Super selective radio embolization of the Porcine Kidney with \u3csup\u3e90\u3c/sup\u3eYttrium Resin Microspheres: A feasibility, safety and dose ranging study

Purpose: We determined whether super selective radio embolization of the porcine kidney was technically feasible and evaluated histopathological changes in the treatment target zone (upper or lower renal pole), adjacent nontargeted kidney, and adjacent and distant organs after administering 90Y labeled vs bland resin microspheres. Materials and Methods: We performed super selective radio embolization with 90Y resin microspheres in 1 kidney and with an equivalent number of bland microspheres in the corresponding pole of the contralateral kidney as a control. The aim was to achieve radio embolization of a target zone equivalent to approximately a third of the kidney volume. A pathologist independently graded macroscopic and microscopic changes in the kidney, and adjacent and distant tissue resulting from incremental increases (0.15 to 0.35 GBq) in implanted activity in 6 pigs. Results: We recorded grade 4 histological changes in the treatment target zone (upper or lower renal pole) in 5 of 6 pigs after injecting 90Y resin microspheres with evidence of nephron sparing effects in the adjacent renal tissue at the lowest activity. At activity greater than 0.3 GBq increasing damage was noted to adjacent renal tissue beyond the treatment target zone. No toxicity was evident in adjacent or distant organs. Conclusions: Delivery of highly targeted intra-arterial radiotherapy to the kidney is feasible and safe in the pig model. Further evaluation is warranted as a potential treatment for advanced renal cell carcinoma or for localized disease in patients who are not candidates for surgery

Reflex ALK immunohistochemistry is feasible and highly specific for ALK gene rearrangements in lung cancer

Fluorescence in situ hybridisation (FISH) is considered the gold standard for the detection of ALK gene rearrangements in lung adenocarcinoma. The presence of ALK gene rearrangement predicts response to specific targeted therapy, but these rearrangements are relatively rare and FISH studies are expensive, not widely available, potentially challenging to interpret and therefore difficult to undertake in all patients with non-small cell lung cancer. We developed and then deployed into the routine clinical setting a screening program for ALK gene rearrangement in all non-small cell lung cancer patients based on immunohistochemistry (IHC) with a mouse monoclonal antibody (clone 5A4). ALK IHC was strongly positive in 12 (4%) of 307 tumours from consecutive patients. Only 10 of these cancers were initially thought to be rearranged by diagnostic FISH studies. The two tumours which were IHC positive but initially interpreted as FISH negative underwent repeat FISH testing because of the discrepancy. Repeat FISH testing confirmed the presence of ALK gene rearrangement with the discrepancy being attributable to an atypical FISH pattern. Therefore, in our experienced hands, IHC for ALK performed on initial diagnosis of lung cancer is 100% specific for the presence of ALK gene rearrangement. When ALK IHC and FISH studies are discrepant, IHC may outperform FISH. Although our study was not intended to formally assess the sensitivity of ALK IHC, the 4% rate of gene rearrangements identified by this approach is consistent with the expected incidence in our population.We conclude that reflex ALK IHC followed by confirmatory FISH testing can be readily integrated into the routine clinical setting and represents a cost effective and practical approach to screening for these clinically significant gene rearrangements

EGFR mutation specific immunohistochemistry is a useful adjunct which helps to identify false negative mutation testing in lung cancer

Mutations in EGFR guide treatment in non-small cell lung cancer (NSCLC). The most common mutations, exon 19 (delE746-A750) and exon 21 (L858R), can be identified by mutation specific immunohistochemistry (IHC). We present our prospective experience of universal reflex IHC and molecular testing in non-squamous NSCLC in the routine clinical setting.A total of 411 specimens from 332 patients were encountered over two years. Of these, 326 (98%) patients underwent EGFR IHC, 15 (5%) were positive for exon 19 deletions and 27 (8%) for exon 21 (L858R); 244 (73%) patients underwent molecular testing. Seventy-six mutations in 64 patients (19% of all patients encountered; 26% with sufficient material for testing) were identified. These comprised nine exon 18 (G719X) mutations, three also with exon 20 mutations; 24 exon 19 deletions, six also with exon 20 mutations; 23 exon 21 (L858R), three also with exon 20 mutations; and 8 exon 20 alone.All 15 exon 19 IHC positive patients were proven mutated (100% specificity, 63% sensitivity). Twenty-two of 27 exon 21 IHC positive cases were proven mutated while three patients had insufficient material for molecular testing (92% specificity, 96% sensitivity). The overall specificity and sensitivity of IHC for any EGFR mutation was 95% and 58%. Five patients initially thought to be wild type for EGFR but IHC positive underwent repeat molecular testing because of the discrepancy which confirmed the IHC result in three cases (60%).We conclude IHC is very specific but not sensitive. Whilst IHC cannot replace molecular testing, it is a useful adjunct which requires minimal tissue and identifies false negative molecular results which occurred in 5% of our patients with eventually confirmed EGFR mutations

Multivariable Cox regression proportional hazards analysis of 1421 CRCs including myc IHC status and MMR/BRAF IHC phenotype interaction terms.

<p>MMRd – DNA mismatch repair deficient; MMRp – DNA mismatch repair proficient; BRAFwt – BRAF wild type; BRAFV600E – BRAFV600E mutant.</p

Multivariable binary logistic regression showing adjusted effect of MMR/BRAF IHC phenotype on myc over-expression in 1421 CRCs.

<p>Multivariable binary logistic regression showing adjusted effect of MMR/BRAF IHC phenotype on myc over-expression in 1421 CRCs.</p

Multivariable Cox regression proportional hazards analysis of 1421 CRCs.

<p>Multivariable Cox regression proportional hazards analysis of 1421 CRCs.</p

Panel A: Myc positive IHC staining; Panel B: Myc negative IHC staining; Panel C: Kaplan Meier analysis (Log Rank test p = 0.01); Panel D: Univariable Cox regression.

<p>Panel A: Myc positive IHC staining; Panel B: Myc negative IHC staining; Panel C: Kaplan Meier analysis (Log Rank test p = 0.01); Panel D: Univariable Cox regression.</p

Clinical and pathological characteristics of 1421 consecutive CRC patients (2004–2009).

<p>*Reports on the significance of differences between myc positive and negative groups for each variable, using either Pearson chi-square test (with continuity correction for 2×2 tables) for categorical variables or Mann-Whitney U test for age.</p

Myc IHC on whole section CRCs from 2004, confirming TMA findings.

<p>Panel A: Kaplan Meier curves showing superior overall survival of CRCs with MYC over-expression compared to myc negative CRCs (Log Rank test p<0.01); Panel B: Univariable Cox regression analysis showing MYC over-expression significantly correlated with improved overall survival [hazard ratio = 0.30 (95%CI = 0.15–0.60), p<0.01].</p