Abstract
Purpose: Ki-67 heterogeneity can impact on gastroenteropancreatic neuroendocrine tumor grade assignment, especially when tissue is scarce. This work is aimed at devising adequacy criteria for grade assessment in biopsy specimens. Method: To analyze the impact of biopsy size on reliability, 360 virtual biopsies of different thickness and lengths were constructed. Furthermore, to estimate the mean amount of non-neoplastic tissue component present in biopsies, 28 real biopsies were collected, the non-neoplastic components (fibrosis and inflammation) quantified and the effective area of neoplastic tissue calculated for each biopsy. Results: Heterogeneity of Ki-67 distribution, G2 tumors and biopsy size all play an important role in reducing the reliability of biopsy samples in Ki-67-based grade assignment. In particular in G2 cases, 59.9% of virtual biopsies downgraded the tumor and the smaller the biopsy, the more frequent downgrading occurs. In real biopsies the presence of non-neoplastic tissue reduced the available total area by a mean of 20%. Conclusions: By coupling the results from these two different approaches we show that both biopsy size and non-neoplastic component must be taken into account for biopsy adequacy. In particular, we can speculate that if the minimum biopsy area, necessary to confidently (80% concordance) grade gastro-entero-pancreatic neuroendocrine tumors on virtual biopsies ranges between 15 and 30 mm2, and if real biopsies are on average composed of only 80% of neoplastic tissue, then biopsies with a surface area not <12 mm2 should be performed; using 18G needles, this corresponds to a minimum total length of 15 mm.
| Original language | English |
|---|---|
| Pages (from-to) | 494-502 |
| Number of pages | 9 |
| Journal | Endocrine |
| Volume | 57 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Sep 1 2017 |
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Keywords
- Biopsy
- Gastroenteropancreatic neuroendocrine tumors
- Grade
- Ki-67
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Endocrinology
Cite this
KI-67 heterogeneity in well differentiated gastro-entero-pancreatic neuroendocrine tumors : when is biopsy reliable for grade assessment? / Grillo, Federica; Valle, Luca; Ferone, Diego; Albertelli, Manuela; Brisigotti, Maria Pia; Cittadini, Giuseppe; Vanoli, Alessandro; Fiocca, Roberto; Mastracci, Luca.
In: Endocrine, Vol. 57, No. 3, 01.09.2017, p. 494-502.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - KI-67 heterogeneity in well differentiated gastro-entero-pancreatic neuroendocrine tumors
T2 - when is biopsy reliable for grade assessment?
AU - Grillo, Federica
AU - Valle, Luca
AU - Ferone, Diego
AU - Albertelli, Manuela
AU - Brisigotti, Maria Pia
AU - Cittadini, Giuseppe
AU - Vanoli, Alessandro
AU - Fiocca, Roberto
AU - Mastracci, Luca
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Purpose: Ki-67 heterogeneity can impact on gastroenteropancreatic neuroendocrine tumor grade assignment, especially when tissue is scarce. This work is aimed at devising adequacy criteria for grade assessment in biopsy specimens. Method: To analyze the impact of biopsy size on reliability, 360 virtual biopsies of different thickness and lengths were constructed. Furthermore, to estimate the mean amount of non-neoplastic tissue component present in biopsies, 28 real biopsies were collected, the non-neoplastic components (fibrosis and inflammation) quantified and the effective area of neoplastic tissue calculated for each biopsy. Results: Heterogeneity of Ki-67 distribution, G2 tumors and biopsy size all play an important role in reducing the reliability of biopsy samples in Ki-67-based grade assignment. In particular in G2 cases, 59.9% of virtual biopsies downgraded the tumor and the smaller the biopsy, the more frequent downgrading occurs. In real biopsies the presence of non-neoplastic tissue reduced the available total area by a mean of 20%. Conclusions: By coupling the results from these two different approaches we show that both biopsy size and non-neoplastic component must be taken into account for biopsy adequacy. In particular, we can speculate that if the minimum biopsy area, necessary to confidently (80% concordance) grade gastro-entero-pancreatic neuroendocrine tumors on virtual biopsies ranges between 15 and 30 mm2, and if real biopsies are on average composed of only 80% of neoplastic tissue, then biopsies with a surface area not <12 mm2 should be performed; using 18G needles, this corresponds to a minimum total length of 15 mm.
AB - Purpose: Ki-67 heterogeneity can impact on gastroenteropancreatic neuroendocrine tumor grade assignment, especially when tissue is scarce. This work is aimed at devising adequacy criteria for grade assessment in biopsy specimens. Method: To analyze the impact of biopsy size on reliability, 360 virtual biopsies of different thickness and lengths were constructed. Furthermore, to estimate the mean amount of non-neoplastic tissue component present in biopsies, 28 real biopsies were collected, the non-neoplastic components (fibrosis and inflammation) quantified and the effective area of neoplastic tissue calculated for each biopsy. Results: Heterogeneity of Ki-67 distribution, G2 tumors and biopsy size all play an important role in reducing the reliability of biopsy samples in Ki-67-based grade assignment. In particular in G2 cases, 59.9% of virtual biopsies downgraded the tumor and the smaller the biopsy, the more frequent downgrading occurs. In real biopsies the presence of non-neoplastic tissue reduced the available total area by a mean of 20%. Conclusions: By coupling the results from these two different approaches we show that both biopsy size and non-neoplastic component must be taken into account for biopsy adequacy. In particular, we can speculate that if the minimum biopsy area, necessary to confidently (80% concordance) grade gastro-entero-pancreatic neuroendocrine tumors on virtual biopsies ranges between 15 and 30 mm2, and if real biopsies are on average composed of only 80% of neoplastic tissue, then biopsies with a surface area not <12 mm2 should be performed; using 18G needles, this corresponds to a minimum total length of 15 mm.
KW - Biopsy
KW - Gastroenteropancreatic neuroendocrine tumors
KW - Grade
KW - Ki-67
UR - http://www.scopus.com/inward/record.url?scp=85025088230&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85025088230&partnerID=8YFLogxK
U2 - 10.1007/s12020-017-1364-8
DO - 10.1007/s12020-017-1364-8
M3 - Article
AN - SCOPUS:85025088230
VL - 57
SP - 494
EP - 502
JO - Endocrine
JF - Endocrine
SN - 1355-008X
IS - 3
ER -