Could targeting bone delay cancer progression? Potential mechanisms of action of bisphosphonates

Systematic review of isolated disseminated carcinomatosis of bone marrow from colorectal cancer

BACKGROUND

Colorectal cancer (CRC) metastasis commonly occurs in the liver and lungs with bone metastasis rarely occurring in isolation. Disseminated carcinomatosis of bone marrow (DCBM) is extremely rare in CRC. We conducted a systematic review to provide more information on the diagnosis, treatment options, and prognosis of the condition.

METHODS

Studies were identified by performing searches on MEDLINE and EMBASE electronic databases according to the PRISMA statement standards. We included a single patient whom we treated for metastatic CRC presenting with DCBM in our study. Statistical analysis was performed using SPSS software version 23.0.

RESULTS

A search through 5502 unique studies yielded 14 studies that were eventually included. There was a total of 17 cases of DCBM in CRC with back pain and constitutional symptoms as the most common presenting complaints. DCBM in CRC was associated with markedly elevated CEA of 275.57 (95% CI 17.13-534.00). There was no predilection for site of primary tumour. Overall median survival was 120 days (95% CI 64.43-175.58). The median survival for patients who received chemotherapy was 240 days (95% CI 71.11-408.89), as compared to 9 days (95% CI 1.80-16.20) for patients who received best supportive treatment.

CONCLUSION

DCBM from CRC is extremely rare. Bone marrow examination remains the gold standard for diagnosis. Colonic stenting or surgical diversion may be more appropriate than primary resection in obstructed CRC in view of the poor prognosis. Systemic chemotherapy shows promise in increasing median survival.

Zoledronic acid alters hematopoiesis and generates breast tumor-suppressive bone marrow cells

BACKGROUND

The bone-targeting agent zoledronic acid (ZOL) increases breast cancer survival in subsets of patients, but the underlying reasons for this protective effect are unknown. ZOL modulates the activity of osteoclasts and osteoblasts, which form hematopoietic stem cell niches, and therefore may affect hematopoietic cells that play a role in breast cancer progression.

METHOD

Immunocompetent and immunocompromised strains of mice commonly used for breast cancer research were injected with a single, clinically relevant dose of ZOL (100 μg/kg) or vehicle control. The effects of ZOL on the bone marrow microenvironment (bone volume, bone cell number/activity, extracellular matrix composition) were established at various time points following treatment, using micro-computed tomography (μCT) analysis, histomorphometry, ELISA and immunofluorescence. The effects on peripheral blood and bone marrow hematopoietic progenitor populations were assessed using a HEMAVET® hematology analyzer and multicolor flow cytometry, respectively. Tumor support function of bone marrow cells was determined using an in vivo functional assay developed in our laboratory.

RESULTS

Using multiple mouse strains, we observed transient changes in numbers of hematopoietic stem cells, myeloid-biased progenitor cells, and lymphoid-biased cells concurrent with changes to hematopoietic stem cell niches following ZOL administration. Importantly, bone marrow cells from mice treated with a single, clinically relevant dose of ZOL inhibited breast tumor outgrowth in vivo. The ZOL-induced tumor suppressive function of the bone marrow persisted beyond the time point at which numbers of hematopoietic progenitor cells had returned to baseline.

CONCLUSIONS

These findings provide novel evidence that alterations to the bone marrow play a role in the anti-tumor activity of ZOL and suggest possibilities for capitalizing on the beneficial effects of ZOL in reducing breast cancer development and progression.

Synthesis and evaluation of alendronate-modified gelatin biopolymer as a novel osteotropic nanocarrier for gene therapy

AIM

To synthesize an osteotropic alendronate functionalized gelatin (ALN-gelatin) biopolymer for nanoparticle preparation and targeted delivery of DNA to osteoblasts for gene therapy applications.

MATERIALS & METHODS

Alendronate coupling to gelatin was confirmed using Fourier transform IR, (31)PNMR, x-ray diffraction (XRD) and differential scanning calorimetry. ALN-gelatin biopolymers prepared at various alendronate/gelatin ratios were utilized to prepare nanoparticles and were optimized in combination with DNA and gemini surfactant for transfecting both HEK-293 and MG-63 cell lines.

RESULTS

Gelatin functionalization was confirmed using the above methods. Uniform nanoparticles were obtained from a nanoprecipitation technique. ALN-gelatin/gemini/DNA complexes exhibited higher transfection efficiency in MG-63 osteosarcoma cell line compared with the positive control.

CONCLUSION

ALN-gelatin is a promising biopolymer for bone targeting of either small molecules or gene therapy applications.

Recent aspects for disseminated carcinomatosis of the bone marrow associated with gastric cancer: What has been done for the past, and what will be needed in future?

Disseminated carcinomatosis of the bone marrow is characterized by widespread bone metastasis (bone marrow infiltration) from solid tumors with hematological disorders coexisted. This disease is frequently complicated with gastric cancer among solid tumors although its incidence is very rare. In recent years, technological innovations in diagnosis and treatment for cancer have remarkably improved, which made survival rates of various cancers prolonged. Prognosis of disseminated carcinomatosis of the bone marrow associated with gastric cancer, however, is still poor (less than a year), possibly because this disease has not been given attention due to low incidence. In this review, I summarize the results obtained for the past, and propose ways to improve the prognosis of this disease.

Preparation of risedronate nanoparticles by solvent evaporation technique

One approach for the enhancement of oral drug bioavailability is the technique of nanoparticle preparation. Risedronate sodium (Biopharmaceutical Classification System Class III) was chosen as a model compound with high water solubility and low intestinal permeability. Eighteen samples of risedronate sodium were prepared by the solvent evaporation technique with sodium dodecyl sulfate, polysorbate, macrogol, sodium carboxymethyl cellulose and sodium carboxymethyl dextran as nanoparticle stabilizers applied in three concentrations. The prepared samples were characterized by dynamic light scattering and scanning electron microscopy. Fourier transform mid-infrared spectroscopy was used for verification of the composition of the samples. The particle size of sixteen samples was less than 200 nm. Polysorbate, sodium carboxymethyl dextran and macrogol were determined as the most favourable excipients; the particle size of the samples of risedronate with these excipients ranged from 2.8 to 10.5 nm.

Addition of zoledronic acid to neoadjuvant chemotherapy does not enhance tumor response in patients with HER2-negative stage II/III breast cancer: the NEOZOTAC trial (BOOG 2010-01)

BACKGROUND

The role of zoledronic acid (ZA) when added to the neoadjuvant treatment of breast cancer (BC) in enhancing the clinical and pathological response of tumors is unclear. The effect of ZA on the antitumor effect of neoadjuvant chemotherapy has not prospectively been studied before.

PATIENTS AND METHODS

NEOZOTAC is a national, multicenter, randomized study comparing the efficacy of TAC (docetaxel, adriamycin and cyclophosphamide i.v.) followed by granulocyte colony-stimulating factor on day 2 with or without ZA 4 mg i.v. q 3 weeks inpatients withstage II/III, HER2-negative BC. We present data on the pathological complete response (pCR in breast and axilla), on clinical response using MRI, and toxicity. Post hoc subgroup analyses were undertaken to address the predictive value of menopausal status.

RESULTS

Addition of ZA to chemotherapy did not improve pCR rates (13.2% for TAC+ZA versus 13.3% for TAC). Postmenopausal women (N = 96) had a numerical benefit from ZA treatment (pCR 14.0% for TAC+ZA versus 8.7% for TAC, P = 0.42). Clinical objective response did not differ between treatment arms (72.9% versus 73.7%). There was no difference in grade III/IV toxicity between treatment arms.

CONCLUSIONS

Addition of ZA to neoadjuvant chemotherapy did not improve pathological or clinical response to chemotherapy. Further investigations are warranted in postmenopausal women with BC, since this subgroup might benefit from ZA treatment.