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Presents a letter to the editor in response to an article about the use of clodronate to manage multiple myeloma.

Background: Unresectable locally advanced pancreatic cancer (LAPC) is generally managed with chemotherapy or chemoradiotherapy, but prognosis is poor with a median survival of ∼13 months (or up to 19 months in some studies). We assessed a novel brachytherapy device, using phosphorous-32 ( 32 P) microparticles, combined with standard-of-care chemotherapy., Patients and Methods: In this international, multicentre, single-arm, open-label pilot study, adult patients with histologically or cytologically proven unresectable LAPC received 32 P microparticles, via endoscopic ultrasound-guided fine-needle implantation, planned for week 4 of 5-fluorouracil, leucovorin, irinotecan and oxaliplatin (FOLFIRINOX) or gemcitabine/nab-paclitaxel chemotherapy, per investigator's choice. The primary endpoint was safety and tolerability measured using Common Terminology Criteria for Adverse Events version 4.0. The lead efficacy endpoint was local disease control rate at 16 weeks., Results: Fifty patients were enrolled and received chemotherapy [intention-to-treat (ITT) population]. Forty-two patients received 32 P microparticle implantation [per protocol (PP) population]. A total of 1102 treatment-emergent adverse events (TEAEs) were reported in the ITT/safety population (956 PP), of which 167 (139 PP) were grade ≥3. In the PP population, 41 TEAEs in 16 (38.1%) patients were possibly or probably related to 32 P microparticles or implantation procedure, including 8 grade ≥3 in 3 (7.1%) patients, compared with 609 TEAEs in 42 (100%) patients attributed to chemotherapy, including 67 grade ≥3 in 28 patients (66.7%). The local disease control rate at 16 weeks was 82.0% (95% confidence interval: 68.6% to 90.9%) (ITT) and 90.5% (95% confidence interval: 77.4% to 97.3%) (PP). Tumour volume, carbohydrate antigen 19-9 levels, and metabolic tumour response at week 12 improved significantly. Ten patients (20.0% ITT; 23.8% PP) had surgical resection and median overall survival was 15.2 and 15.5 months for ITT and PP populations, respectively., Conclusions: Endoscopic ultrasound-guided 32 P microparticle implantation has an acceptable safety profile. This study also suggests clinically relevant benefits of combining 32 P microparticles with standard-of-care systemic chemotherapy for patients with unresectable LAPC., Competing Interests: Disclosure PJR: stock and other ownership interests: Perci Health Ltd. Honoraria: Sirtex Medical, Eisai, Servier, Pierre Fabre, Shire, Roche, AstraZeneca, Merck. Consulting or advisory role: Sirtex Medical, Eisai, Servier, Roche, AstraZeneca, Amgen. Speakers’ bureau: Amgen, Merck, Servier, Boston Scientific. Research funding: Sanofi, Bayer. Travel, accommodations, expenses: Roche, Ipsen. HSW: honoraria: BTG/Biocompatibles, Merck KGaA, and BMS. Consulting or advisory role: Incyte, Bayer, Roche/Genentech/ Foundation Medicine, Sirtex Medical, Celgene, OncoSil Medical, and Zymeworks. Research funding: Pfizer, Sirtex and Zymeworks. Travel, accommodations, expenses: BTG/Biocompatibles, Merck KGaA, and BMS. DC: stock and other ownership interests: MarginClear. Consulting or advisory role: Boston Scientific and OncoSil Medical. Research funding: Boston Scientific. MN: stock and other ownership interests: Pakinax Pty Ltd and Margin Clear Pty Ltd. DB: employment: SA Medical Imaging and SA Health. Research funding: Avener/Pankind and AstraZeneca. NEW: employment: OncoSil Medical Ltd. Stock and other ownership interests: OncoSil Medical Ltd. DMT: employment: OncoSil Medical Ltd. Stock and other ownership interests: OncoSil Medical Ltd. DCJ: employment: OncoSil Medical Ltd. Stock and other ownership interests: OncoSil Medical Ltd. EY: employment: Southern Star Research Pty Ltd (contractor to OncoSil Medical Ltd). All other authors have declared no conflicts of interest., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The functional effects of APC (adenomatous polyposis coli gene) germ-line mutations on crypt fission and cell proliferation were investigated in the normal intestine of human familial adenomatous polyposis (FAP) and multiple intestinal neoplasia (MIN) mice. Compared with controls, there was a 19-fold increase in the proportion of crypts in fission in FAP colon [95 per cent confidence interval (CI): 11-32, P < 0.0001], and a 75 and 61 per cent increase in MIN colon (95 per cent CI: 1.08-2.82, P < 0.02) and small bowel, respectively (95 per cent CI: 1.31-1.99, P < 0.001). In marked contrast, no significant differences in intra-cryptal epithelial cell proliferation or mitotic distribution were seen. Furthermore, 10.9 per cent of crypts in FAP were in asymmetrical fission as opposed to only 1 per cent in controls (P = 0.001). The largest relative increases in MIN crypt fission were in the colon (proximal and distal colon:190 per cent, P = 0.02 and 83 per cent, P = 0.01), suggesting that Apc mutations exert their maximal influence site-specifically. However, sites with the highest relative increases were also those with the largest eventual tumour sizes, but not the highest polyp counts. Three-dimensional serial section reconstruction analysis corroborated that FAP adenomas enlarge by crypt fission, which was frequently both asymmetrical and atypical. It is proposed that the absence of an increase in intestinal cell division infers that APC regulates intestinal crypt differentiation, specifically through the crypt cycle. This role appears analogous to the control of axis re-duplication in embryonic development, when downstream targets of APC are over-expressed. It is concluded that in vivo, the major defect in pre-neoplastic intestine harbouring APC mutations is elevated rates of crypt fission, and that this is also the mode by which micro-adenomas enlarge.

Significant differences in colon cancer incidence worldwide have led to the hypothesis that this variation can be explained largely by environmental, notably dietary influences. Although a positive correlation between dietary fat intake and incidence is suggested from some human epidemiological and rodent carcinogenesis studies, a direct association remains contentious. Using a spontaneous mouse tumor model of multiple intestinal neoplasia, we demonstrate that there is a generalized increase in tumor counts, in both the large and small bowel with higher dietary fat [standard (3%) fat versus high (15%) fat diet (mean +/- SD) 1.59 +/- 1.46 vs. 3.85 +/- 2.37 P < 0.001 and 21.36 +/- 7.4 vs. 31.3 +/- 9.7, respectively, P < 0.001]. Increasing dietary fat also increases polyp size in the small bowel. These changes appear independent of total calorific intake as assessed by body weights. Halving the crude fiber intake together with an increase in dietary fat from 3% to 10% did not have as marked an effect on tumor counts as an increase of fat alone to 15%, which also decreased survival (P < 0.05). These results demonstrate that increasing dietary fat intake from weaning can have a significant adverse effect on polyp numbers in mice genetically predisposed to intestinal tumor development. A further understanding of the biology of this interaction may provide novel strategies aimed at both colonic polyp prevention and treatment.

In advanced disease, androgen deprivation remains the usual treatment. The completion of current trials is awaited to confirm whether total androgen blockade will prolong survival. To make further advances in treatment the fundamental biology of the prostate cell, benign or malignant, and its relationship to endocrine manipulation, must be understood. This may then lead to an understanding of clonal escape mechanisms in transformed cells and the clinical correlate of escape, relapse.