Lymphatic invasion limited for predicting post-surgical RCC outcome
medwireNews: Microvascular and capillary-lymphatic invasion are both associated with patient outcome following nephrectomy for renal cell carcinoma (RCC), but their clinical utility may be limited for different reasons, say researchers.
They found that, while microvascular invasion (MVI) was associated with a significantly increased risk of metastases and cancer death in patients with clear cell (cc)RCC in univariate analysis, significance was lost in multivariate analysis controlling for other established clinicopathologic prognostic variables.
By contrast, capillary-lymphatic invasion (CLI) was significantly associated with metastases and death both in univariate and multivariate analyses, but its occurrence was rare.
Given the findings, Manuel Eisenberg (Mayo Clinic, Rochester, Minnesota, USA) and team say that "further study is required to determine if pathologically ascertained MVI or CLI in apparent localized RCC should merit more intense therapy or surveillance."
A total of 1433 patients surgically treated for sporadic unilateral RCC participated in the trial, of whom 1103 had non-cystic ccRCC, 219 papillary RCC, 86 chromophobe RCC, five collecting duct RCC, and 20 RCC, not otherwise specified.
MVI was present in 119 ccRCC patients, five papillary RCC patients, one chromophobe RCC patient, one collecting duct RCC patient, and three RCC, not otherwise specified patients. CLI was uniformly rare across the subtypes, occurring in just 17, one, none, one, and one of the patients, respectively.
Given the rarity of CLI the association of this factor and MVI with patient outcome was assessed only in patients with ccRCC.
Univariate analysis showed that patients with MVI had a significant 3.5-fold increased risk for metastases and a threefold increased risk for cancer-specific death. However, after taking into account Stage, Sign, Grade and Necrosis (SSIGN) score and PROG score, the relationships were no longer significant.
This finding indicates that "MVI is a component of the neoplastic changes that affect disease outcome, but do not add prognostic ability beyond other commonly assessed features," the team says in The Journal of Urology.
Patients with CLI had a 15.9-fold increased risk for metastases and a 11.6-fold increased risk for death on univariate analysis and respective 3.2-fold and 3.1-fold increased risks on multivariate analysis, all of which were significant.
But the researchers say, however, that "given its rarity; it may prove to be of limited clinical significance."
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By Lucy Piper, Senior medwireNews Reporter