
<b>Tumors that are biopsied or otherwise 'interfered with' have a higher incidence of metastasis than tumors that were removed in an untouched block with wide margins and good tumor hygiene.</b>

In a study reported in The American Journal of Surgical Pathology, the clinical features of 42 LEIOMYOSARCOMAS were analyzed.  " In a univariate analysis age >62 years, size >4 cm, extensive necrosis, modified updated French Federation of Cancer Centers (FFCC) grade, and <b>whether the tumor had been "disrupted" by a previous incisional biopsy or incomplete excision were significantly correlated with metastasis.... Disruption was the only significant risk factor for metastasis in a multivariate analysis (relative risk 2.70; p = 0.0001) but was strongly correlated with large size and deep location ."</b> [9]

The study concluded, <b> "The risk of metastasis can be calculated from a model incorporating age, FFCC grade, and disruption. Because disruption correlates with size and depth, it could represent a surrogate as opposed to causal marker for metastasis. Nevertheless, in view of their vascular origin, the possibility that tumor disruption may facilitate or promote access to the bloodstream merits further study."</b>[9]

Tumor cell displacement was observed in 32% of patients who had undergone large-gauge needle core biopsy of the breast. [27]  Fine needle aspiration may shed breast cells into peripheral blood [28].  

In addition, in people on the LMS list, three of the people with regional lymph node metastasis either had multiple FNA biopsies of the primary lesion (2) or major manipulations to get the primary tumor removed (1).  

Search Pubmed on biopsies, cancer, seeding and metastases.

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