Thermoradiotherapy for persistent cancer in previously irradiated fields

Magnetic nanoparticles for hyperthermia in cancer treatment: an emerging tool

Cancer remains as the major cause of death worldwide. The main reason why available therapies fail is that a vicious cycle in established which initiates multiple pathways and recurrence after metastasis. Hyperthermic treatment, which involves heating tumor tissues to a moderate temperature of 40-43 °C, has emerged as an effective strategy for treating tumors. This method is highly efficient at destroying tumor cells and does not induce the side effects of conventional cancer treatments. On the other hand, hyperthermic treatment method can be co-administered with conventional treatments. Nanotechnology had created huge opportunities in almost all areas of research, including the field of hyperthermic treatment. The utilization of magnetic nanoparticles (MNPs) offers functionalities not possible using conventional magnetic materials. In this review, we detail recent developments and applications of MNPs for hyperthermic treatment and discuss future possibilities.

Hyperthermia and associated changes in membrane fluidity potentiate P2X7 activation to promote tumor cell death

Extracellular ATP (eATP) accumulation within the tumor microenvironment (TME) has the potential to activate purinergic signaling. The eATP evoked signaling effects bolster antitumor immune responses while exerting direct cytotoxicity on tumor cells and vascular endothelial cells, mediated at least in part through P2X7 receptors. Approaches to augment purinergic signaling in TME e.g. by ectonucleotidase CD39 blockade, and/or boosting P2X7 functional responses, might be used as immunomodulatory therapies in cancer treatment. In this study, we delineated the translatable strategy of hyperthermia to demonstrate impacts on P2X7 responsiveness to eATP. Hyperthermia (40°C) was noted to enhance eATP-mediated cytotoxicity on MCA38 colon cancer cells. Increased membrane fluidity induced by hyperthermia boosted P2X7 functionality, potentiating pore opening and modulating downstream AKT/PRAS40/mTOR signaling events. When combined with cisplatin or mitomycin C, hyperthermia and eATP together markedly potentiate cancer cell death. Our data indicate that clinically tolerable hyperthermia with modulated P2X7-purinergic signaling will boost efficacy of conventional cancer treatments.

Hyperthermia and Radiation Therapy in Locoregional Recurrent Breast Cancers: A Systematic Review and Meta-analysis

PURPOSE

To conduct a systematic review and meta-analysis to evaluate the outcome of hyperthermia (HT) and radiation therapy (RT) in locally recurrent breast cancers (LRBCs).

METHODS AND MATERIALS

A total of 708 abstracts were screened from 8 databases according to the PRISMA guidelines. Single-arm and 2-arm studies, treating LRBCs with HT and RT but without surgery (for local recurrence) or concurrent chemotherapy were considered. The evaluated endpoint was complete response (CR).

RESULTS

Thirty-one full text articles, pertaining to 34 studies, were shortlisted for the meta-analysis. Eight were 2-arm (randomized, n=5; nonrandomized, n=3), whereas 26 were single-arm studies. In all, 627 patients were enrolled in 2-arm and 1483 in single-arm studies. Patients were treated with a median of 7 HT sessions, and an average temperature of 42.5°C was attained. Mean RT dose was 38.2 Gy (range, 26-60 Gy). Hyperthermia was most frequently applied after RT. In the 2-arm studies, a CR of 60.2% was achieved with RT + HT versus 38.1% with RT alone (odds ratio 2.64, 95% confidence interval [CI] 1.66-4.18, P<.0001). Risk ratio and risk difference were 1.57 (95% CI 1.25-1.96, P<.0001) and 0.22 (95% CI 0.11-0.33, P<.0001), respectively. In 26 single-arm studies, RT + HT attained a CR of 63.4% (event rate 0.62, 95% CI 0.57-0.66). Moreover, 779 patients had been previously irradiated (696 from single-arm and 83 from 2-arm studies). A CR of 66.6% (event rate 0.64, 95% CI 0.58-0.70) was achieved with HT and reirradiation (mean ± SD dose: 36.7 ± 7.7 Gy). Mean acute and late grade 3/4 toxicities with RT + HT were 14.4% and 5.2%, respectively.

CONCLUSIONS

Thermoradiation therapy enhances the likelihood of CR rates in LRBCs over RT alone by 22% with minimal acute and late morbidities. For even those previously irradiated, reirradiation with HT provides locoregional control in two-thirds of the patients. Thermoradiation therapy could therefore be considered as an effective and safe palliative treatment option for LRBCs.

Nanoparticle-mediated hyperthermia in cancer therapy

A small rise in tumor temperature (hyperthermia) makes cancer cells more susceptible to radiation and chemotherapy. The means of achieving this is not trivial, and traditional methods have certain drawbacks. Loading tumors with systematically asministered energy-transducing nanoparticles can circumvent several of the obstacles to achieve tumor hyperthermia. However, nanoparticles also face unique challenges prior to clinical implementation. This article summarizes the state-of-the-art current technology and discusses the advantages and challenges of the three major nanoparticle formulations in focus: gold nanoshells and nanorods, superparamagnetic iron oxide particles and carbon nanotubes.

Radiation therapy, cisplatin and hyperthermia in combination in management of patients with recurrent carcinomas of the head and neck with metastatic cervical lymph nodes

Twenty-one patients with recurrent carcinomas of the head and neck with metastatic cervical lymph nodes were treated with radiation therapy, cisplatin and hyperthermia in combination, in an attempt to investigate any potential contribution in terms of safety, response, duration of palliation and quality of life. Patients not initially treated with radiation therapy were treated with a median dose of 70 Gy and patients initially treated with radiation therapy with a median dose of 30Gy. The median number of weekly cisplatin courses was five and the median number of twice weekly local external ultrasound hyperthermia sessions was five. Average T90, Average T50 and Average T10 were 39.9 +/- 1.2 degrees C, 42.4 +/- 1.3 degrees C and 44.5 +/- 0.8 degrees C, respectively, and Average CEM 43 degrees C T90, Average CEM 43 degrees C T50 and Average CEM 43 degrees C T10 were 7.8+/-9.6min, 22.6 +/- 18.8min and 39.3 +/- 25.1min, respectively. Mean follow-up was 1 year. Nodal complete response was achieved in eight patients and palliation of presenting symptoms in 19. Overall survival was 39% at 1 year. Grade 3 acute skin toxicity was observed in one patient and Grade 3 acute haematological toxicity in one. Radiation therapy, cisplatin and hyperthermia in combination appear to be safe and might improve response, prolong duration of palliation and reinstate quality of life in patients with recurrent carcinomas of the head and neck with metastatic cervical lymph nodes.

Effects of hyperthermia, radiotherapy and thermoradiotherapy on tumor microvascular permeability

Morphological changes in rabbit VX-2 tumor and its vascular permeability to ferritin following hyperthermia, radiotherapy and thermoradiotherapy were investigated by light and electron microscopy. Tumors treated by thermoradiotherapy successively showed a decrease in volume compared with those treated by hyperthermia or radiotherapy. Light microscopically, degenerative or necrotic changes progressed more widely in tumors treated by thermoradiotherapy than in those treated by hyperthermia or radiotherapy alone. When vascular permeability to ferritin was examined, an increase in tumor vascular permeability occurred at 1 day after hyperthermia or thermoradiotherapy, and at 3 days after radiotherapy. These results suggest that the early reaction of tumor microvasculature is a factor contributing to delayed cell death in tumors after thermoradiotherapy or hyperthermia.