way.