Reply to the Letter to the Editor on Safety of sentinel node biopsy in pregnant patients, by G. Dubernard et al. (Ann Oncol 2005; 16: 987)

Abstract

After more than 7 years experience [1.Veronesi U. Paganelli G. Galimberti V. et al.Sentinel node biopsy can avoid axillary dissection in breast cancer patients with clinically negative lymph-nodes.Lancet. 1997; 349: 1864-1867Abstract Full Text Full Text PDF PubMed Scopus (1805) Google Scholar] and study of over 12 000 patients in our institute, lymphoscintigraphy (LS) and sentinel node biopsy (SNB) are used as routine procedures in early breast cancer. At present, the reliability, reproducibility and staging power of SNB has been clearly demonstrated by several studies, including a recent randomized study [2.Veronesi U. Paganelli G. Viale G. et al.A randomized comparison of sentinel-node biopsy with routine axillary dissection in breast cancer.N Engl J Med. 2003; 349: 546-553Crossref PubMed Scopus (1709) Google Scholar]. In all our LS studies [3.Trifirò G. Viale G. Gentilini O. et al.Sentinel node detection in pre-operative axillary staging.Eur J Nucl Med Mol Imaging. 2004; 31: S46-S55Crossref PubMed Scopus (24) Google Scholar], HSA Tc 99m nanocolloids are subdermally injected and the particles are rapidly trapped in the lymph node [4.Mariani G. Moresco L. Viale G. et al.Radioguided sentinel lymph node biopsy in breast cancer surgery.J Nucl Med. 2001; 42: 1198-1215PubMed Google Scholar]. With this kind of radiopharmaceutical it is quite unlikely that the biokinetics of HSA nanoaggregates will vary and be influenced by hormonal biological changes during pregnancy. The lymphatic drainage of radiocolloids is inversely proportional to the particle size and 99–99.9% of the tracer is retained at the site of injection after subdermal or peritumoral adiministration [5.De Cicco C. Cremonesi M. Luini A. et al.Lymphoscintigraphy and radioguided biopsy of the sentinel axillary node in breast cancer.J Nucl Med. 1998; 39: 2080-2084PubMed Google Scholar]. This was recently confirmed in five patients who underwent SNP at different stages of gestation (2–7 months). The whole-body images showed no relevant differences from those of non-pregnant patients. Moreover, a study addressing the same issue, evaluating safety of lymphatic mapping in pregnant patients, has recently been published [6.Keleher A. Wendt R.I.I.I. Delpassand E. et al.The safety of lymphatic mapping in pregnant breast cancer patients using Tc-99m sulfur colloid.Breast J. 2004; 10: 492-495Crossref PubMed Scopus (119) Google Scholar]. The authors concluded that the risk to the embryo/fetus from breast lymphoscintigraphy with 92.5 MBq (2.5 mCi) of sulfur colloid Tc 99m (which is much higher than the 12 MBq used in our institute) is sufficiently small to validate SNB as an alternative to complete axillary lymph node dissection in pregnant women with breast cancer. Therefore the real concern of Dubernard and colleagues is unclear to us: A radiation risk to the baby? Under-staging of the patients? In the series of 44 pregnant patients with breast cancer reported by Dubernard, 26 were N1 or N2 at the final pathological examination. In other words, 18 (40%) had node-negative disease. Even if we accept that ‘pregnant breast cancer patients theoretically eligible for SNB are infrequent’ and that ‘… the nodal involvement rate is high’, 40% of patients could still avoid axillary dissection, its side-effects, and, most importantly, the risks to the fetus related to the longer surgical and anaesthetic procedures. Thus we disagree with Dubernard and colleagues about the lack of justification for SNB in pregnant breast cancer patients. On the contrary, we believe that our LS technique and SNB may offer an important benefit to pregnant patients. So far, the only obstacle to application of SNB in pregnant patients has been the absence of data regarding the safety of the fetus, and this has now been partially provided by Keleher et al. [6.Keleher A. Wendt R.I.I.I. Delpassand E. et al.The safety of lymphatic mapping in pregnant breast cancer patients using Tc-99m sulfur colloid.Breast J. 2004; 10: 492-495Crossref PubMed Scopus (119) Google Scholar] and Gentilini et al. [7.Gentilini O. Cremonesi M. Trifirò G et al. Safety of sentinel node biopsy in pregnant patients with breast cancer.Ann Oncol. 2004; 15: 1348-1351Abstract Full Text Full Text PDF PubMed Scopus (189) Google Scholar]. Dubernardand colleagues state twice that pregnant patients should not undergo SLNB outside clinical trials. We would like to remind them that the removal of axillary nodes is not curative but is performed with staging intent. Therefore it is not necessary to wait for the results of a prospective randomized trial in pregnant patients to validate the procedure. How many decades do we have to wait before providing pregnant patients with an alternative option to axillary staging? In our opinion, it might be less ethical to prevent pregnant patients, who have received adequate information, from choosing a staging procedure offering the important advantages given above with the same staging power as axillary clearance and much less morbidity.