Acoustic Neuroma
Συγγραφέας Αλέξανδρος Σφακιανάκης Γράφτηκε στις ,
Predicting Acoustic Neuroma Growth
If one could predict which acoustic neuroma (AN) was likely to grow, which might remain stable, and which might regress, it would significantly impact treatment protocols. ANs represent 6 percent of all intracranial tumors and 85 percent of all tumors in the cerebellopontine angle (CPA). In the United States, roughly 2000 to 3000 new cases are diagnosed annually.
Nikolopoulos et al (2010) identified 2,455 articles on acoustic neuroma, 41 of which reported data pertinent to AN growth. After a thorough and comprehensive review they determined there are no reliable predictors of tumor growth. Some previously held clinical “pearls” were shown to not be true. For example, previous studies have indicated the first year of tumor growth may be predictive of future tumor growth, yet this is not necessarily true. Some ANs with extension (4 mm) into the CPA did not grow for six years, and then did. Another report noted a similar tumor with extraordinary growth of 17 mm in just over six months. Some studies stated that larger tumors may be more likely to grow, and others stated the opposite. Some studies reported tumor regression may occur in up to 22 percent of all cases.
Nikolopoulos et al reviewed previous papers and meta-analysis. Of note, of 1,244 patients across 19 studies, 51 percent of ANs did not grow, 43 percent grew, and 6 percent had regression. In another analysis of 879 patients, 51 percent of ANs grew while 4 percent showed regression. In another study of 555 patients, 54 percent of ANs grew. In a study of 1,340 patients, 46 percent of ANs grew, while 8 percent regressed.
With regard to rate of growth, across the entire population of people diagnosed with ANs (including people with ANs that grow, don’t grow or regress), 1 to 2 mm per year appears to be the mean growth rate. However, for people in whom ANs do grow, mean growth appears to be about 2 to 4 mm per year, yet significant growth or regression may occur, and this is essentially unpredictable at this time.
In summary, most ANs do not grow. One cannot predict which AN will or will not grow. There are many patterns of growth and regression that can stop, start, and change. Changes can occur quickly. The general approach of watch, wait, and re-scan appears beneficial for most patients. Careful patient counseling and support are indicated and necessary as patients going through these processes may have an enormous “burden of worry.”
