Carga tumoral total avaliada por OSNA como método preditivo intraoperatório para a determinação de metástases ganglionares no cancro da mama

As recomendações para a realização de linfadenectomia axilar nos doentes com cancro da mama em estádio precoce e sujeitas a biópsia de gânglio sentinela com presença de macrometástase foram recentemente atualizadas, baseadas nos últimos estudos publicados. Mantem-se, no entanto, alguma controvérsia na decisão de não realização de cirurgia radical axilar nos doentes com gânglio sentinela positivo. O presente estudo pretendeu determinar a relação do número de cópias de mRNA da CK19 presente nos gânglios sentinela através do método OSNA com a metastização ganglionar no cancro da mama. Os resultados deste estudo mostraram que a carga tumoral total avaliada por esta técnica pode apresentar capacidade preditiva para a presença de metastização ganglionar e ser desta forma uma ferramenta importante na decisão de linfadenectomia axilar.

Autores e Afiliações:

Celso Nabais ^a, Joana Figueiredo ^a, Paulina Lopes ^a, Manuela Martins ^b, António Araújo ^a

^a Department of Surgery, Centro Hospitalar Lisboa Central, Portugal

^b Department of Pathology, Centro Hospitalar Lisboa Central, Portugal

Abstract:

Background: This study aimed to determine the relationship between CK19 mRNA copy number in sentinel lymph nodes (SLN) assessed by one-step nucleic acid amplification (OSNA) technique, and nonsentinel lymph nodes (NSLN) metastization in invasive breast cancer. A model using total tumor load (TTL) obtained by OSNA technique was also constructed to evaluate its predictability.

Methods: We conducted an observational retrospective study including 598 patients with clinically T1-T3 and node negative invasive breast cancer. Of the 88 patients with positive SLN, 58 patients fulfill the inclusion criteria.

Results: In the analyzed group 25.86% had at least one positive NSLN in axillary lymph node dissection. Univariate analysis showed that tumor size, TTL and number of SLN macrometastases were predictive factors for NSLN metastases. In multivariate analysis just the TTL was predictive for positive NSLN (OR 2.67; 95% CI 1.06-6.70; P = 0.036). The ROC curve for the model using TTL alone was obtained and an AUC of 0.805 (95% CI 0.69-0.92) was achieved. For TTL >1.9 x 10⁵ copies/µL we got 73.3% sensitivity, 74.4% specificity and 88.9% negative predictive value to predict NSLN metastases.

Conclusion: When using OSNA technique to evaluate SLN, NSLN metastases can be predicted intraoperatively. This prediction tool could help in decision for axillary lymph node dissection.

Revista: The Breast

Link: http://www.sciencedirect.com/science/article/pii/S0960977616302788