Random Directed Biopsies: Location of Tumour
Two studies dispute the utility of random biopsies. Tanzler et
al5 included 156 patients who underwent deep tissue
biopsies, and found the pickup rate to be 0% from the nasopharynx and
piriform sinus (Table 1). A systematic review and meta-analysis of 673
patients recommends against random biopsies given pickup rates of often
0% in the literature8.
Several studies have specifically reported on pickup rates from the
practice of random directed biopsy9,5,10,11 (table
1.1). Other authors have and have detailed the positive sites by
location from their general workup including, but no limited to, random
biopsies1,12,13,14,15,16,17(table 1.2).
These studies call into question the utility of random biopsies,
especially for two commonly targeted sub-sites, the nasopharynx and
hypopharynx. In the nasopharynx the pickup rate ranged from
0-9.4%5,11,9. The highest pickup rate reported by
Haas et al9 is a retrospective study published in
2002, using data from a time before modern imaging was routinely
utilised for workup preceding a biopsy. Similarly low pickup rates were
observed in the piriform fossa alone, ranging from
0-4.2%9,5,11,14. When the entire hypopharynx is
considered, a higher pick up rate is evident, ranging from 1.7% to
6%15,13 (table 1.2, note that pickup rate here is of
total number of CUP patients).
The studies demonstrate significant heterogeneity in their workup, as
several include directed biopsies from sites considered suspicious on
imaging, calling into question the nature of the biopsies as ‘true
random biopsies’. No studies have specifically performed biopsies
following negative imaging and shown to be positive for cancer. Given
the generally low pick up rates, in the era of cross-sectional imaging
and PET-CT, the practice of random directed biopsies cannot be
recommended.